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+#
+# (C) Copyright 2000 - 2012
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+Summary:
+========
+
+This directory contains the source code for U-Boot, a boot loader for
+Embedded boards based on PowerPC, ARM, MIPS and several other
+processors, which can be installed in a boot ROM and used to
+initialize and test the hardware or to download and run application
+code.
+
+The development of U-Boot is closely related to Linux: some parts of
+the source code originate in the Linux source tree, we have some
+header files in common, and special provision has been made to
+support booting of Linux images.
+
+Some attention has been paid to make this software easily
+configurable and extendable. For instance, all monitor commands are
+implemented with the same call interface, so that it's very easy to
+add new commands. Also, instead of permanently adding rarely used
+code (for instance hardware test utilities) to the monitor, you can
+load and run it dynamically.
+
+
+Status:
+=======
+
+In general, all boards for which a configuration option exists in the
+Makefile have been tested to some extent and can be considered
+"working". In fact, many of them are used in production systems.
+
+In case of problems see the CHANGELOG and CREDITS files to find out
+who contributed the specific port. The MAINTAINERS file lists board
+maintainers.
+
+Note: There is no CHANGELOG file in the actual U-Boot source tree;
+it can be created dynamically from the Git log using:
+
+ make CHANGELOG
+
+
+Where to get help:
+==================
+
+In case you have questions about, problems with or contributions for
+U-Boot you should send a message to the U-Boot mailing list at
+<u-boot@lists.denx.de>. There is also an archive of previous traffic
+on the mailing list - please search the archive before asking FAQ's.
+Please see http://lists.denx.de/pipermail/u-boot and
+http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
+
+
+Where to get source code:
+=========================
+
+The U-Boot source code is maintained in the git repository at
+git://www.denx.de/git/u-boot.git ; you can browse it online at
+http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
+
+The "snapshot" links on this page allow you to download tarballs of
+any version you might be interested in. Official releases are also
+available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
+directory.
+
+Pre-built (and tested) images are available from
+ftp://ftp.denx.de/pub/u-boot/images/
+
+
+Where we come from:
+===================
+
+- start from 8xxrom sources
+- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
+- clean up code
+- make it easier to add custom boards
+- make it possible to add other [PowerPC] CPUs
+- extend functions, especially:
+ * Provide extended interface to Linux boot loader
+ * S-Record download
+ * network boot
+ * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
+- create ARMBoot project (http://sourceforge.net/projects/armboot)
+- add other CPU families (starting with ARM)
+- create U-Boot project (http://sourceforge.net/projects/u-boot)
+- current project page: see http://www.denx.de/wiki/U-Boot
+
+
+Names and Spelling:
+===================
+
+The "official" name of this project is "Das U-Boot". The spelling
+"U-Boot" shall be used in all written text (documentation, comments
+in source files etc.). Example:
+
+ This is the README file for the U-Boot project.
+
+File names etc. shall be based on the string "u-boot". Examples:
+
+ include/asm-ppc/u-boot.h
+
+ #include <asm/u-boot.h>
+
+Variable names, preprocessor constants etc. shall be either based on
+the string "u_boot" or on "U_BOOT". Example:
+
+ U_BOOT_VERSION u_boot_logo
+ IH_OS_U_BOOT u_boot_hush_start
+
+
+Versioning:
+===========
+
+Starting with the release in October 2008, the names of the releases
+were changed from numerical release numbers without deeper meaning
+into a time stamp based numbering. Regular releases are identified by
+names consisting of the calendar year and month of the release date.
+Additional fields (if present) indicate release candidates or bug fix
+releases in "stable" maintenance trees.
+
+Examples:
+ U-Boot v2009.11 - Release November 2009
+ U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
+ U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
+
+
+Directory Hierarchy:
+====================
+
+/arch Architecture specific files
+ /arm Files generic to ARM architecture
+ /cpu CPU specific files
+ /arm720t Files specific to ARM 720 CPUs
+ /arm920t Files specific to ARM 920 CPUs
+ /at91 Files specific to Atmel AT91RM9200 CPU
+ /imx Files specific to Freescale MC9328 i.MX CPUs
+ /s3c24x0 Files specific to Samsung S3C24X0 CPUs
+ /arm925t Files specific to ARM 925 CPUs
+ /arm926ejs Files specific to ARM 926 CPUs
+ /arm1136 Files specific to ARM 1136 CPUs
+ /ixp Files specific to Intel XScale IXP CPUs
+ /pxa Files specific to Intel XScale PXA CPUs
+ /s3c44b0 Files specific to Samsung S3C44B0 CPUs
+ /sa1100 Files specific to Intel StrongARM SA1100 CPUs
+ /lib Architecture specific library files
+ /avr32 Files generic to AVR32 architecture
+ /cpu CPU specific files
+ /lib Architecture specific library files
+ /blackfin Files generic to Analog Devices Blackfin architecture
+ /cpu CPU specific files
+ /lib Architecture specific library files
+ /x86 Files generic to x86 architecture
+ /cpu CPU specific files
+ /lib Architecture specific library files
+ /m68k Files generic to m68k architecture
+ /cpu CPU specific files
+ /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
+ /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
+ /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
+ /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
+ /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
+ /lib Architecture specific library files
+ /microblaze Files generic to microblaze architecture
+ /cpu CPU specific files
+ /lib Architecture specific library files
+ /mips Files generic to MIPS architecture
+ /cpu CPU specific files
+ /mips32 Files specific to MIPS32 CPUs
+ /xburst Files specific to Ingenic XBurst CPUs
+ /lib Architecture specific library files
+ /nds32 Files generic to NDS32 architecture
+ /cpu CPU specific files
+ /n1213 Files specific to Andes Technology N1213 CPUs
+ /lib Architecture specific library files
+ /nios2 Files generic to Altera NIOS2 architecture
+ /cpu CPU specific files
+ /lib Architecture specific library files
+ /powerpc Files generic to PowerPC architecture
+ /cpu CPU specific files
+ /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
+ /mpc5xx Files specific to Freescale MPC5xx CPUs
+ /mpc5xxx Files specific to Freescale MPC5xxx CPUs
+ /mpc8xx Files specific to Freescale MPC8xx CPUs
+ /mpc824x Files specific to Freescale MPC824x CPUs
+ /mpc8260 Files specific to Freescale MPC8260 CPUs
+ /mpc85xx Files specific to Freescale MPC85xx CPUs
+ /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
+ /lib Architecture specific library files
+ /sh Files generic to SH architecture
+ /cpu CPU specific files
+ /sh2 Files specific to sh2 CPUs
+ /sh3 Files specific to sh3 CPUs
+ /sh4 Files specific to sh4 CPUs
+ /lib Architecture specific library files
+ /sparc Files generic to SPARC architecture
+ /cpu CPU specific files
+ /leon2 Files specific to Gaisler LEON2 SPARC CPU
+ /leon3 Files specific to Gaisler LEON3 SPARC CPU
+ /lib Architecture specific library files
+/api Machine/arch independent API for external apps
+/board Board dependent files
+/common Misc architecture independent functions
+/disk Code for disk drive partition handling
+/doc Documentation (don't expect too much)
+/drivers Commonly used device drivers
+/examples Example code for standalone applications, etc.
+/fs Filesystem code (cramfs, ext2, jffs2, etc.)
+/include Header Files
+/lib Files generic to all architectures
+ /libfdt Library files to support flattened device trees
+ /lzma Library files to support LZMA decompression
+ /lzo Library files to support LZO decompression
+/net Networking code
+/post Power On Self Test
+/rtc Real Time Clock drivers
+/tools Tools to build S-Record or U-Boot images, etc.
+
+Software Configuration:
+=======================
+
+Configuration is usually done using C preprocessor defines; the
+rationale behind that is to avoid dead code whenever possible.
+
+There are two classes of configuration variables:
+
+* Configuration _OPTIONS_:
+ These are selectable by the user and have names beginning with
+ "CONFIG_".
+
+* Configuration _SETTINGS_:
+ These depend on the hardware etc. and should not be meddled with if
+ you don't know what you're doing; they have names beginning with
+ "CONFIG_SYS_".
+
+Later we will add a configuration tool - probably similar to or even
+identical to what's used for the Linux kernel. Right now, we have to
+do the configuration by hand, which means creating some symbolic
+links and editing some configuration files. We use the TQM8xxL boards
+as an example here.
+
+
+Selection of Processor Architecture and Board Type:
+---------------------------------------------------
+
+For all supported boards there are ready-to-use default
+configurations available; just type "make <board_name>_config".
+
+Example: For a TQM823L module type:
+
+ cd u-boot
+ make TQM823L_config
+
+For the Cogent platform, you need to specify the CPU type as well;
+e.g. "make cogent_mpc8xx_config". And also configure the cogent
+directory according to the instructions in cogent/README.
+
+
+Configuration Options:
+----------------------
+
+Configuration depends on the combination of board and CPU type; all
+such information is kept in a configuration file
+"include/configs/<board_name>.h".
+
+Example: For a TQM823L module, all configuration settings are in
+"include/configs/TQM823L.h".
+
+
+Many of the options are named exactly as the corresponding Linux
+kernel configuration options. The intention is to make it easier to
+build a config tool - later.
+
+
+The following options need to be configured:
+
+- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
+
+- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
+
+- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
+ Define exactly one, e.g. CONFIG_ATSTK1002
+
+- CPU Module Type: (if CONFIG_COGENT is defined)
+ Define exactly one of
+ CONFIG_CMA286_60_OLD
+--- FIXME --- not tested yet:
+ CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
+ CONFIG_CMA287_23, CONFIG_CMA287_50
+
+- Motherboard Type: (if CONFIG_COGENT is defined)
+ Define exactly one of
+ CONFIG_CMA101, CONFIG_CMA102
+
+- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
+ Define one or more of
+ CONFIG_CMA302
+
+- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
+ Define one or more of
+ CONFIG_LCD_HEARTBEAT - update a character position on
+ the LCD display every second with
+ a "rotator" |\-/|\-/
+
+- Board flavour: (if CONFIG_MPC8260ADS is defined)
+ CONFIG_ADSTYPE
+ Possible values are:
+ CONFIG_SYS_8260ADS - original MPC8260ADS
+ CONFIG_SYS_8266ADS - MPC8266ADS
+ CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
+ CONFIG_SYS_8272ADS - MPC8272ADS
+
+- Marvell Family Member
+ CONFIG_SYS_MVFS - define it if you want to enable
+ multiple fs option at one time
+ for marvell soc family
+
+- MPC824X Family Member (if CONFIG_MPC824X is defined)
+ Define exactly one of
+ CONFIG_MPC8240, CONFIG_MPC8245
+
+- 8xx CPU Options: (if using an MPC8xx CPU)
+ CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
+ get_gclk_freq() cannot work
+ e.g. if there is no 32KHz
+ reference PIT/RTC clock
+ CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
+ or XTAL/EXTAL)
+
+- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
+ CONFIG_SYS_8xx_CPUCLK_MIN
+ CONFIG_SYS_8xx_CPUCLK_MAX
+ CONFIG_8xx_CPUCLK_DEFAULT
+ See doc/README.MPC866
+
+ CONFIG_SYS_MEASURE_CPUCLK
+
+ Define this to measure the actual CPU clock instead
+ of relying on the correctness of the configured
+ values. Mostly useful for board bringup to make sure
+ the PLL is locked at the intended frequency. Note
+ that this requires a (stable) reference clock (32 kHz
+ RTC clock or CONFIG_SYS_8XX_XIN)
+
+ CONFIG_SYS_DELAYED_ICACHE
+
+ Define this option if you want to enable the
+ ICache only when Code runs from RAM.
+
+- 85xx CPU Options:
+ CONFIG_SYS_PPC64
+
+ Specifies that the core is a 64-bit PowerPC implementation (implements
+ the "64" category of the Power ISA). This is necessary for ePAPR
+ compliance, among other possible reasons.
+
+ CONFIG_SYS_FSL_TBCLK_DIV
+
+ Defines the core time base clock divider ratio compared to the
+ system clock. On most PQ3 devices this is 8, on newer QorIQ
+ devices it can be 16 or 32. The ratio varies from SoC to Soc.
+
+ CONFIG_SYS_FSL_PCIE_COMPAT
+
+ Defines the string to utilize when trying to match PCIe device
+ tree nodes for the given platform.
+
+ CONFIG_SYS_PPC_E500_DEBUG_TLB
+
+ Enables a temporary TLB entry to be used during boot to work
+ around limitations in e500v1 and e500v2 external debugger
+ support. This reduces the portions of the boot code where
+ breakpoints and single stepping do not work. The value of this
+ symbol should be set to the TLB1 entry to be used for this
+ purpose.
+
+ CONFIG_SYS_FSL_ERRATUM_A004510
+
+ Enables a workaround for erratum A004510. If set,
+ then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
+ CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
+
+ CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
+ CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
+
+ Defines one or two SoC revisions (low 8 bits of SVR)
+ for which the A004510 workaround should be applied.
+
+ The rest of SVR is either not relevant to the decision
+ of whether the erratum is present (e.g. p2040 versus
+ p2041) or is implied by the build target, which controls
+ whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
+
+ See Freescale App Note 4493 for more information about
+ this erratum.
+
+ CONFIG_A003399_NOR_WORKAROUND
+ Enables a workaround for IFC erratum A003399. It is only
+ requred during NOR boot.
+
+ CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
+
+ This is the value to write into CCSR offset 0x18600
+ according to the A004510 workaround.
+
+ CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
+ This value denotes start offset of M2 memory
+ which is directly connected to the DSP core.
+
+ CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
+ This value denotes start offset of DSP CCSR space.
+
+- Generic CPU options:
+ CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
+
+ Defines the endianess of the CPU. Implementation of those
+ values is arch specific.
+
+- Intel Monahans options:
+ CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
+
+ Defines the Monahans run mode to oscillator
+ ratio. Valid values are 8, 16, 24, 31. The core
+ frequency is this value multiplied by 13 MHz.
+
+ CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
+
+ Defines the Monahans turbo mode to oscillator
+ ratio. Valid values are 1 (default if undefined) and
+ 2. The core frequency as calculated above is multiplied
+ by this value.
+
+- MIPS CPU options:
+ CONFIG_SYS_INIT_SP_OFFSET
+
+ Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
+ pointer. This is needed for the temporary stack before
+ relocation.
+
+ CONFIG_SYS_MIPS_CACHE_MODE
+
+ Cache operation mode for the MIPS CPU.
+ See also arch/mips/include/asm/mipsregs.h.
+ Possible values are:
+ CONF_CM_CACHABLE_NO_WA
+ CONF_CM_CACHABLE_WA
+ CONF_CM_UNCACHED
+ CONF_CM_CACHABLE_NONCOHERENT
+ CONF_CM_CACHABLE_CE
+ CONF_CM_CACHABLE_COW
+ CONF_CM_CACHABLE_CUW
+ CONF_CM_CACHABLE_ACCELERATED
+
+ CONFIG_SYS_XWAY_EBU_BOOTCFG
+
+ Special option for Lantiq XWAY SoCs for booting from NOR flash.
+ See also arch/mips/cpu/mips32/start.S.
+
+ CONFIG_XWAY_SWAP_BYTES
+
+ Enable compilation of tools/xway-swap-bytes needed for Lantiq
+ XWAY SoCs for booting from NOR flash. The U-Boot image needs to
+ be swapped if a flash programmer is used.
+
+- ARM options:
+ CONFIG_SYS_EXCEPTION_VECTORS_HIGH
+
+ Select high exception vectors of the ARM core, e.g., do not
+ clear the V bit of the c1 register of CP15.
+
+ CONFIG_SYS_THUMB_BUILD
+
+ Use this flag to build U-Boot using the Thumb instruction
+ set for ARM architectures. Thumb instruction set provides
+ better code density. For ARM architectures that support
+ Thumb2 this flag will result in Thumb2 code generated by
+ GCC.
+
+ CONFIG_ARM_ERRATA_716044
+ CONFIG_ARM_ERRATA_742230
+ CONFIG_ARM_ERRATA_743622
+ CONFIG_ARM_ERRATA_751472
+
+ If set, the workarounds for these ARM errata are applied early
+ during U-Boot startup. Note that these options force the
+ workarounds to be applied; no CPU-type/version detection
+ exists, unlike the similar options in the Linux kernel. Do not
+ set these options unless they apply!
+
+- CPU timer options:
+ CONFIG_SYS_HZ
+
+ The frequency of the timer returned by get_timer().
+ get_timer() must operate in milliseconds and this CONFIG
+ option must be set to 1000.
+
+- Linux Kernel Interface:
+ CONFIG_CLOCKS_IN_MHZ
+
+ U-Boot stores all clock information in Hz
+ internally. For binary compatibility with older Linux
+ kernels (which expect the clocks passed in the
+ bd_info data to be in MHz) the environment variable
+ "clocks_in_mhz" can be defined so that U-Boot
+ converts clock data to MHZ before passing it to the
+ Linux kernel.
+ When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
+ "clocks_in_mhz=1" is automatically included in the
+ default environment.
+
+ CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
+
+ When transferring memsize parameter to linux, some versions
+ expect it to be in bytes, others in MB.
+ Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
+
+ CONFIG_OF_LIBFDT
+
+ New kernel versions are expecting firmware settings to be
+ passed using flattened device trees (based on open firmware
+ concepts).
+
+ CONFIG_OF_LIBFDT
+ * New libfdt-based support
+ * Adds the "fdt" command
+ * The bootm command automatically updates the fdt
+
+ OF_CPU - The proper name of the cpus node (only required for
+ MPC512X and MPC5xxx based boards).
+ OF_SOC - The proper name of the soc node (only required for
+ MPC512X and MPC5xxx based boards).
+ OF_TBCLK - The timebase frequency.
+ OF_STDOUT_PATH - The path to the console device
+
+ boards with QUICC Engines require OF_QE to set UCC MAC
+ addresses
+
+ CONFIG_OF_BOARD_SETUP
+
+ Board code has addition modification that it wants to make
+ to the flat device tree before handing it off to the kernel
+
+ CONFIG_OF_BOOT_CPU
+
+ This define fills in the correct boot CPU in the boot
+ param header, the default value is zero if undefined.
+
+ CONFIG_OF_IDE_FIXUP
+
+ U-Boot can detect if an IDE device is present or not.
+ If not, and this new config option is activated, U-Boot
+ removes the ATA node from the DTS before booting Linux,
+ so the Linux IDE driver does not probe the device and
+ crash. This is needed for buggy hardware (uc101) where
+ no pull down resistor is connected to the signal IDE5V_DD7.
+
+ CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
+
+ This setting is mandatory for all boards that have only one
+ machine type and must be used to specify the machine type
+ number as it appears in the ARM machine registry
+ (see http://www.arm.linux.org.uk/developer/machines/).
+ Only boards that have multiple machine types supported
+ in a single configuration file and the machine type is
+ runtime discoverable, do not have to use this setting.
+
+- vxWorks boot parameters:
+
+ bootvx constructs a valid bootline using the following
+ environments variables: bootfile, ipaddr, serverip, hostname.
+ It loads the vxWorks image pointed bootfile.
+
+ CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
+ CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
+ CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
+ CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
+
+ CONFIG_SYS_VXWORKS_ADD_PARAMS
+
+ Add it at the end of the bootline. E.g "u=username pw=secret"
+
+ Note: If a "bootargs" environment is defined, it will overwride
+ the defaults discussed just above.
+
+- Cache Configuration:
+ CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
+ CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
+ CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
+
+- Cache Configuration for ARM:
+ CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
+ controller
+ CONFIG_SYS_PL310_BASE - Physical base address of PL310
+ controller register space
+
+- Serial Ports:
+ CONFIG_PL010_SERIAL
+
+ Define this if you want support for Amba PrimeCell PL010 UARTs.
+
+ CONFIG_PL011_SERIAL
+
+ Define this if you want support for Amba PrimeCell PL011 UARTs.
+
+ CONFIG_PL011_CLOCK
+
+ If you have Amba PrimeCell PL011 UARTs, set this variable to
+ the clock speed of the UARTs.
+
+ CONFIG_PL01x_PORTS
+
+ If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
+ define this to a list of base addresses for each (supported)
+ port. See e.g. include/configs/versatile.h
+
+ CONFIG_PL011_SERIAL_RLCR
+
+ Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
+ have separate receive and transmit line control registers. Set
+ this variable to initialize the extra register.
+
+ CONFIG_PL011_SERIAL_FLUSH_ON_INIT
+
+ On some platforms (e.g. U8500) U-Boot is loaded by a second stage
+ boot loader that has already initialized the UART. Define this
+ variable to flush the UART at init time.
+
+
+- Console Interface:
+ Depending on board, define exactly one serial port
+ (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
+ CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
+ console by defining CONFIG_8xx_CONS_NONE
+
+ Note: if CONFIG_8xx_CONS_NONE is defined, the serial
+ port routines must be defined elsewhere
+ (i.e. serial_init(), serial_getc(), ...)
+
+ CONFIG_CFB_CONSOLE
+ Enables console device for a color framebuffer. Needs following
+ defines (cf. smiLynxEM, i8042)
+ VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
+ (default big endian)
+ VIDEO_HW_RECTFILL graphic chip supports
+ rectangle fill
+ (cf. smiLynxEM)
+ VIDEO_HW_BITBLT graphic chip supports
+ bit-blit (cf. smiLynxEM)
+ VIDEO_VISIBLE_COLS visible pixel columns
+ (cols=pitch)
+ VIDEO_VISIBLE_ROWS visible pixel rows
+ VIDEO_PIXEL_SIZE bytes per pixel
+ VIDEO_DATA_FORMAT graphic data format
+ (0-5, cf. cfb_console.c)
+ VIDEO_FB_ADRS framebuffer address
+ VIDEO_KBD_INIT_FCT keyboard int fct
+ (i.e. i8042_kbd_init())
+ VIDEO_TSTC_FCT test char fct
+ (i.e. i8042_tstc)
+ VIDEO_GETC_FCT get char fct
+ (i.e. i8042_getc)
+ CONFIG_CONSOLE_CURSOR cursor drawing on/off
+ (requires blink timer
+ cf. i8042.c)
+ CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
+ CONFIG_CONSOLE_TIME display time/date info in
+ upper right corner
+ (requires CONFIG_CMD_DATE)
+ CONFIG_VIDEO_LOGO display Linux logo in
+ upper left corner
+ CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
+ linux_logo.h for logo.
+ Requires CONFIG_VIDEO_LOGO
+ CONFIG_CONSOLE_EXTRA_INFO
+ additional board info beside
+ the logo
+
+ When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
+ a limited number of ANSI escape sequences (cursor control,
+ erase functions and limited graphics rendition control).
+
+ When CONFIG_CFB_CONSOLE is defined, video console is
+ default i/o. Serial console can be forced with
+ environment 'console=serial'.
+
+ When CONFIG_SILENT_CONSOLE is defined, all console
+ messages (by U-Boot and Linux!) can be silenced with
+ the "silent" environment variable. See
+ doc/README.silent for more information.
+
+- Console Baudrate:
+ CONFIG_BAUDRATE - in bps
+ Select one of the baudrates listed in
+ CONFIG_SYS_BAUDRATE_TABLE, see below.
+ CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
+
+- Console Rx buffer length
+ With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
+ the maximum receive buffer length for the SMC.
+ This option is actual only for 82xx and 8xx possible.
+ If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
+ must be defined, to setup the maximum idle timeout for
+ the SMC.
+
+- Pre-Console Buffer:
+ Prior to the console being initialised (i.e. serial UART
+ initialised etc) all console output is silently discarded.
+ Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
+ buffer any console messages prior to the console being
+ initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
+ bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
+ a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
+ bytes are output before the console is initialised, the
+ earlier bytes are discarded.
+
+ 'Sane' compilers will generate smaller code if
+ CONFIG_PRE_CON_BUF_SZ is a power of 2
+
+- Safe printf() functions
+ Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
+ the printf() functions. These are defined in
+ include/vsprintf.h and include snprintf(), vsnprintf() and
+ so on. Code size increase is approximately 300-500 bytes.
+ If this option is not given then these functions will
+ silently discard their buffer size argument - this means
+ you are not getting any overflow checking in this case.
+
+- Boot Delay: CONFIG_BOOTDELAY - in seconds
+ Delay before automatically booting the default image;
+ set to -1 to disable autoboot.
+ set to -2 to autoboot with no delay and not check for abort
+ (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
+
+ See doc/README.autoboot for these options that
+ work with CONFIG_BOOTDELAY. None are required.
