diff options
| author | bxing <bxing@6f19259b-4bc3-4df7-8a09-765794883524> | 2006-05-15 11:14:20 +0000 |
|---|---|---|
| committer | bxing <bxing@6f19259b-4bc3-4df7-8a09-765794883524> | 2006-05-15 11:14:20 +0000 |
| commit | 97d92bdaf05d9307d494444cead97c41272eca62 (patch) | |
| tree | cbe5aa3ff333bb976ccb1688e114779329b5694a /MdePkg/Library/BaseLib/X64/Thunk16.asm | |
| parent | 7c28d0e095a592063410d2c5f7d8ff040cf89d10 (diff) | |
| download | edk2-platforms-97d92bdaf05d9307d494444cead97c41272eca62.tar.xz | |
Updated BaseLib for THUNK functions and some CPU functions
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@158 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'MdePkg/Library/BaseLib/X64/Thunk16.asm')
| -rw-r--r-- | MdePkg/Library/BaseLib/X64/Thunk16.asm | 298 |
1 files changed, 172 insertions, 126 deletions
diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.asm b/MdePkg/Library/BaseLib/X64/Thunk16.asm index f3e80840b3..15aaa80090 100644 --- a/MdePkg/Library/BaseLib/X64/Thunk16.asm +++ b/MdePkg/Library/BaseLib/X64/Thunk16.asm @@ -19,34 +19,16 @@ ;
;------------------------------------------------------------------------------
- .data
+EXTERNDEF m16Start:BYTE
+EXTERNDEF m16Size:WORD
+EXTERNDEF mThunk16Attr:WORD
+EXTERNDEF m16Gdt:WORD
+EXTERNDEF m16GdtrBase:WORD
+EXTERNDEF mTransition:WORD
-NullSegSel DQ 0
-_16CsSegSel LABEL QWORD
- DW -1
- DW 0
- DB 0
- DB 9bh
- DB 8fh ; 16-bit segment
- DB 0
-_16BitDsSel LABEL QWORD
- DW -1
- DW 0
- DB 0
- DB 93h
- DB 8fh ; 16-bit segment
- DB 0
-GdtEnd LABEL QWORD
-
- .const
-
-_16Gdtr LABEL FWORD
- DW offset GdtEnd - offset NullSegSel - 1
- DQ offset NullSegSel
-
-_16Idtr FWORD (1 SHL 10) - 1
-
- .code
+THUNK_ATTRIBUTE_BIG_REAL_MODE EQU 1
+THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 EQU 2
+THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL EQU 4
IA32_REGS STRUC 4t
_EDI DD ?
@@ -61,128 +43,192 @@ _DS DW ? _ES DW ?
_FS DW ?
_GS DW ?
-_RFLAGS DQ ?
+_EFLAGS DQ ?
_EIP DD ?
_CS DW ?
_SS DW ?
IA32_REGS ENDS
-InternalAsmThunk16 PROC USES rbp rbx rsi rdi r12 r13 r14 r15
- mov eax, ds
- push rax
- mov eax, es
- push rax
- push fs
- push gs
- mov rsi, rcx ; rsi <- RegSet
- push sizeof (IA32_REGS)
- pop rcx
- movzx r8, (IA32_REGS ptr [rsi])._SS
- xor rdi, rdi
- mov edi, (IA32_REGS ptr [rsi])._ESP
- sub rdi, rcx ; reserve space on realmode stack
- push rdi ; save stack offset
- imul rax, r8, 16
- add rdi, rax ; rdi <- linear address of 16-bit stack
- rep movsb ; copy RegSet
- mov rsi, r8 ; si <- 16-bit stack segment
- pop rbx ; rbx <- 16-bit stack offset
- mov rdi, rdx ; rdi <- realmode patch
- lea eax, @BackToThunk ; rax <- address to back from real mode
- push rax ; use in a far return
- mov eax, cs
- mov [rsp + 4], eax ; save CS
- lea eax, @16Return ; thus @Return must < 4GB
