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/*
* Code that sets up the DRAM registers, calls the
* decompressor to unpack the piggybacked kernel, and jumps.
*
* Copyright (C) 1999 - 2003, Axis Communications AB
*/
#define ASSEMBLER_MACROS_ONLY
#include <asm/arch/hwregs/asm/reg_map_asm.h>
#include <asm/arch/hwregs/asm/gio_defs_asm.h>
#include <asm/arch/hwregs/asm/config_defs_asm.h>
#define RAM_INIT_MAGIC 0x56902387
#define COMMAND_LINE_MAGIC 0x87109563
;; Exported symbols
.globl input_data
.text
start:
di
;; Start clocks for used blocks.
move.d REG_ADDR(config, regi_config, rw_clk_ctrl), $r1
move.d [$r1], $r0
or.d REG_STATE(config, rw_clk_ctrl, cpu, yes) | \
REG_STATE(config, rw_clk_ctrl, bif, yes) | \
REG_STATE(config, rw_clk_ctrl, fix_io, yes), $r0
move.d $r0, [$r1]
;; If booting from NAND flash we first have to copy some
;; data from NAND flash to internal RAM to get the code
;; that initializes the SDRAM. Lets copy 20 KB. This
;; code executes at 0x38010000 if booting from NAND and
;; we are guaranted that at least 0x200 bytes are good so
;; lets start from there. The first 8192 bytes in the nand
;; flash is spliced with zeroes and is thus 16384 bytes.
move.d 0x38010200, $r10
move.d 0x14200, $r11 ; Start offset in NAND flash 0x10200 + 16384
move.d 0x5000, $r12 ; Length of copy
;; Before this code the tools add a partitiontable so the PC
;; has an offset from the linked address.
offset1:
lapcq ., $r13 ; get PC
add.d first_copy_complete-offset1, $r13
#include "../../lib/nand_init.S"
first_copy_complete:
;; Initialze the DRAM registers.
cmp.d RAM_INIT_MAGIC, $r8 ; Already initialized?
beq dram_init_finished
nop
#include "../../lib/dram_init.S"
dram_init_finished:
lapcq ., $r13 ; get PC
add.d second_copy_complete-dram_init_finished, $r13
move.d REG_ADDR(config, regi_config, r_bootsel), $r0
move.d [$r0], $r0
and.d REG_MASK(config, r_bootsel, boot_mode), $r0
cmp.d REG_STATE(config, r_bootsel, boot_mode, nand), $r0
bne second_copy_complete ; No NAND boot
nop
;; Copy 2MB from NAND flash to SDRAM (at 2-4MB into the SDRAM)
move.d 0x40204000, $r10
move.d 0x8000, $r11
move.d 0x200000, $r12
ba copy_nand_to_ram
nop
second_copy_complete:
;; Initiate the PA port.
move.d CONFIG_ETRAX_DEF_GIO_PA_OUT, $r0
move.d REG_ADDR(gio, regi_gio, rw_pa_dout), $r1
move.d $r0, [$r1]
move.d CONFIG_ETRAX_DEF_GIO_PA_OE, $r0
move.d REG_ADDR(gio, regi_gio, rw_pa_oe), $r1
move.d $r0, [$r1]
;; Setup the stack to a suitably high address.
;; We assume 8 MB is the minimum DRAM and put
;; the SP at the top for now.
move.d 0x40800000, $sp
;; Figure out where the compressed piggyback image is
;; in the flash (since we wont try to copy it to DRAM
;; before unpacking). It is at _edata, but in flash.
;; Use (_edata - herami) as offset to the current PC.
move.d REG_ADDR(config, regi_config, r_bootsel), $r0
move.d [$r0], $r0
and.d REG_MASK(config, r_bootsel, boot_mode), $r0
cmp.d REG_STATE(config, r_bootsel, boot_mode, nand), $r0
beq hereami2
nop
hereami:
lapcq ., $r5 ; get PC
and.d 0x7fffffff, $r5 ; strip any non-cache bit
move.d $r5, $r0 ; save for later - flash address of 'herami'
add.d _edata, $r5
sub.d hereami, $r5 ; r5 = flash address of '_edata'
move.d hereami, $r1 ; destination
ba 2f
nop
hereami2:
lapcq ., $r5 ; get PC
and.d 0x00ffffff, $r5 ; strip any non-cache bit
move.d $r5, $r6
or.d 0x40200000, $r6
move.d $r6, $r0 ; save for later - flash address of 'herami'
add.d _edata, $r5
sub.d hereami2, $r5 ; r5 = flash address of '_edata'
add.d 0x40200000, $r5
move.d hereami2, $r1 ; destination
2:
;; Copy text+data to DRAM
move.d _edata, $r2 ; end destination
1: move.w [$r0+], $r3
move.w $r3, [$r1+]
cmp.d $r2, $r1
bcs 1b
nop
move.d input_data, $r0 ; for the decompressor
move.d $r5, [$r0] ; for the decompressor
;; Clear the decompressors BSS (between _edata and _end)
moveq 0, $r0
move.d _edata, $r1
move.d _end, $r2
1: move.w $r0, [$r1+]
cmp.d $r2, $r1
bcs 1b
nop
;; Save command line magic and address.
move.d _cmd_line_magic, $r12
move.d $r10, [$r12]
move.d _cmd_line_addr, $r12
move.d $r11, [$r12]
;; Do the decompression and save compressed size in _inptr
jsr decompress_kernel
nop
;; Restore command line magic and address.
move.d _cmd_line_magic, $r10
move.d [$r10], $r10
move.d _cmd_line_addr, $r11
move.d [$r11], $r11
;; Put start address of root partition in r9 so the kernel can use it
;; when mounting from flash
move.d input_data, $r0
move.d [$r0], $r9 ; flash address of compressed kernel
move.d inptr, $r0
add.d [$r0], $r9 ; size of compressed kernel
cmp.d 0x40200000, $r9
blo enter_kernel
nop
sub.d 0x40200000, $r9
add.d 0x4000, $r9
enter_kernel:
;; Enter the decompressed kernel
move.d RAM_INIT_MAGIC, $r8 ; Tell kernel that DRAM is initialized
jump 0x40004000 ; kernel is linked to this address
nop
.data
input_data:
.dword 0 ; used by the decompressor
_cmd_line_magic:
.dword 0
_cmd_line_addr:
.dword 0
is_nand_boot:
.dword 0
#include "../../lib/hw_settings.S"
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