+ CONFIG_BOOT_RETRY_TIME
+ CONFIG_BOOT_RETRY_MIN
+ CONFIG_AUTOBOOT_KEYED
+ CONFIG_AUTOBOOT_PROMPT
+ CONFIG_AUTOBOOT_DELAY_STR
+ CONFIG_AUTOBOOT_STOP_STR
+ CONFIG_AUTOBOOT_DELAY_STR2
+ CONFIG_AUTOBOOT_STOP_STR2
+ CONFIG_ZERO_BOOTDELAY_CHECK
+ CONFIG_RESET_TO_RETRY
+
+- Autoboot Command:
+ CONFIG_BOOTCOMMAND
+ Only needed when CONFIG_BOOTDELAY is enabled;
+ define a command string that is automatically executed
+ when no character is read on the console interface
+ within "Boot Delay" after reset.
+
+ CONFIG_BOOTARGS
+ This can be used to pass arguments to the bootm
+ command. The value of CONFIG_BOOTARGS goes into the
+ environment value "bootargs".
+
+ CONFIG_RAMBOOT and CONFIG_NFSBOOT
+ The value of these goes into the environment as
+ "ramboot" and "nfsboot" respectively, and can be used
+ as a convenience, when switching between booting from
+ RAM and NFS.
+
+- Pre-Boot Commands:
+ CONFIG_PREBOOT
+
+ When this option is #defined, the existence of the
+ environment variable "preboot" will be checked
+ immediately before starting the CONFIG_BOOTDELAY
+ countdown and/or running the auto-boot command resp.
+ entering interactive mode.
+
+ This feature is especially useful when "preboot" is
+ automatically generated or modified. For an example
+ see the LWMON board specific code: here "preboot" is
+ modified when the user holds down a certain
+ combination of keys on the (special) keyboard when
+ booting the systems
+
+- Serial Download Echo Mode:
+ CONFIG_LOADS_ECHO
+ If defined to 1, all characters received during a
+ serial download (using the "loads" command) are
+ echoed back. This might be needed by some terminal
+ emulations (like "cu"), but may as well just take
+ time on others. This setting #define's the initial
+ value of the "loads_echo" environment variable.
+
+- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
+ CONFIG_KGDB_BAUDRATE
+ Select one of the baudrates listed in
+ CONFIG_SYS_BAUDRATE_TABLE, see below.
+
+- Monitor Functions:
+ Monitor commands can be included or excluded
+ from the build by using the #include files
+ <config_cmd_all.h> and #undef'ing unwanted
+ commands, or using <config_cmd_default.h>
+ and augmenting with additional #define's
+ for wanted commands.
+
+ The default command configuration includes all commands
+ except those marked below with a "*".
+
+ CONFIG_CMD_ASKENV * ask for env variable
+ CONFIG_CMD_BDI bdinfo
+ CONFIG_CMD_BEDBUG * Include BedBug Debugger
+ CONFIG_CMD_BMP * BMP support
+ CONFIG_CMD_BSP * Board specific commands
+ CONFIG_CMD_BOOTD bootd
+ CONFIG_CMD_CACHE * icache, dcache
+ CONFIG_CMD_CONSOLE coninfo
+ CONFIG_CMD_CRC32 * crc32
+ CONFIG_CMD_DATE * support for RTC, date/time...
+ CONFIG_CMD_DHCP * DHCP support
+ CONFIG_CMD_DIAG * Diagnostics
+ CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
+ CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
+ CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
+ CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
+ CONFIG_CMD_DTT * Digital Therm and Thermostat
+ CONFIG_CMD_ECHO echo arguments
+ CONFIG_CMD_EDITENV edit env variable
+ CONFIG_CMD_EEPROM * EEPROM read/write support
+ CONFIG_CMD_ELF * bootelf, bootvx
+ CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
+ CONFIG_CMD_ENV_FLAGS * display details about env flags
+ CONFIG_CMD_EXPORTENV * export the environment
+ CONFIG_CMD_EXT2 * ext2 command support
+ CONFIG_CMD_EXT4 * ext4 command support
+ CONFIG_CMD_SAVEENV saveenv
+ CONFIG_CMD_FDC * Floppy Disk Support
+ CONFIG_CMD_FAT * FAT command support
+ CONFIG_CMD_FDOS * Dos diskette Support
+ CONFIG_CMD_FLASH flinfo, erase, protect
+ CONFIG_CMD_FPGA FPGA device initialization support
+ CONFIG_CMD_FUSE * Device fuse support
+ CONFIG_CMD_GETTIME * Get time since boot
+ CONFIG_CMD_GO * the 'go' command (exec code)
+ CONFIG_CMD_GREPENV * search environment
+ CONFIG_CMD_HASH * calculate hash / digest
+ CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
+ CONFIG_CMD_I2C * I2C serial bus support
+ CONFIG_CMD_IDE * IDE harddisk support
+ CONFIG_CMD_IMI iminfo
+ CONFIG_CMD_IMLS List all images found in NOR flash
+ CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
+ CONFIG_CMD_IMMAP * IMMR dump support
+ CONFIG_CMD_IMPORTENV * import an environment
+ CONFIG_CMD_INI * import data from an ini file into the env
+ CONFIG_CMD_IRQ * irqinfo
+ CONFIG_CMD_ITEST Integer/string test of 2 values
+ CONFIG_CMD_JFFS2 * JFFS2 Support
+ CONFIG_CMD_KGDB * kgdb
+ CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
+ CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
+ (169.254.*.*)
+ CONFIG_CMD_LOADB loadb
+ CONFIG_CMD_LOADS loads
+ CONFIG_CMD_MD5SUM * print md5 message digest
+ (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
+ CONFIG_CMD_MEMINFO * Display detailed memory information
+ CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
+ loop, loopw
+ CONFIG_CMD_MEMTEST * mtest
+ CONFIG_CMD_MISC Misc functions like sleep etc
+ CONFIG_CMD_MMC * MMC memory mapped support
+ CONFIG_CMD_MII * MII utility commands
+ CONFIG_CMD_MTDPARTS * MTD partition support
+ CONFIG_CMD_NAND * NAND support
+ CONFIG_CMD_NET bootp, tftpboot, rarpboot
+ CONFIG_CMD_NFS NFS support
+ CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
+ CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
+ CONFIG_CMD_PCI * pciinfo
+ CONFIG_CMD_PCMCIA * PCMCIA support
+ CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
+ host
+ CONFIG_CMD_PORTIO * Port I/O
+ CONFIG_CMD_READ * Read raw data from partition
+ CONFIG_CMD_REGINFO * Register dump
+ CONFIG_CMD_RUN run command in env variable
+ CONFIG_CMD_SANDBOX * sb command to access sandbox features
+ CONFIG_CMD_SAVES * save S record dump
+ CONFIG_CMD_SCSI * SCSI Support
+ CONFIG_CMD_SDRAM * print SDRAM configuration information
+ (requires CONFIG_CMD_I2C)
+ CONFIG_CMD_SETGETDCR Support for DCR Register access
+ (4xx only)
+ CONFIG_CMD_SF * Read/write/erase SPI NOR flash
+ CONFIG_CMD_SHA1SUM * print sha1 memory digest
+ (requires CONFIG_CMD_MEMORY)
+ CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
+ CONFIG_CMD_SOURCE "source" command Support
+ CONFIG_CMD_SPI * SPI serial bus support
+ CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
+ CONFIG_CMD_TFTPPUT * TFTP put command (upload)
+ CONFIG_CMD_TIME * run command and report execution time (ARM specific)
+ CONFIG_CMD_TIMER * access to the system tick timer
+ CONFIG_CMD_USB * USB support
+ CONFIG_CMD_CDP * Cisco Discover Protocol support
+ CONFIG_CMD_MFSL * Microblaze FSL support
+ CONFIG_CMD_XIMG Load part of Multi Image
+
+
+ EXAMPLE: If you want all functions except of network
+ support you can write:
+
+ #include "config_cmd_all.h"
+ #undef CONFIG_CMD_NET
+
+ Other Commands:
+ fdt (flattened device tree) command: CONFIG_OF_LIBFDT
+
+ Note: Don't enable the "icache" and "dcache" commands
+ (configuration option CONFIG_CMD_CACHE) unless you know
+ what you (and your U-Boot users) are doing. Data
+ cache cannot be enabled on systems like the 8xx or
+ 8260 (where accesses to the IMMR region must be
+ uncached), and it cannot be disabled on all other
+ systems where we (mis-) use the data cache to hold an
+ initial stack and some data.
+
+
+ XXX - this list needs to get updated!
+
+- Regular expression support:
+ CONFIG_REGEX
+ If this variable is defined, U-Boot is linked against
+ the SLRE (Super Light Regular Expression) library,
+ which adds regex support to some commands, as for
+ example "env grep" and "setexpr".
+
+- Device tree:
+ CONFIG_OF_CONTROL
+ If this variable is defined, U-Boot will use a device tree
+ to configure its devices, instead of relying on statically
+ compiled #defines in the board file. This option is
+ experimental and only available on a few boards. The device
+ tree is available in the global data as gd->fdt_blob.
+
+ U-Boot needs to get its device tree from somewhere. This can
+ be done using one of the two options below:
+
+ CONFIG_OF_EMBED
+ If this variable is defined, U-Boot will embed a device tree
+ binary in its image. This device tree file should be in the
+ board directory and called <soc>-<board>.dts. The binary file
+ is then picked up in board_init_f() and made available through
+ the global data structure as gd->blob.
+
+ CONFIG_OF_SEPARATE
+ If this variable is defined, U-Boot will build a device tree
+ binary. It will be called u-boot.dtb. Architecture-specific
+ code will locate it at run-time. Generally this works by:
+
+ cat u-boot.bin u-boot.dtb >image.bin
+
+ and in fact, U-Boot does this for you, creating a file called
+ u-boot-dtb.bin which is useful in the common case. You can
+ still use the individual files if you need something more
+ exotic.
+
+- Watchdog:
+ CONFIG_WATCHDOG
+ If this variable is defined, it enables watchdog
+ support for the SoC. There must be support in the SoC
+ specific code for a watchdog. For the 8xx and 8260
+ CPUs, the SIU Watchdog feature is enabled in the SYPCR
+ register. When supported for a specific SoC is
+ available, then no further board specific code should
+ be needed to use it.
+
+ CONFIG_HW_WATCHDOG
+ When using a watchdog circuitry external to the used
+ SoC, then define this variable and provide board
+ specific code for the "hw_watchdog_reset" function.
+
+- U-Boot Version:
+ CONFIG_VERSION_VARIABLE
+ If this variable is defined, an environment variable
+ named "ver" is created by U-Boot showing the U-Boot
+ version as printed by the "version" command.
+ Any change to this variable will be reverted at the
+ next reset.
+
+- Real-Time Clock:
+
+ When CONFIG_CMD_DATE is selected, the type of the RTC
+ has to be selected, too. Define exactly one of the
+ following options:
+
+ CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
+ CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
+ CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
+ CONFIG_RTC_MC146818 - use MC146818 RTC
+ CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
+ CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
+ CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
+ CONFIG_RTC_DS164x - use Dallas DS164x RTC
+ CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
+ CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
+ CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
+ CONFIG_SYS_RV3029_TCR - enable trickle charger on
+ RV3029 RTC.
+
+ Note that if the RTC uses I2C, then the I2C interface
+ must also be configured. See I2C Support, below.
+
+- GPIO Support:
+ CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
+ CONFIG_PCA953X_INFO - enable pca953x info command
+
+ The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
+ chip-ngpio pairs that tell the PCA953X driver the number of
+ pins supported by a particular chip.
+
+ Note that if the GPIO device uses I2C, then the I2C interface
+ must also be configured. See I2C Support, below.
+
+- Timestamp Support:
+
+ When CONFIG_TIMESTAMP is selected, the timestamp
+ (date and time) of an image is printed by image
+ commands like bootm or iminfo. This option is
+ automatically enabled when you select CONFIG_CMD_DATE .
+
+- Partition Labels (disklabels) Supported:
+ Zero or more of the following:
+ CONFIG_MAC_PARTITION Apple's MacOS partition table.
+ CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
+ Intel architecture, USB sticks, etc.
+ CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
+ CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
+ bootloader. Note 2TB partition limit; see
+ disk/part_efi.c
+ CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
+
+ If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
+ CONFIG_CMD_SCSI) you must configure support for at
+ least one non-MTD partition type as well.
+
+- IDE Reset method:
+ CONFIG_IDE_RESET_ROUTINE - this is defined in several
+ board configurations files but used nowhere!
+
+ CONFIG_IDE_RESET - is this is defined, IDE Reset will
+ be performed by calling the function
+ ide_set_reset(int reset)
+ which has to be defined in a board specific file
+
+- ATAPI Support:
+ CONFIG_ATAPI
+
+ Set this to enable ATAPI support.
+
+- LBA48 Support
+ CONFIG_LBA48
+
+ Set this to enable support for disks larger than 137GB
+ Also look at CONFIG_SYS_64BIT_LBA.
+ Whithout these , LBA48 support uses 32bit variables and will 'only'
+ support disks up to 2.1TB.
+
+ CONFIG_SYS_64BIT_LBA:
+ When enabled, makes the IDE subsystem use 64bit sector addresses.
+ Default is 32bit.
+
+- SCSI Support:
+ At the moment only there is only support for the
+ SYM53C8XX SCSI controller; define
+ CONFIG_SCSI_SYM53C8XX to enable it.
+
+ CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
+ CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
+ CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
+ maximum numbers of LUNs, SCSI ID's and target
+ devices.
+ CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
+
+ The environment variable 'scsidevs' is set to the number of
+ SCSI devices found during the last scan.
+
+- NETWORK Support (PCI):
+ CONFIG_E1000
+ Support for Intel 8254x/8257x gigabit chips.
+
+ CONFIG_E1000_SPI
+ Utility code for direct access to the SPI bus on Intel 8257x.
+ This does not do anything useful unless you set at least one
+ of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
+
+ CONFIG_E1000_SPI_GENERIC
+ Allow generic access to the SPI bus on the Intel 8257x, for
+ example with the "sspi" command.
+
+ CONFIG_CMD_E1000
+ Management command for E1000 devices. When used on devices
+ with SPI support you can reprogram the EEPROM from U-Boot.
+
+ CONFIG_E1000_FALLBACK_MAC
+ default MAC for empty EEPROM after production.
+
+ CONFIG_EEPRO100
+ Support for Intel 82557/82559/82559ER chips.
+ Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
+ write routine for first time initialisation.
+
+ CONFIG_TULIP
+ Support for Digital 2114x chips.
+ Optional CONFIG_TULIP_SELECT_MEDIA for board specific
+ modem chip initialisation (KS8761/QS6611).
+
+ CONFIG_NATSEMI
+ Support for National dp83815 chips.
+
+ CONFIG_NS8382X
+ Support for National dp8382[01] gigabit chips.
+
+- NETWORK Support (other):
+
+ CONFIG_DRIVER_AT91EMAC
+ Support for AT91RM9200 EMAC.
+
+ CONFIG_RMII
+ Define this to use reduced MII inteface
+
+ CONFIG_DRIVER_AT91EMAC_QUIET
+ If this defined, the driver is quiet.
+ The driver doen't show link status messages.
+
+ CONFIG_CALXEDA_XGMAC
+ Support for the Calxeda XGMAC device
+
+ CONFIG_LAN91C96
+ Support for SMSC's LAN91C96 chips.
+
+ CONFIG_LAN91C96_BASE
+ Define this to hold the physical address
+ of the LAN91C96's I/O space
+
+ CONFIG_LAN91C96_USE_32_BIT
+ Define this to enable 32 bit addressing
+
+ CONFIG_SMC91111
+ Support for SMSC's LAN91C111 chip
+
+ CONFIG_SMC91111_BASE
+ Define this to hold the physical address
+ of the device (I/O space)
+
+ CONFIG_SMC_USE_32_BIT
+ Define this if data bus is 32 bits
+
+ CONFIG_SMC_USE_IOFUNCS
+ Define this to use i/o functions instead of macros
+ (some hardware wont work with macros)
+
+ CONFIG_DRIVER_TI_EMAC
+ Support for davinci emac
+
+ CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
+ Define this if you have more then 3 PHYs.
+
+ CONFIG_FTGMAC100
+ Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
+
+ CONFIG_FTGMAC100_EGIGA
+ Define this to use GE link update with gigabit PHY.
+ Define this if FTGMAC100 is connected to gigabit PHY.
+ If your system has 10/100 PHY only, it might not occur
+ wrong behavior. Because PHY usually return timeout or
+ useless data when polling gigabit status and gigabit
+ control registers. This behavior won't affect the
+ correctnessof 10/100 link speed update.
+
+ CONFIG_SMC911X
+ Support for SMSC's LAN911x and LAN921x chips
+
+ CONFIG_SMC911X_BASE
+ Define this to hold the physical address
+ of the device (I/O space)
+
+ CONFIG_SMC911X_32_BIT
+ Define this if data bus is 32 bits
+
+ CONFIG_SMC911X_16_BIT
+ Define this if data bus is 16 bits. If your processor
+ automatically converts one 32 bit word to two 16 bit
+ words you may also try CONFIG_SMC911X_32_BIT.
+
+ CONFIG_SH_ETHER
+ Support for Renesas on-chip Ethernet controller
+
+ CONFIG_SH_ETHER_USE_PORT
+ Define the number of ports to be used
+
+ CONFIG_SH_ETHER_PHY_ADDR
+ Define the ETH PHY's address
+
+ CONFIG_SH_ETHER_CACHE_WRITEBACK
+ If this option is set, the driver enables cache flush.
+
+- TPM Support:
+ CONFIG_TPM
+ Support TPM devices.
+
+ CONFIG_TPM_TIS_I2C
+ Support for i2c bus TPM devices. Only one device
+ per system is supported at this time.
+
+ CONFIG_TPM_TIS_I2C_BUS_NUMBER
+ Define the the i2c bus number for the TPM device
+
+ CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
+ Define the TPM's address on the i2c bus
+
+ CONFIG_TPM_TIS_I2C_BURST_LIMITATION
+ Define the burst count bytes upper limit
+
+ CONFIG_TPM_ATMEL_TWI
+ Support for Atmel TWI TPM device. Requires I2C support.
+
+ CONFIG_TPM_TIS_LPC
+ Support for generic parallel port TPM devices. Only one device
+ per system is supported at this time.
+
+ CONFIG_TPM_TIS_BASE_ADDRESS
+ Base address where the generic TPM device is mapped
+ to. Contemporary x86 systems usually map it at
+ 0xfed40000.
+
+ CONFIG_CMD_TPM
+ Add tpm monitor functions.
+ Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
+ provides monitor access to authorized functions.
+
+ CONFIG_TPM
+ Define this to enable the TPM support library which provides
+ functional interfaces to some TPM commands.
+ Requires support for a TPM device.
+
+ CONFIG_TPM_AUTH_SESSIONS
+ Define this to enable authorized functions in the TPM library.
+ Requires CONFIG_TPM and CONFIG_SHA1.
+
+- USB Support:
+ At the moment only the UHCI host controller is
+ supported (PIP405, MIP405, MPC5200); define
+ CONFIG_USB_UHCI to enable it.
+ define CONFIG_USB_KEYBOARD to enable the USB Keyboard
+ and define CONFIG_USB_STORAGE to enable the USB
+ storage devices.
+ Note:
+ Supported are USB Keyboards and USB Floppy drives
+ (TEAC FD-05PUB).
+ MPC5200 USB requires additional defines:
+ CONFIG_USB_CLOCK
+ for 528 MHz Clock: 0x0001bbbb
+ CONFIG_PSC3_USB
+ for USB on PSC3
+ CONFIG_USB_CONFIG
+ for differential drivers: 0x00001000
+ for single ended drivers: 0x00005000
+ for differential drivers on PSC3: 0x00000100
+ for single ended drivers on PSC3: 0x00004100
+ CONFIG_SYS_USB_EVENT_POLL
+ May be defined to allow interrupt polling
+ instead of using asynchronous interrupts
+
+ CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
+ txfilltuning field in the EHCI controller on reset.
+
+ CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
+ interval for usb hub power-on delay.(minimum 100msec)
+
+- USB Device:
+ Define the below if you wish to use the USB console.
+ Once firmware is rebuilt from a serial console issue the
+ command "setenv stdin usbtty; setenv stdout usbtty" and
+ attach your USB cable. The Unix command "dmesg" should print
+ it has found a new device. The environment variable usbtty
+ can be set to gserial or cdc_acm to enable your device to
+ appear to a USB host as a Linux gserial device or a
+ Common Device Class Abstract Control Model serial device.
+ If you select usbtty = gserial you should be able to enumerate
+ a Linux host by
+ # modprobe usbserial vendor=0xVendorID product=0xProductID
+ else if using cdc_acm, simply setting the environment
+ variable usbtty to be cdc_acm should suffice. The following
+ might be defined in YourBoardName.h
+
+ CONFIG_USB_DEVICE
+ Define this to build a UDC device
+
+ CONFIG_USB_TTY
+ Define this to have a tty type of device available to
+ talk to the UDC device
+
+ CONFIG_USBD_HS
+ Define this to enable the high speed support for usb
+ device and usbtty. If this feature is enabled, a routine
+ int is_usbd_high_speed(void)
+ also needs to be defined by the driver to dynamically poll
+ whether the enumeration has succeded at high speed or full
+ speed.
+
+ CONFIG_SYS_CONSOLE_IS_IN_ENV
+ Define this if you want stdin, stdout &/or stderr to
+ be set to usbtty.
+
+ mpc8xx:
+ CONFIG_SYS_USB_EXTC_CLK 0xBLAH
+ Derive USB clock from external clock "blah"
+ - CONFIG_SYS_USB_EXTC_CLK 0x02
+
+ CONFIG_SYS_USB_BRG_CLK 0xBLAH
+ Derive USB clock from brgclk
+ - CONFIG_SYS_USB_BRG_CLK 0x04
+
+ If you have a USB-IF assigned VendorID then you may wish to
+ define your own vendor specific values either in BoardName.h
+ or directly in usbd_vendor_info.h. If you don't define
+ CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
+ CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
+ should pretend to be a Linux device to it's target host.
+
+ CONFIG_USBD_MANUFACTURER
+ Define this string as the name of your company for
+ - CONFIG_USBD_MANUFACTURER "my company"
+
+ CONFIG_USBD_PRODUCT_NAME
+ Define this string as the name of your product
+ - CONFIG_USBD_PRODUCT_NAME "acme usb device"
+
+ CONFIG_USBD_VENDORID
+ Define this as your assigned Vendor ID from the USB
+ Implementors Forum. This *must* be a genuine Vendor ID
+ to avoid polluting the USB namespace.
+ - CONFIG_USBD_VENDORID 0xFFFF
+
+ CONFIG_USBD_PRODUCTID
+ Define this as the unique Product ID
+ for your device
+ - CONFIG_USBD_PRODUCTID 0xFFFF
+
+- ULPI Layer Support:
+ The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
+ the generic ULPI layer. The generic layer accesses the ULPI PHY
+ via the platform viewport, so you need both the genric layer and
+ the viewport enabled. Currently only Chipidea/ARC based
+ viewport is supported.
+ To enable the ULPI layer support, define CONFIG_USB_ULPI and
+ CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
+ If your ULPI phy needs a different reference clock than the
+ standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
+ the appropriate value in Hz.
+
+- MMC Support:
+ The MMC controller on the Intel PXA is supported. To
+ enable this define CONFIG_MMC. The MMC can be
+ accessed from the boot prompt by mapping the device
+ to physical memory similar to flash. Command line is
+ enabled with CONFIG_CMD_MMC. The MMC driver also works with
+ the FAT fs. This is enabled with CONFIG_CMD_FAT.
+
+ CONFIG_SH_MMCIF
+ Support for Renesas on-chip MMCIF controller
+
+ CONFIG_SH_MMCIF_ADDR
+ Define the base address of MMCIF registers
+
+ CONFIG_SH_MMCIF_CLK
+ Define the clock frequency for MMCIF
+
+- USB Device Firmware Update (DFU) class support:
+ CONFIG_DFU_FUNCTION
+ This enables the USB portion of the DFU USB class
+
+ CONFIG_CMD_DFU
+ This enables the command "dfu" which is used to have
+ U-Boot create a DFU class device via USB. This command
+ requires that the "dfu_alt_info" environment variable be
+ set and define the alt settings to expose to the host.
+
+ CONFIG_DFU_MMC
+ This enables support for exposing (e)MMC devices via DFU.
+
+ CONFIG_DFU_NAND
+ This enables support for exposing NAND devices via DFU.
+
+ CONFIG_SYS_DFU_DATA_BUF_SIZE
+ Dfu transfer uses a buffer before writing data to the
+ raw storage device. Make the size (in bytes) of this buffer
+ configurable. The size of this buffer is also configurable
+ through the "dfu_bufsiz" environment variable.
+
+ CONFIG_SYS_DFU_MAX_FILE_SIZE
+ When updating files rather than the raw storage device,
+ we use a static buffer to copy the file into and then write
+ the buffer once we've been given the whole file. Define
+ this to the maximum filesize (in bytes) for the buffer.
