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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 __sbss_start /* need to include sbss and bss sections */
.Lend = .-.LCTOC1
.long _end
.Lstack = .-.LCTOC1 /* stack address if set by user */
.long __stack
.Ltext_start = .-.LCTOC1 /* beginning of text segment */
.long __text_start
.text
/* PPCBUG ROM bootstrap record */
.ascii "BOOT" /* "magic number" */
.long 0x10 /* offset to first instruction */
.long 0x16 /* length of record, including checksum */
.ascii "BOOT" /* routine name */
b _start /* code of routine */
.short 0x6b79 /* checksum */
.short 0x0000 /* space filler */
.Lptr:
.long .LCTOC1-.Laddr
.globl _start
.type _start,@function
_start:
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 */
/* copy text and data to RAM */
lwz r6,.Ltext_start(r5) /* calculate beginning of the text */
lwz r7,.Lbss_start(r5) /* calculate end of the init data */
cmplw 1,r6,r7
bc 4,4,.Ldone1
subf r8,r6,r7 /* number of bytes to copy */
addi r8,r8,3 /* round up to next word boundary */
srwi r9,r8,2 /* number of words to copy */
mtctr r9
addi r6,r6,-4 /* adjust so we can use stwu */
add r8,r6,r4 /* get source address in ROM */
.Lloop1:
lwzu r0,4(r8) /* load word from ROM */
stwu r0,4(r6) /* store word to RAM */
bdnz .Lloop1
.Ldone1:
/* clear bss */
lwz r6,.Lbss_start(r5) /* calculate beginning of the BSS */
lwz r7,.Lend(r5) /* calculate end of the BSS */
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 */
/* jump to RAM and continue */
ba .Lcontinue
.Lcontinue:
/* invalidate instruction cache */
mfspr r4,1008 /* read hid0 */
ori r5,r4,0x00000800 /* set icfi bit */
mtspr 1008,r5
sync
isync
mtspr 1008,r4 /* restore hid0 */
sync
isync
/* 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
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