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/*
* ACPI wakeup real mode startup stub
*/
#include <asm/segment.h>
#include <asm/msr-index.h>
#include <asm/page_types.h>
#include <asm/pgtable_types.h>
#include <asm/processor-flags.h>
#include "wakeup.h"
.code16
.section ".jump", "ax"
.globl _start
_start:
cli
jmp wakeup_code
/* This should match the structure in wakeup.h */
.section ".header", "a"
.globl wakeup_header
wakeup_header:
video_mode: .short 0 /* Video mode number */
pmode_return: .byte 0x66, 0xea /* ljmpl */
.long 0 /* offset goes here */
.short __KERNEL_CS
pmode_cr0: .long 0 /* Saved %cr0 */
pmode_cr3: .long 0 /* Saved %cr3 */
pmode_cr4: .long 0 /* Saved %cr4 */
pmode_efer: .quad 0 /* Saved EFER */
pmode_gdt: .quad 0
realmode_flags: .long 0
real_magic: .long 0
trampoline_segment: .word 0
_pad1: .byte 0
wakeup_jmp: .byte 0xea /* ljmpw */
wakeup_jmp_off: .word 3f
wakeup_jmp_seg: .word 0
wakeup_gdt: .quad 0, 0, 0
signature: .long WAKEUP_HEADER_SIGNATURE
.text
.code16
wakeup_code:
cld
/* Apparently some dimwit BIOS programmers don't know how to
program a PM to RM transition, and we might end up here with
junk in the data segment descriptor registers. The only way
to repair that is to go into PM and fix it ourselves... */
movw $16, %cx
lgdtl %cs:wakeup_gdt
movl %cr0, %eax
orb $X86_CR0_PE, %al
movl %eax, %cr0
jmp 1f
1: ljmpw $8, $2f
2:
movw %cx, %ds
movw %cx, %es
movw %cx, %ss
movw %cx, %fs
movw %cx, %gs
andb $~X86_CR0_PE, %al
movl %eax, %cr0
jmp wakeup_jmp
3:
/* Set up segments */
movw %cs, %ax
movw %ax, %ds
movw %ax, %es
movw %ax, %ss
lidtl wakeup_idt
movl $wakeup_stack_end, %esp
/* Clear the EFLAGS */
pushl $0
popfl
/* Check header signature... */
movl signature, %eax
cmpl $WAKEUP_HEADER_SIGNATURE, %eax
jne bogus_real_magic
/* Check we really have everything... */
movl end_signature, %eax
cmpl $WAKEUP_END_SIGNATURE, %eax
jne bogus_real_magic
/* Call the C code */
calll main
/* Do any other stuff... */
#ifndef CONFIG_64BIT
/* This could also be done in C code... */
movl pmode_cr3, %eax
movl %eax, %cr3
movl pmode_cr4, %ecx
jecxz 1f
movl %ecx, %cr4
1:
movl pmode_efer, %eax
movl pmode_efer + 4, %edx
movl %eax, %ecx
orl %edx, %ecx
jz 1f
movl $MSR_EFER, %ecx
wrmsr
1:
lgdtl pmode_gdt
/* This really couldn't... */
movl pmode_cr0, %eax
movl %eax, %cr0
jmp pmode_return
#else
pushw $0
pushw trampoline_segment
pushw $0
lret
#endif
bogus_real_magic:
1:
hlt
jmp 1b
.data
.balign 8
/* This is the standard real-mode IDT */
wakeup_idt:
.word 0xffff /* limit */
.long 0 /* address */
.word 0
.globl HEAP, heap_end
HEAP:
.long wakeup_heap
heap_end:
.long wakeup_stack
.bss
wakeup_heap:
.space 2048
wakeup_stack:
.space 2048
wakeup_stack_end:
.section ".signature","a"
end_signature:
.long WAKEUP_END_SIGNATURE
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