+ Default is 4 MiB if undefined.
+
+- Journaling Flash filesystem support:
+ CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
+ CONFIG_JFFS2_NAND_DEV
+ Define these for a default partition on a NAND device
+
+ CONFIG_SYS_JFFS2_FIRST_SECTOR,
+ CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
+ Define these for a default partition on a NOR device
+
+ CONFIG_SYS_JFFS_CUSTOM_PART
+ Define this to create an own partition. You have to provide a
+ function struct part_info* jffs2_part_info(int part_num)
+
+ If you define only one JFFS2 partition you may also want to
+ #define CONFIG_SYS_JFFS_SINGLE_PART 1
+ to disable the command chpart. This is the default when you
+ have not defined a custom partition
+
+- FAT(File Allocation Table) filesystem write function support:
+ CONFIG_FAT_WRITE
+
+ Define this to enable support for saving memory data as a
+ file in FAT formatted partition.
+
+ This will also enable the command "fatwrite" enabling the
+ user to write files to FAT.
+
+CBFS (Coreboot Filesystem) support
+ CONFIG_CMD_CBFS
+
+ Define this to enable support for reading from a Coreboot
+ filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
+ and cbfsload.
+
+- Keyboard Support:
+ CONFIG_ISA_KEYBOARD
+
+ Define this to enable standard (PC-Style) keyboard
+ support
+
+ CONFIG_I8042_KBD
+ Standard PC keyboard driver with US (is default) and
+ GERMAN key layout (switch via environment 'keymap=de') support.
+ Export function i8042_kbd_init, i8042_tstc and i8042_getc
+ for cfb_console. Supports cursor blinking.
+
+ CONFIG_CROS_EC_KEYB
+ Enables a Chrome OS keyboard using the CROS_EC interface.
+ This uses CROS_EC to communicate with a second microcontroller
+ which provides key scans on request.
+
+- Video support:
+ CONFIG_VIDEO
+
+ Define this to enable video support (for output to
+ video).
+
+ CONFIG_VIDEO_CT69000
+
+ Enable Chips & Technologies 69000 Video chip
+
+ CONFIG_VIDEO_SMI_LYNXEM
+ Enable Silicon Motion SMI 712/710/810 Video chip. The
+ video output is selected via environment 'videoout'
+ (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
+ assumed.
+
+ For the CT69000 and SMI_LYNXEM drivers, videomode is
+ selected via environment 'videomode'. Two different ways
+ are possible:
+ - "videomode=num" 'num' is a standard LiLo mode numbers.
+ Following standard modes are supported (* is default):
+
+ Colors 640x480 800x600 1024x768 1152x864 1280x1024
+ -------------+---------------------------------------------
+ 8 bits | 0x301* 0x303 0x305 0x161 0x307
+ 15 bits | 0x310 0x313 0x316 0x162 0x319
+ 16 bits | 0x311 0x314 0x317 0x163 0x31A
+ 24 bits | 0x312 0x315 0x318 ? 0x31B
+ -------------+---------------------------------------------
+ (i.e. setenv videomode 317; saveenv; reset;)
+
+ - "videomode=bootargs" all the video parameters are parsed
+ from the bootargs. (See drivers/video/videomodes.c)
+
+
+ CONFIG_VIDEO_SED13806
+ Enable Epson SED13806 driver. This driver supports 8bpp
+ and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
+ or CONFIG_VIDEO_SED13806_16BPP
+
+ CONFIG_FSL_DIU_FB
+ Enable the Freescale DIU video driver. Reference boards for
+ SOCs that have a DIU should define this macro to enable DIU
+ support, and should also define these other macros:
+
+ CONFIG_SYS_DIU_ADDR
+ CONFIG_VIDEO
+ CONFIG_CMD_BMP
+ CONFIG_CFB_CONSOLE
+ CONFIG_VIDEO_SW_CURSOR
+ CONFIG_VGA_AS_SINGLE_DEVICE
+ CONFIG_VIDEO_LOGO
+ CONFIG_VIDEO_BMP_LOGO
+
+ The DIU driver will look for the 'video-mode' environment
+ variable, and if defined, enable the DIU as a console during
+ boot. See the documentation file README.video for a
+ description of this variable.
+
+ CONFIG_VIDEO_VGA
+
+ Enable the VGA video / BIOS for x86. The alternative if you
+ are using coreboot is to use the coreboot frame buffer
+ driver.
+
+
+- Keyboard Support:
+ CONFIG_KEYBOARD
+
+ Define this to enable a custom keyboard support.
+ This simply calls drv_keyboard_init() which must be
+ defined in your board-specific files.
+ The only board using this so far is RBC823.
+
+- LCD Support: CONFIG_LCD
+
+ Define this to enable LCD support (for output to LCD
+ display); also select one of the supported displays
+ by defining one of these:
+
+ CONFIG_ATMEL_LCD:
+
+ HITACHI TX09D70VM1CCA, 3.5", 240x320.
+
+ CONFIG_NEC_NL6448AC33:
+
+ NEC NL6448AC33-18. Active, color, single scan.
+
+ CONFIG_NEC_NL6448BC20
+
+ NEC NL6448BC20-08. 6.5", 640x480.
+ Active, color, single scan.
+
+ CONFIG_NEC_NL6448BC33_54
+
+ NEC NL6448BC33-54. 10.4", 640x480.
+ Active, color, single scan.
+
+ CONFIG_SHARP_16x9
+
+ Sharp 320x240. Active, color, single scan.
+ It isn't 16x9, and I am not sure what it is.
+
+ CONFIG_SHARP_LQ64D341
+
+ Sharp LQ64D341 display, 640x480.
+ Active, color, single scan.
+
+ CONFIG_HLD1045
+
+ HLD1045 display, 640x480.
+ Active, color, single scan.
+
+ CONFIG_OPTREX_BW
+
+ Optrex CBL50840-2 NF-FW 99 22 M5
+ or
+ Hitachi LMG6912RPFC-00T
+ or
+ Hitachi SP14Q002
+
+ 320x240. Black & white.
+
+ Normally display is black on white background; define
+ CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
+
+ CONFIG_LCD_ALIGNMENT
+
+ Normally the LCD is page-aligned (tyically 4KB). If this is
+ defined then the LCD will be aligned to this value instead.
+ For ARM it is sometimes useful to use MMU_SECTION_SIZE
+ here, since it is cheaper to change data cache settings on
+ a per-section basis.
+
+ CONFIG_CONSOLE_SCROLL_LINES
+
+ When the console need to be scrolled, this is the number of
+ lines to scroll by. It defaults to 1. Increasing this makes
+ the console jump but can help speed up operation when scrolling
+ is slow.
+
+ CONFIG_LCD_BMP_RLE8
+
+ Support drawing of RLE8-compressed bitmaps on the LCD.
+
+ CONFIG_I2C_EDID
+
+ Enables an 'i2c edid' command which can read EDID
+ information over I2C from an attached LCD display.
+
+- Splash Screen Support: CONFIG_SPLASH_SCREEN
+
+ If this option is set, the environment is checked for
+ a variable "splashimage". If found, the usual display
+ of logo, copyright and system information on the LCD
+ is suppressed and the BMP image at the address
+ specified in "splashimage" is loaded instead. The
+ console is redirected to the "nulldev", too. This
+ allows for a "silent" boot where a splash screen is
+ loaded very quickly after power-on.
+
+ CONFIG_SPLASHIMAGE_GUARD
+
+ If this option is set, then U-Boot will prevent the environment
+ variable "splashimage" from being set to a problematic address
+ (see README.displaying-bmps and README.arm-unaligned-accesses).
+ This option is useful for targets where, due to alignment
+ restrictions, an improperly aligned BMP image will cause a data
+ abort. If you think you will not have problems with unaligned
+ accesses (for example because your toolchain prevents them)
+ there is no need to set this option.
+
+ CONFIG_SPLASH_SCREEN_ALIGN
+
+ If this option is set the splash image can be freely positioned
+ on the screen. Environment variable "splashpos" specifies the
+ position as "x,y". If a positive number is given it is used as
+ number of pixel from left/top. If a negative number is given it
+ is used as number of pixel from right/bottom. You can also
+ specify 'm' for centering the image.
+
+ Example:
+ setenv splashpos m,m
+ => image at center of screen
+
+ setenv splashpos 30,20
+ => image at x = 30 and y = 20
+
+ setenv splashpos -10,m
+ => vertically centered image
+ at x = dspWidth - bmpWidth - 9
+
+- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
+
+ If this option is set, additionally to standard BMP
+ images, gzipped BMP images can be displayed via the
+ splashscreen support or the bmp command.
+
+- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
+
+ If this option is set, 8-bit RLE compressed BMP images
+ can be displayed via the splashscreen support or the
+ bmp command.
+
+- Do compresssing for memory range:
+ CONFIG_CMD_ZIP
+
+ If this option is set, it would use zlib deflate method
+ to compress the specified memory at its best effort.
+
+- Compression support:
+ CONFIG_BZIP2
+
+ If this option is set, support for bzip2 compressed
+ images is included. If not, only uncompressed and gzip
+ compressed images are supported.
+
+ NOTE: the bzip2 algorithm requires a lot of RAM, so
+ the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
+ be at least 4MB.
+
+ CONFIG_LZMA
+
+ If this option is set, support for lzma compressed
+ images is included.
+
+ Note: The LZMA algorithm adds between 2 and 4KB of code and it
+ requires an amount of dynamic memory that is given by the
+ formula:
+
+ (1846 + 768 << (lc + lp)) * sizeof(uint16)
+
+ Where lc and lp stand for, respectively, Literal context bits
+ and Literal pos bits.
+
+ This value is upper-bounded by 14MB in the worst case. Anyway,
+ for a ~4MB large kernel image, we have lc=3 and lp=0 for a
+ total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
+ a very small buffer.
+
+ Use the lzmainfo tool to determinate the lc and lp values and
+ then calculate the amount of needed dynamic memory (ensuring
+ the appropriate CONFIG_SYS_MALLOC_LEN value).
+
+- MII/PHY support:
+ CONFIG_PHY_ADDR
+
+ The address of PHY on MII bus.
+
+ CONFIG_PHY_CLOCK_FREQ (ppc4xx)
+
+ The clock frequency of the MII bus
+
+ CONFIG_PHY_GIGE
+
+ If this option is set, support for speed/duplex
+ detection of gigabit PHY is included.
+
+ CONFIG_PHY_RESET_DELAY
+
+ Some PHY like Intel LXT971A need extra delay after
+ reset before any MII register access is possible.
+ For such PHY, set this option to the usec delay
+ required. (minimum 300usec for LXT971A)
+
+ CONFIG_PHY_CMD_DELAY (ppc4xx)
+
+ Some PHY like Intel LXT971A need extra delay after
+ command issued before MII status register can be read
+
+- Ethernet address:
+ CONFIG_ETHADDR
+ CONFIG_ETH1ADDR
+ CONFIG_ETH2ADDR
+ CONFIG_ETH3ADDR
+ CONFIG_ETH4ADDR
+ CONFIG_ETH5ADDR
+
+ Define a default value for Ethernet address to use
+ for the respective Ethernet interface, in case this
+ is not determined automatically.
+
+- IP address:
+ CONFIG_IPADDR
+
+ Define a default value for the IP address to use for
+ the default Ethernet interface, in case this is not
+ determined through e.g. bootp.
+ (Environment variable "ipaddr")
+
+- Server IP address:
+ CONFIG_SERVERIP
+
+ Defines a default value for the IP address of a TFTP
+ server to contact when using the "tftboot" command.
+ (Environment variable "serverip")
+
+ CONFIG_KEEP_SERVERADDR
+
+ Keeps the server's MAC address, in the env 'serveraddr'
+ for passing to bootargs (like Linux's netconsole option)
+
+- Gateway IP address:
+ CONFIG_GATEWAYIP
+
+ Defines a default value for the IP address of the
+ default router where packets to other networks are
+ sent to.
+ (Environment variable "gatewayip")
+
+- Subnet mask:
+ CONFIG_NETMASK
+
+ Defines a default value for the subnet mask (or
+ routing prefix) which is used to determine if an IP
+ address belongs to the local subnet or needs to be
+ forwarded through a router.
+ (Environment variable "netmask")
+
+- Multicast TFTP Mode:
+ CONFIG_MCAST_TFTP
+
+ Defines whether you want to support multicast TFTP as per
+ rfc-2090; for example to work with atftp. Lets lots of targets
+ tftp down the same boot image concurrently. Note: the Ethernet
+ driver in use must provide a function: mcast() to join/leave a
+ multicast group.
+
+- BOOTP Recovery Mode:
+ CONFIG_BOOTP_RANDOM_DELAY
+
+ If you have many targets in a network that try to
+ boot using BOOTP, you may want to avoid that all
+ systems send out BOOTP requests at precisely the same
+ moment (which would happen for instance at recovery
+ from a power failure, when all systems will try to
+ boot, thus flooding the BOOTP server. Defining
+ CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
+ inserted before sending out BOOTP requests. The
+ following delays are inserted then:
+
+ 1st BOOTP request: delay 0 ... 1 sec
+ 2nd BOOTP request: delay 0 ... 2 sec
+ 3rd BOOTP request: delay 0 ... 4 sec
+ 4th and following
+ BOOTP requests: delay 0 ... 8 sec
+
+- DHCP Advanced Options:
+ You can fine tune the DHCP functionality by defining
+ CONFIG_BOOTP_* symbols:
+
+ CONFIG_BOOTP_SUBNETMASK
+ CONFIG_BOOTP_GATEWAY
+ CONFIG_BOOTP_HOSTNAME
+ CONFIG_BOOTP_NISDOMAIN
+ CONFIG_BOOTP_BOOTPATH
+ CONFIG_BOOTP_BOOTFILESIZE
+ CONFIG_BOOTP_DNS
+ CONFIG_BOOTP_DNS2
+ CONFIG_BOOTP_SEND_HOSTNAME
+ CONFIG_BOOTP_NTPSERVER
+ CONFIG_BOOTP_TIMEOFFSET
+ CONFIG_BOOTP_VENDOREX
+ CONFIG_BOOTP_MAY_FAIL
+
+ CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
+ environment variable, not the BOOTP server.
+
+ CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
+ after the configured retry count, the call will fail
+ instead of starting over. This can be used to fail over
+ to Link-local IP address configuration if the DHCP server
+ is not available.
+
+ CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
+ serverip from a DHCP server, it is possible that more
+ than one DNS serverip is offered to the client.
+ If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
+ serverip will be stored in the additional environment
+ variable "dnsip2". The first DNS serverip is always
+ stored in the variable "dnsip", when CONFIG_BOOTP_DNS
+ is defined.
+
+ CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
+ to do a dynamic update of a DNS server. To do this, they
+ need the hostname of the DHCP requester.
+ If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
+ of the "hostname" environment variable is passed as
+ option 12 to the DHCP server.
+
+ CONFIG_BOOTP_DHCP_REQUEST_DELAY
+
+ A 32bit value in microseconds for a delay between
+ receiving a "DHCP Offer" and sending the "DHCP Request".
+ This fixes a problem with certain DHCP servers that don't
+ respond 100% of the time to a "DHCP request". E.g. On an
+ AT91RM9200 processor running at 180MHz, this delay needed
+ to be *at least* 15,000 usec before a Windows Server 2003
+ DHCP server would reply 100% of the time. I recommend at
+ least 50,000 usec to be safe. The alternative is to hope
+ that one of the retries will be successful but note that
+ the DHCP timeout and retry process takes a longer than
+ this delay.
+
+ - Link-local IP address negotiation:
+ Negotiate with other link-local clients on the local network
+ for an address that doesn't require explicit configuration.
+ This is especially useful if a DHCP server cannot be guaranteed
+ to exist in all environments that the device must operate.
+
+ See doc/README.link-local for more information.
+
+ - CDP Options:
+ CONFIG_CDP_DEVICE_ID
+
+ The device id used in CDP trigger frames.
+
+ CONFIG_CDP_DEVICE_ID_PREFIX
+
+ A two character string which is prefixed to the MAC address
+ of the device.
+
+ CONFIG_CDP_PORT_ID
+
+ A printf format string which contains the ascii name of
+ the port. Normally is set to "eth%d" which sets
+ eth0 for the first Ethernet, eth1 for the second etc.
+
+ CONFIG_CDP_CAPABILITIES
+
+ A 32bit integer which indicates the device capabilities;
+ 0x00000010 for a normal host which does not forwards.
+
+ CONFIG_CDP_VERSION
+
+ An ascii string containing the version of the software.
+
+ CONFIG_CDP_PLATFORM
+
+ An ascii string containing the name of the platform.
+
+ CONFIG_CDP_TRIGGER
+
+ A 32bit integer sent on the trigger.
+
+ CONFIG_CDP_POWER_CONSUMPTION
+
+ A 16bit integer containing the power consumption of the
+ device in .1 of milliwatts.
+
+ CONFIG_CDP_APPLIANCE_VLAN_TYPE
+
+ A byte containing the id of the VLAN.
+
+- Status LED: CONFIG_STATUS_LED
+
+ Several configurations allow to display the current
+ status using a LED. For instance, the LED will blink
+ fast while running U-Boot code, stop blinking as
+ soon as a reply to a BOOTP request was received, and
+ start blinking slow once the Linux kernel is running
+ (supported by a status LED driver in the Linux
+ kernel). Defining CONFIG_STATUS_LED enables this
+ feature in U-Boot.
+
+- CAN Support: CONFIG_CAN_DRIVER
+
+ Defining CONFIG_CAN_DRIVER enables CAN driver support
+ on those systems that support this (optional)
+ feature, like the TQM8xxL modules.
+
+- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
+
+ These enable I2C serial bus commands. Defining either of
+ (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
+ include the appropriate I2C driver for the selected CPU.
+
+ This will allow you to use i2c commands at the u-boot
+ command line (as long as you set CONFIG_CMD_I2C in
+ CONFIG_COMMANDS) and communicate with i2c based realtime
+ clock chips. See common/cmd_i2c.c for a description of the
+ command line interface.
+
+ CONFIG_HARD_I2C selects a hardware I2C controller.
+
+ CONFIG_SOFT_I2C configures u-boot to use a software (aka
+ bit-banging) driver instead of CPM or similar hardware
+ support for I2C.
+
+ There are several other quantities that must also be
+ defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
+
+ In both cases you will need to define CONFIG_SYS_I2C_SPEED
+ to be the frequency (in Hz) at which you wish your i2c bus
+ to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
+ the CPU's i2c node address).
+
+ Now, the u-boot i2c code for the mpc8xx
+ (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
+ and so its address should therefore be cleared to 0 (See,
+ eg, MPC823e User's Manual p.16-473). So, set
+ CONFIG_SYS_I2C_SLAVE to 0.
+
+ CONFIG_SYS_I2C_INIT_MPC5XXX
+
+ When a board is reset during an i2c bus transfer
+ chips might think that the current transfer is still
+ in progress. Reset the slave devices by sending start
+ commands until the slave device responds.
+
+ That's all that's required for CONFIG_HARD_I2C.
+
+ If you use the software i2c interface (CONFIG_SOFT_I2C)
+ then the following macros need to be defined (examples are
+ from include/configs/lwmon.h):
+
+ I2C_INIT
+
+ (Optional). Any commands necessary to enable the I2C
+ controller or configure ports.
+
+ eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
+
+ I2C_PORT
+
+ (Only for MPC8260 CPU). The I/O port to use (the code
+ assumes both bits are on the same port). Valid values
+ are 0..3 for ports A..D.
+
+ I2C_ACTIVE
+
+ The code necessary to make the I2C data line active
+ (driven). If the data line is open collector, this
+ define can be null.
+
+ eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
+
+ I2C_TRISTATE
+
+ The code necessary to make the I2C data line tri-stated
+ (inactive). If the data line is open collector, this
+ define can be null.
+
+ eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
+
+ I2C_READ
+
+ Code that returns true if the I2C data line is high,
+ false if it is low.
+
+ eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
+
+ I2C_SDA(bit)
+
+ If <bit> is true, sets the I2C data line high. If it
+ is false, it clears it (low).
+
+ eg: #define I2C_SDA(bit) \
+ if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
+ else immr->im_cpm.cp_pbdat &= ~PB_SDA
+
+ I2C_SCL(bit)
+
+ If <bit> is true, sets the I2C clock line high. If it
+ is false, it clears it (low).
+
+ eg: #define I2C_SCL(bit) \
+ if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
+ else immr->im_cpm.cp_pbdat &= ~PB_SCL
+
+ I2C_DELAY
+
+ This delay is invoked four times per clock cycle so this
+ controls the rate of data transfer. The data rate thus
+ is 1 / (I2C_DELAY * 4). Often defined to be something
+ like:
+
+ #define I2C_DELAY udelay(2)
+
+ CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
+
+ If your arch supports the generic GPIO framework (asm/gpio.h),
+ then you may alternatively define the two GPIOs that are to be
+ used as SCL / SDA. Any of the previous I2C_xxx macros will
+ have GPIO-based defaults assigned to them as appropriate.
+
+ You should define these to the GPIO value as given directly to
+ the generic GPIO functions.
+
+ CONFIG_SYS_I2C_INIT_BOARD
+
+ When a board is reset during an i2c bus transfer
+ chips might think that the current transfer is still
+ in progress. On some boards it is possible to access
+ the i2c SCLK line directly, either by using the
+ processor pin as a GPIO or by having a second pin
+ connected to the bus. If this option is defined a
+ custom i2c_init_board() routine in boards/xxx/board.c
+ is run early in the boot sequence.
+
+ CONFIG_SYS_I2C_BOARD_LATE_INIT
+
+ An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
+ defined a custom i2c_board_late_init() routine in
+ boards/xxx/board.c is run AFTER the operations in i2c_init()
+ is completed. This callpoint can be used to unreset i2c bus
+ using CPU i2c controller register accesses for CPUs whose i2c
+ controller provide such a method. It is called at the end of
+ i2c_init() to allow i2c_init operations to setup the i2c bus
+ controller on the CPU (e.g. setting bus speed & slave address).
+
+ CONFIG_I2CFAST (PPC405GP|PPC405EP only)
+
+ This option enables configuration of bi_iic_fast[] flags
+ in u-boot bd_info structure based on u-boot environment
+ variable "i2cfast". (see also i2cfast)
+
+ CONFIG_I2C_MULTI_BUS
+
+ This option allows the use of multiple I2C buses, each of which
+ must have a controller. At any point in time, only one bus is
+ active. To switch to a different bus, use the 'i2c dev' command.
+ Note that bus numbering is zero-based.
+
+ CONFIG_SYS_I2C_NOPROBES
+
+ This option specifies a list of I2C devices that will be skipped
+ when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
+ is set, specify a list of bus-device pairs. Otherwise, specify
+ a 1D array of device addresses
+
+ e.g.
+ #undef CONFIG_I2C_MULTI_BUS
+ #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
+
+ will skip addresses 0x50 and 0x68 on a board with one I2C bus
+
+ #define CONFIG_I2C_MULTI_BUS
+ #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
+
+ will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
+
+ CONFIG_SYS_SPD_BUS_NUM
+
+ If defined, then this indicates the I2C bus number for DDR SPD.
+ If not defined, then U-Boot assumes that SPD is on I2C bus 0.
+
+ CONFIG_SYS_RTC_BUS_NUM
+
+ If defined, then this indicates the I2C bus number for the RTC.
+ If not defined, then U-Boot assumes that RTC is on I2C bus 0.
+
+ CONFIG_SYS_DTT_BUS_NUM
+
+ If defined, then this indicates the I2C bus number for the DTT.
+ If not defined, then U-Boot assumes that DTT is on I2C bus 0.
+
+ CONFIG_SYS_I2C_DTT_ADDR:
+
+ If defined, specifies the I2C address of the DTT device.
+ If not defined, then U-Boot uses predefined value for
+ specified DTT device.
+
+ CONFIG_FSL_I2C
+
+ Define this option if you want to use Freescale's I2C driver in
+ drivers/i2c/fsl_i2c.c.
+
+ CONFIG_I2C_MUX
+
+ Define this option if you have I2C devices reached over 1 .. n
+ I2C Muxes like the pca9544a. This option addes a new I2C
+ Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
+ new I2C Bus to the existing I2C Busses. If you select the
+ new Bus with "i2c dev", u-bbot sends first the commandos for
+ the muxes to activate this new "bus".
+
+ CONFIG_I2C_MULTI_BUS must be also defined, to use this
+ feature!
