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-rw-r--r--arch/x86/kernel/acpi/realmode/wakeup.S38
-rw-r--r--arch/x86/kernel/acpi/realmode/wakeup.h5
-rw-r--r--arch/x86/kernel/acpi/sleep.c16
3 files changed, 57 insertions, 2 deletions
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.S b/arch/x86/kernel/acpi/realmode/wakeup.S
index f9b77fb..3355973 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.S
+++ b/arch/x86/kernel/acpi/realmode/wakeup.S
@@ -5,6 +5,7 @@
#include <asm/msr-index.h>
#include <asm/page.h>
#include <asm/pgtable.h>
+#include <asm/processor-flags.h>
.code16
.section ".header", "a"
@@ -24,6 +25,11 @@ 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 0x51ee1111
.text
@@ -34,11 +40,34 @@ _start:
cli
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
@@ -98,7 +127,14 @@ bogus_real_magic:
jmp 1b
.data
- .balign 4
+ .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
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.h b/arch/x86/kernel/acpi/realmode/wakeup.h
index ef8166f..69d38d0 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.h
+++ b/arch/x86/kernel/acpi/realmode/wakeup.h
@@ -24,6 +24,11 @@ struct wakeup_header {
u32 realmode_flags;
u32 real_magic;
u16 trampoline_segment; /* segment with trampoline code, 64-bit only */
+ u8 _pad1;
+ u8 wakeup_jmp;
+ u16 wakeup_jmp_off;
+ u16 wakeup_jmp_seg;
+ u64 wakeup_gdt[3];
u32 signature; /* To check we have correct structure */
} __attribute__((__packed__));
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index afc25ee..36af01f 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -50,6 +50,20 @@ int acpi_save_state_mem(void)
header->video_mode = saved_video_mode;
+ header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
+ /* GDT[0]: GDT self-pointer */
+ header->wakeup_gdt[0] =
+ (u64)(sizeof(header->wakeup_gdt) - 1) +
+ ((u64)(acpi_wakeup_address +
+ ((char *)&header->wakeup_gdt - (char *)acpi_realmode))
+ << 16);
+ /* GDT[1]: real-mode-like code segment */
+ header->wakeup_gdt[1] = (0x009bULL << 40) +
+ ((u64)acpi_wakeup_address << 16) + 0xffff;
+ /* GDT[2]: real-mode-like data segment */
+ header->wakeup_gdt[2] = (0x0093ULL << 40) +
+ ((u64)acpi_wakeup_address << 16) + 0xffff;
+
#ifndef CONFIG_64BIT
store_gdt((struct desc_ptr *)&header->pmode_gdt);
@@ -111,7 +125,7 @@ void __init acpi_reserve_bootmem(void)
return;
}
- acpi_wakeup_address = acpi_realmode;
+ acpi_wakeup_address = virt_to_phys((void *)acpi_realmode);
}
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