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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 /* a procedure descriptor used when booting this as a COFF file */ .globl _zimage_start_opd _zimage_start_opd: .long _zimage_start, 0, 0, 0 .weak _zimage_start .globl _zimage_start _zimage_start: .globl _zimage_start_lib _zimage_start_lib: /* Work out the offset between the address we were linked at and the address where we're running. */ bl 1f 1: mflr r0 lis r9,1b@ha addi r9,r9,1b@l subf. r0,r9,r0 beq 3f /* if running at same address as linked */ /* The .got2 section contains a list of addresses, so add the address offset onto each entry. */ lis r9,__got2_start@ha addi r9,r9,__got2_start@l lis r8,__got2_end@ha addi r8,r8,__got2_end@l subf. r8,r9,r8 beq 3f srwi. r8,r8,2 mtctr r8 add r9,r0,r9 2: lwz r8,0(r9) add r8,r8,r0 stw r8,0(r9) addi r9,r9,4 bdnz 2b /* Do a cache flush for our text, in case the loader didn't */ 3: lis r9,_start@ha addi r9,r9,_start@l add r9,r0,r9 lis r8,_etext@ha addi r8,r8,_etext@l add r8,r0,r8 4: dcbf r0,r9 icbi r0,r9 addi r9,r9,0x20 cmplw cr0,r9,r8 blt 4b sync isync /* Clear the BSS */ lis r9,__bss_start@ha addi r9,r9,__bss_start@l add r9,r0,r9 lis r8,_end@ha addi r8,r8,_end@l add r8,r0,r8 li r10,0 5: stw r10,0(r9) addi r9,r9,4 cmplw cr0,r9,r8 blt 5b /* Possibly set up a custom stack */ .weak _platform_stack_top lis r8,_platform_stack_top@ha addi r8,r8,_platform_stack_top@l cmpwi r8,0 beq 6f add r8,r0,r8 lwz r1,0(r8) add r1,r0,r1 li r0,0 stwu r0,-16(r1) /* establish a stack frame */ 6: /* Call platform_init() */ bl platform_init /* Call start */ b start |