+
+ Example:
+ Adding a new I2C Bus reached over 2 pca9544a muxes
+ The First mux with address 70 and channel 6
+ The Second mux with address 71 and channel 4
+
+ => i2c bus pca9544a:70:6:pca9544a:71:4
+
+ Use the "i2c bus" command without parameter, to get a list
+ of I2C Busses with muxes:
+
+ => i2c bus
+ Busses reached over muxes:
+ Bus ID: 2
+ reached over Mux(es):
+ pca9544a@70 ch: 4
+ Bus ID: 3
+ reached over Mux(es):
+ pca9544a@70 ch: 6
+ pca9544a@71 ch: 4
+ =>
+
+ If you now switch to the new I2C Bus 3 with "i2c dev 3"
+ u-boot first sends the command to the mux@70 to enable
+ channel 6, and then the command to the mux@71 to enable
+ the channel 4.
+
+ After that, you can use the "normal" i2c commands as
+ usual to communicate with your I2C devices behind
+ the 2 muxes.
+
+ This option is actually implemented for the bitbanging
+ algorithm in common/soft_i2c.c and for the Hardware I2C
+ Bus on the MPC8260. But it should be not so difficult
+ to add this option to other architectures.
+
+ CONFIG_SOFT_I2C_READ_REPEATED_START
+
+ defining this will force the i2c_read() function in
+ the soft_i2c driver to perform an I2C repeated start
+ between writing the address pointer and reading the
+ data. If this define is omitted the default behaviour
+ of doing a stop-start sequence will be used. Most I2C
+ devices can use either method, but some require one or
+ the other.
+
+- SPI Support: CONFIG_SPI
+
+ Enables SPI driver (so far only tested with
+ SPI EEPROM, also an instance works with Crystal A/D and
+ D/As on the SACSng board)
+
+ CONFIG_SH_SPI
+
+ Enables the driver for SPI controller on SuperH. Currently
+ only SH7757 is supported.
+
+ CONFIG_SPI_X
+
+ Enables extended (16-bit) SPI EEPROM addressing.
+ (symmetrical to CONFIG_I2C_X)
+
+ CONFIG_SOFT_SPI
+
+ Enables a software (bit-bang) SPI driver rather than
+ using hardware support. This is a general purpose
+ driver that only requires three general I/O port pins
+ (two outputs, one input) to function. If this is
+ defined, the board configuration must define several
+ SPI configuration items (port pins to use, etc). For
+ an example, see include/configs/sacsng.h.
+
+ CONFIG_HARD_SPI
+
+ Enables a hardware SPI driver for general-purpose reads
+ and writes. As with CONFIG_SOFT_SPI, the board configuration
+ must define a list of chip-select function pointers.
+ Currently supported on some MPC8xxx processors. For an
+ example, see include/configs/mpc8349emds.h.
+
+ CONFIG_MXC_SPI
+
+ Enables the driver for the SPI controllers on i.MX and MXC
+ SoCs. Currently i.MX31/35/51 are supported.
+
+- FPGA Support: CONFIG_FPGA
+
+ Enables FPGA subsystem.
+
+ CONFIG_FPGA_<vendor>
+
+ Enables support for specific chip vendors.
+ (ALTERA, XILINX)
+
+ CONFIG_FPGA_<family>
+
+ Enables support for FPGA family.
+ (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
+
+ CONFIG_FPGA_COUNT
+
+ Specify the number of FPGA devices to support.
+
+ CONFIG_SYS_FPGA_PROG_FEEDBACK
+
+ Enable printing of hash marks during FPGA configuration.
+
+ CONFIG_SYS_FPGA_CHECK_BUSY
+
+ Enable checks on FPGA configuration interface busy
+ status by the configuration function. This option
+ will require a board or device specific function to
+ be written.
+
+ CONFIG_FPGA_DELAY
+
+ If defined, a function that provides delays in the FPGA
+ configuration driver.
+
+ CONFIG_SYS_FPGA_CHECK_CTRLC
+ Allow Control-C to interrupt FPGA configuration
+
+ CONFIG_SYS_FPGA_CHECK_ERROR
+
+ Check for configuration errors during FPGA bitfile
+ loading. For example, abort during Virtex II
+ configuration if the INIT_B line goes low (which
+ indicated a CRC error).
+
+ CONFIG_SYS_FPGA_WAIT_INIT
+
+ Maximum time to wait for the INIT_B line to deassert
+ after PROB_B has been deasserted during a Virtex II
+ FPGA configuration sequence. The default time is 500
+ ms.
+
+ CONFIG_SYS_FPGA_WAIT_BUSY
+
+ Maximum time to wait for BUSY to deassert during
+ Virtex II FPGA configuration. The default is 5 ms.
+
+ CONFIG_SYS_FPGA_WAIT_CONFIG
+
+ Time to wait after FPGA configuration. The default is
+ 200 ms.
+
+- Configuration Management:
+ CONFIG_IDENT_STRING
+
+ If defined, this string will be added to the U-Boot
+ version information (U_BOOT_VERSION)
+
+- Vendor Parameter Protection:
+
+ U-Boot considers the values of the environment
+ variables "serial#" (Board Serial Number) and
+ "ethaddr" (Ethernet Address) to be parameters that
+ are set once by the board vendor / manufacturer, and
+ protects these variables from casual modification by
+ the user. Once set, these variables are read-only,
+ and write or delete attempts are rejected. You can
+ change this behaviour:
+
+ If CONFIG_ENV_OVERWRITE is #defined in your config
+ file, the write protection for vendor parameters is
+ completely disabled. Anybody can change or delete
+ these parameters.
+
+ Alternatively, if you #define _both_ CONFIG_ETHADDR
+ _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
+ Ethernet address is installed in the environment,
+ which can be changed exactly ONCE by the user. [The
+ serial# is unaffected by this, i. e. it remains
+ read-only.]
+
+ The same can be accomplished in a more flexible way
+ for any variable by configuring the type of access
+ to allow for those variables in the ".flags" variable
+ or define CONFIG_ENV_FLAGS_LIST_STATIC.
+
+- Protected RAM:
+ CONFIG_PRAM
+
+ Define this variable to enable the reservation of
+ "protected RAM", i. e. RAM which is not overwritten
+ by U-Boot. Define CONFIG_PRAM to hold the number of
+ kB you want to reserve for pRAM. You can overwrite
+ this default value by defining an environment
+ variable "pram" to the number of kB you want to
+ reserve. Note that the board info structure will
+ still show the full amount of RAM. If pRAM is
+ reserved, a new environment variable "mem" will
+ automatically be defined to hold the amount of
+ remaining RAM in a form that can be passed as boot
+ argument to Linux, for instance like that:
+
+ setenv bootargs ... mem=\${mem}
+ saveenv
+
+ This way you can tell Linux not to use this memory,
+ either, which results in a memory region that will
+ not be affected by reboots.
+
+ *WARNING* If your board configuration uses automatic
+ detection of the RAM size, you must make sure that
+ this memory test is non-destructive. So far, the
+ following board configurations are known to be
+ "pRAM-clean":
+
+ IVMS8, IVML24, SPD8xx, TQM8xxL,
+ HERMES, IP860, RPXlite, LWMON,
+ FLAGADM, TQM8260
+
+- Access to physical memory region (> 4GB)
+ Some basic support is provided for operations on memory not
+ normally accessible to U-Boot - e.g. some architectures
+ support access to more than 4GB of memory on 32-bit
+ machines using physical address extension or similar.
+ Define CONFIG_PHYSMEM to access this basic support, which
+ currently only supports clearing the memory.
+
+- Error Recovery:
+ CONFIG_PANIC_HANG
+
+ Define this variable to stop the system in case of a
+ fatal error, so that you have to reset it manually.
+ This is probably NOT a good idea for an embedded
+ system where you want the system to reboot
+ automatically as fast as possible, but it may be
+ useful during development since you can try to debug
+ the conditions that lead to the situation.
+
+ CONFIG_NET_RETRY_COUNT
+
+ This variable defines the number of retries for
+ network operations like ARP, RARP, TFTP, or BOOTP
+ before giving up the operation. If not defined, a
+ default value of 5 is used.
+
+ CONFIG_ARP_TIMEOUT
+
+ Timeout waiting for an ARP reply in milliseconds.
+
+ CONFIG_NFS_TIMEOUT
+
+ Timeout in milliseconds used in NFS protocol.
+ If you encounter "ERROR: Cannot umount" in nfs command,
+ try longer timeout such as
+ #define CONFIG_NFS_TIMEOUT 10000UL
+
+- Command Interpreter:
+ CONFIG_AUTO_COMPLETE
+
+ Enable auto completion of commands using TAB.
+
+ Note that this feature has NOT been implemented yet
+ for the "hush" shell.
+
+
+ CONFIG_SYS_HUSH_PARSER
+
+ Define this variable to enable the "hush" shell (from
+ Busybox) as command line interpreter, thus enabling
+ powerful command line syntax like
+ if...then...else...fi conditionals or `&&' and '||'
+ constructs ("shell scripts").
+
+ If undefined, you get the old, much simpler behaviour
+ with a somewhat smaller memory footprint.
+
+
+ CONFIG_SYS_PROMPT_HUSH_PS2
+
+ This defines the secondary prompt string, which is
+ printed when the command interpreter needs more input
+ to complete a command. Usually "> ".
+
+ Note:
+
+ In the current implementation, the local variables
+ space and global environment variables space are
+ separated. Local variables are those you define by
+ simply typing `name=value'. To access a local
+ variable later on, you have write `$name' or
+ `${name}'; to execute the contents of a variable
+ directly type `$name' at the command prompt.
+
+ Global environment variables are those you use
+ setenv/printenv to work with. To run a command stored
+ in such a variable, you need to use the run command,
+ and you must not use the '$' sign to access them.
+
+ To store commands and special characters in a
+ variable, please use double quotation marks
+ surrounding the whole text of the variable, instead
+ of the backslashes before semicolons and special
+ symbols.
+
+- Commandline Editing and History:
+ CONFIG_CMDLINE_EDITING
+
+ Enable editing and History functions for interactive
+ commandline input operations
+
+- Default Environment:
+ CONFIG_EXTRA_ENV_SETTINGS
+
+ Define this to contain any number of null terminated
+ strings (variable = value pairs) that will be part of
+ the default environment compiled into the boot image.
+
+ For example, place something like this in your
+ board's config file:
+
+ #define CONFIG_EXTRA_ENV_SETTINGS \
+ "myvar1=value1\0" \
+ "myvar2=value2\0"
+
+ Warning: This method is based on knowledge about the
+ internal format how the environment is stored by the
+ U-Boot code. This is NOT an official, exported
+ interface! Although it is unlikely that this format
+ will change soon, there is no guarantee either.
+ You better know what you are doing here.
+
+ Note: overly (ab)use of the default environment is
+ discouraged. Make sure to check other ways to preset
+ the environment like the "source" command or the
+ boot command first.
+
+ CONFIG_ENV_VARS_UBOOT_CONFIG
+
+ Define this in order to add variables describing the
+ U-Boot build configuration to the default environment.
+ These will be named arch, cpu, board, vendor, and soc.
+
+ Enabling this option will cause the following to be defined:
+
+ - CONFIG_SYS_ARCH
+ - CONFIG_SYS_CPU
+ - CONFIG_SYS_BOARD
+ - CONFIG_SYS_VENDOR
+ - CONFIG_SYS_SOC
+
+ CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
+
+ Define this in order to add variables describing certain
+ run-time determined information about the hardware to the
+ environment. These will be named board_name, board_rev.
+
+ CONFIG_DELAY_ENVIRONMENT
+
+ Normally the environment is loaded when the board is
+ intialised so that it is available to U-Boot. This inhibits
+ that so that the environment is not available until
+ explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
+ this is instead controlled by the value of
+ /config/load-environment.
+
+- DataFlash Support:
+ CONFIG_HAS_DATAFLASH
+
+ Defining this option enables DataFlash features and
+ allows to read/write in Dataflash via the standard
+ commands cp, md...
+
+- Serial Flash support
+ CONFIG_CMD_SF
+
+ Defining this option enables SPI flash commands
+ 'sf probe/read/write/erase/update'.
+
+ Usage requires an initial 'probe' to define the serial
+ flash parameters, followed by read/write/erase/update
+ commands.
+
+ The following defaults may be provided by the platform
+ to handle the common case when only a single serial
+ flash is present on the system.
+
+ CONFIG_SF_DEFAULT_BUS Bus identifier
+ CONFIG_SF_DEFAULT_CS Chip-select
+ CONFIG_SF_DEFAULT_MODE (see include/spi.h)
+ CONFIG_SF_DEFAULT_SPEED in Hz
+
+ CONFIG_CMD_SF_TEST
+
+ Define this option to include a destructive SPI flash
+ test ('sf test').
+
+ CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
+
+ Define this option to use the Bank addr/Extended addr
+ support on SPI flashes which has size > 16Mbytes.
+
+- SystemACE Support:
+ CONFIG_SYSTEMACE
+
+ Adding this option adds support for Xilinx SystemACE
+ chips attached via some sort of local bus. The address
+ of the chip must also be defined in the
+ CONFIG_SYS_SYSTEMACE_BASE macro. For example:
+
+ #define CONFIG_SYSTEMACE
+ #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
+
+ When SystemACE support is added, the "ace" device type
+ becomes available to the fat commands, i.e. fatls.
+
+- TFTP Fixed UDP Port:
+ CONFIG_TFTP_PORT
+
+ If this is defined, the environment variable tftpsrcp
+ is used to supply the TFTP UDP source port value.
+ If tftpsrcp isn't defined, the normal pseudo-random port
+ number generator is used.
+
+ Also, the environment variable tftpdstp is used to supply
+ the TFTP UDP destination port value. If tftpdstp isn't
+ defined, the normal port 69 is used.
+
+ The purpose for tftpsrcp is to allow a TFTP server to
+ blindly start the TFTP transfer using the pre-configured
+ target IP address and UDP port. This has the effect of
+ "punching through" the (Windows XP) firewall, allowing
+ the remainder of the TFTP transfer to proceed normally.
+ A better solution is to properly configure the firewall,
+ but sometimes that is not allowed.
+
+- Hashing support:
+ CONFIG_CMD_HASH
+
+ This enables a generic 'hash' command which can produce
+ hashes / digests from a few algorithms (e.g. SHA1, SHA256).
+
+ CONFIG_HASH_VERIFY
+
+ Enable the hash verify command (hash -v). This adds to code
+ size a little.
+
+ CONFIG_SHA1 - support SHA1 hashing
+ CONFIG_SHA256 - support SHA256 hashing
+
+ Note: There is also a sha1sum command, which should perhaps
+ be deprecated in favour of 'hash sha1'.
+
+- Signing support:
+ CONFIG_RSA
+
+ This enables the RSA algorithm used for FIT image verification
+ in U-Boot. See doc/uImage/signature for more information.
+
+ The signing part is build into mkimage regardless of this
+ option.
+
+
+- Show boot progress:
+ CONFIG_SHOW_BOOT_PROGRESS
+
+ Defining this option allows to add some board-
+ specific code (calling a user-provided function
+ "show_boot_progress(int)") that enables you to show
+ the system's boot progress on some display (for
+ example, some LED's) on your board. At the moment,
+ the following checkpoints are implemented:
+
+- Detailed boot stage timing
+ CONFIG_BOOTSTAGE
+ Define this option to get detailed timing of each stage
+ of the boot process.
+
+ CONFIG_BOOTSTAGE_USER_COUNT
+ This is the number of available user bootstage records.
+ Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
+ a new ID will be allocated from this stash. If you exceed
+ the limit, recording will stop.
+
+ CONFIG_BOOTSTAGE_REPORT
+ Define this to print a report before boot, similar to this:
+
+ Timer summary in microseconds:
+ Mark Elapsed Stage
+ 0 0 reset
+ 3,575,678 3,575,678 board_init_f start
+ 3,575,695 17 arch_cpu_init A9
+ 3,575,777 82 arch_cpu_init done
+ 3,659,598 83,821 board_init_r start
+ 3,910,375 250,777 main_loop
+ 29,916,167 26,005,792 bootm_start
+ 30,361,327 445,160 start_kernel
+
+ CONFIG_CMD_BOOTSTAGE
+ Add a 'bootstage' command which supports printing a report
+ and un/stashing of bootstage data.
+
+ CONFIG_BOOTSTAGE_FDT
+ Stash the bootstage information in the FDT. A root 'bootstage'
+ node is created with each bootstage id as a child. Each child
+ has a 'name' property and either 'mark' containing the
+ mark time in microsecond, or 'accum' containing the
+ accumulated time for that bootstage id in microseconds.
+ For example:
+
+ bootstage {
+ 154 {
+ name = "board_init_f";
+ mark = <3575678>;
+ };
+ 170 {
+ name = "lcd";
+ accum = <33482>;
+ };
+ };
+
+ Code in the Linux kernel can find this in /proc/devicetree.
+
+Legacy uImage format:
+
+ Arg Where When
+ 1 common/cmd_bootm.c before attempting to boot an image
+ -1 common/cmd_bootm.c Image header has bad magic number
+ 2 common/cmd_bootm.c Image header has correct magic number
+ -2 common/cmd_bootm.c Image header has bad checksum
+ 3 common/cmd_bootm.c Image header has correct checksum
+ -3 common/cmd_bootm.c Image data has bad checksum
+ 4 common/cmd_bootm.c Image data has correct checksum
+ -4 common/cmd_bootm.c Image is for unsupported architecture
+ 5 common/cmd_bootm.c Architecture check OK
+ -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
+ 6 common/cmd_bootm.c Image Type check OK
+ -6 common/cmd_bootm.c gunzip uncompression error
+ -7 common/cmd_bootm.c Unimplemented compression type
+ 7 common/cmd_bootm.c Uncompression OK
+ 8 common/cmd_bootm.c No uncompress/copy overwrite error
+ -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
+
+ 9 common/image.c Start initial ramdisk verification
+ -10 common/image.c Ramdisk header has bad magic number
+ -11 common/image.c Ramdisk header has bad checksum
+ 10 common/image.c Ramdisk header is OK
+ -12 common/image.c Ramdisk data has bad checksum
+ 11 common/image.c Ramdisk data has correct checksum
+ 12 common/image.c Ramdisk verification complete, start loading
+ -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
+ 13 common/image.c Start multifile image verification
+ 14 common/image.c No initial ramdisk, no multifile, continue.
+
+ 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
+
+ -30 arch/powerpc/lib/board.c Fatal error, hang the system
+ -31 post/post.c POST test failed, detected by post_output_backlog()
+ -32 post/post.c POST test failed, detected by post_run_single()
+
+ 34 common/cmd_doc.c before loading a Image from a DOC device
+ -35 common/cmd_doc.c Bad usage of "doc" command
+ 35 common/cmd_doc.c correct usage of "doc" command
+ -36 common/cmd_doc.c No boot device
+ 36 common/cmd_doc.c correct boot device
+ -37 common/cmd_doc.c Unknown Chip ID on boot device
+ 37 common/cmd_doc.c correct chip ID found, device available
+ -38 common/cmd_doc.c Read Error on boot device
+ 38 common/cmd_doc.c reading Image header from DOC device OK
+ -39 common/cmd_doc.c Image header has bad magic number
+ 39 common/cmd_doc.c Image header has correct magic number
+ -40 common/cmd_doc.c Error reading Image from DOC device
+ 40 common/cmd_doc.c Image header has correct magic number
+ 41 common/cmd_ide.c before loading a Image from a IDE device
+ -42 common/cmd_ide.c Bad usage of "ide" command
+ 42 common/cmd_ide.c correct usage of "ide" command
+ -43 common/cmd_ide.c No boot device
+ 43 common/cmd_ide.c boot device found
+ -44 common/cmd_ide.c Device not available
+ 44 common/cmd_ide.c Device available
+ -45 common/cmd_ide.c wrong partition selected
+ 45 common/cmd_ide.c partition selected
+ -46 common/cmd_ide.c Unknown partition table
+ 46 common/cmd_ide.c valid partition table found
+ -47 common/cmd_ide.c Invalid partition type
+ 47 common/cmd_ide.c correct partition type
+ -48 common/cmd_ide.c Error reading Image Header on boot device
+ 48 common/cmd_ide.c reading Image Header from IDE device OK
+ -49 common/cmd_ide.c Image header has bad magic number
+ 49 common/cmd_ide.c Image header has correct magic number
+ -50 common/cmd_ide.c Image header has bad checksum
+ 50 common/cmd_ide.c Image header has correct checksum
+ -51 common/cmd_ide.c Error reading Image from IDE device
+ 51 common/cmd_ide.c reading Image from IDE device OK
+ 52 common/cmd_nand.c before loading a Image from a NAND device
+ -53 common/cmd_nand.c Bad usage of "nand" command
+ 53 common/cmd_nand.c correct usage of "nand" command
+ -54 common/cmd_nand.c No boot device
+ 54 common/cmd_nand.c boot device found
+ -55 common/cmd_nand.c Unknown Chip ID on boot device
+ 55 common/cmd_nand.c correct chip ID found, device available
+ -56 common/cmd_nand.c Error reading Image Header on boot device
+ 56 common/cmd_nand.c reading Image Header from NAND device OK
+ -57 common/cmd_nand.c Image header has bad magic number
+ 57 common/cmd_nand.c Image header has correct magic number
+ -58 common/cmd_nand.c Error reading Image from NAND device
+ 58 common/cmd_nand.c reading Image from NAND device OK
+
+ -60 common/env_common.c Environment has a bad CRC, using default
+
+ 64 net/eth.c starting with Ethernet configuration.
+ -64 net/eth.c no Ethernet found.
+ 65 net/eth.c Ethernet found.
+
+ -80 common/cmd_net.c usage wrong
+ 80 common/cmd_net.c before calling NetLoop()
+ -81 common/cmd_net.c some error in NetLoop() occurred
+ 81 common/cmd_net.c NetLoop() back without error
+ -82 common/cmd_net.c size == 0 (File with size 0 loaded)
+ 82 common/cmd_net.c trying automatic boot
+ 83 common/cmd_net.c running "source" command
+ -83 common/cmd_net.c some error in automatic boot or "source" command
+ 84 common/cmd_net.c end without errors
+
+FIT uImage format:
+
+ Arg Where When
+ 100 common/cmd_bootm.c Kernel FIT Image has correct format
+ -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
+ 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
+ -101 common/cmd_bootm.c Can't get configuration for kernel subimage
+ 102 common/cmd_bootm.c Kernel unit name specified
+ -103 common/cmd_bootm.c Can't get kernel subimage node offset
+ 103 common/cmd_bootm.c Found configuration node
+ 104 common/cmd_bootm.c Got kernel subimage node offset
+ -104 common/cmd_bootm.c Kernel subimage hash verification failed
+ 105 common/cmd_bootm.c Kernel subimage hash verification OK
+ -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
+ 106 common/cmd_bootm.c Architecture check OK
+ -106 common/cmd_bootm.c Kernel subimage has wrong type
+ 107 common/cmd_bootm.c Kernel subimage type OK
+ -107 common/cmd_bootm.c Can't get kernel subimage data/size
+ 108 common/cmd_bootm.c Got kernel subimage data/size
+ -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
+ -109 common/cmd_bootm.c Can't get kernel subimage type
+ -110 common/cmd_bootm.c Can't get kernel subimage comp
+ -111 common/cmd_bootm.c Can't get kernel subimage os
+ -112 common/cmd_bootm.c Can't get kernel subimage load address
+ -113 common/cmd_bootm.c Image uncompress/copy overwrite error
+
+ 120 common/image.c Start initial ramdisk verification
+ -120 common/image.c Ramdisk FIT image has incorrect format
+ 121 common/image.c Ramdisk FIT image has correct format
+ 122 common/image.c No ramdisk subimage unit name, using configuration
+ -122 common/image.c Can't get configuration for ramdisk subimage
+ 123 common/image.c Ramdisk unit name specified
+ -124 common/image.c Can't get ramdisk subimage node offset
+ 125 common/image.c Got ramdisk subimage node offset
+ -125 common/image.c Ramdisk subimage hash verification failed
+ 126 common/image.c Ramdisk subimage hash verification OK
+ -126 common/image.c Ramdisk subimage for unsupported architecture
+ 127 common/image.c Architecture check OK
+ -127 common/image.c Can't get ramdisk subimage data/size
+ 128 common/image.c Got ramdisk subimage data/size
+ 129 common/image.c Can't get ramdisk load address
+ -129 common/image.c Got ramdisk load address
+
+ -130 common/cmd_doc.c Incorrect FIT image format
+ 131 common/cmd_doc.c FIT image format OK
+
+ -140 common/cmd_ide.c Incorrect FIT image format
+ 141 common/cmd_ide.c FIT image format OK
+
+ -150 common/cmd_nand.c Incorrect FIT image format
+ 151 common/cmd_nand.c FIT image format OK
+
+- FIT image support:
+ CONFIG_FIT
+ Enable support for the FIT uImage format.
