blackfin architecture

This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix!  Tinyboards.

The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc.  (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000.  Since then ADI has put this core into its Blackfin
processor family of devices.  The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set.  It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.

The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdf

The Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibc

This patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/

We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel

[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 774 insertions, 0 deletions

diff --git a/arch/blackfin/mach-bf533/head.S b/arch/blackfin/mach-bf533/head.S
new file mode 100644
index 0000000..4808edb
--- /dev/null
+++ b/arch/blackfin/mach-bf533/head.S
@@ -0,0 +1,774 @@
+/*
+ * File:         arch/blackfin/mach-bf533/head.S
+ * Based on:
+ * Author:       Jeff Dionne <jeff@uclinux.org> COPYRIGHT 1998 D. Jeff Dionne
+ *
+ * Created:      1998
+ * Description:  bf533 startup file
+ *
+ * Modified:
+ *               Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/linkage.h>
+#include <asm/blackfin.h>
+#if CONFIG_BFIN_KERNEL_CLOCK
+#include <asm/mach/mem_init.h>
+#endif
+#if CONFIG_DEBUG_KERNEL_START
+#include <asm/mach-common/def_LPBlackfin.h>
+#endif
+
+.global __rambase
+.global __ramstart
+.global __ramend
+.extern ___bss_stop
+.extern ___bss_start
+.extern _bf53x_relocate_l1_mem
+
+#define INITIAL_STACK	0xFFB01000
+
+.text
+
+ENTRY(__start)
+ENTRY(__stext)
+	/* R0: argument of command line string, passed from uboot, save it */
+	R7 = R0;
+	/* Set the SYSCFG register */
+	R0 = 0x36;
+	/*Enable Cycle Counter and Nesting Of Interrupts(3rd Bit)*/
+	SYSCFG = R0;
+	R0 = 0;
+
+	/*Clear Out All the data and pointer  Registers*/
+	R1 = R0;
+	R2 = R0;
+	R3 = R0;
+	R4 = R0;
+	R5 = R0;
+	R6 = R0;
+
+	P0 = R0;
+	P1 = R0;
+	P2 = R0;
+	P3 = R0;
+	P4 = R0;
+	P5 = R0;
+
+	LC0 = r0;
+	LC1 = r0;
+	L0 = r0;
+	L1 = r0;
+	L2 = r0;
+	L3 = r0;
+
+	/* Clear Out All the DAG Registers*/
+	B0 = r0;
+	B1 = r0;
+	B2 = r0;
+	B3 = r0;
+
+	I0 = r0;
+	I1 = r0;
+	I2 = r0;
+	I3 = r0;
+
+	M0 = r0;
+	M1 = r0;
+	M2 = r0;
+	M3 = r0;
+
+#if CONFIG_DEBUG_KERNEL_START
+
+/*
+ * Set up a temporary Event Vector Table, so if something bad happens before
+ * the kernel is fully started, it doesn't vector off into the bootloaders
+ * table
+ */
+	P0.l = lo(EVT2);
+	P0.h = hi(EVT2);
+	P1.l = lo(EVT15);
+	P1.h = hi(EVT15);
+	P2.l = debug_kernel_start_trap;
+	P2.h = debug_kernel_start_trap;
+
+	RTS = P2;
+	RTI = P2;
+	RTX = P2;
+	RTN = P2;
+	RTE = P2;
+
+.Lfill_temp_vector_table:
+	[P0++] = P2;	/* Core Event Vector Table */
+	CC = P0 == P1;
