aboutsummaryrefslogtreecommitdiffstats
path: root/MdePkg/Library/BaseLib/X64/Thunk16.S
diff options
context:
space:
mode:
Diffstat (limited to 'MdePkg/Library/BaseLib/X64/Thunk16.S')
-rw-r--r--MdePkg/Library/BaseLib/X64/Thunk16.S334
1 files changed, 0 insertions, 334 deletions
diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.S b/MdePkg/Library/BaseLib/X64/Thunk16.S
deleted file mode 100644
index 823e927dd445..000000000000
--- a/MdePkg/Library/BaseLib/X64/Thunk16.S
+++ /dev/null
@@ -1,334 +0,0 @@
-#------------------------------------------------------------------------------
-#
-# Copyright (c) 2006 - 2013, 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
-# 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>
-
-ASM_GLOBAL ASM_PFX(m16Start)
-ASM_GLOBAL ASM_PFX(m16Size)
-ASM_GLOBAL ASM_PFX(mThunk16Attr)
-ASM_GLOBAL ASM_PFX(m16Gdt)
-ASM_GLOBAL ASM_PFX(m16GdtrBase)
-ASM_GLOBAL 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 8
-.set _EIP, 48 #size 4
-.set _CS, 52 #size 2
-.set _SS, 54 #size 2
-.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)
-ASM_PFX(mThunk16Attr): .word LmThunk16Attr
-.set Lm16Gdt, ASM_PFX(NullSeg) - ASM_PFX(m16Start)
-ASM_PFX(m16Gdt): .word Lm16Gdt
-.set Lm16GdtrBase, _16GdtrBase - ASM_PFX(m16Start)
-ASM_PFX(m16GdtrBase): .word Lm16GdtrBase
-.set LmTransition, _EntryPoint - ASM_PFX(m16Start)
-ASM_PFX(mTransition): .word LmTransition
-
- .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.
-#------------------------------------------------------------------------------
-ASM_GLOBAL 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
-L_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:
- xorw %ax, %ax # xor eax, eax
- movl %ss, %eax # mov ax, ss
- 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
-L_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
-L_SavedCr0: .space 4
- movq %rax, %cr0
- .byte 0x66,0xea # jmp far cs:L_64Bit
-L_64Eip: .space 4
-L_SavedCs: .space 2
-L_64BitCode:
- .byte 0x90
- .byte 0x48,0xbc # mov rsp, imm64
-L_SavedSp: .space 8 # restore stack
- nop
- ret
-
-_EntryPoint: .long ASM_PFX(ToUserCode) - ASM_PFX(m16Start)
- .word CODE16
-_16Gdtr: .word GDT_SIZE - 1
-_16GdtrBase: .quad 0
-_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.
-#------------------------------------------------------------------------------
-ASM_GLOBAL 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 $0xfe, %ah # $0b11111110
- 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
-
-.set CODE16, ASM_PFX(_16Code) - .
-.set DATA16, ASM_PFX(_16Data) - .
-.set DATA32, ASM_PFX(_32Data) - .
-
-ASM_PFX(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
-
-.set GDT_SIZE, . - ASM_PFX(NullSeg)
-
-#------------------------------------------------------------------------------
-# IA32_REGISTER_SET *
-# EFIAPI
-# InternalAsmThunk16 (
-# IN IA32_REGISTER_SET *RegisterSet,
-# IN OUT VOID *Transition
-# );
-#------------------------------------------------------------------------------
-
-ASM_GLOBAL ASM_PFX(InternalAsmThunk16)
-ASM_PFX(InternalAsmThunk16):
- pushq %rbp
- pushq %rbx
- pushq %rsi
- pushq %rdi
-
- movl %ds, %ebx
- pushq %rbx # Save ds segment register on the stack
- movl %es, %ebx
- pushq %rbx # Save es segment register on the stack
- movl %ss, %ebx
- pushq %rbx # Save ss segment register on the stack
-
- .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 (L_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
- .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
-
- 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
- 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
- movl %eax, (LSavedCrDelta)(%rcx)
- andl $0x7ffffffe,%eax # clear PE, PG bits
- movq %cr4, %rbp
- movl %ebp, (%rcx) # save CR4 in SavedCr4
- andl $0xffffffcf,%ebp # clear PAE, PSE bits
- movl %r8d, %esi # esi <- 16-bit stack segment
- .byte 0x6a, DATA32
- popq %rdx
- lgdt (_16Gdtr - L_SavedCr4)(%rcx)
- movl %edx,%ss
- pushfq
- lea -8(%rdx), %edx
- lea L_RetFromRealMode(%rip), %r8
- pushq %r8
- movl %cs, %r8d
- movw %r8w, (L_SavedCs - L_SavedCr4)(%rcx)
- movq %rsp, (L_SavedSp - L_SavedCr4)(%rcx)
- .byte 0xff, 0x69 # jmp (_EntryPoint - L_SavedCr4)(%rcx)
- .set Ltemp1, _EntryPoint - L_SavedCr4
- .byte Ltemp1
-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
- popq %rbp
-
- ret