+
+ CONFIG_FIT_BEST_MATCH
+ When no configuration is explicitly selected, default to the
+ one whose fdt's compatibility field best matches that of
+ U-Boot itself. A match is considered "best" if it matches the
+ most specific compatibility entry of U-Boot's fdt's root node.
+ The order of entries in the configuration's fdt is ignored.
+
+ CONFIG_FIT_SIGNATURE
+ This option enables signature verification of FIT uImages,
+ using a hash signed and verified using RSA. See
+ doc/uImage.FIT/signature.txt for more details.
+
+- Standalone program support:
+ CONFIG_STANDALONE_LOAD_ADDR
+
+ This option defines a board specific value for the
+ address where standalone program gets loaded, thus
+ overwriting the architecture dependent default
+ settings.
+
+- Frame Buffer Address:
+ CONFIG_FB_ADDR
+
+ Define CONFIG_FB_ADDR if you want to use specific
+ address for frame buffer. This is typically the case
+ when using a graphics controller has separate video
+ memory. U-Boot will then place the frame buffer at
+ the given address instead of dynamically reserving it
+ in system RAM by calling lcd_setmem(), which grabs
+ the memory for the frame buffer depending on the
+ configured panel size.
+
+ Please see board_init_f function.
+
+- Automatic software updates via TFTP server
+ CONFIG_UPDATE_TFTP
+ CONFIG_UPDATE_TFTP_CNT_MAX
+ CONFIG_UPDATE_TFTP_MSEC_MAX
+
+ These options enable and control the auto-update feature;
+ for a more detailed description refer to doc/README.update.
+
+- MTD Support (mtdparts command, UBI support)
+ CONFIG_MTD_DEVICE
+
+ Adds the MTD device infrastructure from the Linux kernel.
+ Needed for mtdparts command support.
+
+ CONFIG_MTD_PARTITIONS
+
+ Adds the MTD partitioning infrastructure from the Linux
+ kernel. Needed for UBI support.
+
+- UBI support
+ CONFIG_CMD_UBI
+
+ Adds commands for interacting with MTD partitions formatted
+ with the UBI flash translation layer
+
+ Requires also defining CONFIG_RBTREE
+
+ CONFIG_UBI_SILENCE_MSG
+
+ Make the verbose messages from UBI stop printing. This leaves
+ warnings and errors enabled.
+
+- UBIFS support
+ CONFIG_CMD_UBIFS
+
+ Adds commands for interacting with UBI volumes formatted as
+ UBIFS. UBIFS is read-only in u-boot.
+
+ Requires UBI support as well as CONFIG_LZO
+
+ CONFIG_UBIFS_SILENCE_MSG
+
+ Make the verbose messages from UBIFS stop printing. This leaves
+ warnings and errors enabled.
+
+- SPL framework
+ CONFIG_SPL
+ Enable building of SPL globally.
+
+ CONFIG_SPL_LDSCRIPT
+ LDSCRIPT for linking the SPL binary.
+
+ CONFIG_SPL_MAX_FOOTPRINT
+ Maximum size in memory allocated to the SPL, BSS included.
+ When defined, the linker checks that the actual memory
+ used by SPL from _start to __bss_end does not exceed it.
+ CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
+ must not be both defined at the same time.
+
+ CONFIG_SPL_MAX_SIZE
+ Maximum size of the SPL image (text, data, rodata, and
+ linker lists sections), BSS excluded.
+ When defined, the linker checks that the actual size does
+ not exceed it.
+
+ CONFIG_SPL_TEXT_BASE
+ TEXT_BASE for linking the SPL binary.
+
+ CONFIG_SPL_RELOC_TEXT_BASE
+ Address to relocate to. If unspecified, this is equal to
+ CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
+
+ CONFIG_SPL_BSS_START_ADDR
+ Link address for the BSS within the SPL binary.
+
+ CONFIG_SPL_BSS_MAX_SIZE
+ Maximum size in memory allocated to the SPL BSS.
+ When defined, the linker checks that the actual memory used
+ by SPL from __bss_start to __bss_end does not exceed it.
+ CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
+ must not be both defined at the same time.
+
+ CONFIG_SPL_STACK
+ Adress of the start of the stack SPL will use
+
+ CONFIG_SPL_RELOC_STACK
+ Adress of the start of the stack SPL will use after
+ relocation. If unspecified, this is equal to
+ CONFIG_SPL_STACK.
+
+ CONFIG_SYS_SPL_MALLOC_START
+ Starting address of the malloc pool used in SPL.
+
+ CONFIG_SYS_SPL_MALLOC_SIZE
+ The size of the malloc pool used in SPL.
+
+ CONFIG_SPL_FRAMEWORK
+ Enable the SPL framework under common/. This framework
+ supports MMC, NAND and YMODEM loading of U-Boot and NAND
+ NAND loading of the Linux Kernel.
+
+ CONFIG_SPL_DISPLAY_PRINT
+ For ARM, enable an optional function to print more information
+ about the running system.
+
+ CONFIG_SPL_INIT_MINIMAL
+ Arch init code should be built for a very small image
+
+ CONFIG_SPL_LIBCOMMON_SUPPORT
+ Support for common/libcommon.o in SPL binary
+
+ CONFIG_SPL_LIBDISK_SUPPORT
+ Support for disk/libdisk.o in SPL binary
+
+ CONFIG_SPL_I2C_SUPPORT
+ Support for drivers/i2c/libi2c.o in SPL binary
+
+ CONFIG_SPL_GPIO_SUPPORT
+ Support for drivers/gpio/libgpio.o in SPL binary
+
+ CONFIG_SPL_MMC_SUPPORT
+ Support for drivers/mmc/libmmc.o in SPL binary
+
+ CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
+ CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
+ CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
+ Address, size and partition on the MMC to load U-Boot from
+ when the MMC is being used in raw mode.
+
+ CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
+ Sector to load kernel uImage from when MMC is being
+ used in raw mode (for Falcon mode)
+
+ CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
+ CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
+ Sector and number of sectors to load kernel argument
+ parameters from when MMC is being used in raw mode
+ (for falcon mode)
+
+ CONFIG_SPL_FAT_SUPPORT
+ Support for fs/fat/libfat.o in SPL binary
+
+ CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
+ Filename to read to load U-Boot when reading from FAT
+
+ CONFIG_SPL_FAT_LOAD_KERNEL_NAME
+ Filename to read to load kernel uImage when reading
+ from FAT (for Falcon mode)
+
+ CONFIG_SPL_FAT_LOAD_ARGS_NAME
+ Filename to read to load kernel argument parameters
+ when reading from FAT (for Falcon mode)
+
+ CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
+ Set this for NAND SPL on PPC mpc83xx targets, so that
+ start.S waits for the rest of the SPL to load before
+ continuing (the hardware starts execution after just
+ loading the first page rather than the full 4K).
+
+ CONFIG_SPL_NAND_BASE
+ Include nand_base.c in the SPL. Requires
+ CONFIG_SPL_NAND_DRIVERS.
+
+ CONFIG_SPL_NAND_DRIVERS
+ SPL uses normal NAND drivers, not minimal drivers.
+
+ CONFIG_SPL_NAND_ECC
+ Include standard software ECC in the SPL
+
+ CONFIG_SPL_NAND_SIMPLE
+ Support for NAND boot using simple NAND drivers that
+ expose the cmd_ctrl() interface.
+
+ CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
+ CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
+ CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
+ CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
+ CONFIG_SYS_NAND_ECCBYTES
+ Defines the size and behavior of the NAND that SPL uses
+ to read U-Boot
+
+ CONFIG_SYS_NAND_U_BOOT_OFFS
+ Location in NAND to read U-Boot from
+
+ CONFIG_SYS_NAND_U_BOOT_DST
+ Location in memory to load U-Boot to
+
+ CONFIG_SYS_NAND_U_BOOT_SIZE
+ Size of image to load
+
+ CONFIG_SYS_NAND_U_BOOT_START
+ Entry point in loaded image to jump to
+
+ CONFIG_SYS_NAND_HW_ECC_OOBFIRST
+ Define this if you need to first read the OOB and then the
+ data. This is used for example on davinci plattforms.
+
+ CONFIG_SPL_OMAP3_ID_NAND
+ Support for an OMAP3-specific set of functions to return the
+ ID and MFR of the first attached NAND chip, if present.
+
+ CONFIG_SPL_SERIAL_SUPPORT
+ Support for drivers/serial/libserial.o in SPL binary
+
+ CONFIG_SPL_SPI_FLASH_SUPPORT
+ Support for drivers/mtd/spi/libspi_flash.o in SPL binary
+
+ CONFIG_SPL_SPI_SUPPORT
+ Support for drivers/spi/libspi.o in SPL binary
+
+ CONFIG_SPL_RAM_DEVICE
+ Support for running image already present in ram, in SPL binary
+
+ CONFIG_SPL_LIBGENERIC_SUPPORT
+ Support for lib/libgeneric.o in SPL binary
+
+ CONFIG_SPL_ENV_SUPPORT
+ Support for the environment operating in SPL binary
+
+ CONFIG_SPL_NET_SUPPORT
+ Support for the net/libnet.o in SPL binary.
+ It conflicts with SPL env from storage medium specified by
+ CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
+
+ CONFIG_SPL_PAD_TO
+ Image offset to which the SPL should be padded before appending
+ the SPL payload. By default, this is defined as
+ CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
+ CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
+ payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
+
+ CONFIG_SPL_TARGET
+ Final target image containing SPL and payload. Some SPLs
+ use an arch-specific makefile fragment instead, for
+ example if more than one image needs to be produced.
+
+ CONFIG_FIT_SPL_PRINT
+ Printing information about a FIT image adds quite a bit of
+ code to SPL. So this is normally disabled in SPL. Use this
+ option to re-enable it. This will affect the output of the
+ bootm command when booting a FIT image.
+
+Modem Support:
+--------------
+
+[so far only for SMDK2400 boards]
+
+- Modem support enable:
+ CONFIG_MODEM_SUPPORT
+
+- RTS/CTS Flow control enable:
+ CONFIG_HWFLOW
+
+- Modem debug support:
+ CONFIG_MODEM_SUPPORT_DEBUG
+
+ Enables debugging stuff (char screen[1024], dbg())
+ for modem support. Useful only with BDI2000.
+
+- Interrupt support (PPC):
+
+ There are common interrupt_init() and timer_interrupt()
+ for all PPC archs. interrupt_init() calls interrupt_init_cpu()
+ for CPU specific initialization. interrupt_init_cpu()
+ should set decrementer_count to appropriate value. If
+ CPU resets decrementer automatically after interrupt
+ (ppc4xx) it should set decrementer_count to zero.
+ timer_interrupt() calls timer_interrupt_cpu() for CPU
+ specific handling. If board has watchdog / status_led
+ / other_activity_monitor it works automatically from
+ general timer_interrupt().
+
+- General:
+
+ In the target system modem support is enabled when a
+ specific key (key combination) is pressed during
+ power-on. Otherwise U-Boot will boot normally
+ (autoboot). The key_pressed() function is called from
+ board_init(). Currently key_pressed() is a dummy
+ function, returning 1 and thus enabling modem
+ initialization.
+
+ If there are no modem init strings in the
+ environment, U-Boot proceed to autoboot; the
+ previous output (banner, info printfs) will be
+ suppressed, though.
+
+ See also: doc/README.Modem
+
+Board initialization settings:
+------------------------------
+
+During Initialization u-boot calls a number of board specific functions
+to allow the preparation of board specific prerequisites, e.g. pin setup
+before drivers are initialized. To enable these callbacks the
+following configuration macros have to be defined. Currently this is
+architecture specific, so please check arch/your_architecture/lib/board.c
+typically in board_init_f() and board_init_r().
+
+- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
+- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
+- CONFIG_BOARD_LATE_INIT: Call board_late_init()
+- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
+
+Configuration Settings:
+-----------------------
+
+- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
+ undefine this when you're short of memory.
+
+- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
+ width of the commands listed in the 'help' command output.
+
+- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
+ prompt for user input.
+
+- CONFIG_SYS_CBSIZE: Buffer size for input from the Console
+
+- CONFIG_SYS_PBSIZE: Buffer size for Console output
+
+- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
+
+- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
+ the application (usually a Linux kernel) when it is
+ booted
+
+- CONFIG_SYS_BAUDRATE_TABLE:
+ List of legal baudrate settings for this board.
+
+- CONFIG_SYS_CONSOLE_INFO_QUIET
+ Suppress display of console information at boot.
+
+- CONFIG_SYS_CONSOLE_IS_IN_ENV
+ If the board specific function
+ extern int overwrite_console (void);
+ returns 1, the stdin, stderr and stdout are switched to the
+ serial port, else the settings in the environment are used.
+
+- CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
+ Enable the call to overwrite_console().
+
+- CONFIG_SYS_CONSOLE_ENV_OVERWRITE
+ Enable overwrite of previous console environment settings.
+
+- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
+ Begin and End addresses of the area used by the
+ simple memory test.
+
+- CONFIG_SYS_ALT_MEMTEST:
+ Enable an alternate, more extensive memory test.
+
+- CONFIG_SYS_MEMTEST_SCRATCH:
+ Scratch address used by the alternate memory test
+ You only need to set this if address zero isn't writeable
+
+- CONFIG_SYS_MEM_TOP_HIDE (PPC only):
+ If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
+ this specified memory area will get subtracted from the top
+ (end) of RAM and won't get "touched" at all by U-Boot. By
+ fixing up gd->ram_size the Linux kernel should gets passed
+ the now "corrected" memory size and won't touch it either.
+ This should work for arch/ppc and arch/powerpc. Only Linux
+ board ports in arch/powerpc with bootwrapper support that
+ recalculate the memory size from the SDRAM controller setup
+ will have to get fixed in Linux additionally.
+
+ This option can be used as a workaround for the 440EPx/GRx
+ CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
+ be touched.
+
+ WARNING: Please make sure that this value is a multiple of
+ the Linux page size (normally 4k). If this is not the case,
+ then the end address of the Linux memory will be located at a
+ non page size aligned address and this could cause major
+ problems.
+
+- CONFIG_SYS_LOADS_BAUD_CHANGE:
+ Enable temporary baudrate change while serial download
+
+- CONFIG_SYS_SDRAM_BASE:
+ Physical start address of SDRAM. _Must_ be 0 here.
+
+- CONFIG_SYS_MBIO_BASE:
+ Physical start address of Motherboard I/O (if using a
+ Cogent motherboard)
+
+- CONFIG_SYS_FLASH_BASE:
+ Physical start address of Flash memory.
+
+- CONFIG_SYS_MONITOR_BASE:
+ Physical start address of boot monitor code (set by
+ make config files to be same as the text base address
+ (CONFIG_SYS_TEXT_BASE) used when linking) - same as
+ CONFIG_SYS_FLASH_BASE when booting from flash.
+
+- CONFIG_SYS_MONITOR_LEN:
+ Size of memory reserved for monitor code, used to
+ determine _at_compile_time_ (!) if the environment is
+ embedded within the U-Boot image, or in a separate
+ flash sector.
+
+- CONFIG_SYS_MALLOC_LEN:
+ Size of DRAM reserved for malloc() use.
+
+- CONFIG_SYS_BOOTM_LEN:
+ Normally compressed uImages are limited to an
+ uncompressed size of 8 MBytes. If this is not enough,
+ you can define CONFIG_SYS_BOOTM_LEN in your board config file
+ to adjust this setting to your needs.
+
+- CONFIG_SYS_BOOTMAPSZ:
+ Maximum size of memory mapped by the startup code of
+ the Linux kernel; all data that must be processed by
+ the Linux kernel (bd_info, boot arguments, FDT blob if
+ used) must be put below this limit, unless "bootm_low"
+ enviroment variable is defined and non-zero. In such case
+ all data for the Linux kernel must be between "bootm_low"
+ and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
+ variable "bootm_mapsize" will override the value of
+ CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
+ then the value in "bootm_size" will be used instead.
+
+- CONFIG_SYS_BOOT_RAMDISK_HIGH:
+ Enable initrd_high functionality. If defined then the
+ initrd_high feature is enabled and the bootm ramdisk subcommand
+ is enabled.
+
+- CONFIG_SYS_BOOT_GET_CMDLINE:
+ Enables allocating and saving kernel cmdline in space between
+ "bootm_low" and "bootm_low" + BOOTMAPSZ.
+
+- CONFIG_SYS_BOOT_GET_KBD:
+ Enables allocating and saving a kernel copy of the bd_info in
+ space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
+
+- CONFIG_SYS_MAX_FLASH_BANKS:
+ Max number of Flash memory banks
+
+- CONFIG_SYS_MAX_FLASH_SECT:
+ Max number of sectors on a Flash chip
+
+- CONFIG_SYS_FLASH_ERASE_TOUT:
+ Timeout for Flash erase operations (in ms)
+
+- CONFIG_SYS_FLASH_WRITE_TOUT:
+ Timeout for Flash write operations (in ms)
+
+- CONFIG_SYS_FLASH_LOCK_TOUT
+ Timeout for Flash set sector lock bit operation (in ms)
+
+- CONFIG_SYS_FLASH_UNLOCK_TOUT
+ Timeout for Flash clear lock bits operation (in ms)
+
+- CONFIG_SYS_FLASH_PROTECTION
+ If defined, hardware flash sectors protection is used
+ instead of U-Boot software protection.
+
+- CONFIG_SYS_DIRECT_FLASH_TFTP:
+
+ Enable TFTP transfers directly to flash memory;
+ without this option such a download has to be
+ performed in two steps: (1) download to RAM, and (2)
+ copy from RAM to flash.
+
+ The two-step approach is usually more reliable, since
+ you can check if the download worked before you erase
+ the flash, but in some situations (when system RAM is
+ too limited to allow for a temporary copy of the
+ downloaded image) this option may be very useful.
+
+- CONFIG_SYS_FLASH_CFI:
+ Define if the flash driver uses extra elements in the
+ common flash structure for storing flash geometry.
+
+- CONFIG_FLASH_CFI_DRIVER
+ This option also enables the building of the cfi_flash driver
+ in the drivers directory
+
+- CONFIG_FLASH_CFI_MTD
+ This option enables the building of the cfi_mtd driver
+ in the drivers directory. The driver exports CFI flash
+ to the MTD layer.
+
+- CONFIG_SYS_FLASH_USE_BUFFER_WRITE
+ Use buffered writes to flash.
+
+- CONFIG_FLASH_SPANSION_S29WS_N
+ s29ws-n MirrorBit flash has non-standard addresses for buffered
+ write commands.
+
+- CONFIG_SYS_FLASH_QUIET_TEST
+ If this option is defined, the common CFI flash doesn't
+ print it's warning upon not recognized FLASH banks. This
+ is useful, if some of the configured banks are only
+ optionally available.
+
+- CONFIG_FLASH_SHOW_PROGRESS
+ If defined (must be an integer), print out countdown
+ digits and dots. Recommended value: 45 (9..1) for 80
+ column displays, 15 (3..1) for 40 column displays.
+
+- CONFIG_FLASH_VERIFY
+ If defined, the content of the flash (destination) is compared
+ against the source after the write operation. An error message
+ will be printed when the contents are not identical.
+ Please note that this option is useless in nearly all cases,
+ since such flash programming errors usually are detected earlier
+ while unprotecting/erasing/programming. Please only enable
+ this option if you really know what you are doing.
+
+- CONFIG_SYS_RX_ETH_BUFFER:
+ Defines the number of Ethernet receive buffers. On some
+ Ethernet controllers it is recommended to set this value
+ to 8 or even higher (EEPRO100 or 405 EMAC), since all
+ buffers can be full shortly after enabling the interface
+ on high Ethernet traffic.
+ Defaults to 4 if not defined.
+
+- CONFIG_ENV_MAX_ENTRIES
+
+ Maximum number of entries in the hash table that is used
+ internally to store the environment settings. The default
+ setting is supposed to be generous and should work in most
+ cases. This setting can be used to tune behaviour; see
+ lib/hashtable.c for details.
+
+- CONFIG_ENV_FLAGS_LIST_DEFAULT
+- CONFIG_ENV_FLAGS_LIST_STATIC
+ Enable validation of the values given to enviroment variables when
+ calling env set. Variables can be restricted to only decimal,
+ hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
+ the variables can also be restricted to IP address or MAC address.
+
+ The format of the list is:
+ type_attribute = [s|d|x|b|i|m]
+ access_atribute = [a|r|o|c]
+ attributes = type_attribute[access_atribute]
+ entry = variable_name[:attributes]
+ list = entry[,list]
+
+ The type attributes are:
+ s - String (default)
+ d - Decimal
+ x - Hexadecimal
+ b - Boolean ([1yYtT|0nNfF])
+ i - IP address
+ m - MAC address
+
+ The access attributes are:
+ a - Any (default)
+ r - Read-only
+ o - Write-once
+ c - Change-default
+
+ - CONFIG_ENV_FLAGS_LIST_DEFAULT
+ Define this to a list (string) to define the ".flags"
+ envirnoment variable in the default or embedded environment.
+
+ - CONFIG_ENV_FLAGS_LIST_STATIC
+ Define this to a list (string) to define validation that
+ should be done if an entry is not found in the ".flags"
+ environment variable. To override a setting in the static
+ list, simply add an entry for the same variable name to the
+ ".flags" variable.
+
+- CONFIG_ENV_ACCESS_IGNORE_FORCE
+ If defined, don't allow the -f switch to env set override variable
+ access flags.
+
+- CONFIG_SYS_GENERIC_BOARD
+ This selects the architecture-generic board system instead of the
+ architecture-specific board files. It is intended to move boards
+ to this new framework over time. Defining this will disable the
+ arch/foo/lib/board.c file and use common/board_f.c and
+ common/board_r.c instead. To use this option your architecture
+ must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
+ its config.mk file). If you find problems enabling this option on
+ your board please report the problem and send patches!
+
+- CONFIG_SYS_SYM_OFFSETS
+ This is set by architectures that use offsets for link symbols
+ instead of absolute values. So bss_start is obtained using an
+ offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
+ directly. You should not need to touch this setting.
+
+- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
+ This is set by OMAP boards for the max time that reset should
+ be asserted. See doc/README.omap-reset-time for details on how
+ the value can be calulated on a given board.
+
+The following definitions that deal with the placement and management
+of environment data (variable area); in general, we support the
+following configurations:
+
+- CONFIG_BUILD_ENVCRC:
+
+ Builds up envcrc with the target environment so that external utils
+ may easily extract it and embed it in final U-Boot images.
+
+- CONFIG_ENV_IS_IN_FLASH:
+
+ Define this if the environment is in flash memory.
+
+ a) The environment occupies one whole flash sector, which is
+ "embedded" in the text segment with the U-Boot code. This
+ happens usually with "bottom boot sector" or "top boot
+ sector" type flash chips, which have several smaller
+ sectors at the start or the end. For instance, such a
+ layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
+ such a case you would place the environment in one of the
+ 4 kB sectors - with U-Boot code before and after it. With
+ "top boot sector" type flash chips, you would put the
+ environment in one of the last sectors, leaving a gap
+ between U-Boot and the environment.
+
+ - CONFIG_ENV_OFFSET:
+
+ Offset of environment data (variable area) to the
+ beginning of flash memory; for instance, with bottom boot
+ type flash chips the second sector can be used: the offset
+ for this sector is given here.
+
+ CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
+
+ - CONFIG_ENV_ADDR:
+
+ This is just another way to specify the start address of
+ the flash sector containing the environment (instead of
+ CONFIG_ENV_OFFSET).
+
+ - CONFIG_ENV_SECT_SIZE:
+
+ Size of the sector containing the environment.
+
+
+ b) Sometimes flash chips have few, equal sized, BIG sectors.
+ In such a case you don't want to spend a whole sector for
+ the environment.
+
+ - CONFIG_ENV_SIZE:
+
+ If you use this in combination with CONFIG_ENV_IS_IN_FLASH
+ and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
+ of this flash sector for the environment. This saves
+ memory for the RAM copy of the environment.
+
+ It may also save flash memory if you decide to use this
+ when your environment is "embedded" within U-Boot code,
+ since then the remainder of the flash sector could be used
+ for U-Boot code. It should be pointed out that this is
+ STRONGLY DISCOURAGED from a robustness point of view:
+ updating the environment in flash makes it always
+ necessary to erase the WHOLE sector. If something goes
+ wrong before the contents has been restored from a copy in
+ RAM, your target system will be dead.
+
+ - CONFIG_ENV_ADDR_REDUND
+ CONFIG_ENV_SIZE_REDUND
+
+ These settings describe a second storage area used to hold
+ a redundant copy of the environment data, so that there is
+ a valid backup copy in case there is a power failure during
+ a "saveenv" operation.
+
+BE CAREFUL! Any changes to the flash layout, and some changes to the
+source code will make it necessary to adapt <board>/u-boot.lds*
+accordingly!
