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kernel/linux-rt-4.4.41/arch/cris/boot/compressed/head_v10.S 2.85 KB
5113f6f70   김현기   kernel add
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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.
   *
   */
  
  #define ASSEMBLER_MACROS_ONLY
  #include <arch/sv_addr_ag.h>
  
  #define RAM_INIT_MAGIC 0x56902387
  #define COMMAND_LINE_MAGIC 0x87109563
  
  	;; 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 "../../arch-v10/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
  
  	;;  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
  
  	;; 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
  
  	;; 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
  
  	;; 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
  _cmd_line_magic:
  	.dword 0
  _cmd_line_addr:
  	.dword 0
  #include "../../arch-v10/lib/hw_settings.S"