+	if !CC JUMP .Lfill_temp_vector_table
+	P0 = r0;
+	P1 = r0;
+	P2 = r0;
+
+#endif
+
+	p0.h = hi(FIO_MASKA_C);
+	p0.l = lo(FIO_MASKA_C);
+	r0 = 0xFFFF(Z);
+	w[p0] = r0.L;	/* Disable all interrupts */
+	ssync;
+
+	p0.h = hi(FIO_MASKB_C);
+	p0.l = lo(FIO_MASKB_C);
+	r0 = 0xFFFF(Z);
+	w[p0] = r0.L;	/* Disable all interrupts */
+	ssync;
+
+	/* Turn off the icache */
+	p0.l = (IMEM_CONTROL & 0xFFFF);
+	p0.h = (IMEM_CONTROL >> 16);
+	R1 = [p0];
+	R0 = ~ENICPLB;
+	R0 = R0 & R1;
+
+	/* Anomaly 05000125 */
+#ifdef ANOMALY_05000125
+	CLI R2;
+	SSYNC;
+#endif
+	[p0] = R0;
+	SSYNC;
+#ifdef ANOMALY_05000125
+	STI R2;
+#endif
+
+	/* Turn off the dcache */
+	p0.l = (DMEM_CONTROL & 0xFFFF);
+	p0.h = (DMEM_CONTROL >> 16);
+	R1 = [p0];
+	R0 = ~ENDCPLB;
+	R0 = R0 & R1;
+
+	/* Anomaly 05000125 */
+#ifdef ANOMALY_05000125
+	CLI R2;
+	SSYNC;
+#endif
+	[p0] = R0;
+	SSYNC;
+#ifdef ANOMALY_05000125
+	STI R2;
+#endif
+
+	/* Initialise UART */
+	p0.h = hi(UART_LCR);
+	p0.l = lo(UART_LCR);
+	r0 = 0x0(Z);
+	w[p0] = r0.L;	/* To enable DLL writes */
+	ssync;
+
+	p0.h = hi(UART_DLL);
+	p0.l = lo(UART_DLL);
+	r0 = 0x0(Z);
+	w[p0] = r0.L;
+	ssync;
+
+	p0.h = hi(UART_DLH);
+	p0.l = lo(UART_DLH);
+	r0 = 0x00(Z);
+	w[p0] = r0.L;
+	ssync;
+
+	p0.h = hi(UART_GCTL);
+	p0.l = lo(UART_GCTL);
+	r0 = 0x0(Z);
+	w[p0] = r0.L;	/* To enable UART clock */
+	ssync;
+
+	/* Initialize stack pointer */
+	sp.l = lo(INITIAL_STACK);
+	sp.h = hi(INITIAL_STACK);
+	fp = sp;
+	usp = sp;
+
+	/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
+	call _bf53x_relocate_l1_mem;
+#if CONFIG_BFIN_KERNEL_CLOCK
+	call _start_dma_code;
+#endif
+
+	/* Code for initializing Async memory banks */
+
+	p2.h = hi(EBIU_AMBCTL1);
+	p2.l = lo(EBIU_AMBCTL1);
+	r0.h = hi(AMBCTL1VAL);
+	r0.l = lo(AMBCTL1VAL);
+	[p2] = r0;
+	ssync;
+
+	p2.h = hi(EBIU_AMBCTL0);
+	p2.l = lo(EBIU_AMBCTL0);
+	r0.h = hi(AMBCTL0VAL);
+	r0.l = lo(AMBCTL0VAL);
+	[p2] = r0;
+	ssync;
+
+	p2.h = hi(EBIU_AMGCTL);
+	p2.l = lo(EBIU_AMGCTL);
+	r0 = AMGCTLVAL;
+	w[p2] = r0;
+	ssync;
+
+	/* This section keeps the processor in supervisor mode
+	 * during kernel boot.  Switches to user mode at end of boot.
+	 * See page 3-9 of Hardware Reference manual for documentation.
+	 */
+
+	/* EVT15 = _real_start */
+
+	p0.l = lo(EVT15);
+	p0.h = hi(EVT15);
+	p1.l = _real_start;
+	p1.h = _real_start;
+	[p0] = p1;
+	csync;
+
+	p0.l = lo(IMASK);
+	p0.h = hi(IMASK);
+	p1.l = IMASK_IVG15;
+	p1.h = 0x0;
+	[p0] = p1;
+	csync;
+
+	raise 15;
+	p0.l = .LWAIT_HERE;
+	p0.h = .LWAIT_HERE;
+	reti = p0;
+#if defined(ANOMALY_05000281)
+	nop; nop; nop;
+#endif
+	rti;
+
+.LWAIT_HERE:
+	jump .LWAIT_HERE;
+
+ENTRY(_real_start)
+	[ -- sp ] = reti;
+	p0.l = lo(WDOG_CTL);
+	p0.h = hi(WDOG_CTL);
+	r0 = 0xAD6(z);
+	w[p0] = r0;	/* watchdog off for now */
+	ssync;
+
+	/* Code update for BSS size == 0
+	 * Zero out the bss region.
