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- /*
- * Copyright (C) Paul Mackerras 1997.
- *
- * 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.
- *
- * NOTE: this code runs in 32 bit mode and is packaged as ELF32.
- */
- #include "ppc_asm.h"
- .text
- .globl _start
- _start:
- lis r9,_start@h
- lis r8,_etext@ha
- addi r8,r8,_etext@l
- 1: dcbf r0,r9
- icbi r0,r9
- addi r9,r9,0x20
- cmplwi 0,r9,8
- blt 1b
- sync
- isync
- ## Clear out the BSS as per ANSI C requirements
- lis r7,_end@ha
- addi r7,r7,_end@l # r7 = &_end
- lis r8,__bss_start@ha #
- addi r8,r8,__bss_start@l # r8 = &_bss_start
- ## Determine how large an area, in number of words, to clear
- subf r7,r8,r7 # r7 = &_end - &_bss_start + 1
- addi r7,r7,3 # r7 += 3
- srwi. r7,r7,2 # r7 = size in words.
- beq 3f # If the size is zero, don't bother
- addi r8,r8,-4 # r8 -= 4
- mtctr r7 # SPRN_CTR = number of words to clear
- li r0,0 # r0 = 0
- 2: stwu r0,4(r8) # Clear out a word
- bdnz 2b # Keep clearing until done
- 3:
- b start
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