+
+
+- CONFIG_ENV_IS_IN_NVRAM:
+
+ Define this if you have some non-volatile memory device
+ (NVRAM, battery buffered SRAM) which you want to use for the
+ environment.
+
+ - CONFIG_ENV_ADDR:
+ - CONFIG_ENV_SIZE:
+
+ These two #defines are used to determine the memory area you
+ want to use for environment. It is assumed that this memory
+ can just be read and written to, without any special
+ provision.
+
+BE CAREFUL! The first access to the environment happens quite early
+in U-Boot initalization (when we try to get the setting of for the
+console baudrate). You *MUST* have mapped your NVRAM area then, or
+U-Boot will hang.
+
+Please note that even with NVRAM we still use a copy of the
+environment in RAM: we could work on NVRAM directly, but we want to
+keep settings there always unmodified except somebody uses "saveenv"
+to save the current settings.
+
+
+- CONFIG_ENV_IS_IN_EEPROM:
+
+ Use this if you have an EEPROM or similar serial access
+ device and a driver for it.
+
+ - CONFIG_ENV_OFFSET:
+ - CONFIG_ENV_SIZE:
+
+ These two #defines specify the offset and size of the
+ environment area within the total memory of your EEPROM.
+
+ - CONFIG_SYS_I2C_EEPROM_ADDR:
+ If defined, specified the chip address of the EEPROM device.
+ The default address is zero.
+
+ - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
+ If defined, the number of bits used to address bytes in a
+ single page in the EEPROM device. A 64 byte page, for example
+ would require six bits.
+
+ - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
+ If defined, the number of milliseconds to delay between
+ page writes. The default is zero milliseconds.
+
+ - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
+ The length in bytes of the EEPROM memory array address. Note
+ that this is NOT the chip address length!
+
+ - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
+ EEPROM chips that implement "address overflow" are ones
+ like Catalyst 24WC04/08/16 which has 9/10/11 bits of
+ address and the extra bits end up in the "chip address" bit
+ slots. This makes a 24WC08 (1Kbyte) chip look like four 256
+ byte chips.
+
+ Note that we consider the length of the address field to
+ still be one byte because the extra address bits are hidden
+ in the chip address.
+
+ - CONFIG_SYS_EEPROM_SIZE:
+ The size in bytes of the EEPROM device.
+
+ - CONFIG_ENV_EEPROM_IS_ON_I2C
+ define this, if you have I2C and SPI activated, and your
+ EEPROM, which holds the environment, is on the I2C bus.
+
+ - CONFIG_I2C_ENV_EEPROM_BUS
+ if you have an Environment on an EEPROM reached over
+ I2C muxes, you can define here, how to reach this
+ EEPROM. For example:
+
+ #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
+
+ EEPROM which holds the environment, is reached over
+ a pca9547 i2c mux with address 0x70, channel 3.
+
+- CONFIG_ENV_IS_IN_DATAFLASH:
+
+ Define this if you have a DataFlash memory device which you
+ want to use for the environment.
+
+ - CONFIG_ENV_OFFSET:
+ - CONFIG_ENV_ADDR:
+ - CONFIG_ENV_SIZE:
+
+ These three #defines specify the offset and size of the
+ environment area within the total memory of your DataFlash placed
+ at the specified address.
+
+- CONFIG_ENV_IS_IN_REMOTE:
+
+ Define this if you have a remote memory space which you
+ want to use for the local device's environment.
+
+ - CONFIG_ENV_ADDR:
+ - CONFIG_ENV_SIZE:
+
+ These two #defines specify the address and size of the
+ environment area within the remote memory space. The
+ local device can get the environment from remote memory
+ space by SRIO or PCIE links.
+
+BE CAREFUL! For some special cases, the local device can not use
+"saveenv" command. For example, the local device will get the
+environment stored in a remote NOR flash by SRIO or PCIE link,
+but it can not erase, write this NOR flash by SRIO or PCIE interface.
+
+- CONFIG_ENV_IS_IN_NAND:
+
+ Define this if you have a NAND device which you want to use
+ for the environment.
+
+ - CONFIG_ENV_OFFSET:
+ - CONFIG_ENV_SIZE:
+
+ These two #defines specify the offset and size of the environment
+ area within the first NAND device. CONFIG_ENV_OFFSET must be
+ aligned to an erase block boundary.
+
+ - CONFIG_ENV_OFFSET_REDUND (optional):
+
+ This setting describes a second storage area of CONFIG_ENV_SIZE
+ size used to hold a redundant copy of the environment data, so
+ that there is a valid backup copy in case there is a power failure
+ during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
+ aligned to an erase block boundary.
+
+ - CONFIG_ENV_RANGE (optional):
+
+ Specifies the length of the region in which the environment
+ can be written. This should be a multiple of the NAND device's
+ block size. Specifying a range with more erase blocks than
+ are needed to hold CONFIG_ENV_SIZE allows bad blocks within
+ the range to be avoided.
+
+ - CONFIG_ENV_OFFSET_OOB (optional):
+
+ Enables support for dynamically retrieving the offset of the
+ environment from block zero's out-of-band data. The
+ "nand env.oob" command can be used to record this offset.
+ Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
+ using CONFIG_ENV_OFFSET_OOB.
+
+- CONFIG_NAND_ENV_DST
+
+ Defines address in RAM to which the nand_spl code should copy the
+ environment. If redundant environment is used, it will be copied to
+ CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
+
+- CONFIG_ENV_IS_IN_UBI:
+
+ Define this if you have an UBI volume that you want to use for the
+ environment. This has the benefit of wear-leveling the environment
+ accesses, which is important on NAND.
+
+ - CONFIG_ENV_UBI_PART:
+
+ Define this to a string that is the mtd partition containing the UBI.
+
+ - CONFIG_ENV_UBI_VOLUME:
+
+ Define this to the name of the volume that you want to store the
+ environment in.
+
+ - CONFIG_ENV_UBI_VOLUME_REDUND:
+
+ Define this to the name of another volume to store a second copy of
+ the environment in. This will enable redundant environments in UBI.
+ It is assumed that both volumes are in the same MTD partition.
+
+ - CONFIG_UBI_SILENCE_MSG
+ - CONFIG_UBIFS_SILENCE_MSG
+
+ You will probably want to define these to avoid a really noisy system
+ when storing the env in UBI.
+
+- CONFIG_ENV_IS_IN_MMC:
+
+ Define this if you have an MMC device which you want to use for the
+ environment.
+
+ - CONFIG_SYS_MMC_ENV_DEV:
+
+ Specifies which MMC device the environment is stored in.
+
+ - CONFIG_SYS_MMC_ENV_PART (optional):
+
+ Specifies which MMC partition the environment is stored in. If not
+ set, defaults to partition 0, the user area. Common values might be
+ 1 (first MMC boot partition), 2 (second MMC boot partition).
+
+ - CONFIG_ENV_OFFSET:
+ - CONFIG_ENV_SIZE:
+
+ These two #defines specify the offset and size of the environment
+ area within the specified MMC device.
+
+ If offset is positive (the usual case), it is treated as relative to
+ the start of the MMC partition. If offset is negative, it is treated
+ as relative to the end of the MMC partition. This can be useful if
+ your board may be fitted with different MMC devices, which have
+ different sizes for the MMC partitions, and you always want the
+ environment placed at the very end of the partition, to leave the
+ maximum possible space before it, to store other data.
+
+ These two values are in units of bytes, but must be aligned to an
+ MMC sector boundary.
+
+ - CONFIG_ENV_OFFSET_REDUND (optional):
+
+ Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
+ hold a redundant copy of the environment data. This provides a
+ valid backup copy in case the other copy is corrupted, e.g. due
+ to a power failure during a "saveenv" operation.
+
+ This value may also be positive or negative; this is handled in the
+ same way as CONFIG_ENV_OFFSET.
+
+ This value is also in units of bytes, but must also be aligned to
+ an MMC sector boundary.
+
+ - CONFIG_ENV_SIZE_REDUND (optional):
+
+ This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
+ set. If this value is set, it must be set to the same value as
+ CONFIG_ENV_SIZE.
+
+- CONFIG_SYS_SPI_INIT_OFFSET
+
+ Defines offset to the initial SPI buffer area in DPRAM. The
+ area is used at an early stage (ROM part) if the environment
+ is configured to reside in the SPI EEPROM: We need a 520 byte
+ scratch DPRAM area. It is used between the two initialization
+ calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
+ to be a good choice since it makes it far enough from the
+ start of the data area as well as from the stack pointer.
+
+Please note that the environment is read-only until the monitor
+has been relocated to RAM and a RAM copy of the environment has been
+created; also, when using EEPROM you will have to use getenv_f()
+until then to read environment variables.
+
+The environment is protected by a CRC32 checksum. Before the monitor
+is relocated into RAM, as a result of a bad CRC you will be working
+with the compiled-in default environment - *silently*!!! [This is
+necessary, because the first environment variable we need is the
+"baudrate" setting for the console - if we have a bad CRC, we don't
+have any device yet where we could complain.]
+
+Note: once the monitor has been relocated, then it will complain if
+the default environment is used; a new CRC is computed as soon as you
+use the "saveenv" command to store a valid environment.
+
+- CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
+ Echo the inverted Ethernet link state to the fault LED.
+
+ Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
+ also needs to be defined.
+
+- CONFIG_SYS_FAULT_MII_ADDR:
+ MII address of the PHY to check for the Ethernet link state.
+
+- CONFIG_NS16550_MIN_FUNCTIONS:
+ Define this if you desire to only have use of the NS16550_init
+ and NS16550_putc functions for the serial driver located at
+ drivers/serial/ns16550.c. This option is useful for saving
+ space for already greatly restricted images, including but not
+ limited to NAND_SPL configurations.
+
+- CONFIG_DISPLAY_BOARDINFO
+ Display information about the board that U-Boot is running on
+ when U-Boot starts up. The board function checkboard() is called
+ to do this.
+
+- CONFIG_DISPLAY_BOARDINFO_LATE
+ Similar to the previous option, but display this information
+ later, once stdio is running and output goes to the LCD, if
+ present.
+
+Low Level (hardware related) configuration options:
+---------------------------------------------------
+
+- CONFIG_SYS_CACHELINE_SIZE:
+ Cache Line Size of the CPU.
+
+- CONFIG_SYS_DEFAULT_IMMR:
+ Default address of the IMMR after system reset.
+
+ Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
+ and RPXsuper) to be able to adjust the position of
+ the IMMR register after a reset.
+
+- CONFIG_SYS_CCSRBAR_DEFAULT:
+ Default (power-on reset) physical address of CCSR on Freescale
+ PowerPC SOCs.
+
+- CONFIG_SYS_CCSRBAR:
+ Virtual address of CCSR. On a 32-bit build, this is typically
+ the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
+
+ CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
+ for cross-platform code that uses that macro instead.
+
+- CONFIG_SYS_CCSRBAR_PHYS:
+ Physical address of CCSR. CCSR can be relocated to a new
+ physical address, if desired. In this case, this macro should
+ be set to that address. Otherwise, it should be set to the
+ same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
+ is typically relocated on 36-bit builds. It is recommended
+ that this macro be defined via the _HIGH and _LOW macros:
+
+ #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
+ * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
+
+- CONFIG_SYS_CCSRBAR_PHYS_HIGH:
+ Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
+ either 0 (32-bit build) or 0xF (36-bit build). This macro is
+ used in assembly code, so it must not contain typecasts or
+ integer size suffixes (e.g. "ULL").
+
+- CONFIG_SYS_CCSRBAR_PHYS_LOW:
+ Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
+ used in assembly code, so it must not contain typecasts or
+ integer size suffixes (e.g. "ULL").
+
+- CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
+ If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
+ forced to a value that ensures that CCSR is not relocated.
+
+- Floppy Disk Support:
+ CONFIG_SYS_FDC_DRIVE_NUMBER
+
+ the default drive number (default value 0)
+
+ CONFIG_SYS_ISA_IO_STRIDE
+
+ defines the spacing between FDC chipset registers
+ (default value 1)
+
+ CONFIG_SYS_ISA_IO_OFFSET
+
+ defines the offset of register from address. It
+ depends on which part of the data bus is connected to
+ the FDC chipset. (default value 0)
+
+ If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
+ CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
+ default value.
+
+ if CONFIG_SYS_FDC_HW_INIT is defined, then the function
+ fdc_hw_init() is called at the beginning of the FDC
+ setup. fdc_hw_init() must be provided by the board
+ source code. It is used to make hardware dependant
+ initializations.
+
+- CONFIG_IDE_AHB:
+ Most IDE controllers were designed to be connected with PCI
+ interface. Only few of them were designed for AHB interface.
+ When software is doing ATA command and data transfer to
+ IDE devices through IDE-AHB controller, some additional
+ registers accessing to these kind of IDE-AHB controller
+ is requierd.
+
+- CONFIG_SYS_IMMR: Physical address of the Internal Memory.
+ DO NOT CHANGE unless you know exactly what you're
+ doing! (11-4) [MPC8xx/82xx systems only]
+
+- CONFIG_SYS_INIT_RAM_ADDR:
+
+ Start address of memory area that can be used for
+ initial data and stack; please note that this must be
+ writable memory that is working WITHOUT special
+ initialization, i. e. you CANNOT use normal RAM which
+ will become available only after programming the
+ memory controller and running certain initialization
+ sequences.
+
+ U-Boot uses the following memory types:
+ - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
+ - MPC824X: data cache
+ - PPC4xx: data cache
+
+- CONFIG_SYS_GBL_DATA_OFFSET:
+
+ Offset of the initial data structure in the memory
+ area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
+ CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
+ data is located at the end of the available space
+ (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
+ CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
+ below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
+ CONFIG_SYS_GBL_DATA_OFFSET) downward.
+
+ Note:
+ On the MPC824X (or other systems that use the data
+ cache for initial memory) the address chosen for
+ CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
+ point to an otherwise UNUSED address space between
+ the top of RAM and the start of the PCI space.
+
+- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
+
+- CONFIG_SYS_SYPCR: System Protection Control (11-9)
+
+- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
+
+- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
+
+- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
+
+- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
+
+- CONFIG_SYS_OR_TIMING_SDRAM:
+ SDRAM timing
+
+- CONFIG_SYS_MAMR_PTA:
+ periodic timer for refresh
+
+- CONFIG_SYS_DER: Debug Event Register (37-47)
+
+- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
+ CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
+ CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
+ CONFIG_SYS_BR1_PRELIM:
+ Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
+
+- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
+ CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
+ CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
+ Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
+
+- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
+ CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
+ Machine Mode Register and Memory Periodic Timer
+ Prescaler definitions (SDRAM timing)
+
+- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
+ enable I2C microcode relocation patch (MPC8xx);
+ define relocation offset in DPRAM [DSP2]
+
+- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
+ enable SMC microcode relocation patch (MPC8xx);
+ define relocation offset in DPRAM [SMC1]
+
+- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
+ enable SPI microcode relocation patch (MPC8xx);
+ define relocation offset in DPRAM [SCC4]
+
+- CONFIG_SYS_USE_OSCCLK:
+ Use OSCM clock mode on MBX8xx board. Be careful,
+ wrong setting might damage your board. Read
+ doc/README.MBX before setting this variable!
+
+- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
+ Offset of the bootmode word in DPRAM used by post
+ (Power On Self Tests). This definition overrides
+ #define'd default value in commproc.h resp.
+ cpm_8260.h.
+
+- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
+ CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
+ CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
+ CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
+ CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
+ CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
+ CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
+ CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
+ Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
+
+- CONFIG_PCI_DISABLE_PCIE:
+ Disable PCI-Express on systems where it is supported but not
+ required.
+
+- CONFIG_PCI_ENUM_ONLY
+ Only scan through and get the devices on the busses.
+ Don't do any setup work, presumably because someone or
+ something has already done it, and we don't need to do it
+ a second time. Useful for platforms that are pre-booted
+ by coreboot or similar.
+
+- CONFIG_PCI_INDIRECT_BRIDGE:
+ Enable support for indirect PCI bridges.
+
+- CONFIG_SYS_SRIO:
+ Chip has SRIO or not
+
+- CONFIG_SRIO1:
+ Board has SRIO 1 port available
+
+- CONFIG_SRIO2:
+ Board has SRIO 2 port available
+
+- CONFIG_SRIO_PCIE_BOOT_MASTER
+ Board can support master function for Boot from SRIO and PCIE
+
+- CONFIG_SYS_SRIOn_MEM_VIRT:
+ Virtual Address of SRIO port 'n' memory region
+
+- CONFIG_SYS_SRIOn_MEM_PHYS:
+ Physical Address of SRIO port 'n' memory region
+
+- CONFIG_SYS_SRIOn_MEM_SIZE:
+ Size of SRIO port 'n' memory region
+
+- CONFIG_SYS_NAND_BUSWIDTH_16BIT
+ Defined to tell the NAND controller that the NAND chip is using
+ a 16 bit bus.
+ Not all NAND drivers use this symbol.
+ Example of drivers that use it:
+ - drivers/mtd/nand/ndfc.c
+ - drivers/mtd/nand/mxc_nand.c
+
+- CONFIG_SYS_NDFC_EBC0_CFG
+ Sets the EBC0_CFG register for the NDFC. If not defined
+ a default value will be used.
+
+- CONFIG_SPD_EEPROM
+ Get DDR timing information from an I2C EEPROM. Common
+ with pluggable memory modules such as SODIMMs
+
+ SPD_EEPROM_ADDRESS
+ I2C address of the SPD EEPROM
+
+- CONFIG_SYS_SPD_BUS_NUM
+ If SPD EEPROM is on an I2C bus other than the first
+ one, specify here. Note that the value must resolve
+ to something your driver can deal with.
+
+- CONFIG_SYS_DDR_RAW_TIMING
+ Get DDR timing information from other than SPD. Common with
+ soldered DDR chips onboard without SPD. DDR raw timing
+ parameters are extracted from datasheet and hard-coded into
+ header files or board specific files.
+
+- CONFIG_FSL_DDR_INTERACTIVE
+ Enable interactive DDR debugging. See doc/README.fsl-ddr.
+
+- CONFIG_SYS_83XX_DDR_USES_CS0
+ Only for 83xx systems. If specified, then DDR should
+ be configured using CS0 and CS1 instead of CS2 and CS3.
+
+- CONFIG_ETHER_ON_FEC[12]
+ Define to enable FEC[12] on a 8xx series processor.
+
+- CONFIG_FEC[12]_PHY
+ Define to the hardcoded PHY address which corresponds
+ to the given FEC; i. e.
+ #define CONFIG_FEC1_PHY 4
+ means that the PHY with address 4 is connected to FEC1
+
+ When set to -1, means to probe for first available.
+
+- CONFIG_FEC[12]_PHY_NORXERR
+ The PHY does not have a RXERR line (RMII only).
+ (so program the FEC to ignore it).
+
+- CONFIG_RMII
+ Enable RMII mode for all FECs.
+ Note that this is a global option, we can't
+ have one FEC in standard MII mode and another in RMII mode.
+
+- CONFIG_CRC32_VERIFY
+ Add a verify option to the crc32 command.
+ The syntax is:
+
+ => crc32 -v <address> <count> <crc32>
+
+ Where address/count indicate a memory area
+ and crc32 is the correct crc32 which the
+ area should have.
+
+- CONFIG_LOOPW
+ Add the "loopw" memory command. This only takes effect if
+ the memory commands are activated globally (CONFIG_CMD_MEM).
+
+- CONFIG_MX_CYCLIC
+ Add the "mdc" and "mwc" memory commands. These are cyclic
+ "md/mw" commands.
+ Examples:
+
+ => mdc.b 10 4 500
+ This command will print 4 bytes (10,11,12,13) each 500 ms.
+
+ => mwc.l 100 12345678 10
+ This command will write 12345678 to address 100 all 10 ms.
+
+ This only takes effect if the memory commands are activated
+ globally (CONFIG_CMD_MEM).
+
+- CONFIG_SKIP_LOWLEVEL_INIT
+ [ARM, NDS32, MIPS only] If this variable is defined, then certain
+ low level initializations (like setting up the memory
+ controller) are omitted and/or U-Boot does not
+ relocate itself into RAM.
+
+ Normally this variable MUST NOT be defined. The only
+ exception is when U-Boot is loaded (to RAM) by some
+ other boot loader or by a debugger which performs
+ these initializations itself.
+
+- CONFIG_SPL_BUILD
+ Modifies the behaviour of start.S when compiling a loader
+ that is executed before the actual U-Boot. E.g. when
+ compiling a NAND SPL.
+
+- CONFIG_SYS_MPC85XX_NO_RESETVEC
+ Only for 85xx systems. If this variable is specified, the section
+ .resetvec is not kept and the section .bootpg is placed in the
+ previous 4k of the .text section.
+
+- CONFIG_ARCH_MAP_SYSMEM
+ Generally U-Boot (and in particular the md command) uses
+ effective address. It is therefore not necessary to regard
+ U-Boot address as virtual addresses that need to be translated
+ to physical addresses. However, sandbox requires this, since
+ it maintains its own little RAM buffer which contains all
+ addressable memory. This option causes some memory accesses
+ to be mapped through map_sysmem() / unmap_sysmem().
+
+- CONFIG_USE_ARCH_MEMCPY
+ CONFIG_USE_ARCH_MEMSET
+ If these options are used a optimized version of memcpy/memset will
+ be used if available. These functions may be faster under some
+ conditions but may increase the binary size.
+
+- CONFIG_X86_RESET_VECTOR
+ If defined, the x86 reset vector code is included. This is not
+ needed when U-Boot is running from Coreboot.
+
+- CONFIG_SYS_MPUCLK
+ Defines the MPU clock speed (in MHz).
+
+ NOTE : currently only supported on AM335x platforms.
+
+Freescale QE/FMAN Firmware Support:
+-----------------------------------
+
+The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
+loading of "firmware", which is encoded in the QE firmware binary format.
+This firmware often needs to be loaded during U-Boot booting, so macros
+are used to identify the storage device (NOR flash, SPI, etc) and the address
+within that device.
+
+- CONFIG_SYS_QE_FMAN_FW_ADDR
+ The address in the storage device where the firmware is located. The
+ meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
+ is also specified.
+
+- CONFIG_SYS_QE_FMAN_FW_LENGTH
+ The maximum possible size of the firmware. The firmware binary format
+ has a field that specifies the actual size of the firmware, but it
+ might not be possible to read any part of the firmware unless some
+ local storage is allocated to hold the entire firmware first.
+
+- CONFIG_SYS_QE_FMAN_FW_IN_NOR
+ Specifies that QE/FMAN firmware is located in NOR flash, mapped as
+ normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
+ virtual address in NOR flash.
+
+- CONFIG_SYS_QE_FMAN_FW_IN_NAND
+ Specifies that QE/FMAN firmware is located in NAND flash.
+ CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
+
+- CONFIG_SYS_QE_FMAN_FW_IN_MMC
+ Specifies that QE/FMAN firmware is located on the primary SD/MMC
+ device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
+
+- CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
+ Specifies that QE/FMAN firmware is located on the primary SPI
+ device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
+
+- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
+ Specifies that QE/FMAN firmware is located in the remote (master)
+ memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
+ can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
+ window->master inbound window->master LAW->the ucode address in
+ master's memory space.
+
+Building the Software:
+======================
+
+Building U-Boot has been tested in several native build environments
+and in many different cross environments. Of course we cannot support
+all possibly existing versions of cross development tools in all
+(potentially obsolete) versions. In case of tool chain problems we
+recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
+which is extensively used to build and test U-Boot.
+
+If you are not using a native environment, it is assumed that you
+have GNU cross compiling tools available in your path. In this case,
+you must set the environment variable CROSS_COMPILE in your shell.
+Note that no changes to the Makefile or any other source files are
+necessary. For example using the ELDK on a 4xx CPU, please enter:
+
+ $ CROSS_COMPILE=ppc_4xx-
+ $ export CROSS_COMPILE
+
+Note: If you wish to generate Windows versions of the utilities in
+ the tools directory you can use the MinGW toolchain
+ (http://www.mingw.org). Set your HOST tools to the MinGW
+ toolchain and execute 'make tools'. For example:
+
+ $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
+
+ Binaries such as tools/mkimage.exe will be created which can
+ be executed on computers running Windows.
+
+U-Boot is intended to be simple to build. After installing the
+sources you must configure U-Boot for one specific board type. This
+is done by typing:
+
+ make NAME_config
+
+where "NAME_config" is the name of one of the existing configu-
+rations; see boards.cfg for supported names.
+
+Note: for some board special configuration names may exist; check if
+ additional information is available from the board vendor; for
+ instance, the TQM823L systems are available without (standard)
+ or with LCD support. You can select such additional "features"
+ when choosing the configuration, i. e.
