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/*
* This is based on the mvme-crt0.S file from libgloss/rs6000.
* crt0.S -- startup file for PowerPC systems.
*
* Copyright (c) 1995 Cygnus Support
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*
* $Id$
*/
#include "ppc-asm.h"
.file "start.s"
.section ".got2","aw"
.align 2
.LCTOC1 = .+32768
.extern FUNC_NAME(atexit)
.globl FUNC_NAME(__atexit)
.section ".sdata","aw"
.align 2
FUNC_NAME(__atexit): /* tell C's eabi-ctor's we have an atexit function */
.long FUNC_NAME(atexit)@fixup /* and that it is to register __do_global_dtors */
.section ".fixup","aw"
.align 2
.long FUNC_NAME(__atexit)
.section ".got2","aw"
.Ltable = .-.LCTOC1
.long .LCTOC1 /* address we think .LCTOC1 is loaded at */
.Lbss_start = .-.LCTOC1
.long __bss_start
.Lend = .-.LCTOC1
.long _end
.Lstack = .-.LCTOC1 /* stack address if set by user */
.long __stack
.text
.Lptr:
.long .LCTOC1-.Laddr
.globl _start
.type _start,@function
_start:
lis r5,0
mr r4,r5
ori r4,r4,0x0000 /* 0x2030 */
mtmsr r4
/* Add special purpose register initialization based upon the console driver
* initialization of these registers XXXXX
*/
bl .Laddr /* get current address */
.Laddr:
mflr r4 /* real address of .Laddr */
lwz r5,(.Lptr-.Laddr)(r4) /* linker generated address of .LCTOC1 */
add r5,r5,r4 /* correct to real pointer */
lwz r4,.Ltable(r5) /* get linker's idea of where .Laddr is */
subf r4,r4,r5 /* calculate difference between where linked and current */
/* clear bss */
lwz r6,.Lbss_start(r5) /* calculate beginning of the BSS */
lwz r7,.Lend(r5) /* calculate end of the BSS */
add r6,r6,r4 /* adjust pointers */
add r7,r7,r4
cmplw 1,r6,r7
bc 4,4,.Ldone
subf r8,r6,r7 /* number of bytes to zero */
srwi r9,r8,2 /* number of words to zero */
mtctr r9
li r0,0 /* zero to clear memory */
addi r6,r6,-4 /* adjust so we can use stwu */
.Lloop:
stwu r0,4(r6) /* zero bss */
bdnz .Lloop
.Ldone:
lwz r0,.Lstack(r5) /* stack address or 0 */
cmplwi 1,r0,0 /* equal to 0? */
bc 12,6,.Lnostack /* use default stack if == 0 */
mr sp,r0 /* use user defined stack */
.Lnostack:
/* set up initial stack frame */
addi sp,sp,-4 /* make sure we don't overwrite debug mem */
lis r0,0
stw r0,0(sp) /* clear back chain */
stwu sp,-56(sp) /* push another stack frame */
lis r5,environ@ha
la r5,environ@l(r5) /* environp */
li r4, 0 /* argv */
li r3, 0 /* argc */
/* Let her rip */
bl FUNC_NAME(boot_card)
/* return value from boot_card is argument to exit */
/* bl FUNC_NAME(exit) */
trap
.Lstart:
.size _start,.Lstart-_start
.comm environ,4,4
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