diff options
Diffstat (limited to 'MdePkg/Library/BaseLib/X64/Thunk16.S')
-rw-r--r-- | MdePkg/Library/BaseLib/X64/Thunk16.S | 596 |
1 files changed, 298 insertions, 298 deletions
diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.S b/MdePkg/Library/BaseLib/X64/Thunk16.S index 83c121f525..5885bb3a57 100644 --- a/MdePkg/Library/BaseLib/X64/Thunk16.S +++ b/MdePkg/Library/BaseLib/X64/Thunk16.S @@ -1,298 +1,298 @@ -#------------------------------------------------------------------------------ -# -# Copyright (c) 2006 - 2008, Intel Corporation -# All rights reserved. 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 -# http://opensource.org/licenses/bsd-license.php -# -# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, -# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. -# -# Module Name: -# -# Thunk16.S -# -# Abstract: -# -# Real mode thunk -# -#------------------------------------------------------------------------------ - -#include <Library/BaseLib.h> - -.globl ASM_PFX(m16Start) -.globl ASM_PFX(m16Size) -.globl ASM_PFX(mThunk16Attr) -.globl ASM_PFX(m16Gdt) -.globl ASM_PFX(m16GdtrBase) -.globl ASM_PFX(mTransition) -.globl ASM_PFX(InternalAsmThunk16) - -# define the structure of IA32_REGS -.equ _EDI, 0 #size 4 -.equ _ESI, 4 #size 4 -.equ _EBP, 8 #size 4 -.equ _ESP, 12 #size 4 -.equ _EBX, 16 #size 4 -.equ _EDX, 20 #size 4 -.equ _ECX, 24 #size 4 -.equ _EAX, 28 #size 4 -.equ _DS, 32 #size 2 -.equ _ES, 34 #size 2 -.equ _FS, 36 #size 2 -.equ _GS, 38 #size 2 -.equ _EFLAGS, 40 #size 8 -.equ _EIP, 48 #size 4 -.equ _CS, 52 #size 2 -.equ _SS, 54 #size 2 -.equ IA32_REGS_SIZE, 56 - - .data - -ASM_PFX(m16Size): .word ASM_PFX(InternalAsmThunk16) - ASM_PFX(m16Start) -ASM_PFX(mThunk16Attr): .word _ThunkAttr - ASM_PFX(m16Start) -ASM_PFX(m16Gdt): .word _NullSeg - ASM_PFX(m16Start) -ASM_PFX(m16GdtrBase): .word _16GdtrBase - ASM_PFX(m16Start) -ASM_PFX(mTransition): .word _EntryPoint - ASM_PFX(m16Start) - - .text - -ASM_PFX(m16Start): - -SavedGdt: .space 10 - -#------------------------------------------------------------------------------ -# _BackFromUserCode() takes control in real mode after 'retf' has been executed -# by user code. It will be shadowed to somewhere in memory below 1MB. -#------------------------------------------------------------------------------ -.globl ASM_PFX(BackFromUserCode) -ASM_PFX(BackFromUserCode): - # - # The order of saved registers on the stack matches the order they appears - # in IA32_REGS structure. This facilitates wrapper function to extract them - # into that structure. - # - # Some instructions for manipulation of segment registers have to be written - # in opcode since 64-bit MASM prevents accesses to those registers. - # - .byte 0x16 # push ss - .byte 0xe # push cs - .byte 0x66 - call L_Base # push eip -L_Base: - .byte 0x66 - pushq $0 # reserved high order 32 bits of EFlags - .byte 0x66, 0x9c # pushfd actually - cli # disable interrupts - push %gs - push %fs - .byte 6 # push es - .byte 0x1e # push ds - .byte 0x66,0x60 # pushad - .byte 0x66,0xba # mov edx, imm32 -_ThunkAttr: .space 4 - testb $THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15, %dl - jz L_1 - movl $0x15cd2401,%eax # mov ax, 2401h & int 15h - cli # disable interrupts - jnc L_2 -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: - movl %ss,%eax - lea IA32_REGS_SIZE(%esp), %bp - # - # rsi in the following 2 instructions is indeed bp in 16-bit code - # - movw %bp, (_ESP - IA32_REGS_SIZE)(%rsi) - .byte 0x66 - movl (_EIP - IA32_REGS_SIZE)(%rsi), %ebx - shlw $4,%ax # shl eax, 4 - addw %ax,%bp # add ebp, eax - movw %cs,%ax - shlw $4,%ax - lea (L_64BitCode - L_Base)(%ebx, %eax), %ax - .byte 0x66,0x2e,0x89,0x87 # mov cs:[bx + (L_64Eip - L_Base)], eax - .word L_64Eip - L_Base - .byte 0x66,0xb8 # mov eax, imm32 -SavedCr4: .space 4 - movq %rax, %cr4 - # - # rdi in the instruction below is indeed bx in 16-bit code - # - .byte 0x66,0x2e # 2eh is "cs:" segment override - lgdt (SavedGdt - L_Base)(%rdi) - .byte 0x66 - movl $0xc0000080,%ecx - rdmsr - orb $1,%ah - wrmsr - .byte 0x66,0xb8 # mov eax, imm32 -SavedCr0: .space 4 - movq %rax, %cr0 - .byte 0x66,0xea # jmp far cs:L_64Bit -L_64Eip: .space 4 -SavedCs: .space 2 -L_64BitCode: - movq %r8, %rsp - ret - -_EntryPoint: .long ASM_PFX(ToUserCode) - ASM_PFX(m16Start) - .word CODE16 -_16Gdtr: .word GDT_SIZE - 1 -_16GdtrBase: .quad _NullSeg -_16Idtr: .word 0x3ff - .long 0 - -#------------------------------------------------------------------------------ -# _ToUserCode() takes control in real mode before passing control to user code. -# It will be shadowed to somewhere in memory below 1MB. -#------------------------------------------------------------------------------ -.globl ASM_PFX(ToUserCode) -ASM_PFX(ToUserCode): - movl %edx,%ss # set new segment selectors - movl %edx,%ds - movl %edx,%es - movl %edx,%fs - movl %edx,%gs - .byte 0x66 - movl $0xc0000080,%ecx - movq %rax, %cr0 - rdmsr - andb $0b11111110, %ah - wrmsr - movq %rbp, %cr4 - movl %esi,%ss # set up 16-bit stack segment - movw %bx,%sp # set up 16-bit stack pointer - .byte 0x66 # make the following call 32-bit - call L_Base1 # push eip -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: - .byte 0x66,0x2e # CS and operand size override - lidt (_16Idtr - L_Base1)(%rsi) - .byte 0x66,0x61 # popad - .byte 0x1f # pop ds - .byte 0x7 # pop es - .byte 0x0f, 0xa1 # pop fs - .byte 0x0f, 0xa9 # pop gs - .byte 0x66, 0x9d # popfd - leaw 4(%esp),%sp # skip high order 32 bits of EFlags - .byte 0x66 # make the following retf 32-bit - lret # transfer control to user code - -.equ CODE16, ASM_PFX(16Code) - . -.equ DATA16, ASM_PFX(16Data) - . -.equ DATA32, ASM_PFX(32Data) - . - -_NullSeg: .quad 0 -ASM_PFX(16Code): - .word -1 - .word 0 - .byte 0 - .byte 0x9b - .byte 0x8f # 16-bit segment, 4GB limit - .byte 0 -ASM_PFX(16Data): - .word -1 - .word 0 - .byte 0 - .byte 0x93 - .byte 0x8f # 16-bit segment, 4GB limit - .byte 0 -ASM_PFX(32Data): - .word -1 - .word 0 - .byte 0 - .byte 0x93 - .byte 0xcf # 16-bit segment, 4GB limit - .byte 0 - -.equ GDT_SIZE, . - ASM_PFX(NullSeg) - -#------------------------------------------------------------------------------ -# IA32_REGISTER_SET * -# EFIAPI -# InternalAsmThunk16 ( -# IN IA32_REGISTER_SET *RegisterSet, -# IN OUT VOID *Transition -# ); -#------------------------------------------------------------------------------ -# MISMATCH: "InternalAsmThunk16 PROC USES rbp rbx rsi rdi" - -.globl ASM_PFX(InternalAsmThunk16) -ASM_PFX(InternalAsmThunk16): - pushq %rbp - pushq %rbx - pushq %rsi - pushq %rdi - - movl %ds, %r10d # r9 ~ r11 are not accessible in 16-bit - movl %es, %r11d # so use them for saving seg registers - movl %ss, %r9d - .byte 0x0f, 0xa0 #push fs - .byte 0x0f, 0xa8 #push gs - movq %rcx, %rsi - movzwl _SS(%rsi), %r8d - movl _ESP(%rsi), %edi - lea -(IA32_REGS_SIZE + 4)(%edi), %rdi - 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 - popq %rcx - rep - movsl # copy RegSet - lea (SavedCr4 - ASM_PFX(m16Start))(%rdx), %ecx - movl %edx,%eax # eax <- transition code address - andl $0xf,%edx - shll $12,%eax # segment address in high order 16 bits - lea (_BackFromUserCode - ASM_PFX(m16Start))(%rdx), %ax - stosl # [edi] <- return address of user code - sgdt (SavedGdt - SavedCr4)(%rcx) - sidt 0x38(%rsp) - movq %cr0, %rax - movl %eax, (SavedCr0 - SavedCr4)(%rcx) - andl $0x7ffffffe,%eax # clear PE, PG bits - movq %cr4, %rbp - movl %ebp, (%rcx) # save CR4 in SavedCr4 - andl $0x300,%ebp # clear all but PCE and OSFXSR bits - movl %r8d, %esi # esi <- 16-bit stack segment - .byte 0x6a, DATA32 - popq %rdx - lgdt (_16Gdtr - SavedCr4)(%rcx) - movl %edx,%ss - pushfq - lea -8(%rdx), %edx - lea L_RetFromRealMode, %r8 - pushq %r8 - movl %cs, %r8d - movw %r8w, (SavedCs - SavedCr4)(%rcx) - movq %rsp, %r8 - .byte 0xff, 0x69 # jmp (_EntryPoint - SavedCr4)(%rcx) - .byte _EntryPoint - SavedCr4 -L_RetFromRealMode: - popfq - lidt 0x38(%rsp) - lea -IA32_REGS_SIZE(%rbp), %eax - .byte 0x0f, 0xa9 # pop gs - .byte 0x0f, 0xa1 # pop fs - movl %r9d, %ss - movl %r11d, %es - movl %r10d, %ds - - popq %rdi - popq %rsi - popq %rbx - popq %rbp - - ret +#------------------------------------------------------------------------------
+#
+# Copyright (c) 2006 - 2008, Intel Corporation
+# All rights reserved. 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
+# http://opensource.org/licenses/bsd-license.php
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+# Module Name:
+#
+# Thunk16.S
+#
+# Abstract:
+#
+# Real mode thunk
+#
+#------------------------------------------------------------------------------
+
+#include <Library/BaseLib.h>
+
+.globl ASM_PFX(m16Start)
+.globl ASM_PFX(m16Size)
+.globl ASM_PFX(mThunk16Attr)
+.globl ASM_PFX(m16Gdt)
+.globl ASM_PFX(m16GdtrBase)
+.globl ASM_PFX(mTransition)
+.globl ASM_PFX(InternalAsmThunk16)
+
+# define the structure of IA32_REGS
+.equ _EDI, 0 #size 4
+.equ _ESI, 4 #size 4
+.equ _EBP, 8 #size 4
+.equ _ESP, 12 #size 4
+.equ _EBX, 16 #size 4
+.equ _EDX, 20 #size 4
+.equ _ECX, 24 #size 4
+.equ _EAX, 28 #size 4
+.equ _DS, 32 #size 2
+.equ _ES, 34 #size 2
+.equ _FS, 36 #size 2
+.equ _GS, 38 #size 2
+.equ _EFLAGS, 40 #size 8
+.equ _EIP, 48 #size 4
+.equ _CS, 52 #size 2
+.equ _SS, 54 #size 2
+.equ IA32_REGS_SIZE, 56
+
+ .data
+
+ASM_PFX(m16Size): .word ASM_PFX(InternalAsmThunk16) - ASM_PFX(m16Start)
+ASM_PFX(mThunk16Attr): .word _ThunkAttr - ASM_PFX(m16Start)
+ASM_PFX(m16Gdt): .word _NullSeg - ASM_PFX(m16Start)
+ASM_PFX(m16GdtrBase): .word _16GdtrBase - ASM_PFX(m16Start)
+ASM_PFX(mTransition): .word _EntryPoint - ASM_PFX(m16Start)
+
+ .text
+
+ASM_PFX(m16Start):
+
+SavedGdt: .space 10
+
+#------------------------------------------------------------------------------
+# _BackFromUserCode() takes control in real mode after 'retf' has been executed
+# by user code. It will be shadowed to somewhere in memory below 1MB.