+
+ make TQM823L_config
+ - will configure for a plain TQM823L, i. e. no LCD support
+
+ make TQM823L_LCD_config
+ - will configure for a TQM823L with U-Boot console on LCD
+
+ etc.
+
+
+Finally, type "make all", and you should get some working U-Boot
+images ready for download to / installation on your system:
+
+- "u-boot.bin" is a raw binary image
+- "u-boot" is an image in ELF binary format
+- "u-boot.srec" is in Motorola S-Record format
+
+By default the build is performed locally and the objects are saved
+in the source directory. One of the two methods can be used to change
+this behavior and build U-Boot to some external directory:
+
+1. Add O= to the make command line invocations:
+
+ make O=/tmp/build distclean
+ make O=/tmp/build NAME_config
+ make O=/tmp/build all
+
+2. Set environment variable BUILD_DIR to point to the desired location:
+
+ export BUILD_DIR=/tmp/build
+ make distclean
+ make NAME_config
+ make all
+
+Note that the command line "O=" setting overrides the BUILD_DIR environment
+variable.
+
+
+Please be aware that the Makefiles assume you are using GNU make, so
+for instance on NetBSD you might need to use "gmake" instead of
+native "make".
+
+
+If the system board that you have is not listed, then you will need
+to port U-Boot to your hardware platform. To do this, follow these
+steps:
+
+1. Add a new configuration option for your board to the toplevel
+ "boards.cfg" file, using the existing entries as examples.
+ Follow the instructions there to keep the boards in order.
+2. Create a new directory to hold your board specific code. Add any
+ files you need. In your board directory, you will need at least
+ the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
+3. Create a new configuration file "include/configs/<board>.h" for
+ your board
+3. If you're porting U-Boot to a new CPU, then also create a new
+ directory to hold your CPU specific code. Add any files you need.
+4. Run "make <board>_config" with your new name.
+5. Type "make", and you should get a working "u-boot.srec" file
+ to be installed on your target system.
+6. Debug and solve any problems that might arise.
+ [Of course, this last step is much harder than it sounds.]
+
+
+Testing of U-Boot Modifications, Ports to New Hardware, etc.:
+==============================================================
+
+If you have modified U-Boot sources (for instance added a new board
+or support for new devices, a new CPU, etc.) you are expected to
+provide feedback to the other developers. The feedback normally takes
+the form of a "patch", i. e. a context diff against a certain (latest
+official or latest in the git repository) version of U-Boot sources.
+
+But before you submit such a patch, please verify that your modifi-
+cation did not break existing code. At least make sure that *ALL* of
+the supported boards compile WITHOUT ANY compiler warnings. To do so,
+just run the "MAKEALL" script, which will configure and build U-Boot
+for ALL supported system. Be warned, this will take a while. You can
+select which (cross) compiler to use by passing a `CROSS_COMPILE'
+environment variable to the script, i. e. to use the ELDK cross tools
+you can type
+
+ CROSS_COMPILE=ppc_8xx- MAKEALL
+
+or to build on a native PowerPC system you can type
+
+ CROSS_COMPILE=' ' MAKEALL
+
+When using the MAKEALL script, the default behaviour is to build
+U-Boot in the source directory. This location can be changed by
+setting the BUILD_DIR environment variable. Also, for each target
+built, the MAKEALL script saves two log files (<target>.ERR and
+<target>.MAKEALL) in the <source dir>/LOG directory. This default
+location can be changed by setting the MAKEALL_LOGDIR environment
+variable. For example:
+
+ export BUILD_DIR=/tmp/build
+ export MAKEALL_LOGDIR=/tmp/log
+ CROSS_COMPILE=ppc_8xx- MAKEALL
+
+With the above settings build objects are saved in the /tmp/build,
+log files are saved in the /tmp/log and the source tree remains clean
+during the whole build process.
+
+
+See also "U-Boot Porting Guide" below.
+
+
+Monitor Commands - Overview:
+============================
+
+go - start application at address 'addr'
+run - run commands in an environment variable
+bootm - boot application image from memory
+bootp - boot image via network using BootP/TFTP protocol
+bootz - boot zImage from memory
+tftpboot- boot image via network using TFTP protocol
+ and env variables "ipaddr" and "serverip"
+ (and eventually "gatewayip")
+tftpput - upload a file via network using TFTP protocol
+rarpboot- boot image via network using RARP/TFTP protocol
+diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
+loads - load S-Record file over serial line
+loadb - load binary file over serial line (kermit mode)
+md - memory display
+mm - memory modify (auto-incrementing)
+nm - memory modify (constant address)
+mw - memory write (fill)
+cp - memory copy
+cmp - memory compare
+crc32 - checksum calculation
+i2c - I2C sub-system
+sspi - SPI utility commands
+base - print or set address offset
+printenv- print environment variables
+setenv - set environment variables
+saveenv - save environment variables to persistent storage
+protect - enable or disable FLASH write protection
+erase - erase FLASH memory
+flinfo - print FLASH memory information
+nand - NAND memory operations (see doc/README.nand)
+bdinfo - print Board Info structure
+iminfo - print header information for application image
+coninfo - print console devices and informations
+ide - IDE sub-system
+loop - infinite loop on address range
+loopw - infinite write loop on address range
+mtest - simple RAM test
+icache - enable or disable instruction cache
+dcache - enable or disable data cache
+reset - Perform RESET of the CPU
+echo - echo args to console
+version - print monitor version
+help - print online help
+? - alias for 'help'
+
+
+Monitor Commands - Detailed Description:
+========================================
+
+TODO.
+
+For now: just type "help <command>".
+
+
+Environment Variables:
+======================
+
+U-Boot supports user configuration using Environment Variables which
+can be made persistent by saving to Flash memory.
+
+Environment Variables are set using "setenv", printed using
+"printenv", and saved to Flash using "saveenv". Using "setenv"
+without a value can be used to delete a variable from the
+environment. As long as you don't save the environment you are
+working with an in-memory copy. In case the Flash area containing the
+environment is erased by accident, a default environment is provided.
+
+Some configuration options can be set using Environment Variables.
+
+List of environment variables (most likely not complete):
+
+ baudrate - see CONFIG_BAUDRATE
+
+ bootdelay - see CONFIG_BOOTDELAY
+
+ bootcmd - see CONFIG_BOOTCOMMAND
+
+ bootargs - Boot arguments when booting an RTOS image
+
+ bootfile - Name of the image to load with TFTP
+
+ bootm_low - Memory range available for image processing in the bootm
+ command can be restricted. This variable is given as
+ a hexadecimal number and defines lowest address allowed
+ for use by the bootm command. See also "bootm_size"
+ environment variable. Address defined by "bootm_low" is
+ also the base of the initial memory mapping for the Linux
+ kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
+ bootm_mapsize.
+
+ bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
+ This variable is given as a hexadecimal number and it
+ defines the size of the memory region starting at base
+ address bootm_low that is accessible by the Linux kernel
+ during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
+ as the default value if it is defined, and bootm_size is
+ used otherwise.
+
+ bootm_size - Memory range available for image processing in the bootm
+ command can be restricted. This variable is given as
+ a hexadecimal number and defines the size of the region
+ allowed for use by the bootm command. See also "bootm_low"
+ environment variable.
+
+ updatefile - Location of the software update file on a TFTP server, used
+ by the automatic software update feature. Please refer to
+ documentation in doc/README.update for more details.
+
+ autoload - if set to "no" (any string beginning with 'n'),
+ "bootp" will just load perform a lookup of the
+ configuration from the BOOTP server, but not try to
+ load any image using TFTP
+
+ autostart - if set to "yes", an image loaded using the "bootp",
+ "rarpboot", "tftpboot" or "diskboot" commands will
+ be automatically started (by internally calling
+ "bootm")
+
+ If set to "no", a standalone image passed to the
+ "bootm" command will be copied to the load address
+ (and eventually uncompressed), but NOT be started.
+ This can be used to load and uncompress arbitrary
+ data.
+
+ fdt_high - if set this restricts the maximum address that the
+ flattened device tree will be copied into upon boot.
+ For example, if you have a system with 1 GB memory
+ at physical address 0x10000000, while Linux kernel
+ only recognizes the first 704 MB as low memory, you
+ may need to set fdt_high as 0x3C000000 to have the
+ device tree blob be copied to the maximum address
+ of the 704 MB low memory, so that Linux kernel can
+ access it during the boot procedure.
+
+ If this is set to the special value 0xFFFFFFFF then
+ the fdt will not be copied at all on boot. For this
+ to work it must reside in writable memory, have
+ sufficient padding on the end of it for u-boot to
+ add the information it needs into it, and the memory
+ must be accessible by the kernel.
+
+ fdtcontroladdr- if set this is the address of the control flattened
+ device tree used by U-Boot when CONFIG_OF_CONTROL is
+ defined.
+
+ i2cfast - (PPC405GP|PPC405EP only)
+ if set to 'y' configures Linux I2C driver for fast
+ mode (400kHZ). This environment variable is used in
+ initialization code. So, for changes to be effective
+ it must be saved and board must be reset.
+
+ initrd_high - restrict positioning of initrd images:
+ If this variable is not set, initrd images will be
+ copied to the highest possible address in RAM; this
+ is usually what you want since it allows for
+ maximum initrd size. If for some reason you want to
+ make sure that the initrd image is loaded below the
+ CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
+ variable to a value of "no" or "off" or "0".
+ Alternatively, you can set it to a maximum upper
+ address to use (U-Boot will still check that it
+ does not overwrite the U-Boot stack and data).
+
+ For instance, when you have a system with 16 MB
+ RAM, and want to reserve 4 MB from use by Linux,
+ you can do this by adding "mem=12M" to the value of
+ the "bootargs" variable. However, now you must make
+ sure that the initrd image is placed in the first
+ 12 MB as well - this can be done with
+
+ setenv initrd_high 00c00000
+
+ If you set initrd_high to 0xFFFFFFFF, this is an
+ indication to U-Boot that all addresses are legal
+ for the Linux kernel, including addresses in flash
+ memory. In this case U-Boot will NOT COPY the
+ ramdisk at all. This may be useful to reduce the
+ boot time on your system, but requires that this
+ feature is supported by your Linux kernel.
+
+ ipaddr - IP address; needed for tftpboot command
+
+ loadaddr - Default load address for commands like "bootp",
+ "rarpboot", "tftpboot", "loadb" or "diskboot"
+
+ loads_echo - see CONFIG_LOADS_ECHO
+
+ serverip - TFTP server IP address; needed for tftpboot command
+
+ bootretry - see CONFIG_BOOT_RETRY_TIME
+
+ bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
+
+ bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
+
+ ethprime - controls which interface is used first.
+
+ ethact - controls which interface is currently active.
+ For example you can do the following
+
+ => setenv ethact FEC
+ => ping 192.168.0.1 # traffic sent on FEC
+ => setenv ethact SCC
+ => ping 10.0.0.1 # traffic sent on SCC
+
+ ethrotate - When set to "no" U-Boot does not go through all
+ available network interfaces.
+ It just stays at the currently selected interface.
+
+ netretry - When set to "no" each network operation will
+ either succeed or fail without retrying.
+ When set to "once" the network operation will
+ fail when all the available network interfaces
+ are tried once without success.
+ Useful on scripts which control the retry operation
+ themselves.
+
+ npe_ucode - set load address for the NPE microcode
+
+ tftpsrcport - If this is set, the value is used for TFTP's
+ UDP source port.
+
+ tftpdstport - If this is set, the value is used for TFTP's UDP
+ destination port instead of the Well Know Port 69.
+
+ tftpblocksize - Block size to use for TFTP transfers; if not set,
+ we use the TFTP server's default block size
+
+ tftptimeout - Retransmission timeout for TFTP packets (in milli-
+ seconds, minimum value is 1000 = 1 second). Defines
+ when a packet is considered to be lost so it has to
+ be retransmitted. The default is 5000 = 5 seconds.
+ Lowering this value may make downloads succeed
+ faster in networks with high packet loss rates or
+ with unreliable TFTP servers.
+
+ vlan - When set to a value < 4095 the traffic over
+ Ethernet is encapsulated/received over 802.1q
+ VLAN tagged frames.
+
+The following image location variables contain the location of images
+used in booting. The "Image" column gives the role of the image and is
+not an environment variable name. The other columns are environment
+variable names. "File Name" gives the name of the file on a TFTP
+server, "RAM Address" gives the location in RAM the image will be
+loaded to, and "Flash Location" gives the image's address in NOR
+flash or offset in NAND flash.
+
+*Note* - these variables don't have to be defined for all boards, some
+boards currenlty use other variables for these purposes, and some
+boards use these variables for other purposes.
+
+Image File Name RAM Address Flash Location
+----- --------- ----------- --------------
+u-boot u-boot u-boot_addr_r u-boot_addr
+Linux kernel bootfile kernel_addr_r kernel_addr
+device tree blob fdtfile fdt_addr_r fdt_addr
+ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
+
+The following environment variables may be used and automatically
+updated by the network boot commands ("bootp" and "rarpboot"),
+depending the information provided by your boot server:
+
+ bootfile - see above
+ dnsip - IP address of your Domain Name Server
+ dnsip2 - IP address of your secondary Domain Name Server
+ gatewayip - IP address of the Gateway (Router) to use
+ hostname - Target hostname
+ ipaddr - see above
+ netmask - Subnet Mask
+ rootpath - Pathname of the root filesystem on the NFS server
+ serverip - see above
+
+
+There are two special Environment Variables:
+
+ serial# - contains hardware identification information such
+ as type string and/or serial number
+ ethaddr - Ethernet address
+
+These variables can be set only once (usually during manufacturing of
+the board). U-Boot refuses to delete or overwrite these variables
+once they have been set once.
+
+
+Further special Environment Variables:
+
+ ver - Contains the U-Boot version string as printed
+ with the "version" command. This variable is
+ readonly (see CONFIG_VERSION_VARIABLE).
+
+
+Please note that changes to some configuration parameters may take
+only effect after the next boot (yes, that's just like Windoze :-).
+
+
+Callback functions for environment variables:
+---------------------------------------------
+
+For some environment variables, the behavior of u-boot needs to change
+when their values are changed. This functionailty allows functions to
+be associated with arbitrary variables. On creation, overwrite, or
+deletion, the callback will provide the opportunity for some side
+effect to happen or for the change to be rejected.
+
+The callbacks are named and associated with a function using the
+U_BOOT_ENV_CALLBACK macro in your board or driver code.
+
+These callbacks are associated with variables in one of two ways. The
+static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
+in the board configuration to a string that defines a list of
+associations. The list must be in the following format:
+
+ entry = variable_name[:callback_name]
+ list = entry[,list]
+
+If the callback name is not specified, then the callback is deleted.
+Spaces are also allowed anywhere in the list.
+
+Callbacks can also be associated by defining the ".callbacks" variable
+with the same list format above. Any association in ".callbacks" will
+override any association in the static list. You can define
+CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
+".callbacks" envirnoment variable in the default or embedded environment.
+
+
+Command Line Parsing:
+=====================
+
+There are two different command line parsers available with U-Boot:
+the old "simple" one, and the much more powerful "hush" shell:
+
+Old, simple command line parser:
+--------------------------------
+
+- supports environment variables (through setenv / saveenv commands)
+- several commands on one line, separated by ';'
+- variable substitution using "... ${name} ..." syntax
+- special characters ('$', ';') can be escaped by prefixing with '\',
+ for example:
+ setenv bootcmd bootm \${address}
+- You can also escape text by enclosing in single apostrophes, for example:
+ setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
+
+Hush shell:
+-----------
+
+- similar to Bourne shell, with control structures like
+ if...then...else...fi, for...do...done; while...do...done,
+ until...do...done, ...
+- supports environment ("global") variables (through setenv / saveenv
+ commands) and local shell variables (through standard shell syntax
+ "name=value"); only environment variables can be used with "run"
+ command
+
+General rules:
+--------------
+
+(1) If a command line (or an environment variable executed by a "run"
+ command) contains several commands separated by semicolon, and
+ one of these commands fails, then the remaining commands will be
+ executed anyway.
+
+(2) If you execute several variables with one call to run (i. e.
+ calling run with a list of variables as arguments), any failing
+ command will cause "run" to terminate, i. e. the remaining
+ variables are not executed.
+
+Note for Redundant Ethernet Interfaces:
+=======================================
+
+Some boards come with redundant Ethernet interfaces; U-Boot supports
+such configurations and is capable of automatic selection of a
+"working" interface when needed. MAC assignment works as follows:
+
+Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
+MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
+"eth1addr" (=>eth1), "eth2addr", ...
+
+If the network interface stores some valid MAC address (for instance
+in SROM), this is used as default address if there is NO correspon-
+ding setting in the environment; if the corresponding environment
+variable is set, this overrides the settings in the card; that means:
+
+o If the SROM has a valid MAC address, and there is no address in the
+ environment, the SROM's address is used.
+
+o If there is no valid address in the SROM, and a definition in the
+ environment exists, then the value from the environment variable is
+ used.
+
+o If both the SROM and the environment contain a MAC address, and
+ both addresses are the same, this MAC address is used.
+
+o If both the SROM and the environment contain a MAC address, and the
+ addresses differ, the value from the environment is used and a
+ warning is printed.
+
+o If neither SROM nor the environment contain a MAC address, an error
+ is raised.
+
+If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
+will be programmed into hardware as part of the initialization process. This
+may be skipped by setting the appropriate 'ethmacskip' environment variable.
+The naming convention is as follows:
+"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
+
+Image Formats:
+==============
+
+U-Boot is capable of booting (and performing other auxiliary operations on)
+images in two formats:
+
+New uImage format (FIT)
+-----------------------
+
+Flexible and powerful format based on Flattened Image Tree -- FIT (similar
+to Flattened Device Tree). It allows the use of images with multiple
+components (several kernels, ramdisks, etc.), with contents protected by
+SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
+
+
+Old uImage format
+-----------------
+
+Old image format is based on binary files which can be basically anything,
+preceded by a special header; see the definitions in include/image.h for
+details; basically, the header defines the following image properties:
+
+* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
+ 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
+ LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
+ Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
+ INTEGRITY).
+* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
+ IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
+ Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
+* Compression Type (uncompressed, gzip, bzip2)
+* Load Address
+* Entry Point
+* Image Name
+* Image Timestamp
+
+The header is marked by a special Magic Number, and both the header
+and the data portions of the image are secured against corruption by
+CRC32 checksums.
+
+
+Linux Support:
+==============
+
+Although U-Boot should support any OS or standalone application
+easily, the main focus has always been on Linux during the design of
+U-Boot.
+
+U-Boot includes many features that so far have been part of some
+special "boot loader" code within the Linux kernel. Also, any
+"initrd" images to be used are no longer part of one big Linux image;
+instead, kernel and "initrd" are separate images. This implementation
+serves several purposes:
+
+- the same features can be used for other OS or standalone
+ applications (for instance: using compressed images to reduce the
+ Flash memory footprint)
+
+- it becomes much easier to port new Linux kernel versions because
+ lots of low-level, hardware dependent stuff are done by U-Boot
+
+- the same Linux kernel image can now be used with different "initrd"
+ images; of course this also means that different kernel images can
+ be run with the same "initrd". This makes testing easier (you don't
+ have to build a new "zImage.initrd" Linux image when you just
+ change a file in your "initrd"). Also, a field-upgrade of the
+ software is easier now.
+
+
+Linux HOWTO:
+============
+
+Porting Linux to U-Boot based systems:
+---------------------------------------
+
+U-Boot cannot save you from doing all the necessary modifications to
+configure the Linux device drivers for use with your target hardware
+(no, we don't intend to provide a full virtual machine interface to
+Linux :-).
+
+But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
+
+Just make sure your machine specific header file (for instance
+include/asm-ppc/tqm8xx.h) includes the same definition of the Board
+Information structure as we define in include/asm-<arch>/u-boot.h,
+and make sure that your definition of IMAP_ADDR uses the same value
+as your U-Boot configuration in CONFIG_SYS_IMMR.
+
+
+Configuring the Linux kernel:
+-----------------------------
+
+No specific requirements for U-Boot. Make sure you have some root
+device (initial ramdisk, NFS) for your target system.
+
+
+Building a Linux Image:
+-----------------------
+
+With U-Boot, "normal" build targets like "zImage" or "bzImage" are
+not used. If you use recent kernel source, a new build target
+"uImage" will exist which automatically builds an image usable by
+U-Boot. Most older kernels also have support for a "pImage" target,
+which was introduced for our predecessor project PPCBoot and uses a
+100% compatible format.
+
+Example:
+
+ make TQM850L_config
+ make oldconfig
+ make dep
+ make uImage
+
+The "uImage" build target uses a special tool (in 'tools/mkimage') to
+encapsulate a compressed Linux kernel image with header information,
+CRC32 checksum etc. for use with U-Boot. This is what we are doing:
+
+* build a standard "vmlinux" kernel image (in ELF binary format):
+
+* convert the kernel into a raw binary image:
+
+ ${CROSS_COMPILE}-objcopy -O binary \
+ -R .note -R .comment \
+ -S vmlinux linux.bin
+
+* compress the binary image:
+
+ gzip -9 linux.bin
+
+* package compressed binary image for U-Boot:
+
+ mkimage -A ppc -O linux -T kernel -C gzip \
+ -a 0 -e 0 -n "Linux Kernel Image" \
+ -d linux.bin.gz uImage
+
+
+The "mkimage" tool can also be used to create ramdisk images for use
+with U-Boot, either separated from the Linux kernel image, or
+combined into one file. "mkimage" encapsulates the images with a 64
+byte header containing information about target architecture,
+operating system, image type, compression method, entry points, time
+stamp, CRC32 checksums, etc.
+
+"mkimage" can be called in two ways: to verify existing images and
+print the header information, or to build new images.
+
+In the first form (with "-l" option) mkimage lists the information
+contained in the header of an existing U-Boot image; this includes
+checksum verification:
+
+ tools/mkimage -l image
+ -l ==> list image header information
+
+The second form (with "-d" option) is used to build a U-Boot image
+from a "data file" which is used as image payload:
+
+ tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
+ -n name -d data_file image
+ -A ==> set architecture to 'arch'
+ -O ==> set operating system to 'os'
+ -T ==> set image type to 'type'
+ -C ==> set compression type 'comp'
+ -a ==> set load address to 'addr' (hex)
+ -e ==> set entry point to 'ep' (hex)
+ -n ==> set image name to 'name'
+ -d ==> use image data from 'datafile'
+
+Right now, all Linux kernels for PowerPC systems use the same load
+address (0x00000000), but the entry point address depends on the
+kernel version:
+
+- 2.2.x kernels have the entry point at 0x0000000C,
+- 2.3.x and later kernels have the entry point at 0x00000000.
+
+So a typical call to build a U-Boot image would read:
+
+ -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
+ > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
+ > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
+ > examples/uImage.TQM850L
+ Image Name: 2.4.4 kernel for TQM850L
+ Created: Wed Jul 19 02:34:59 2000
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
+ Load Address: 0x00000000
+ Entry Point: 0x00000000
+
+To verify the contents of the image (or check for corruption):
+
+ -> tools/mkimage -l examples/uImage.TQM850L
+ Image Name: 2.4.4 kernel for TQM850L
+ Created: Wed Jul 19 02:34:59 2000
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
+ Load Address: 0x00000000
+ Entry Point: 0x00000000
+
+NOTE: for embedded systems where boot time is critical you can trade
+speed for memory and install an UNCOMPRESSED image instead: this
+needs more space in Flash, but boots much faster since it does not
+need to be uncompressed:
+
+ -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
+ -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
+ > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
+ > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
+ > examples/uImage.TQM850L-uncompressed
+ Image Name: 2.4.4 kernel for TQM850L
+ Created: Wed Jul 19 02:34:59 2000
+ Image Type: PowerPC Linux Kernel Image (uncompressed)
+ Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
+ Load Address: 0x00000000
+ Entry Point: 0x00000000
+
+
+Similar you can build U-Boot images from a 'ramdisk.image.gz' file
+when your kernel is intended to use an initial ramdisk:
+
+ -> tools/mkimage -n 'Simple Ramdisk Image' \
+ > -A ppc -O linux -T ramdisk -C gzip \
+ > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
+ Image Name: Simple Ramdisk Image
+ Created: Wed Jan 12 14:01:50 2000
+ Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
+ Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
+ Load Address: 0x00000000
+ Entry Point: 0x00000000
+
+
+Installing a Linux Image:
+-------------------------
+
+To downloading a U-Boot image over the serial (console) interface,
+you must convert the image to S-Record format:
+
+ objcopy -I binary -O srec examples/image examples/image.srec
+
+The 'objcopy' does not understand the information in the U-Boot
+image header, so the resulting S-Record file will be relative to
+address 0x00000000. To load it to a given address, you need to
+specify the target address as 'offset' parameter with the 'loads'
+command.