+	 */
+
+	p1.l = ___bss_start;
+	p1.h = ___bss_start;
+	p2.l = ___bss_stop;
+	p2.h = ___bss_stop;
+	r0 = 0;
+	p2 -= p1;
+	lsetup (.L_clear_bss, .L_clear_bss) lc0 = p2;
+.L_clear_bss:
+	B[p1++] = r0;
+
+	/* In case there is a NULL pointer reference
+	 * Zero out region before stext
+	 */
+
+	p1.l = 0x0;
+	p1.h = 0x0;
+	r0.l = __stext;
+	r0.h = __stext;
+	r0 = r0 >> 1;
+	p2 = r0;
+	r0 = 0;
+	lsetup (.L_clear_zero, .L_clear_zero) lc0 = p2;
+.L_clear_zero:
+	W[p1++] = r0;
+
+/* pass the uboot arguments to the global value command line */
+	R0 = R7;
+	call _cmdline_init;
+
+	p1.l = __rambase;
+	p1.h = __rambase;
+	r0.l = __sdata;
+	r0.h = __sdata;
+	[p1] = r0;
+
+	p1.l = __ramstart;
+	p1.h = __ramstart;
+	p3.l = ___bss_stop;
+	p3.h = ___bss_stop;
+
+	r1 = p3;
+	[p1] = r1;
+
+	/*
+	 *  load the current thread pointer and stack
+	 */
+	r1.l = _init_thread_union;
+	r1.h = _init_thread_union;
+
+	r2.l = 0x2000;
+	r2.h = 0x0000;
+	r1 = r1 + r2;
+	sp = r1;
+	usp = sp;
+	fp = sp;
+	call _start_kernel;
+.L_exit:
+	jump.s	.L_exit;
+
+.section .l1.text
+#if CONFIG_BFIN_KERNEL_CLOCK
+ENTRY(_start_dma_code)
+	p0.h = hi(SIC_IWR);
+	p0.l = lo(SIC_IWR);
+	r0.l = 0x1;
+	r0.h = 0x0;
+	[p0] = r0;
+	SSYNC;
+
+	/*
+	 *  Set PLL_CTL
+	 *   - [14:09] = MSEL[5:0] : CLKIN / VCO multiplication factors
+	 *   - [8]     = BYPASS    : BYPASS the PLL, run CLKIN into CCLK/SCLK
+	 *   - [7]     = output delay (add 200ps of delay to mem signals)
+	 *   - [6]     = input delay (add 200ps of input delay to mem signals)
+	 *   - [5]     = PDWN      : 1=All Clocks off
+	 *   - [3]     = STOPCK    : 1=Core Clock off
+	 *   - [1]     = PLL_OFF   : 1=Disable Power to PLL
+	 *   - [0]     = DF        : 1=Pass CLKIN/2 to PLL / 0=Pass CLKIN to PLL
+	 *   all other bits set to zero
+	 */
+
+	p0.h = hi(PLL_LOCKCNT);
+	p0.l = lo(PLL_LOCKCNT);
+	r0 = 0x300(Z);
+	w[p0] = r0.l;
+	ssync;
+
+	P2.H = hi(EBIU_SDGCTL);
+	P2.L = lo(EBIU_SDGCTL);
+	R0 = [P2];
+	BITSET (R0, 24);
+	[P2] = R0;
+	SSYNC;
+
+	r0 = CONFIG_VCO_MULT & 63;       /* Load the VCO multiplier         */
+	r0 = r0 << 9;                    /* Shift it over,                  */
+	r1 = CLKIN_HALF;                 /* Do we need to divide CLKIN by 2?*/
+	r0 = r1 | r0;
+	r1 = PLL_BYPASS;                 /* Bypass the PLL?                 */
+	r1 = r1 << 8;                    /* Shift it over                   */
+	r0 = r1 | r0;                    /* add them all together           */
+
+	p0.h = hi(PLL_CTL);
+	p0.l = lo(PLL_CTL);              /* Load the address                */
+	cli r2;                          /* Disable interrupts              */
+	ssync;
