| /* |
| * 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 |
| |
