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/*
* purgatory: setup code
*
* Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com)
*
* 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 (version 2 of the License).
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#undef i386
.text
.arch i386
.globl entry32, entry32_regs
entry32:
.code32
/* Setup a gdt that should that is generally usefully */
lgdt %cs:gdt
/* load the data segments */
movl $0x18, %eax /* data segment */
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
movl %eax, %fs
movl %eax, %gs
/* load the code segment */
ljmp $0x10,$1f
1:
/* Load the registers */
movl eax, %eax
movl ecx, %ecx
movl edx, %edx
movl esi, %esi
movl edi, %edi
movl esp, %esp
movl ebp, %ebp
movl ebx, %ebx
/* Jump to the loaded image */
jmpl *(eip)
.section ".rodata"
.balign 16
gdt:
/* 0x00 unusable segment so used as the gdt ptr */
.word gdt_end - gdt - 1
.long gdt
.word 0
/* 0x08 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* Documented linux kernel segments */
/* 0x10 4GB flat code segment */
.word 0xFFFF, 0x0000, 0x9A00, 0x00CF
/* 0x18 4GB flat data segment */
.word 0xFFFF, 0x0000, 0x9200, 0x00CF
/* 0x20 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* 0x28 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* 0x30 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* 0x38 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* 0x40 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* 0x48 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* 0x50 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* 0x58 dummy */
.word 0x0000, 0x0000, 0x0000, 0x000
/* Segments used by the 2.5.x kernel */
/* 0x60 4GB flat code segment */
.word 0xFFFF, 0x0000, 0x9A00, 0x00CF
/* 0x68 4GB flat data segment */
.word 0xFFFF, 0x0000, 0x9200, 0x00CF
gdt_end:
.data
.balign 4
entry32_regs:
eax: .long 0x00000000
ebx: .long 0x00000000
ecx: .long 0x00000000
edx: .long 0x00000000
esi: .long 0x00000000
edi: .long 0x00000000
esp: .long 0x00000000
ebp: .long 0x00000000
eip: .long entry16
.size entry32_regs, . - entry32_regs
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