- stosd ; set ret address offset
- xor eax, eax
- stosw ; set ret CS base to 0
- mov eax, esp
- stosd ; rsp must < 4GB
- mov eax, ss
- stosd
- mov rax, cr0
- mov ecx, eax ; ecx <- CR0
- and ecx, 7ffffffeh ; clear PE, PG bits
- stosd
- mov rax, cr4
- mov ebp, eax
- and ebp, 300h ; clear all but PCE and OSFXSR bits
- stosd
- sidt fword ptr [rsp + 70h] ; use parameter space to save IDTR
- sgdt fword ptr [rdi]
- lea edi, _16Idtr
- lea eax, @16Start ; rax <- seg:offset of @16Start
- push rax
- mov dword ptr [rsp + 4], 8
- push 10h
- pop rax ; rax <- 10h as dataseg selector
- lgdt _16Gdtr
- retf
-@16Start: ; 16-bit starts here
- mov ss, eax ; set SS to be a 16-bit segment
- mov cr0, rcx ; disable protected mode
- mov cr4, rbp
- DB 66h
- mov ecx, 0c0000080h
- rdmsr
- and ah, NOT 1 ; clear LME
- wrmsr
- mov ss, esi ; set up 16-bit stack
- mov sp, bx ; mov esp, ebx actually
- lidt fword ptr [edi]
- DB 66h, 61h ; popad
- DB 1fh ; pop ds
- DB 7 ; pop es
- pop fs
- pop gs
- add sp, 8 ; skip _RFLAGS
+ .const
+
+m16Size DW offset InternalAsmThunk16 - offset m16Start
+mThunk16Attr DW offset _ThunkAttr - offset m16Start
+m16Gdt DW offset _NullSegDesc - offset m16Start
+m16GdtrBase DW offset _16GdtrBase - offset m16Start
+mTransition DW offset _EntryPoint - offset m16Start
+
+ .code
+
+m16Start LABEL BYTE
+
+SavedGdt LABEL FWORD
+ DW ?
+ DQ ?
+
+_BackFromUserCode PROC
+ DB 16h ; push ss
+ DB 0eh ; push cs
DB 66h
- retf ; transfer control to 16-bit code
-@16Return:
+ call @Base ; push eip
+@Base:
DB 66h
- push 0 ; high order 32 bits of rflags
+ push 0 ; reserved high order 32 bits of EFlags
pushf ; pushfd actually
+ cli ; disable interrupts
push gs
push fs
DB 6 ; push es
DB 1eh ; push ds
DB 66h, 60h ; pushad
- DB 67h, 66h, 0c5h, 74h, 24h, 30h ; lds esi, [esp + 12*4]
- DB 66h
- mov eax, [esi + 12]
- mov cr4, rax ; restore CR4
- DB 66h
- lgdt fword ptr [esi + 16]
+ DB 66h, 0bah ; mov edx, imm32
+_ThunkAttr DD ?
+ test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15
+ jz @1
+ mov eax, 15cd2401h ; mov ax, 2401h & int 15h
+ cli ; disable interrupts
+ jnc @2
+@1:
+ test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL
+ jz @2
+ in al, 92h
+ or al, 2
+ out 92h, al ; deactivate A20M#
+@2:
+ mov eax, ss
+ lea bp, [esp + sizeof (IA32_REGS)]
+ mov word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp
+ mov ebx, (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._EIP
+ shl ax, 4 ; shl eax, 4
+ add bp, ax ; add ebp, eax
+ DB 66h, 0b8h ; mov eax, imm32
+SavedCr4 DD ?
+ mov cr4, rax
+ DB 66h, 2eh
+ lgdt fword ptr [rdi + (offset SavedGdt - offset @Base)]
DB 66h
mov ecx, 0c0000080h
rdmsr
- or ah, 1 ; set LME
+ or ah, 1
wrmsr
+ DB 66h, 0b8h ; mov eax, imm32
+SavedCr0 DD ?
+ mov cr0, rax
+ DB 0b8h ; mov ax, imm16
+SavedSs DW ?
+ mov ss, eax
+ DB 66h, 0bch ; mov esp, imm32
+SavedEsp DD ?
