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kolibrios/drivers/devman/acpinfo/utils.asm
Sergey Semyonov (Serge) f86662005e acpinfo
git-svn-id: svn://kolibrios.org@2293 a494cfbc-eb01-0410-851d-a64ba20cac60
2011-10-17 12:16:37 +00:00

80 lines
1.4 KiB
NASM

format MS COFF
extrn _acpi_rsdt_base
public _acpi_locate
public @rsdt_find@8
OS_BASE equ 0x80000000
ACPI_HI_RSDP_WINDOW_START equ (OS_BASE+0x000E0000)
ACPI_HI_RSDP_WINDOW_END equ (OS_BASE+0x00100000)
ACPI_RSDP_CHECKSUM_LENGTH equ 20
section '.text' code readable executable align 16
_acpi_locate:
push ebx
mov ebx, ACPI_HI_RSDP_WINDOW_START
.check:
cmp [ebx], dword 0x20445352
jne .next
cmp [ebx+4], dword 0x20525450
jne .next
mov edx, ebx
mov ecx, ACPI_RSDP_CHECKSUM_LENGTH
xor eax, eax
.sum:
add al, [edx]
inc edx
loop .sum
test al, al
jnz .next
mov eax, ebx
pop ebx
ret
.next:
add ebx, 16
cmp ebx, ACPI_HI_RSDP_WINDOW_END
jb .check
pop ebx
xor eax, eax
ret
align 4
@rsdt_find@8: ;ecx= rsdt edx= SIG
push ebx
push esi
lea ebx, [ecx+36]
mov esi, [ecx+4]
add esi, ecx
.next:
mov eax, [ebx]
sub eax, [_acpi_rsdt_base]
add eax, ecx
cmp [eax], edx
je .done
add ebx, 4
cmp ebx, esi
jb .next
xor eax, eax
pop esi
pop ebx
ret
.done:
mov eax, [ebx]
pop esi
pop ebx
ret