Sync all bug fixes between EDK1.04 and EDK1.06 into EdkCompatibilityPkg.

[mirror_edk2.git] / EdkCompatibilityPkg / Foundation / Library / Thunk16 / Ia32 / Thunk16.S

#*****************************************************************************\r
#*\r
#*   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r
#*   This program and the accompanying materials                          \r
#*   are licensed and made available under the terms and conditions of the BSD License         \r
#*   which accompanies this distribution.  The full text of the license may be found at        \r
#*   http://opensource.org/licenses/bsd-license.php                                            \r
#*                                                                                             \r
#*   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     \r
#*   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             \r
#*   \r
#*   Module Name:\r
#*\r
#*    Thunk.asm\r
#*  \r
#*   Abstract:\r
#*  \r
#*    Real mode thunk\r
#*  \r
#*****************************************************************************\r
#include <EfiBind.h>\r
\r
    .686p: \r
\r
.globl ASM_PFX(mCode16Size)\r
\r
.data\r
mCode16Size:    .long   _TEXT16SIZE\r
\r
.data\r
\r
NullSegSel:     .quad   0\r
_16BitCsSel:    \r
                .word   -1\r
                .word   0\r
                .byte   0\r
                .byte   0x9b\r
                .byte   0x8f            # 16-bit segment\r
                .byte   0\r
_16BitSsSel:\r
                .word   -1\r
                .word   0\r
                .byte   0\r
                .byte   0x93\r
                .byte   0x8f           # 16-bit segment\r
                .byte   0\r
\r
_16Gdtr:\r
                .word      _16Gdtr - NullSegSel - 1\r
                .long      NullSegSel\r
\r
\r
.text\r
\r
\r
ASM_PFX(Thunk16):\r
    push   %ebp\r
    push   %ebx\r
    push   %esi\r
    push   %edi\r
    push   %ds\r
    push   %es\r
    push   %fs\r
    push   %gs\r
    mov    0x24(%esp),%esi\r
    movzwl 0x32(%esi),%edx\r
    mov    0xc(%esi),%edi\r
    add    $0xffffffb0,%edi\r
    push   %edi                       #; save stack offset\r
    imul   $0x10,%edx,%eax            #; eax <- edx*16\r
    add    %eax,%edi                  #; edi <- linear address of 16-bit stack\r
    push   $0xd\r
    pop    %ecx\r
    rep movsl %ds:(%esi),%es:(%edi)   #; copy context to 16-bit stack\r
    #; copy eflags to stack frame\r
    mov    -12(%esi), %eax\r
    mov    %eax, -72(%edi) \r
    pop    %ebx                       #; ebx <- 16-bit stack offset\r
    mov    $L_Lable1,%eax\r
    stos   %eax,%es:(%edi)\r
    movl   %cs,%eax\r
    stos   %ax,%es:(%edi)\r
    mov    0x28(%esp),%eax\r
    stos   %ax,%es:(%edi)\r
    mov    %esp,%eax\r
    stos   %eax,%es:(%edi)\r
    movl   %ss,%eax\r
    stos   %ax,%es:(%edi)\r
    sgdtl  (%edi)\r
    sidtl  0x24(%esp)\r
    mov    %cr0,%esi\r
    mov    %esi,0x6(%edi)             #; save CR0\r
    and    $0x7ffffffe,%esi           #; esi <- CR0 to set\r
    mov    %cr4,%eax\r
    mov    %eax,0xa(%edi)             #; save CR4\r
    and    $0xcf,%al                  #; clear PAE & PSE\r
    mov    %edx,%edi                  #; edi <- 16-bit stack segment\r
    mov    0x2c(%esp),%edx\r
    shl    $0x10,%edx\r
    push   %edx\r
    pop    %edx\r
    mov    $(_16BitSsSel - NullSegSel),%dx\r
    lgdtl  _16Gdtr                    #bugbug mismatch.\r
    .byte  0xea\r
    .long  L_16Bit                    #bugbug mismatch.\r
    .word  _16BitCsSel - NullSegSel\r
L_16Bit:   \r
    .byte  0x66 \r
    movw   %dx,%ss\r
    mov    %esi,%cr0\r
    mov    %eax,%cr4\r
    .byte  0x67\r
    .byte  0xff\r
    .byte  0x6c\r
    .byte  0x24\r
    .byte  0xfc\r
    \r
L_Lable1:\r
    movl   %ss,%eax\r
    shl    $0x4,%eax\r
    add    %esp,%eax\r
    lss    0x3c(%esp),%esp\r
    lidtl  0x24(%esp)\r
    pop    %gs\r
    pop    %fs\r
    pop    %es\r
    pop    %ds\r
    pop    %edi\r
    pop    %esi\r
    pop    %ebx\r
    pop    %ebp\r
    ret \r
\r
.code16\r
_Code16Addr:\r
ASM_PFX(RealMode):\r
    movw    %di, %ss                    # set up stack\r
    movl    %ebx, %esp\r
    lidt    %cs:_16Idtr - _Code16Addr  #lidt    fword ptr cs:[_16Idtr - _Code16Addr]\r
    .byte   0x66\r
    popaw\r
    popw    %ds\r
    popw    %es\r
    popw    %fs\r
    popw    %gs\r
    sub     60, %esp\r
    popfw\r
    testw   $1, 74(%esp)                #(_STK16 ptr [esp + STACK_PARAM_SIZE + sizeof(IA32_REGS)]).ThunkFlags, 1\r
\r
    jz      1f\r
    pushf                               # push Flags when it's INT#\r
1: \r
    pushw   %cs\r
#    push    @FarCallRet - _Code16Addr\r
    .byte   0x68                        # push /iw\r
    .word   FarCallRet - _Code16Addr\r
    jz      2f\r
    ljmp    *66(%esp)                   #[esp + 6 + STACK_PARAM_SIZE + sizeof(IA32_REGS) - 8]\r
2: \r
    ljmp    *64(%esp)                   #[esp + 4 + STACK_PARAM_SIZE + sizeof(IA32_REGS) - 8]\r
FarCallRet: \r
    add     60, %esp\r
    pushfl\r
    pushw   %gs\r
    pushw   %fs\r
    pushw   %es\r
    pushw   %ds\r
    pushal\r
    cli\r
    .byte   0x66                        # sizeof (IA32_REGS) = 13 * 4 = 52\r
    lgdt    66(%esp)                    #lgdt    (_STK16 ptr [esp + sizeof (IA32_REGS)]).SavedGdtr\r
    mov     76(%esp), %eax\r
    movl    %eax, %cr4\r
    mov     72(%esp), %eax\r
    movl    %eax, %cr0                   # restore CR0\r
    ljmpl   *52(%esp)                    \r
#RealMode ENDP\r
\r
.text\r
_16Idtr:\r
    .word 0x3ff                         #_16Idtr     FWORD   (1 SHL 10) - 1\r
    .byte 0x00\r
\r
_TEXT16END: \r
\r
_TEXT16SIZE = _TEXT16END - _Code16Addr\r
\r
\r