FreeBSD-5.3/sys/i386/acpica/acpi_wakecode.S
/*-
* Copyright (c) 2001 Takanori Watanabe <takawata@jp.freebsd.org>
* Copyright (c) 2001 Mitsuru IWASAKI <iwasaki@jp.freebsd.org>
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD: src/sys/i386/acpica/acpi_wakecode.S,v 1.9 2004/01/01 22:57:22 njl Exp $
*/
#define LOCORE
#include <machine/asmacros.h>
#include <machine/param.h>
#include <machine/specialreg.h>
.align 4
.code16
wakeup_16:
nop
cli
/*
* Set up segment registers for real mode and a small stack for
* any calls we make.
*/
movw %cs,%ax
movw %ax,%ds
movw %ax,%ss
movw $PAGE_SIZE,%sp
/* Re-initialize video BIOS if the reset_video tunable is set. */
cmp $0,reset_video
je wakeup_16_gdt
lcall $0xc000,$3
/*
* Set up segment registers for real mode again in case the
* previous BIOS call clobbers them.
*/
movw %cs,%ax
movw %ax,%ds
movw %ax,%ss
wakeup_16_gdt:
/* Load GDT for real mode */
lgdt physical_gdt
/* Restore CR2, CR3 and CR4 */
mov previous_cr2,%eax
mov %eax,%cr2
mov previous_cr3,%eax
mov %eax,%cr3
mov previous_cr4,%eax
mov %eax,%cr4
/* Transfer some values to protected mode */
#define NVALUES 9
#define TRANSFER_STACK32(val, idx) \
mov val,%eax; \
mov %eax,wakeup_32stack+(idx+1)+(idx*4);
TRANSFER_STACK32(previous_ss, (NVALUES - 9))
TRANSFER_STACK32(previous_fs, (NVALUES - 8))
TRANSFER_STACK32(previous_ds, (NVALUES - 7))
TRANSFER_STACK32(physical_gdt+2, (NVALUES - 6))
TRANSFER_STACK32(where_to_recover, (NVALUES - 5))
TRANSFER_STACK32(previous_idt+2, (NVALUES - 4))
TRANSFER_STACK32(previous_ldt, (NVALUES - 3))
TRANSFER_STACK32(previous_gdt+2, (NVALUES - 2))
TRANSFER_STACK32(previous_tr, (NVALUES - 1))
TRANSFER_STACK32(previous_cr0, (NVALUES - 0))
mov physical_esp,%esi /* to be used in 32bit code */
/* Enable protected mode */
mov %cr0,%eax
orl $(CR0_PE),%eax
mov %eax,%cr0
wakeup_sw32:
/* Switch to protected mode by intersegmental jump */
ljmpl $0x8,$0x12345678 /* Code location, to be replaced */
.code32
wakeup_32:
/*
* Switched to protected mode w/o paging
* %esi: KERNEL stack pointer (physical address)
*/
nop
/* Set up segment registers for protected mode */
movw $0x10,%ax /* KDSEL to segment registers */
movw %ax,%ds
movw %ax,%es
movw %ax,%gs
movw %ax,%ss
movw $0x18,%ax /* KPSEL to %fs */
movw %ax,%fs
movl %esi,%esp /* physical address stack pointer */
wakeup_32stack:
/* Operands are overwritten in 16bit code */
pushl $0xabcdef09 /* ss + dummy */
pushl $0xabcdef08 /* fs + gs */
pushl $0xabcdef07 /* ds + es */
pushl $0xabcdef06 /* gdt:base (physical address) */
pushl $0xabcdef05 /* recover address */
pushl $0xabcdef04 /* idt:base */
pushl $0xabcdef03 /* ldt + idt:limit */
pushl $0xabcdef02 /* gdt:base */
pushl $0xabcdef01 /* TR + gdt:limit */
pushl $0xabcdef00 /* CR0 */
movl %esp,%ebp
#define CR0_REGISTER 0(%ebp)
#define TASK_REGISTER 4(%ebp)
#define PREVIOUS_GDT 6(%ebp)
#define PREVIOUS_LDT 12(%ebp)
#define PREVIOUS_IDT 14(%ebp)
#define RECOVER_ADDR 20(%ebp)
#define PHYSICAL_GDT_BASE 24(%ebp)
#define PREVIOUS_DS 28(%ebp)
#define PREVIOUS_ES 30(%ebp)
#define PREVIOUS_FS 32(%ebp)
#define PREVIOUS_GS 34(%ebp)
#define PREVIOUS_SS 36(%ebp)
/* Fixup TSS type field */
#define TSS_TYPEFIX_MASK 0xf9
xorl %esi,%esi
movl PHYSICAL_GDT_BASE,%ebx
movw TASK_REGISTER,%si
leal (%ebx,%esi),%eax /* get TSS segment descriptor */
andb $TSS_TYPEFIX_MASK,5(%eax)
/* Prepare to return to sleep/wakeup code point */
lgdt PREVIOUS_GDT
lidt PREVIOUS_IDT
xorl %eax,%eax
movl %eax,%ebx
movl %eax,%ecx
movl %eax,%edx
movl %eax,%esi
movl %eax,%edi
movl PREVIOUS_DS,%ebx
movl PREVIOUS_FS,%ecx
movl PREVIOUS_SS,%edx
movw TASK_REGISTER,%si
shll $16,%esi
movw PREVIOUS_LDT,%si
movl RECOVER_ADDR,%edi
/* Enable paging and etc. */
movl CR0_REGISTER,%eax
movl %eax,%cr0
/* Flush the prefetch queue */
jmp 1f
1: jmp 1f
1:
/*
* Now that we are in kernel virtual memory addressing
* %ebx: ds + es
* %ecx: fs + gs
* %edx: ss + dummy
* %esi: LDTR + TR
* %edi: recover address
*/
nop
movl %esi,%eax /* LDTR + TR */
lldt %ax /* load LDT register */
shrl $16,%eax
ltr %ax /* load task register */
/* Restore segment registers */
movl %ebx,%eax /* ds + es */
movw %ax,%ds
shrl $16,%eax
movw %ax,%es
movl %ecx,%eax /* fs + gs */
movw %ax,%fs
shrl $16,%eax
movw %ax,%gs
movl %edx,%eax /* ss */
movw %ax,%ss
/* Jump to acpi_restorecpu() */
jmp *%edi
/* used in real mode */
physical_gdt: .word 0
.long 0
physical_esp: .long 0
previous_cr2: .long 0
previous_cr3: .long 0
previous_cr4: .long 0
reset_video: .long 0
/* transfer from real mode to protected mode */
previous_cr0: .long 0
previous_tr: .word 0
previous_gdt: .word 0
.long 0
previous_ldt: .word 0
previous_idt: .word 0
.long 0
where_to_recover: .long 0
previous_ds: .word 0
previous_es: .word 0
previous_fs: .word 0
previous_gs: .word 0
previous_ss: .word 0
dummy: .word 0