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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2009 Rudolf Marek <r.marek@assembler.cz>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2 as published by
* the Free Software Foundation.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
.text
.code32
.globl acpi_jmp_to_realm_wakeup
/* This function does the PM -> RM switch, but
it can run >1MB even in real mode */
acpi_jmp_to_realm_wakeup:
mov 0x4(%esp), %eax
/* last 4 bits of linear addr are taken as offset */
andw $0x0f, %ax
movw %ax, (jmp_off)
mov 0x4(%esp), %eax
/* the rest is taken as segment */
shr $4, %eax
movw %ax, (jmp_seg)
lgdt gdtaddr_wakeup
movl $0x008,%eax
mov %eax,%ds
movl %eax,%es
movl %eax,%ss
movl %eax,%fs
movl %eax,%gs
ljmp $0x0010,$reload_cs
.code16gcc
reload_cs:
/* switch off PE */
movl %cr0, %eax
andb $0xfe,%al
movl %eax, %cr0
movw $0x0, %ax
movw %ax, %ds
movw %ax, %es
movw %ax, %ss
movw %ax, %fs
movw %ax, %gs
/* far jump to OS waking vector. The linear addr is changed to SEG and OFFSET
check ACPI specs or above code for details */
.byte 0xea
jmp_off:
.word 0
jmp_seg:
.word 0
.code32
gdt_wakeup_limit = gdt_wakeup_end - gdt_wakeup - 1 /* compute the table limit */
gdtaddr_wakeup:
.word gdt_wakeup_limit /* the table limit */
.long gdt_wakeup /* we know the offset */
.data
/* This is the gdt for GCC part of coreboot.
* It is different from the gdt in ROMCC/ASM part of coreboot
* which is defined in entry32.inc */
gdt_wakeup:
/* selgdt 0, unused */
.word 0x0000, 0x0000 /* dummy */
.byte 0x00, 0x00, 0x00, 0x00
/* selgdt 8, flat data segment 16bit */
.word 0x0000, 0x0000 /* dummy */
.byte 0x00, 0x93, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */
/* selgdt 0x10, flat code segment 16bit */
.word 0xffff, 0x0000
.byte 0x00, 0x9b, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */
gdt_wakeup_end:
.previous
.code32
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