+#------------------------------------------------------------------------------
+.globl ASM_PFX(BackFromUserCode)
+ASM_PFX(BackFromUserCode):
+ #
+ # The order of saved registers on the stack matches the order they appears
+ # in IA32_REGS structure. This facilitates wrapper function to extract them
+ # into that structure.
+ #
+ # Some instructions for manipulation of segment registers have to be written
+ # in opcode since 64-bit MASM prevents accesses to those registers.
+ #
+ .byte 0x16 # push ss
+ .byte 0xe # push cs
+ .byte 0x66
+ call L_Base # push eip
+L_Base:
+ .byte 0x66
+ pushq $0 # reserved high order 32 bits of EFlags
+ .byte 0x66, 0x9c # pushfd actually
+ cli # disable interrupts
+ push %gs
+ push %fs
+ .byte 6 # push es
+ .byte 0x1e # push ds
+ .byte 0x66,0x60 # pushad
+ .byte 0x66,0xba # mov edx, imm32
+_ThunkAttr: .space 4
+ testb $THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15, %dl
+ jz L_1
+ movl $0x15cd2401,%eax # mov ax, 2401h & int 15h
+ cli # disable interrupts
+ jnc L_2
+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:
+ movl %ss,%eax
+ lea IA32_REGS_SIZE(%esp), %bp
+ #
+ # rsi in the following 2 instructions is indeed bp in 16-bit code
+ #
+ movw %bp, (_ESP - IA32_REGS_SIZE)(%rsi)
+ .byte 0x66
+ movl (_EIP - IA32_REGS_SIZE)(%rsi), %ebx
+ shlw $4,%ax # shl eax, 4
+ addw %ax,%bp # add ebp, eax
+ movw %cs,%ax
+ shlw $4,%ax
+ lea (L_64BitCode - L_Base)(%ebx, %eax), %ax
+ .byte 0x66,0x2e,0x89,0x87 # mov cs:[bx + (L_64Eip - L_Base)], eax
+ .word L_64Eip - L_Base
+ .byte 0x66,0xb8 # mov eax, imm32
+SavedCr4: .space 4
+ movq %rax, %cr4
+ #
+ # rdi in the instruction below is indeed bx in 16-bit code
+ #
+ .byte 0x66,0x2e # 2eh is "cs:" segment override
+ lgdt (SavedGdt - L_Base)(%rdi)
+ .byte 0x66
+ movl $0xc0000080,%ecx
+ rdmsr
+ orb $1,%ah
+ wrmsr
+ .byte 0x66,0xb8 # mov eax, imm32
+SavedCr0: .space 4
+ movq %rax, %cr0
+ .byte 0x66,0xea # jmp far cs:L_64Bit
+L_64Eip: .space 4
+SavedCs: .space 2
+L_64BitCode:
+ movq %r8, %rsp
+ ret
+
+_EntryPoint: .long ASM_PFX(ToUserCode) - ASM_PFX(m16Start)
+ .word CODE16
+_16Gdtr: .word GDT_SIZE - 1
+_16GdtrBase: .quad _NullSeg
+_16Idtr: .word 0x3ff
+ .long 0
+
+#------------------------------------------------------------------------------
+# _ToUserCode() takes control in real mode before passing control to user code.
+# It will be shadowed to somewhere in memory below 1MB.
+#------------------------------------------------------------------------------
+.globl ASM_PFX(ToUserCode)
+ASM_PFX(ToUserCode):
+ movl %edx,%ss # set new segment selectors
+ movl %edx,%ds
+ movl %edx,%es
+ movl %edx,%fs
+ movl %edx,%gs
+ .byte 0x66
+ movl $0xc0000080,%ecx
+ movq %rax, %cr0
+ rdmsr
+ andb $0b11111110, %ah
+ wrmsr
+ movq %rbp, %cr4
+ movl %esi,%ss # set up 16-bit stack segment
+ movw %bx,%sp # set up 16-bit stack pointer
+ .byte 0x66 # make the following call 32-bit
+ call L_Base1 # push eip
+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:
+ .byte 0x66,0x2e # CS and operand size override
+ lidt (_16Idtr - L_Base1)(%rsi)
+ .byte 0x66,0x61 # popad
+ .byte 0x1f # pop ds
+ .byte 0x7 # pop es
+ .byte 0x0f, 0xa1 # pop fs
+ .byte 0x0f, 0xa9 # pop gs
+ .byte 0x66, 0x9d # popfd
+ leaw 4(%esp),%sp # skip high order 32 bits of EFlags
+ .byte 0x66 # make the following retf 32-bit
+ lret # transfer control to user code
+
+.equ CODE16, ASM_PFX(16Code) - .