+
+Example: install the image to address 0x40100000 (which on the
+TQM8xxL is in the first Flash bank):
+
+ => erase 40100000 401FFFFF
+
+ .......... done
+ Erased 8 sectors
+
+ => loads 40100000
+ ## Ready for S-Record download ...
+ ~>examples/image.srec
+ 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
+ ...
+ 15989 15990 15991 15992
+ [file transfer complete]
+ [connected]
+ ## Start Addr = 0x00000000
+
+
+You can check the success of the download using the 'iminfo' command;
+this includes a checksum verification so you can be sure no data
+corruption happened:
+
+ => imi 40100000
+
+ ## Checking Image at 40100000 ...
+ Image Name: 2.2.13 for initrd on TQM850L
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 335725 Bytes = 327 kB = 0 MB
+ Load Address: 00000000
+ Entry Point: 0000000c
+ Verifying Checksum ... OK
+
+
+Boot Linux:
+-----------
+
+The "bootm" command is used to boot an application that is stored in
+memory (RAM or Flash). In case of a Linux kernel image, the contents
+of the "bootargs" environment variable is passed to the kernel as
+parameters. You can check and modify this variable using the
+"printenv" and "setenv" commands:
+
+
+ => printenv bootargs
+ bootargs=root=/dev/ram
+
+ => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
+
+ => printenv bootargs
+ bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
+
+ => bootm 40020000
+ ## Booting Linux kernel at 40020000 ...
+ Image Name: 2.2.13 for NFS on TQM850L
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 381681 Bytes = 372 kB = 0 MB
+ Load Address: 00000000
+ Entry Point: 0000000c
+ Verifying Checksum ... OK
+ Uncompressing Kernel Image ... OK
+ Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
+ Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
+ time_init: decrementer frequency = 187500000/60
+ Calibrating delay loop... 49.77 BogoMIPS
+ Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
+ ...
+
+If you want to boot a Linux kernel with initial RAM disk, you pass
+the memory addresses of both the kernel and the initrd image (PPBCOOT
+format!) to the "bootm" command:
+
+ => imi 40100000 40200000
+
+ ## Checking Image at 40100000 ...
+ Image Name: 2.2.13 for initrd on TQM850L
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 335725 Bytes = 327 kB = 0 MB
+ Load Address: 00000000
+ Entry Point: 0000000c
+ Verifying Checksum ... OK
+
+ ## Checking Image at 40200000 ...
+ Image Name: Simple Ramdisk Image
+ Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
+ Data Size: 566530 Bytes = 553 kB = 0 MB
+ Load Address: 00000000
+ Entry Point: 00000000
+ Verifying Checksum ... OK
+
+ => bootm 40100000 40200000
+ ## Booting Linux kernel at 40100000 ...
+ Image Name: 2.2.13 for initrd on TQM850L
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 335725 Bytes = 327 kB = 0 MB
+ Load Address: 00000000
+ Entry Point: 0000000c
+ Verifying Checksum ... OK
+ Uncompressing Kernel Image ... OK
+ ## Loading RAMDisk Image at 40200000 ...
+ Image Name: Simple Ramdisk Image
+ Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
+ Data Size: 566530 Bytes = 553 kB = 0 MB
+ Load Address: 00000000
+ Entry Point: 00000000
+ Verifying Checksum ... OK
+ Loading Ramdisk ... OK
+ Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
+ Boot arguments: root=/dev/ram
+ time_init: decrementer frequency = 187500000/60
+ Calibrating delay loop... 49.77 BogoMIPS
+ ...
+ RAMDISK: Compressed image found at block 0
+ VFS: Mounted root (ext2 filesystem).
+
+ bash#
+
+Boot Linux and pass a flat device tree:
+-----------
+
+First, U-Boot must be compiled with the appropriate defines. See the section
+titled "Linux Kernel Interface" above for a more in depth explanation. The
+following is an example of how to start a kernel and pass an updated
+flat device tree:
+
+=> print oftaddr
+oftaddr=0x300000
+=> print oft
+oft=oftrees/mpc8540ads.dtb
+=> tftp $oftaddr $oft
+Speed: 1000, full duplex
+Using TSEC0 device
+TFTP from server 192.168.1.1; our IP address is 192.168.1.101
+Filename 'oftrees/mpc8540ads.dtb'.
+Load address: 0x300000
+Loading: #
+done
+Bytes transferred = 4106 (100a hex)
+=> tftp $loadaddr $bootfile
+Speed: 1000, full duplex
+Using TSEC0 device
+TFTP from server 192.168.1.1; our IP address is 192.168.1.2
+Filename 'uImage'.
+Load address: 0x200000
+Loading:############
+done
+Bytes transferred = 1029407 (fb51f hex)
+=> print loadaddr
+loadaddr=200000
+=> print oftaddr
+oftaddr=0x300000
+=> bootm $loadaddr - $oftaddr
+## Booting image at 00200000 ...
+ Image Name: Linux-2.6.17-dirty
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 1029343 Bytes = 1005.2 kB
+ Load Address: 00000000
+ Entry Point: 00000000
+ Verifying Checksum ... OK
+ Uncompressing Kernel Image ... OK
+Booting using flat device tree at 0x300000
+Using MPC85xx ADS machine description
+Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
+[snip]
+
+
+More About U-Boot Image Types:
+------------------------------
+
+U-Boot supports the following image types:
+
+ "Standalone Programs" are directly runnable in the environment
+ provided by U-Boot; it is expected that (if they behave
+ well) you can continue to work in U-Boot after return from
+ the Standalone Program.
+ "OS Kernel Images" are usually images of some Embedded OS which
+ will take over control completely. Usually these programs
+ will install their own set of exception handlers, device
+ drivers, set up the MMU, etc. - this means, that you cannot
+ expect to re-enter U-Boot except by resetting the CPU.
+ "RAMDisk Images" are more or less just data blocks, and their
+ parameters (address, size) are passed to an OS kernel that is
+ being started.
+ "Multi-File Images" contain several images, typically an OS
+ (Linux) kernel image and one or more data images like
+ RAMDisks. This construct is useful for instance when you want
+ to boot over the network using BOOTP etc., where the boot
+ server provides just a single image file, but you want to get
+ for instance an OS kernel and a RAMDisk image.
+
+ "Multi-File Images" start with a list of image sizes, each
+ image size (in bytes) specified by an "uint32_t" in network
+ byte order. This list is terminated by an "(uint32_t)0".
+ Immediately after the terminating 0 follow the images, one by
+ one, all aligned on "uint32_t" boundaries (size rounded up to
+ a multiple of 4 bytes).
+
+ "Firmware Images" are binary images containing firmware (like
+ U-Boot or FPGA images) which usually will be programmed to
+ flash memory.
+
+ "Script files" are command sequences that will be executed by
+ U-Boot's command interpreter; this feature is especially
+ useful when you configure U-Boot to use a real shell (hush)
+ as command interpreter.
+
+Booting the Linux zImage:
+-------------------------
+
+On some platforms, it's possible to boot Linux zImage. This is done
+using the "bootz" command. The syntax of "bootz" command is the same
+as the syntax of "bootm" command.
+
+Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
+kernel with raw initrd images. The syntax is slightly different, the
+address of the initrd must be augmented by it's size, in the following
+format: "<initrd addres>:<initrd size>".
+
+
+Standalone HOWTO:
+=================
+
+One of the features of U-Boot is that you can dynamically load and
+run "standalone" applications, which can use some resources of
+U-Boot like console I/O functions or interrupt services.
+
+Two simple examples are included with the sources:
+
+"Hello World" Demo:
+-------------------
+
+'examples/hello_world.c' contains a small "Hello World" Demo
+application; it is automatically compiled when you build U-Boot.
+It's configured to run at address 0x00040004, so you can play with it
+like that:
+
+ => loads
+ ## Ready for S-Record download ...
+ ~>examples/hello_world.srec
+ 1 2 3 4 5 6 7 8 9 10 11 ...
+ [file transfer complete]
+ [connected]
+ ## Start Addr = 0x00040004
+
+ => go 40004 Hello World! This is a test.
+ ## Starting application at 0x00040004 ...
+ Hello World
+ argc = 7
+ argv[0] = "40004"
+ argv[1] = "Hello"
+ argv[2] = "World!"
+ argv[3] = "This"
+ argv[4] = "is"
+ argv[5] = "a"
+ argv[6] = "test."
+ argv[7] = "<NULL>"
+ Hit any key to exit ...
+
+ ## Application terminated, rc = 0x0
+
+Another example, which demonstrates how to register a CPM interrupt
+handler with the U-Boot code, can be found in 'examples/timer.c'.
+Here, a CPM timer is set up to generate an interrupt every second.
+The interrupt service routine is trivial, just printing a '.'
+character, but this is just a demo program. The application can be
+controlled by the following keys:
+
+ ? - print current values og the CPM Timer registers
+ b - enable interrupts and start timer
+ e - stop timer and disable interrupts
+ q - quit application
+
+ => loads
+ ## Ready for S-Record download ...
+ ~>examples/timer.srec
+ 1 2 3 4 5 6 7 8 9 10 11 ...
+ [file transfer complete]
+ [connected]
+ ## Start Addr = 0x00040004
+
+ => go 40004
+ ## Starting application at 0x00040004 ...
+ TIMERS=0xfff00980
+ Using timer 1
+ tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
+
+Hit 'b':
+ [q, b, e, ?] Set interval 1000000 us
+ Enabling timer
+Hit '?':
+ [q, b, e, ?] ........
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
+Hit '?':
+ [q, b, e, ?] .
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
+Hit '?':
+ [q, b, e, ?] .
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
+Hit '?':
+ [q, b, e, ?] .
+ tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
+Hit 'e':
+ [q, b, e, ?] ...Stopping timer
+Hit 'q':
+ [q, b, e, ?] ## Application terminated, rc = 0x0
+
+
+Minicom warning:
+================
+
+Over time, many people have reported problems when trying to use the
+"minicom" terminal emulation program for serial download. I (wd)
+consider minicom to be broken, and recommend not to use it. Under
+Unix, I recommend to use C-Kermit for general purpose use (and
+especially for kermit binary protocol download ("loadb" command), and
+use "cu" for S-Record download ("loads" command). See
+http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
+for help with kermit.
+
+
+Nevertheless, if you absolutely want to use it try adding this
+configuration to your "File transfer protocols" section:
+
+ Name Program Name U/D FullScr IO-Red. Multi
+ X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
+ Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
+
+
+NetBSD Notes:
+=============
+
+Starting at version 0.9.2, U-Boot supports NetBSD both as host
+(build U-Boot) and target system (boots NetBSD/mpc8xx).
+
+Building requires a cross environment; it is known to work on
+NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
+need gmake since the Makefiles are not compatible with BSD make).
+Note that the cross-powerpc package does not install include files;
+attempting to build U-Boot will fail because <machine/ansi.h> is
+missing. This file has to be installed and patched manually:
+
+ # cd /usr/pkg/cross/powerpc-netbsd/include
+ # mkdir powerpc
+ # ln -s powerpc machine
+ # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
+ # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
+
+Native builds *don't* work due to incompatibilities between native
+and U-Boot include files.
+
+Booting assumes that (the first part of) the image booted is a
+stage-2 loader which in turn loads and then invokes the kernel
+proper. Loader sources will eventually appear in the NetBSD source
+tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
+meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
+
+
+Implementation Internals:
+=========================
+
+The following is not intended to be a complete description of every
+implementation detail. However, it should help to understand the
+inner workings of U-Boot and make it easier to port it to custom
+hardware.
+
+
+Initial Stack, Global Data:
+---------------------------
+
+The implementation of U-Boot is complicated by the fact that U-Boot
+starts running out of ROM (flash memory), usually without access to
+system RAM (because the memory controller is not initialized yet).
+This means that we don't have writable Data or BSS segments, and BSS
+is not initialized as zero. To be able to get a C environment working
+at all, we have to allocate at least a minimal stack. Implementation
+options for this are defined and restricted by the CPU used: Some CPU
+models provide on-chip memory (like the IMMR area on MPC8xx and
+MPC826x processors), on others (parts of) the data cache can be
+locked as (mis-) used as memory, etc.
+
+ Chris Hallinan posted a good summary of these issues to the
+ U-Boot mailing list:
+
+ Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
+ From: "Chris Hallinan" <clh@net1plus.com>
+ Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
+ ...
+
+ Correct me if I'm wrong, folks, but the way I understand it
+ is this: Using DCACHE as initial RAM for Stack, etc, does not
+ require any physical RAM backing up the cache. The cleverness
+ is that the cache is being used as a temporary supply of
+ necessary storage before the SDRAM controller is setup. It's
+ beyond the scope of this list to explain the details, but you
+ can see how this works by studying the cache architecture and
+ operation in the architecture and processor-specific manuals.
+
+ OCM is On Chip Memory, which I believe the 405GP has 4K. It
+ is another option for the system designer to use as an
+ initial stack/RAM area prior to SDRAM being available. Either
+ option should work for you. Using CS 4 should be fine if your
+ board designers haven't used it for something that would
+ cause you grief during the initial boot! It is frequently not
+ used.
+
+ CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
+ with your processor/board/system design. The default value
+ you will find in any recent u-boot distribution in
+ walnut.h should work for you. I'd set it to a value larger
+ than your SDRAM module. If you have a 64MB SDRAM module, set
+ it above 400_0000. Just make sure your board has no resources
+ that are supposed to respond to that address! That code in
+ start.S has been around a while and should work as is when
+ you get the config right.
+
+ -Chris Hallinan
+ DS4.COM, Inc.
+
+It is essential to remember this, since it has some impact on the C
+code for the initialization procedures:
+
+* Initialized global data (data segment) is read-only. Do not attempt
+ to write it.
+
+* Do not use any uninitialized global data (or implicitely initialized
+ as zero data - BSS segment) at all - this is undefined, initiali-
+ zation is performed later (when relocating to RAM).
+
+* Stack space is very limited. Avoid big data buffers or things like
+ that.
+
+Having only the stack as writable memory limits means we cannot use
+normal global data to share information beween the code. But it
+turned out that the implementation of U-Boot can be greatly
+simplified by making a global data structure (gd_t) available to all
+functions. We could pass a pointer to this data as argument to _all_
+functions, but this would bloat the code. Instead we use a feature of
+the GCC compiler (Global Register Variables) to share the data: we
+place a pointer (gd) to the global data into a register which we
+reserve for this purpose.
+
+When choosing a register for such a purpose we are restricted by the
+relevant (E)ABI specifications for the current architecture, and by
+GCC's implementation.
+
+For PowerPC, the following registers have specific use:
+ R1: stack pointer
+ R2: reserved for system use
+ R3-R4: parameter passing and return values
+ R5-R10: parameter passing
+ R13: small data area pointer
+ R30: GOT pointer
+ R31: frame pointer
+
+ (U-Boot also uses R12 as internal GOT pointer. r12
+ is a volatile register so r12 needs to be reset when
+ going back and forth between asm and C)
+
+ ==> U-Boot will use R2 to hold a pointer to the global data
+
+ Note: on PPC, we could use a static initializer (since the
+ address of the global data structure is known at compile time),
+ but it turned out that reserving a register results in somewhat
+ smaller code - although the code savings are not that big (on
+ average for all boards 752 bytes for the whole U-Boot image,
+ 624 text + 127 data).
+
+On Blackfin, the normal C ABI (except for P3) is followed as documented here:
+ http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
+
+ ==> U-Boot will use P3 to hold a pointer to the global data
+
+On ARM, the following registers are used:
+
+ R0: function argument word/integer result
+ R1-R3: function argument word
+ R9: GOT pointer
+ R10: stack limit (used only if stack checking if enabled)
+ R11: argument (frame) pointer
+ R12: temporary workspace
+ R13: stack pointer
+ R14: link register
+ R15: program counter
+
+ ==> U-Boot will use R8 to hold a pointer to the global data
+
+On Nios II, the ABI is documented here:
+ http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
+
+ ==> U-Boot will use gp to hold a pointer to the global data
+
+ Note: on Nios II, we give "-G0" option to gcc and don't use gp
+ to access small data sections, so gp is free.
+
+On NDS32, the following registers are used:
+
+ R0-R1: argument/return
+ R2-R5: argument
+ R15: temporary register for assembler
+ R16: trampoline register
+ R28: frame pointer (FP)
+ R29: global pointer (GP)
+ R30: link register (LP)
+ R31: stack pointer (SP)
+ PC: program counter (PC)
+
+ ==> U-Boot will use R10 to hold a pointer to the global data
+
+NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
+or current versions of GCC may "optimize" the code too much.
+
+Memory Management:
+------------------
+
+U-Boot runs in system state and uses physical addresses, i.e. the
+MMU is not used either for address mapping nor for memory protection.
+
+The available memory is mapped to fixed addresses using the memory
+controller. In this process, a contiguous block is formed for each
+memory type (Flash, SDRAM, SRAM), even when it consists of several
+physical memory banks.
+
+U-Boot is installed in the first 128 kB of the first Flash bank (on
+TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
+booting and sizing and initializing DRAM, the code relocates itself
+to the upper end of DRAM. Immediately below the U-Boot code some
+memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
+configuration setting]. Below that, a structure with global Board
+Info data is placed, followed by the stack (growing downward).
+
+Additionally, some exception handler code is copied to the low 8 kB
+of DRAM (0x00000000 ... 0x00001FFF).
+
+So a typical memory configuration with 16 MB of DRAM could look like
+this:
+
+ 0x0000 0000 Exception Vector code
+ :
+ 0x0000 1FFF
+ 0x0000 2000 Free for Application Use
+ :
+ :
+
+ :
+ :
+ 0x00FB FF20 Monitor Stack (Growing downward)
+ 0x00FB FFAC Board Info Data and permanent copy of global data
+ 0x00FC 0000 Malloc Arena
+ :
+ 0x00FD FFFF
+ 0x00FE 0000 RAM Copy of Monitor Code
+ ... eventually: LCD or video framebuffer
+ ... eventually: pRAM (Protected RAM - unchanged by reset)
+ 0x00FF FFFF [End of RAM]
+
+
+System Initialization:
+----------------------
+
+In the reset configuration, U-Boot starts at the reset entry point
+(on most PowerPC systems at address 0x00000100). Because of the reset
+configuration for CS0# this is a mirror of the onboard Flash memory.
+To be able to re-map memory U-Boot then jumps to its link address.
+To be able to implement the initialization code in C, a (small!)
+initial stack is set up in the internal Dual Ported RAM (in case CPUs
+which provide such a feature like MPC8xx or MPC8260), or in a locked
+part of the data cache. After that, U-Boot initializes the CPU core,
+the caches and the SIU.
+
+Next, all (potentially) available memory banks are mapped using a
+preliminary mapping. For example, we put them on 512 MB boundaries
+(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
+on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
+programmed for SDRAM access. Using the temporary configuration, a
+simple memory test is run that determines the size of the SDRAM
+banks.
+
+When there is more than one SDRAM bank, and the banks are of
+different size, the largest is mapped first. For equal size, the first
+bank (CS2#) is mapped first. The first mapping is always for address
+0x00000000, with any additional banks following immediately to create
+contiguous memory starting from 0.
+
+Then, the monitor installs itself at the upper end of the SDRAM area
+and allocates memory for use by malloc() and for the global Board
+Info data; also, the exception vector code is copied to the low RAM
+pages, and the final stack is set up.
+
+Only after this relocation will you have a "normal" C environment;
+until that you are restricted in several ways, mostly because you are
+running from ROM, and because the code will have to be relocated to a
+new address in RAM.
+
+
+U-Boot Porting Guide:
+----------------------
+
+[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
+list, October 2002]
+
+
+int main(int argc, char *argv[])
+{
+ sighandler_t no_more_time;
+
+ signal(SIGALRM, no_more_time);
+ alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
+
+ if (available_money > available_manpower) {
+ Pay consultant to port U-Boot;
+ return 0;
+ }
+
+ Download latest U-Boot source;
+
+ Subscribe to u-boot mailing list;
+
+ if (clueless)
+ email("Hi, I am new to U-Boot, how do I get started?");
+
+ while (learning) {
+ Read the README file in the top level directory;
+ Read http://www.denx.de/twiki/bin/view/DULG/Manual;
+ Read applicable doc/*.README;
+ Read the source, Luke;
+ /* find . -name "*.[chS]" | xargs grep -i <keyword> */
+ }
+
+ if (available_money > toLocalCurrency ($2500))
+ Buy a BDI3000;
+ else
+ Add a lot of aggravation and time;
+
+ if (a similar board exists) { /* hopefully... */
+ cp -a board/<similar> board/<myboard>
+ cp include/configs/<similar>.h include/configs/<myboard>.h
+ } else {
+ Create your own board support subdirectory;
+ Create your own board include/configs/<myboard>.h file;
+ }
+ Edit new board/<myboard> files
+ Edit new include/configs/<myboard>.h
+
+ while (!accepted) {
+ while (!running) {
+ do {
+ Add / modify source code;
+ } until (compiles);
+ Debug;
+ if (clueless)
+ email("Hi, I am having problems...");
+ }
+ Send patch file to the U-Boot email list;
+ if (reasonable critiques)
+ Incorporate improvements from email list code review;
+ else
+ Defend code as written;
+ }
+
+ return 0;
+}
+
+void no_more_time (int sig)
+{
+ hire_a_guru();
+}
+
+
+Coding Standards:
+-----------------
+
+All contributions to U-Boot should conform to the Linux kernel
+coding style; see the file "Documentation/CodingStyle" and the script
+"scripts/Lindent" in your Linux kernel source directory.
+
+Source files originating from a different project (for example the
+MTD subsystem) are generally exempt from these guidelines and are not
+reformated to ease subsequent migration to newer versions of those
+sources.
+
+Please note that U-Boot is implemented in C (and to some small parts in
+Assembler); no C++ is used, so please do not use C++ style comments (//)
+in your code.
+
+Please also stick to the following formatting rules:
+- remove any trailing white space
+- use TAB characters for indentation and vertical alignment, not spaces
+- make sure NOT to use DOS '\r\n' line feeds
+- do not add more than 2 consecutive empty lines to source files
+- do not add trailing empty lines to source files
+
+Submissions which do not conform to the standards may be returned
+with a request to reformat the changes.
+
+
+Submitting Patches:
+-------------------
+
+Since the number of patches for U-Boot is growing, we need to
+establish some rules. Submissions which do not conform to these rules
+may be rejected, even when they contain important and valuable stuff.
+
+Please see http://www.denx.de/wiki/U-Boot/Patches for details.
+
+Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
+see http://lists.denx.de/mailman/listinfo/u-boot
+
+When you send a patch, please include the following information with
+it:
+
+* For bug fixes: a description of the bug and how your patch fixes
+ this bug. Please try to include a way of demonstrating that the
+ patch actually fixes something.
+
+* For new features: a description of the feature and your
+ implementation.
+
+* A CHANGELOG entry as plaintext (separate from the patch)
+
+* For major contributions, your entry to the CREDITS file
+
+* When you add support for a new board, don't forget to add this
+ board to the MAINTAINERS file, too.
+
+* If your patch adds new configuration options, don't forget to
+ document these in the README file.
+
+* The patch itself. If you are using git (which is *strongly*
+ recommended) you can easily generate the patch using the
+ "git format-patch". If you then use "git send-email" to send it to
+ the U-Boot mailing list, you will avoid most of the common problems
+ with some other mail clients.
+
+ If you cannot use git, use "diff -purN OLD NEW". If your version of
+ diff does not support these options, then get the latest version of
+ GNU diff.
+
+ The current directory when running this command shall be the parent
+ directory of the U-Boot source tree (i. e. please make sure that
+ your patch includes sufficient directory information for the
+ affected files).
+
+ We prefer patches as plain text. MIME attachments are discouraged,
+ and compressed attachments must not be used.
+
+* If one logical set of modifications affects or creates several
+ files, all these changes shall be submitted in a SINGLE patch file.
+
+* Changesets that contain different, unrelated modifications shall be
+ submitted as SEPARATE patches, one patch per changeset.
+
+
+Notes:
+
+* Before sending the patch, run the MAKEALL script on your patched
+ source tree and make sure that no errors or warnings are reported
+ for any of the boards.
+
+* Keep your modifications to the necessary minimum: A patch
+ containing several unrelated changes or arbitrary reformats will be
+ returned with a request to re-formatting / split it.
+
+* If you modify existing code, make sure that your new code does not
+ add to the memory footprint of the code ;-) Small is beautiful!
+ When adding new features, these should compile conditionally only
+ (using #ifdef), and the resulting code with the new feature
+ disabled must not need more memory than the old code without your
+ modification.
+
+* Remember that there is a size limit of 100 kB per message on the
+ u-boot mailing list. Bigger patches will be moderated. If they are
+ reasonable and not too big, they will be acknowledged. But patches
+ bigger than the size limit should be avoided.
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