diff options
author | Jordan Justen <jordan.l.justen@intel.com> | 2014-09-01 17:23:57 +0000 |
---|---|---|
committer | jljusten <jljusten@6f19259b-4bc3-4df7-8a09-765794883524> | 2014-09-01 17:23:57 +0000 |
commit | 7458df400cc77fde6940bde211285c37ee642dc4 (patch) | |
tree | 073fb01d80a03a82f5dd3ee414d8f1036ac37df2 /MdePkg/Library/BaseLib/X64 | |
parent | f6888eea465a8e293cb46b56c16f9f63eed43f3d (diff) | |
download | edk2-platforms-7458df400cc77fde6940bde211285c37ee642dc4.tar.xz |
MdePkg BaseLib NASM Thunk16: Remove remaining 'DB' code
Convert remaining 'DB' code to assembly code by:
* Move instruction immediate data labels to end of instruction
* Use strict keyword to make sure immediate data size is not optimized
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16024 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'MdePkg/Library/BaseLib/X64')
-rw-r--r-- | MdePkg/Library/BaseLib/X64/Thunk16.nasm | 48 |
1 files changed, 23 insertions, 25 deletions
diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.nasm b/MdePkg/Library/BaseLib/X64/Thunk16.nasm index 5fa705998e..d15984b01c 100644 --- a/MdePkg/Library/BaseLib/X64/Thunk16.nasm +++ b/MdePkg/Library/BaseLib/X64/Thunk16.nasm @@ -57,7 +57,7 @@ SECTION .data ; These are global constant to convey information to C code.
;
ASM_PFX(m16Size) DW InternalAsmThunk16 - ASM_PFX(m16Start)
-ASM_PFX(mThunk16Attr) DW _BackFromUserCode.ThunkAttr - ASM_PFX(m16Start)
+ASM_PFX(mThunk16Attr) DW _BackFromUserCode.ThunkAttrEnd - 4 - ASM_PFX(m16Start)
ASM_PFX(m16Gdt) DW _NullSeg - ASM_PFX(m16Start)
ASM_PFX(m16GdtrBase) DW _16GdtrBase - ASM_PFX(m16Start)
ASM_PFX(mTransition) DW _EntryPoint - ASM_PFX(m16Start)
@@ -93,8 +93,8 @@ o32 call dword .Base ; push eip push es
push ds
pushad
- DB 66h, 0bah ; mov edx, imm32
-.ThunkAttr: dd 0
+ mov edx, strict dword 0
+.ThunkAttrEnd:
test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15
jz .1
mov ax, 2401h
@@ -117,27 +117,25 @@ o32 call dword .Base ; push eip add ebp, eax ; add ebp, eax
mov eax, cs
shl eax, 4
- lea eax, [eax + ebx + (.64BitCode - .Base)]
- mov [cs:bx + (.64Eip - .Base)], eax
- DB 66h, 0b8h ; mov eax, imm32
-.SavedCr4: DD 0
+ lea eax, [eax + ebx + (.X64JmpEnd - .Base)]
+ mov [cs:bx + (.X64JmpEnd - 6 - .Base)], eax
+ mov eax, strict dword 0
+.SavedCr4End:
mov cr4, eax
o32 lgdt [cs:bx + (SavedGdt - .Base)]
mov ecx, 0c0000080h
rdmsr
or ah, 1
wrmsr
- DB 66h, 0b8h ; mov eax, imm32
-.SavedCr0: DD 0
+ mov eax, strict dword 0
+.SavedCr0End:
mov cr0, eax
- DB 66h, 0eah ; jmp far cs:.64Bit
-.64Eip: DD 0
-.SavedCs: DW 0
-.64BitCode:
+ jmp 0:strict dword 0
+.X64JmpEnd:
BITS 64
nop
- db 048h, 0bch ; mov rsp, imm64
-.SavedSp: DQ 0 ; restore stack