+	w[p0] = r0.l;                    /* Set the value                   */
+	idle;                            /* Wait for the PLL to stablize    */
+	sti r2;                          /* Enable interrupts               */
+
+.Lcheck_again:
+	p0.h = hi(PLL_STAT);
+	p0.l = lo(PLL_STAT);
+	R0 = W[P0](Z);
+	CC = BITTST(R0,5);
+	if ! CC jump .Lcheck_again;
+
+	/* Configure SCLK & CCLK Dividers */
+	r0 = (CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
+	p0.h = hi(PLL_DIV);
+	p0.l = lo(PLL_DIV);
+	w[p0] = r0.l;
+	ssync;
+
+	p0.l = lo(EBIU_SDRRC);
+	p0.h = hi(EBIU_SDRRC);
+	r0 = mem_SDRRC;
+	w[p0] = r0.l;
+	ssync;
+
+	p0.l = (EBIU_SDBCTL & 0xFFFF);
+	p0.h = (EBIU_SDBCTL >> 16);     /* SDRAM Memory Bank Control Register */
+	r0 = mem_SDBCTL;
+	w[p0] = r0.l;
+	ssync;
+
+	P2.H = hi(EBIU_SDGCTL);
+	P2.L = lo(EBIU_SDGCTL);
+	R0 = [P2];
+	BITCLR (R0, 24);
+	p0.h = hi(EBIU_SDSTAT);
+	p0.l = lo(EBIU_SDSTAT);
+	r2.l = w[p0];
+	cc = bittst(r2,3);
+	if !cc jump .Lskip;
+	NOP;
+	BITSET (R0, 23);
+.Lskip:
+	[P2] = R0;
+	SSYNC;
+
+	R0.L = lo(mem_SDGCTL);
+	R0.H = hi(mem_SDGCTL);
+	R1 = [p2];
+	R1 = R1 | R0;
+	[P2] = R1;
+	SSYNC;
+
+	p0.h = hi(SIC_IWR);
+	p0.l = lo(SIC_IWR);
+	r0.l = lo(IWR_ENABLE_ALL)
+	r0.h = hi(IWR_ENABLE_ALL)
+	[p0] = r0;
+	SSYNC;
+
+	RTS;
+#endif /* CONFIG_BFIN_KERNEL_CLOCK */
+
+ENTRY(_bfin_reset)
+	/* No more interrupts to be handled*/
+	CLI R6;
+	SSYNC;
+
+#if defined(CONFIG_BFIN_SHARED_FLASH_ENET)
+	p0.h = hi(FIO_INEN);
+	p0.l = lo(FIO_INEN);
+	r0.l = ~(1 << CONFIG_ENET_FLASH_PIN);
+	w[p0] = r0.l;
+
+	p0.h = hi(FIO_DIR);
+	p0.l = lo(FIO_DIR);
+	r0.l = (1 << CONFIG_ENET_FLASH_PIN);
+	w[p0] = r0.l;
+
+	p0.h = hi(FIO_FLAG_C);
+	p0.l = lo(FIO_FLAG_C);
+	r0.l = (1 << CONFIG_ENET_FLASH_PIN);
+	w[p0] = r0.l;
+#endif
+
+	/* Clear the bits 13-15 in SWRST if they werent cleared */
+	p0.h = hi(SWRST);
+	p0.l = lo(SWRST);
+	csync;
+	r0.l = w[p0];
+
+	/* Clear the IMASK register */
+	p0.h = hi(IMASK);
+	p0.l = lo(IMASK);
+	r0 = 0x0;
+	[p0] = r0;
+
+	/* Clear the ILAT register */
+	p0.h = hi(ILAT);
+	p0.l = lo(ILAT);
+	r0 = [p0];
+	[p0] = r0;
+	SSYNC;
+
+	/* Disable the WDOG TIMER */
+	p0.h = hi(WDOG_CTL);
+	p0.l = lo(WDOG_CTL);
+	r0.l = 0xAD6;
+	w[p0] = r0.l;
+	SSYNC;
+
+	/* Clear the sticky bit incase it is already set */
+	p0.h = hi(WDOG_CTL);
+	p0.l = lo(WDOG_CTL);
+	r0.l = 0x8AD6;
+	w[p0] = r0.l;
+	SSYNC;
+
+	/* Program the count value */
+	R0.l = 0x100;
+	R0.h = 0x0;
+	P0.h = hi(WDOG_CNT);
+	P0.l = lo(WDOG_CNT);
+	[P0] = R0;
+	SSYNC;
+
+	/* Program WDOG_STAT if necessary */
+	P0.h = hi(WDOG_CTL);
+	P0.l = lo(WDOG_CTL);
+	R0 = W[P0](Z);
+	CC = BITTST(R0,1);
+	if !CC JUMP .LWRITESTAT;