DB 66h
- mov eax, [esi + 8]
- mov cr0, rax ; restore CR0
- xor ax, ax ; xor eax, eax actually
- mov eax, ss
- mov dword ptr (IA32_REGS ptr [esp])._SS, eax
- shl ax, 4 ; shl eax, 4 actually
- add ax, sp ; add eax, esp actually
- add sp, sizeof (IA32_REGS) ; add esp, sizeof (IA32_REGS)
+ retf ; return to protected mode
+_BackFromUserCode ENDP
+
+_EntryPoint DD offset _ToUserCode - offset m16Start
+ DW 8h
+_16Gdtr LABEL FWORD
+ DW offset GdtEnd - offset _NullSegDesc - 1
+_16GdtrBase DQ offset _NullSegDesc
+_16Idtr FWORD (1 SHL 10) - 1
+
+_ToUserCode PROC
+ mov edi, ss
+ mov ss, edx ; set new segment selectors
+ mov ds, edx
+ mov es, edx
+ mov fs, edx
+ mov gs, edx
DB 66h
- mov dword ptr (IA32_REGS ptr [esp - sizeof (IA32_REGS)])._ESP, esp
+ mov ecx, 0c0000080h
+ mov cr0, rax ; real mode starts at next instruction
+ rdmsr
+ and ah, NOT 1
+ wrmsr
+ mov cr4, rbp
+ mov ss, esi ; set up 16-bit stack segment
+ xchg sp, bx ; set up 16-bit stack pointer
DB 66h
- lss esp, fword ptr [esi] ; restore protected mode stack
+ call @Base ; push eip
+@Base:
+ pop bp ; ebp <- offset @Base
+ DB 2eh ; cs:
+ mov [rsi + (offset SavedSs - offset @Base)], edi
+ DB 2eh ; cs:
+ mov [rsi + (offset SavedEsp - offset @Base)], bx
+ DB 66h, 2eh ; CS and operand size override
+ lidt fword ptr [rsi + (offset _16Idtr - offset @Base)]
+ DB 66h, 61h ; popad
+ DB 1fh ; pop ds
+ DB 07h ; pop es
+ pop fs
+ pop gs
+ popf ; popfd
+ lea sp, [esp + 4] ; skip high order 32 bits of EFlags
DB 66h
- retf ; go back to protected mode
-@BackToThunk:
- lidt fword ptr [rsp + 68h] ; restore protected mode IDTR
- shl rax, 32
- shr rax, 32 ; clear high order 32 bits of RAX
+ retf ; transfer control to user code
+_ToUserCode ENDP
+
+_NullSegDesc DQ 0
+_16CsDesc LABEL QWORD
+ DW -1
+ DW 0
+ DB 0
+ DB 9bh
+ DB 8fh ; 16-bit segment, 4GB limit
+ DB 0
+_16DsDesc LABEL QWORD
+ DW -1
+ DW 0
+ DB 0
+ DB 93h
+ DB 8fh ; 16-bit segment, 4GB limit
+ DB 0
+GdtEnd LABEL QWORD
+
+;
+; @param RegSet Pointer to a IA32_DWORD_REGS structure
+; @param Transition Pointer to the transition code
+; @return The address of the 16-bit stack after returning from user code
+;
+InternalAsmThunk16 PROC USES rbp rbx rsi rdi
+ mov r10d, ds
+ mov r11d, es
+ push fs
+ push gs
+ mov rsi, rcx
+ movzx r8d, (IA32_REGS ptr [rsi])._SS
+ mov edi, (IA32_REGS ptr [rsi])._ESP
+ lea rdi, [edi - (sizeof (IA32_REGS) + 4)]
+ imul eax, r8d, 16 ; eax <- r8d(stack segment) * 16
+ mov ebx, edi ; ebx <- stack offset for 16-bit code
+ push sizeof (IA32_REGS) / 4
+ add edi, eax ; edi <- linear address of 16-bit stack
+ pop rcx
+ rep movsd ; copy RegSet
+ lea ecx, [rdx + (offset SavedCr4 - offset m16Start)]
+ mov eax, edx ; eax <- transition code address
+ and edx, 0fh
+ shl eax, 12
+ lea edx, [rdx + (offset _BackFromUserCode - offset m16Start)]
+ mov ax, dx
+ stosd ; [edi] <- return address of user code
+ sgdt fword ptr [rcx + (offset SavedGdt - offset SavedCr4)]
+ sidt fword ptr [rsp + 38h] ; save IDT stack in argument space
+ mov rax, cr0
+ mov [rcx + (offset SavedCr0 - offset SavedCr4)], eax
+ and eax, 7ffffffeh ; clear PE, PG bits
+ mov rbp, cr4
+ mov [rcx], ebp ; save CR4 in SavedCr4
+ and ebp, 300h ; clear all but PCE and OSFXSR bits
+ mov esi, r8d ; esi <- 16-bit stack segment
+ push 10h
+ pop rdx ; rdx <- selector for data segments
+ lgdt fword ptr [rcx + (offset _16Gdtr - offset SavedCr4)]
+ call fword ptr [rcx + (offset _EntryPoint - offset SavedCr4)]
+ lidt fword ptr [rsp + 38h] ; restore protected mode IDTR
+ lea eax, [rbp - sizeof (IA32_REGS)]
pop gs
pop fs
- pop rcx
- mov es, ecx
- pop rcx
- mov ds, ecx
+ mov es, r11d
+ mov ds, r10d
ret
InternalAsmThunk16 ENDP
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