diff options
Diffstat (limited to 'arch/x86/realmode/rm/wakeup/wakeup_asm.S')
| -rw-r--r-- | arch/x86/realmode/rm/wakeup/wakeup_asm.S | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/arch/x86/realmode/rm/wakeup/wakeup_asm.S b/arch/x86/realmode/rm/wakeup/wakeup_asm.S new file mode 100644 index 000000000000..b61126cb599e --- /dev/null +++ b/arch/x86/realmode/rm/wakeup/wakeup_asm.S @@ -0,0 +1,189 @@ +/* + * 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 + +/* This should match the structure in wakeup.h */ + .section ".data", "aw" + .globl wakeup_header +wakeup_header: +video_mode: .short 0 /* Video mode number */ +pmode_entry: .long 0 +pmode_cs: .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 +pmode_misc_en: .quad 0 /* Saved MISC_ENABLE MSR */ +pmode_behavior: .long 0 /* Wakeup behavior flags */ +realmode_flags: .long 0 +real_magic: .long 0 +signature: .long WAKEUP_HEADER_SIGNATURE + .size wakeup_header, .-wakeup_header + + .text + .code16 + .globl wakeup_start +wakeup_start: + cli + cld + + .byte 0xea /* ljmpw */ + .word 3f + .word real_mode_seg +3: + /* 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 + 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 + .byte 0xea /* ljmpw */ + .word 3f + .word real_mode_seg +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 + + /* Restore MISC_ENABLE before entering protected mode, in case + BIOS decided to clear XD_DISABLE during S3. */ + movl pmode_behavior, %eax + btl $WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE, %eax + jnc 1f + + movl pmode_misc_en, %eax + movl pmode_misc_en + 4, %edx + movl $MSR_IA32_MISC_ENABLE, %ecx + wrmsr +1: + + /* 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 + ljmpl *pmode_entry +#else + jmp trampoline_data +#endif + +bogus_real_magic: +1: + hlt + jmp 1b + + .section ".rodata","a" + + /* + * Set up the wakeup GDT. We set these up as Big Real Mode, + * that is, with limits set to 4 GB. At least the Lenovo + * Thinkpad X61 is known to need this for the video BIOS + * initialization quirk to work; this is likely to also + * be the case for other laptops or integrated video devices. + */ + + .globl wakeup_gdt + .balign 16 +wakeup_gdt: + .word 3*8-1 /* Self-descriptor */ + .long pa_wakeup_gdt + .word 0 + + .word 0xffff /* 16-bit code segment @ real_mode_base */ + .long 0x9b000000 + pa_real_mode_base + .word 0x008f /* big real mode */ + + .word 0xffff /* 16-bit data segment @ real_mode_base */ + .long 0x93000000 + pa_real_mode_base + .word 0x008f /* big real mode */ + .size wakeup_gdt, .-wakeup_gdt + + .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 |