diff options
Diffstat (limited to 'MdePkg/Library/BaseLib/X64/Thunk16.S')
| -rw-r--r-- | MdePkg/Library/BaseLib/X64/Thunk16.S | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.S b/MdePkg/Library/BaseLib/X64/Thunk16.S index f592a2868c..fd03b97b56 100644 --- a/MdePkg/Library/BaseLib/X64/Thunk16.S +++ b/MdePkg/Library/BaseLib/X64/Thunk16.S @@ -1,6 +1,6 @@ #------------------------------------------------------------------------------
#
-# Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
# This program and the accompanying materials
# are licensed and made available under the terms and conditions of the BSD License
# which accompanies this distribution. The full text of the license may be found at
@@ -49,7 +49,7 @@ ASM_GLOBAL ASM_PFX(InternalAsmThunk16) .set IA32_REGS_SIZE, 56
.data
-
+
.set Lm16Size, ASM_PFX(InternalAsmThunk16) - ASM_PFX(m16Start)
ASM_PFX(m16Size): .word Lm16Size
.set LmThunk16Attr, L_ThunkAttr - ASM_PFX(m16Start)
@@ -85,7 +85,7 @@ ASM_PFX(BackFromUserCode): .byte 0xe # push cs
.byte 0x66
call L_Base # push eip
-L_Base:
+L_Base:
.byte 0x66
pushq $0 # reserved high order 32 bits of EFlags
.byte 0x66, 0x9c # pushfd actually
@@ -102,13 +102,13 @@ L_ThunkAttr: .space 4 movl $0x15cd2401,%eax # mov ax, 2401h & int 15h
cli # disable interrupts
jnc L_2
-L_1:
+L_1:
testb $THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL, %dl
jz L_2
inb $0x92,%al
orb $2,%al
outb %al, $0x92 # deactivate A20M#
-L_2:
+L_2:
xorw %ax, %ax # xor eax, eax
movl %ss, %eax # mov ax, ss
lea IA32_REGS_SIZE(%esp), %bp
@@ -180,13 +180,13 @@ ASM_PFX(ToUserCode): movw %bx,%sp # set up 16-bit stack pointer
.byte 0x66 # make the following call 32-bit
call L_Base1 # push eip
-L_Base1:
+L_Base1:
popw %bp # ebp <- address of L_Base1
pushq (IA32_REGS_SIZE + 2)(%esp)
lea 0x0c(%rsi), %eax
pushq %rax
lret # execution begins at next instruction
-L_RealMode:
+L_RealMode:
.byte 0x66,0x2e # CS and operand size override
lidt (_16Idtr - L_Base1)(%rsi)
.byte 0x66,0x61 # popad
@@ -243,7 +243,7 @@ ASM_PFX(InternalAsmThunk16): pushq %rbx
pushq %rsi
pushq %rdi
-
+
movl %ds, %ebx
pushq %rbx # Save ds segment register on the stack
movl %es, %ebx
@@ -257,7 +257,7 @@ ASM_PFX(InternalAsmThunk16): movzwl _SS(%rsi), %r8d
movl _ESP(%rsi), %edi
lea -(IA32_REGS_SIZE + 4)(%edi), %rdi
- imul $16, %r8d, %eax
+ imul $16, %r8d, %eax
movl %edi,%ebx # ebx <- stack for 16-bit code
pushq $(IA32_REGS_SIZE / 4)
addl %eax,%edi # edi <- linear address of 16-bit stack
@@ -268,26 +268,26 @@ ASM_PFX(InternalAsmThunk16): movl %edx,%eax # eax <- transition code address
andl $0xf,%edx
shll $12,%eax # segment address in high order 16 bits
- .set LBackFromUserCodeDelta, ASM_PFX(BackFromUserCode) - ASM_PFX(m16Start)
+ .set LBackFromUserCodeDelta, ASM_PFX(BackFromUserCode) - ASM_PFX(m16Start)
lea (LBackFromUserCodeDelta)(%rdx), %ax
stosl # [edi] <- return address of user code
sgdt 0x60(%rsp) # save GDT stack in argument space
- movzwq 0x60(%rsp), %r10 # r10 <- GDT limit
- lea ((ASM_PFX(InternalAsmThunk16) - L_SavedCr4) + 0xf)(%rcx), %r11
- andq $0xfffffffffffffff0, %r11 # r11 <- 16-byte aligned shadowed GDT table in real mode buffer
-
+ movzwq 0x60(%rsp), %r10 # r10 <- GDT limit
+ lea ((ASM_PFX(InternalAsmThunk16) - L_SavedCr4) + 0xf)(%rcx), %r11
+ andq $0xfffffffffffffff0, %r11 # r11 <- 16-byte aligned shadowed GDT table in real mode buffer
+
movw %r10w, (SavedGdt - L_SavedCr4)(%rcx) # save the limit of shadowed GDT table
movq %r11, (SavedGdt - L_SavedCr4 + 0x2)(%rcx) # save the base address of shadowed GDT table
-
+
movq 0x62(%rsp) ,%rsi # rsi <- the original GDT base address
- xchg %r10, %rcx # save rcx to r10 and initialize rcx to be the limit of GDT table
+ xchg %r10, %rcx # save rcx to r10 and initialize rcx to be the limit of GDT table
incq %rcx # rcx <- the size of memory to copy
xchg %r11, %rdi # save rdi to r11 and initialize rdi to the base address of shadowed GDT table
rep
movsb # perform memory copy to shadow GDT table
movq %r10, %rcx # restore the orignal rcx before memory copy
movq %r11, %rdi # restore the original rdi before memory copy
-
+
sidt 0x50(%rsp)
movq %cr0, %rax
.set LSavedCrDelta, L_SavedCr0 - L_SavedCr4
@@ -311,21 +311,21 @@ ASM_PFX(InternalAsmThunk16): .byte 0xff, 0x69 # jmp (_EntryPoint - L_SavedCr4)(%rcx)
.set Ltemp1, _EntryPoint - L_SavedCr4
.byte Ltemp1
-L_RetFromRealMode:
+L_RetFromRealMode:
popfq
lgdt 0x60(%rsp) # restore protected mode GDTR
lidt 0x50(%rsp) # restore protected mode IDTR
lea -IA32_REGS_SIZE(%rbp), %eax
.byte 0x0f, 0xa9 # pop gs
.byte 0x0f, 0xa1 # pop fs
-
+
popq %rbx
movl %ebx, %ss
popq %rbx
movl %ebx, %es
popq %rbx
movl %ebx, %ds
-
+
popq %rdi
popq %rsi
popq %rbx
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