+	CC = BITTST(R0,2);
+	if !CC JUMP .LWRITESTAT;
+	JUMP .LSKIP_WRITE;
+
+.LWRITESTAT:
+	/* When watch dog timer is enabled, a write to STAT will load the contents of CNT to STAT */
+	R0 = 0x0000(z);
+	P0.h = hi(WDOG_STAT);
+	P0.l = lo(WDOG_STAT)
+	[P0] = R0;
+	SSYNC;
+
+.LSKIP_WRITE:
+	/* Enable the reset event */
+	P0.h = hi(WDOG_CTL);
+	P0.l = lo(WDOG_CTL);
+	R0 = W[P0](Z);
+	BITCLR(R0,1);
+	BITCLR(R0,2);
+	W[P0] = R0.L;
+	SSYNC;
+	NOP;
+
+	/* Enable the wdog counter */
+	R0 = W[P0](Z);
+	BITCLR(R0,4);
+	W[P0] = R0.L;
+	SSYNC;
+
+	IDLE;
+
+	RTS;
+
+#if CONFIG_DEBUG_KERNEL_START
+debug_kernel_start_trap:
+	/* Set up a temp stack in L1 - SDRAM might not be working  */
+	P0.L = lo(L1_DATA_A_START + 0x100);
+	P0.H = hi(L1_DATA_A_START + 0x100);
+	SP = P0;
+
+	/* Make sure the Clocks are the way I think they should be */
+	r0 = CONFIG_VCO_MULT & 63;       /* Load the VCO multiplier         */
+	r0 = r0 << 9;                    /* Shift it over,                  */
+	r1 = CLKIN_HALF;                 /* Do we need to divide CLKIN by 2?*/
+	r0 = r1 | r0;
+	r1 = PLL_BYPASS;                 /* Bypass the PLL?                 */
+	r1 = r1 << 8;                    /* Shift it over                   */
+	r0 = r1 | r0;                    /* add them all together           */
+
+	p0.h = hi(PLL_CTL);
+	p0.l = lo(PLL_CTL);              /* Load the address                */
+	cli r2;                          /* Disable interrupts              */
+	ssync;
+	w[p0] = r0.l;                    /* Set the value                   */
+	idle;                            /* Wait for the PLL to stablize    */
+	sti r2;                          /* Enable interrupts               */
+
+.Lcheck_again1:
+	p0.h = hi(PLL_STAT);
+	p0.l = lo(PLL_STAT);
+	R0 = W[P0](Z);
+	CC = BITTST(R0,5);
+	if ! CC jump .Lcheck_again1;
+
+	/* Configure SCLK & CCLK Dividers */
+	r0 = (CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
+	p0.h = hi(PLL_DIV);
+	p0.l = lo(PLL_DIV);
+	w[p0] = r0.l;
+	ssync;
+
+	/* Make sure UART is enabled - you can never be sure */
+
+/*
+ * Setup for console. Argument comes from the menuconfig
+ */
+
+#ifdef CONFIG_BAUD_9600
+#define CONSOLE_BAUD_RATE       9600
+#elif CONFIG_BAUD_19200
+#define CONSOLE_BAUD_RATE       19200
+#elif CONFIG_BAUD_38400
+#define CONSOLE_BAUD_RATE       38400
+#elif CONFIG_BAUD_57600
+#define CONSOLE_BAUD_RATE       57600
+#elif CONFIG_BAUD_115200
+#define CONSOLE_BAUD_RATE       115200
+#endif
+
+	p0.h = hi(UART_GCTL);
+	p0.l = lo(UART_GCTL);
+	r0 = 0x00(Z);
+	w[p0] = r0.L;   /* To Turn off UART clocks */
+	ssync;
+
+	p0.h = hi(UART_LCR);
+	p0.l = lo(UART_LCR);
