diff options
Diffstat (limited to 'EdkCompatibilityPkg')
| -rw-r--r-- | EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ia32/Thunk16.S | 63 |
1 files changed, 20 insertions, 43 deletions
diff --git a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ia32/Thunk16.S b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ia32/Thunk16.S index a2ba94bdaa..0f144e714b 100644 --- a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ia32/Thunk16.S +++ b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ia32/Thunk16.S @@ -24,27 +24,6 @@ .globl ASM_PFX(m16Start), ASM_PFX(m16Size), ASM_PFX(mThunk16Attr), ASM_PFX(m16Gdt), ASM_PFX(m16GdtrBase), ASM_PFX(mTransition)
.globl 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
@@ -78,17 +57,15 @@ ASM_PFX(ThunkAttr): .space 4 2:
xorw %ax, %ax # xor eax, eax
movl %ss, %eax # mov ax, ss
- .byte 0x67
- lea IA32_REGS_SIZE(%esp), %bp
- .byte 0x66
- mov %ebp, (_ESP - IA32_REGS_SIZE)(%esi)
- mov (_EIP - IA32_REGS_SIZE)(%esi), %ebx
+ .byte 0x67, 0x66, 0x8d, 0x6c, 0x24, 0x34, 0x66
+ mov %ebp, 0xffffffd8(%esi)
+ mov 0xfffffff8(%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:(SavedGdt - L_Base1)(%edi)
+ lgdtw %cs:0xfffffff2(%edi)
.byte 0x66, 0xb8 # mov eax, imm32
SavedCr0: .space 4
movl %eax, %cr0
@@ -123,15 +100,15 @@ ASM_PFX(ToUserCode): L_Base:
popw %bp # ebp <- offset L_Base
.byte 0x67; # address size override
- push (IA32_REGS_SIZE + 2)(%esp)
- lea (L_RealMode - L_Base)(%esi), %eax
+ push 54(%esp)
+ lea 0xc(%esi), %eax
push %eax
lret
L_RealMode:
- mov %edx, %cs:(SavedSs - L_Base)(%esi)
- mov %bx, %cs:(SavedEsp - L_Base)(%esi)
- lidtw %cs:(_16Idtr - L_Base)(%esi)
+ mov %edx, %cs:0xffffffc5(%esi)
+ mov %bx, %cs:0xffffffcb(%esi)
+ lidtw %cs:0xffffffd7(%esi)
popaw # popad actually
pop %ds
pop %es
@@ -172,41 +149,41 @@ ASM_PFX(InternalAsmThunk16): push %fs
push %gs
movl 36(%esp), %esi # esi <- RegSet
- movzwl _SS(%esi), %edx
- mov _ESP(%esi), %edi
- add $(-(IA32_REGS_SIZE + 4)), %edi
+ movzwl 0x32(%esi), %edx
+ mov 0xc(%esi), %edi
+ add $0xffffffc8, %edi
movl %edi, %ebx # ebx <- stack offset
imul $0x10, %edx, %eax
- push $(IA32_REGS_SIZE / 4)
+ push $0xd
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 (SavedCr0 - ASM_PFX(m16Start))(%eax), %edx
+ lea 0x61(%eax), %edx
movl %eax, %ecx
andl $0xf, %ecx
shll $12, %eax
- lea (ASM_PFX(BackFromUserCode) - ASM_PFX(m16Start))(%ecx), %ecx
+ lea 0x6(%ecx), %ecx
movw %cx, %ax
stosl # [edi] <- return address of user code
- sgdtl (SavedGdt - SavedCr0)(%edx)
+ sgdtl 0xffffff9f(%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, (SavedCr4 - SavedCr0)(%edx)
+ mov %ebp, 0xfffffff1(%edx)
andl $0x300, %ebp # clear all but PCE and OSFXSR bits
pushl $0x10
pop %ecx # ecx <- selector for data segments
- lgdtl (_16Gdtr - SavedCr0)(%edx)
+ lgdtl 0x20(%edx)
pushfl
- lcall *(_EntryPoint - SavedCr0)(%edx)
+ lcall *0x14(%edx)
popfl
lidtl 0x24(%esp)
- lea -IA32_REGS_SIZE(%ebp), %eax
+ lea 0xffffffcc(%ebp), %eax
pop %gs
pop %fs
pop %es
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