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author | lgao4 <lgao4@6f19259b-4bc3-4df7-8a09-765794883524> | 2011-12-20 09:50:19 +0000 |
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committer | lgao4 <lgao4@6f19259b-4bc3-4df7-8a09-765794883524> | 2011-12-20 09:50:19 +0000 |
commit | fe2876127550a7c8a0e7d2d0f47203154a5d6969 (patch) | |
tree | adf47a7fe855f88377f51eb84762777ecef98947 /MdePkg/Library/BaseLib/Ia32/Thunk16.S | |
parent | 665e08a0ca7e2c9a64eb86036913e87298d86277 (diff) | |
download | edk2-platforms-fe2876127550a7c8a0e7d2d0f47203154a5d6969.tar.xz |
Clean up the hard code offset in MdePkg BaseLib Ia32 Thunk16.S and EcpPkg GlueLib BaseLib Ia32 Thunk16.S.
Signed-off-by: lgao4
Reviewed-by: rsun3
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12889 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'MdePkg/Library/BaseLib/Ia32/Thunk16.S')
-rw-r--r-- | MdePkg/Library/BaseLib/Ia32/Thunk16.S | 63 |
1 files changed, 43 insertions, 20 deletions
diff --git a/MdePkg/Library/BaseLib/Ia32/Thunk16.S b/MdePkg/Library/BaseLib/Ia32/Thunk16.S index d45a0d40b1..2cb781582a 100644 --- a/MdePkg/Library/BaseLib/Ia32/Thunk16.S +++ b/MdePkg/Library/BaseLib/Ia32/Thunk16.S @@ -24,6 +24,27 @@ ASM_GLOBAL ASM_PFX(m16Start), ASM_PFX(m16Size), ASM_PFX(mThunk16Attr), ASM_PFX(m16Gdt), ASM_PFX(m16GdtrBase), ASM_PFX(mTransition)
ASM_GLOBAL ASM_PFX(InternalAsmThunk16)
+# define the structure of IA32_REGS
+.set _EDI, 0 #size 4
+.set _ESI, 4 #size 4
+.set _EBP, 8 #size 4
+.set _ESP, 12 #size 4
+.set _EBX, 16 #size 4
+.set _EDX, 20 #size 4
+.set _ECX, 24 #size 4
+.set _EAX, 28 #size 4
+.set _DS, 32 #size 2
+.set _ES, 34 #size 2
+.set _FS, 36 #size 2
+.set _GS, 38 #size 2
+.set _EFLAGS, 40 #size 4
+.set _EIP, 44 #size 4
+.set _CS, 48 #size 2
+.set _SS, 50 #size 2
+.set IA32_REGS_SIZE, 52
+
+ .text
+
ASM_PFX(m16Start):
SavedGdt: .space 6
@@ -57,15 +78,17 @@ ASM_PFX(ThunkAttr): .space 4 2:
xorw %ax, %ax # xor eax, eax
movl %ss, %eax # mov ax, ss
- .byte 0x67, 0x66, 0x8d, 0x6c, 0x24, 0x34, 0x66
- mov %ebp, 0xffffffd8(%esi)
- mov 0xfffffff8(%esi), %ebx
+ .byte 0x67
+ lea IA32_REGS_SIZE(%esp), %bp
+ .byte 0x66
+ mov %ebp, (_ESP - IA32_REGS_SIZE)(%esi)
+ mov (_EIP - IA32_REGS_SIZE)(%esi), %ebx
shlw $4, %ax # shl eax, 4
addw %ax, %bp # add ebp, eax
.byte 0x66, 0xb8 # mov eax, imm32
SavedCr4: .space 4
movl %eax, %cr4
- lgdtw %cs:0xfffffff2(%edi)
+ lgdtw %cs:(SavedGdt - L_Base1)(%edi)
.byte 0x66, 0xb8 # mov eax, imm32
SavedCr0: .space 4
movl %eax, %cr0
@@ -100,15 +123,15 @@ ASM_PFX(ToUserCode): L_Base:
popw %bp # ebp <- offset L_Base
.byte 0x67; # address size override
- push 54(%esp)
- lea 0xc(%esi), %eax
+ push (IA32_REGS_SIZE + 2)(%esp)
+ lea (L_RealMode - L_Base)(%esi), %eax
push %eax
lret
L_RealMode:
- mov %edx, %cs:0xffffffc5(%esi)
- mov %bx, %cs:0xffffffcb(%esi)
- lidtw %cs:0xffffffd7(%esi)
+ mov %edx, %cs:(SavedSs - L_Base)(%esi)
+ mov %bx, %cs:(SavedEsp - L_Base)(%esi)
+ lidtw %cs:(_16Idtr - L_Base)(%esi)
popaw # popad actually
pop %ds
pop %es
@@ -149,41 +172,41 @@ ASM_PFX(InternalAsmThunk16): push %fs
push %gs
movl 36(%esp), %esi # esi <- RegSet
- movzwl 0x32(%esi), %edx
- mov 0xc(%esi), %edi
- add $0xffffffc8, %edi
+ movzwl _SS(%esi), %edx
+ mov _ESP(%esi), %edi
+ add $(-(IA32_REGS_SIZE + 4)), %edi
movl %edi, %ebx # ebx <- stack offset
imul $0x10, %edx, %eax
- push $0xd
+ push $(IA32_REGS_SIZE / 4)
addl %eax, %edi # edi <- linear address of 16-bit stack
pop %ecx
rep
movsl # copy RegSet
movl 40(%esp), %eax # eax <- address of transition code
movl %edx, %esi # esi <- 16-bit stack segment
- lea 0x5f(%eax), %edx
+ lea (SavedCr0 - ASM_PFX(m16Start))(%eax), %edx
movl %eax, %ecx
andl $0xf, %ecx
shll $12, %eax
- lea 0x6(%ecx), %ecx
+ lea (ASM_PFX(BackFromUserCode) - ASM_PFX(m16Start))(%ecx), %ecx
movw %cx, %ax
stosl # [edi] <- return address of user code
- sgdtl 0xffffffa1(%edx)
+ sgdtl (SavedGdt - SavedCr0)(%edx)
sidtl 0x24(%esp)
movl %cr0, %eax
movl %eax, (%edx) # save CR0 in SavedCr0
andl $0x7ffffffe, %eax # clear PE, PG bits
movl %cr4, %ebp
- mov %ebp, 0xfffffff1(%edx)
+ mov %ebp, (SavedCr4 - SavedCr0)(%edx)
andl $0x300, %ebp # clear all but PCE and OSFXSR bits
pushl $0x10
pop %ecx # ecx <- selector for data segments
- lgdtl 0x20(%edx)
+ lgdtl (_16Gdtr - SavedCr0)(%edx)
pushfl
- lcall *0x14(%edx)
+ lcall *(_EntryPoint - SavedCr0)(%edx)
popfl
lidtl 0x24(%esp)
- lea 0xffffffcc(%ebp), %eax
+ lea -IA32_REGS_SIZE(%ebp), %eax
pop %gs
pop %fs
pop %es
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