+	r0 = 0x83(Z);
+	w[p0] = r0.L;   /* To enable DLL writes */
+	ssync;
+
+	R1 = (((CONFIG_CLKIN_HZ * CONFIG_VCO_MULT) / CONFIG_SCLK_DIV) / (CONSOLE_BAUD_RATE * 16));
+
+	p0.h = hi(UART_DLL);
+	p0.l = lo(UART_DLL);
+	r0 = 0xFF(Z);
+	r0 = R1 & R0;
+	w[p0] = r0.L;
+	ssync;
+
+	p0.h = hi(UART_DLH);
+	p0.l = lo(UART_DLH);
+	r1 >>= 8 ;
+	w[p0] = r1.L;
+	ssync;
+
+	p0.h = hi(UART_GCTL);
+	p0.l = lo(UART_GCTL);
+	r0 = 0x0(Z);
+	w[p0] = r0.L;   /* To enable UART clock */
+	ssync;
+
+	p0.h = hi(UART_LCR);
+	p0.l = lo(UART_LCR);
+	r0 = 0x03(Z);
+	w[p0] = r0.L;   /* To Turn on UART */
+	ssync;
+
+	p0.h = hi(UART_GCTL);
+	p0.l = lo(UART_GCTL);
+	r0 = 0x01(Z);
+	w[p0] = r0.L;   /* To Turn on UART Clocks */
+	ssync;
+
+	P0.h = hi(UART_THR);
+	P0.l = lo(UART_THR);
+	P1.h = hi(UART_LSR);
+	P1.l = lo(UART_LSR);
+
+	R0.L = 'K';
+	call .Lwait_char;
+	R0.L='e';
+	call .Lwait_char;
+	R0.L='r';
+	call .Lwait_char;
+	R0.L='n'
+	call .Lwait_char;
+	R0.L='e'
+	call .Lwait_char;
+	R0.L='l';
+	call .Lwait_char;
+	R0.L=' ';
+	call .Lwait_char;
+	R0.L='c';
+	call .Lwait_char;
+	R0.L='r';
+	call .Lwait_char;
+	R0.L='a';
+	call .Lwait_char;
+	R0.L='s';
+	call .Lwait_char;
+	R0.L='h';
+	call .Lwait_char;
+	R0.L='\r';
+	call .Lwait_char;
+	R0.L='\n';
+	call .Lwait_char;
+
+	R0.L='S';
+	call .Lwait_char;
+	R0.L='E';
+	call .Lwait_char;
+	R0.L='Q'
+	call .Lwait_char;
+	R0.L='S'
+	call .Lwait_char;
+	R0.L='T';
+	call .Lwait_char;
+	R0.L='A';
+	call .Lwait_char;
+	R0.L='T';
+	call .Lwait_char;
+	R0.L='=';
+	call .Lwait_char;
+	R2 = SEQSTAT;
+	call .Ldump_reg;
+
+	R0.L=' ';
+	call .Lwait_char;
+	R0.L='R';
+	call .Lwait_char;
+	R0.L='E'
+	call .Lwait_char;
+	R0.L='T'
+	call .Lwait_char;
+	R0.L='X';
+	call .Lwait_char;
+	R0.L='=';
+	call .Lwait_char;
+	R2 = RETX;
+	call .Ldump_reg;
+
+	R0.L='\r';
+	call .Lwait_char;
+	R0.L='\n';
+	call .Lwait_char;
+
+.Ldebug_kernel_start_trap_done:
+	JUMP    .Ldebug_kernel_start_trap_done;
+.Ldump_reg:
+	R3 = 32;
+	R4 = 0x0F;
+	R5 = ':';  /* one past 9 */
+
+.Ldump_reg2:
+	R0 = R2;
+	R3 += -4;
+	R0 >>>= R3;
+	R0 = R0 & R4;
+	R0 += 0x30;
+	CC = R0 <= R5;
+	if CC JUMP .Ldump_reg1;
+	R0 += 7;
+
+.Ldump_reg1:
+	R1.l = W[P1];
+	CC = BITTST(R1, 5);
+	if !CC JUMP .Ldump_reg1;
+	W[P0] = r0;
+
+	CC = R3 == 0;
+	if !CC JUMP .Ldump_reg2
+	RTS;
+
+.Lwait_char:
+	R1.l = W[P1];
+	CC = BITTST(R1, 5);
+	if !CC JUMP .Lwait_char;
+	W[P0] = r0;
+	RTS;
+
+#endif  /* CONFIG_DEBUG_KERNEL_START  */
+
+.data
+
+/*
+ * Set up the usable of RAM stuff. Size of RAM is determined then
+ * an initial stack set up at the end.
+ */
+
+.align 4
+__rambase:
+.long   0
+__ramstart:
+.long   0
+__ramend:
+.long   0