+.equ DATA16, ASM_PFX(16Data) - .
+.equ DATA32, ASM_PFX(32Data) - .
+
+_NullSeg: .quad 0
+ASM_PFX(16Code):
+ .word -1
+ .word 0
+ .byte 0
+ .byte 0x9b
+ .byte 0x8f # 16-bit segment, 4GB limit
+ .byte 0
+ASM_PFX(16Data):
+ .word -1
+ .word 0
+ .byte 0
+ .byte 0x93
+ .byte 0x8f # 16-bit segment, 4GB limit
+ .byte 0
+ASM_PFX(32Data):
+ .word -1
+ .word 0
+ .byte 0
+ .byte 0x93
+ .byte 0xcf # 16-bit segment, 4GB limit
+ .byte 0
+
+.equ GDT_SIZE, . - ASM_PFX(NullSeg)
+
+#------------------------------------------------------------------------------
+# IA32_REGISTER_SET *
+# EFIAPI
+# InternalAsmThunk16 (
+# IN IA32_REGISTER_SET *RegisterSet,
+# IN OUT VOID *Transition
+# );
+#------------------------------------------------------------------------------
+# MISMATCH: "InternalAsmThunk16 PROC USES rbp rbx rsi rdi"
+
+.globl ASM_PFX(InternalAsmThunk16)
+ASM_PFX(InternalAsmThunk16):
+ pushq %rbp
+ pushq %rbx
+ pushq %rsi
+ pushq %rdi
+
+ movl %ds, %r10d # r9 ~ r11 are not accessible in 16-bit
+ movl %es, %r11d # so use them for saving seg registers
+ movl %ss, %r9d
+ .byte 0x0f, 0xa0 #push fs
+ .byte 0x0f, 0xa8 #push gs
+ movq %rcx, %rsi
+ movzwl _SS(%rsi), %r8d
+ movl _ESP(%rsi), %edi
+ lea -(IA32_REGS_SIZE + 4)(%edi), %rdi
+ 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
+ popq %rcx
+ rep
+ movsl # copy RegSet
+ lea (SavedCr4 - ASM_PFX(m16Start))(%rdx), %ecx
+ movl %edx,%eax # eax <- transition code address
+ andl $0xf,%edx
+ shll $12,%eax # segment address in high order 16 bits
+ lea (_BackFromUserCode - ASM_PFX(m16Start))(%rdx), %ax
+ stosl # [edi] <- return address of user code
+ sgdt (SavedGdt - SavedCr4)(%rcx)
+ sidt 0x38(%rsp)
+ movq %cr0, %rax
+ movl %eax, (SavedCr0 - SavedCr4)(%rcx)
+ andl $0x7ffffffe,%eax # clear PE, PG bits
+ movq %cr4, %rbp
+ movl %ebp, (%rcx) # save CR4 in SavedCr4
+ andl $0x300,%ebp # clear all but PCE and OSFXSR bits
+ movl %r8d, %esi # esi <- 16-bit stack segment
+ .byte 0x6a, DATA32
+ popq %rdx
+ lgdt (_16Gdtr - SavedCr4)(%rcx)
+ movl %edx,%ss
+ pushfq
+ lea -8(%rdx), %edx
+ lea L_RetFromRealMode, %r8
+ pushq %r8
+ movl %cs, %r8d
+ movw %r8w, (SavedCs - SavedCr4)(%rcx)
+ movq %rsp, %r8
+ .byte 0xff, 0x69 # jmp (_EntryPoint - SavedCr4)(%rcx)
+ .byte _EntryPoint - SavedCr4
+L_RetFromRealMode:
+ popfq
+ lidt 0x38(%rsp)
+ lea -IA32_REGS_SIZE(%rbp), %eax
+ .byte 0x0f, 0xa9 # pop gs
+ .byte 0x0f, 0xa1 # pop fs
+ movl %r9d, %ss
+ movl %r11d, %es
+ movl %r10d, %ds
+
+ popq %rdi
+ popq %rsi
+ popq %rbx
+ popq %rbp
+
+ ret
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