Source to i386/stand/srt0.c
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)srt0.c 8.1 (Berkeley) 6/11/93
*/
/*
* Startup code for standalone system
* Non-relocating version -- for programs which are loaded by boot
* Relocating version for boot
* Small relocating version for "micro" boot
*/
.globl _end
.globl _edata
.globl _main
.globl __rtt
.globl _exit
.globl _bootdev
.globl _cyloffset
#ifdef SMALL
/* where the disklabel goes if we have one */
.globl _disklabel
_disklabel:
.space 512
#endif
entry: .globl entry
.globl start
#if defined(REL) && !defined(SMALL)
/* relocate program and enter at symbol "start" */
#movl $entry-RELOC,%esi # from beginning of ram
movl $0,%esi
#movl $entry,%edi # to relocated area
movl $ RELOC,%edi # to relocated area
# movl $_edata-RELOC,%ecx # this much
movl $64*1024,%ecx
cld
rep
movsb
# relocate program counter to relocation base
pushl $start
ret
#endif
start:
/* setup stack pointer */
#ifdef REL
leal 4(%esp),%eax /* ignore old pc */
movl $ RELOC-4*4,%esp
/* copy down boot parameters */
movl %esp,%ebx
pushl $3*4
pushl %ebx
pushl %eax
call _bcopy
movl %ebx,%esp
#else
/* save old stack state */
movl %esp,savearea
movl %ebp,savearea+4
movl $ RELOC-0x2400,%esp
#endif
/* clear memory as needed */
movl %esp,%esi
#ifdef REL
/*
* Clear Bss and up to 64K heap
*/
movl $64*1024,%ebx
movl $_end,%eax # should be movl $_end-_edata but ...
subl $_edata,%eax
addl %ebx,%eax
pushl %eax
pushl $_edata
call _bzero
/*
* Clear 64K of stack
*/
movl %esi,%eax
subl %ebx,%eax
subl $5*4,%ebx
pushl %ebx
pushl %eax
call _bzero
#else
movl $_edata,%edx
movl %esp,%eax
subl %edx,%eax
pushl %edx
pushl %esp
call _bzero
#endif
movl %esi,%esp
pushl $0
popf
#ifndef SMALL
call _kbdreset /* resets keyboard and gatea20 brain damage */
#endif
call _main
jmp 1f
.data
_bootdev: .long 0
_cyloffset: .long 0
savearea: .long 0,0 # sp & bp to return to
.text
#ifndef SMALL
.globl _getchar
#endif
.globl _wait
__rtt:
#ifndef SMALL
call _getchar
#else
_exit:
pushl $1000000
call _wait
popl %eax
#endif
movl $-7,%eax
jmp 1f
#ifndef SMALL
_exit:
call _getchar
#endif
movl 4(%esp),%eax
1:
#ifdef REL
#ifndef SMALL
call _reset_cpu
#endif
movw $0x1234,%ax
movw %ax,0x472 # warm boot
movl $0,%esp # segment violation
ret
#else
movl savearea,%esp
movl savearea+4,%ebp
ret
#endif
.globl _inb
_inb: movl 4(%esp),%edx
subl %eax,%eax # clr eax
inb %dx,%al
ret
.globl _outb
_outb: movl 4(%esp),%edx
movl 8(%esp),%eax
outb %al,%dx
ret
.globl ___udivsi3
___udivsi3:
movl 4(%esp),%eax
xorl %edx,%edx
divl 8(%esp)
ret
.globl ___divsi3
___divsi3:
movl 4(%esp),%eax
xorl %edx,%edx
cltd
idivl 8(%esp)
ret
#
# bzero (base,cnt)
#
.globl _bzero
_bzero:
pushl %edi
movl 8(%esp),%edi
movl 12(%esp),%ecx
movb $0x00,%al
cld
rep
stosb
popl %edi
ret
#
# bcopy (src,dst,cnt)
# NOTE: does not (yet) handle overlapped copies
#
.globl _bcopy
_bcopy:
pushl %esi
pushl %edi
movl 12(%esp),%esi
movl 16(%esp),%edi
movl 20(%esp),%ecx
cld
rep
movsb
popl %edi
popl %esi
ret
# insw(port,addr,cnt)
.globl _insw
_insw:
pushl %edi
movw 8(%esp),%dx
movl 12(%esp),%edi
movl 16(%esp),%ecx
cld
nop
.byte 0x66,0xf2,0x6d # rep insw
nop
movl %edi,%eax
popl %edi
ret
# outsw(port,addr,cnt)
.globl _outsw
_outsw:
pushl %esi
movw 8(%esp),%dx
movl 12(%esp),%esi
movl 16(%esp),%ecx
cld
nop
.byte 0x66,0xf2,0x6f # rep outsw
nop
movl %esi,%eax
popl %esi
ret