+ mov rsp, strict qword 0
+.SavedSpEnd:
nop
ret
@@ -258,7 +256,7 @@ BITS 64 add edi, eax ; edi <- linear address of 16-bit stack
pop rcx
rep movsd ; copy RegSet
- lea ecx, [rdx + (_BackFromUserCode.SavedCr4 - ASM_PFX(m16Start))]
+ lea ecx, [rdx + (_BackFromUserCode.SavedCr4End - ASM_PFX(m16Start))]
mov eax, edx ; eax <- transition code address
and edx, 0fh
shl eax, 12 ; segment address in high order 16 bits
@@ -267,11 +265,11 @@ BITS 64 sgdt [rsp + 60h] ; save GDT stack in argument space
movzx r10, word [rsp + 60h] ; r10 <- GDT limit
- lea r11, [rcx + (InternalAsmThunk16 - _BackFromUserCode.SavedCr4) + 0xf]
+ lea r11, [rcx + (InternalAsmThunk16 - _BackFromUserCode.SavedCr4End) + 0xf]
and r11, ~0xf ; r11 <- 16-byte aligned shadowed GDT table in real mode buffer
- mov [rcx + (SavedGdt - _BackFromUserCode.SavedCr4)], r10w ; save the limit of shadowed GDT table
- mov [rcx + (SavedGdt - _BackFromUserCode.SavedCr4) + 2], r11 ; save the base address of shadowed GDT table
+ mov [rcx + (SavedGdt - _BackFromUserCode.SavedCr4End)], r10w ; save the limit of shadowed GDT table
+ mov [rcx + (SavedGdt - _BackFromUserCode.SavedCr4End) + 2], r11 ; save the base address of shadowed GDT table
mov rsi, [rsp + 62h] ; rsi <- the original GDT base address
xchg rcx, r10 ; save rcx to r10 and initialize rcx to be the limit of GDT table
@@ -283,24 +281,24 @@ BITS 64 sidt [rsp + 50h] ; save IDT stack in argument space
mov rax, cr0
- mov [rcx + (_BackFromUserCode.SavedCr0 - _BackFromUserCode.SavedCr4)], eax
+ mov [rcx + (_BackFromUserCode.SavedCr0End - 4 - _BackFromUserCode.SavedCr4End)], eax
and eax, 7ffffffeh ; clear PE, PG bits
mov rbp, cr4
- mov [rcx], ebp ; save CR4 in _BackFromUserCode.SavedCr4
+ mov [rcx - 4], ebp ; save CR4 in _BackFromUserCode.SavedCr4End - 4
and ebp, ~30h ; clear PAE, PSE bits
mov esi, r8d ; esi <- 16-bit stack segment
push DATA32
pop rdx ; rdx <- 32-bit data segment selector
- lgdt [rcx + (_16Gdtr - _BackFromUserCode.SavedCr4)]
+ lgdt [rcx + (_16Gdtr - _BackFromUserCode.SavedCr4End)]
mov ss, edx
pushfq
lea edx, [rdx + DATA16 - DATA32]
lea r8, [REL .RetFromRealMode]
push r8
mov r8d, cs
- mov [rcx + (_BackFromUserCode.SavedCs - _BackFromUserCode.SavedCr4)], r8w
- mov [rcx + (_BackFromUserCode.SavedSp - _BackFromUserCode.SavedCr4)], rsp
- jmp dword far [rcx + (_EntryPoint - _BackFromUserCode.SavedCr4)]
+ mov [rcx + (_BackFromUserCode.X64JmpEnd - 2 - _BackFromUserCode.SavedCr4End)], r8w
+ mov [rcx + (_BackFromUserCode.SavedSpEnd - 8 - _BackFromUserCode.SavedCr4End)], rsp
+ jmp dword far [rcx + (_EntryPoint - _BackFromUserCode.SavedCr4End)]
.RetFromRealMode:
popfq
lgdt [rsp + 60h] ; restore protected mode GDTR
|