EXTERNDEF m16GdtrBase:WORD\r
EXTERNDEF mTransition:WORD\r
\r
-THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 EQU 2\r
-THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL EQU 4\r
-\r
IA32_REGS STRUC 4t\r
_EDI DD ?\r
_ESI DD ?\r
\r
.const\r
\r
-m16Size DW offset InternalAsmThunk16 - offset m16Start\r
-mThunk16Attr DW offset _ThunkAttr - offset m16Start\r
-m16Gdt DW offset _NullSegDesc - offset m16Start\r
-m16GdtrBase DW offset _16GdtrBase - offset m16Start\r
-mTransition DW offset _EntryPoint - offset m16Start\r
+m16Size DW InternalAsmThunk16 - m16Start\r
+mThunk16Attr DW _ThunkAttr - m16Start\r
+m16Gdt DW _NullSegDesc - m16Start\r
+m16GdtrBase DW _16GdtrBase - m16Start\r
+mTransition DW _EntryPoint - m16Start\r
\r
.code\r
\r
m16Start LABEL BYTE\r
\r
-SavedGdt LABEL FWORD\r
- DW ?\r
- DQ ?\r
+SavedGdt LABEL FWORD\r
+ DW ?\r
+ DQ ?\r
\r
_BackFromUserCode PROC\r
DB 16h ; push ss\r
SavedCr4 DD ?\r
mov cr4, rax\r
DB 66h, 2eh\r
- lgdt fword ptr [rdi + (offset SavedGdt - offset @Base)]\r
+ lgdt fword ptr [rdi + (SavedGdt - @Base)]\r
DB 66h\r
mov ecx, 0c0000080h\r
rdmsr\r
retf ; return to protected mode\r
_BackFromUserCode ENDP\r
\r
-_EntryPoint DD offset _ToUserCode - offset m16Start\r
- DW 8h\r
-_16Gdtr LABEL FWORD\r
- DW offset GdtEnd - offset _NullSegDesc - 1\r
-_16GdtrBase DQ offset _NullSegDesc\r
-_16Idtr FWORD (1 SHL 10) - 1\r
+_EntryPoint DD _ToUserCode - m16Start\r
+ DW 8h\r
+_16Gdtr LABEL FWORD\r
+ DW GdtEnd - _NullSegDesc - 1\r
+_16GdtrBase DQ _NullSegDesc\r
+_16Idtr FWORD (1 SHL 10) - 1\r
\r
_ToUserCode PROC\r
mov edi, ss\r
DB 66h\r
call @Base ; push eip\r
@Base:\r
- pop bp ; ebp <- offset @Base\r
+ pop bp ; ebp <- address of @Base\r
push [esp + sizeof (IA32_REGS) + 2]\r
- lea eax, [rsi + (offset @RealMode - offset @Base)]\r
+ lea eax, [rsi + (@RealMode - @Base)]\r
push rax\r
retf\r
@RealMode:\r
DB 2eh ; cs:\r
- mov [rsi + (offset SavedSs - offset @Base)], edi\r
+ mov [rsi + (SavedSs - @Base)], edi\r
DB 2eh ; cs:\r
- mov [rsi + (offset SavedEsp - offset @Base)], bx\r
+ mov [rsi + (SavedEsp - @Base)], bx\r
DB 66h, 2eh ; CS and operand size override\r
- lidt fword ptr [rsi + (offset _16Idtr - offset @Base)]\r
+ lidt fword ptr [rsi + (_16Idtr - @Base)]\r
DB 66h, 61h ; popad\r
DB 1fh ; pop ds\r
DB 07h ; pop es\r
mov edi, (IA32_REGS ptr [rsi])._ESP\r
lea rdi, [edi - (sizeof (IA32_REGS) + 4)]\r
imul eax, r8d, 16 ; eax <- r8d(stack segment) * 16\r
- mov ebx, edi ; ebx <- stack offset for 16-bit code\r
+ mov ebx, edi ; ebx <- stack for 16-bit code\r
push sizeof (IA32_REGS) / 4\r
add edi, eax ; edi <- linear address of 16-bit stack\r
pop rcx\r
rep movsd ; copy RegSet\r
- lea ecx, [rdx + (offset SavedCr4 - offset m16Start)]\r
+ lea ecx, [rdx + (SavedCr4 - m16Start)]\r
mov eax, edx ; eax <- transition code address\r
and edx, 0fh\r
shl eax, 12\r
- lea edx, [rdx + (offset _BackFromUserCode - offset m16Start)]\r
+ lea edx, [rdx + (_BackFromUserCode - m16Start)]\r
mov ax, dx\r
stosd ; [edi] <- return address of user code\r
- sgdt fword ptr [rcx + (offset SavedGdt - offset SavedCr4)]\r
+ sgdt fword ptr [rcx + (SavedGdt - SavedCr4)]\r
sidt fword ptr [rsp + 38h] ; save IDT stack in argument space\r
mov rax, cr0\r
- mov [rcx + (offset SavedCr0 - offset SavedCr4)], eax\r
+ mov [rcx + (SavedCr0 - SavedCr4)], eax\r
and eax, 7ffffffeh ; clear PE, PG bits\r
mov rbp, cr4\r
mov [rcx], ebp ; save CR4 in SavedCr4\r
mov esi, r8d ; esi <- 16-bit stack segment\r
push 10h\r
pop rdx ; rdx <- selector for data segments\r
- lgdt fword ptr [rcx + (offset _16Gdtr - offset SavedCr4)]\r
+ lgdt fword ptr [rcx + (_16Gdtr - SavedCr4)]\r
pushfq\r
- call fword ptr [rcx + (offset _EntryPoint - offset SavedCr4)]\r
+ call fword ptr [rcx + (_EntryPoint - SavedCr4)]\r
popfq\r
lidt fword ptr [rsp + 38h] ; restore protected mode IDTR\r
lea eax, [rbp - sizeof (IA32_REGS)]\r