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/*
* arch/cris/boot/compressed/head.S
*
* Copyright (C) 1999, 2001 Axis Communications AB
*
* Code that sets up the DRAM registers, calls the
* decompressor to unpack the piggybacked kernel, and jumps.
*
*/
#include <linux/config.h>
#define ASSEMBLER_MACROS_ONLY
#include <asm/arch/sv_addr_ag.h>
#define RAM_INIT_MAGIC 0x56902387
;; Exported symbols
.globl _input_data
.text
nop
di
;; We need to initialze DRAM registers before we start using the DRAM
cmp.d RAM_INIT_MAGIC, r8 ; Already initialized?
beq dram_init_finished
nop
#include "../../lib/dram_init.S"
dram_init_finished:
;; Initiate the PA and PB ports
move.b CONFIG_ETRAX_DEF_R_PORT_PA_DATA, r0
move.b r0, [R_PORT_PA_DATA]
move.b CONFIG_ETRAX_DEF_R_PORT_PA_DIR, r0
move.b r0, [R_PORT_PA_DIR]
move.b CONFIG_ETRAX_DEF_R_PORT_PB_DATA, r0
move.b r0, [R_PORT_PB_DATA]
move.b CONFIG_ETRAX_DEF_R_PORT_PB_DIR, r0
move.b r0, [R_PORT_PB_DIR]
;; Setup the stack to a suitably high address.
;; We assume 8 MB is the minimum DRAM in an eLinux
;; product 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 - basse) as offset to the current PC.
basse: move.d pc, r5
and.d 0x7fffffff, r5 ; strip any non-cache bit
subq 2, r5 ; compensate for the move.d pc instr
move.d r5, r0 ; save for later - flash address of 'basse'
add.d _edata, r5
sub.d basse, r5 ; r5 = flash address of '_edata'
;; Copy text+data to DRAM
move.d basse, r1 ; destination
move.d _edata, r2 ; end destination
1: move.w [r0+], r3
move.w r3, [r1+]
cmp.d r2, r1
bcs 1b
nop
move.d r5, [_input_data] ; 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
;; Do the decompression and save compressed size in _inptr
jsr _decompress_kernel
;; Put start address of root partition in r9 so the kernel can use it
;; when mounting from flash
move.d [_input_data], r9 ; flash address of compressed kernel
add.d [_inptr], r9 ; size of compressed 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
.data
_input_data:
.dword 0 ; used by the decompressor
#include "../../lib/hw_settings.S"
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