[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / Thunk16.asm

;------------------------------------------------------------------------------\r
;\r
; Copyright (c) 2006, Intel Corporation\r
; All rights reserved. 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
\r
EXTERNDEF   m16Start:BYTE\r
EXTERNDEF   m16Size:WORD\r
EXTERNDEF   mThunk16Attr:WORD\r
EXTERNDEF   m16Gdt:WORD\r
EXTERNDEF   m16GdtrBase:WORD\r
EXTERNDEF   mTransition:WORD\r
\r
IA32_REGS   STRUC   4t\r
_EDI        DD      ?\r
_ESI        DD      ?\r
_EBP        DD      ?\r
_ESP        DD      ?\r
_EBX        DD      ?\r
_EDX        DD      ?\r
_ECX        DD      ?\r
_EAX        DD      ?\r
_DS         DW      ?\r
_ES         DW      ?\r
_FS         DW      ?\r
_GS         DW      ?\r
_EFLAGS     DQ      ?\r
_EIP        DD      ?\r
_CS         DW      ?\r
_SS         DW      ?\r
IA32_REGS   ENDS\r
\r
    .const\r
\r
m16Size         DW      InternalAsmThunk16 - m16Start\r
mThunk16Attr    DW      _ThunkAttr - m16Start\r
m16Gdt          DW      _NullSegDesc - m16Start\r
m16GdtrBase     DW      _16GdtrBase - m16Start\r
mTransition     DW      _EntryPoint - m16Start\r
\r
    .code\r
\r
m16Start    LABEL   BYTE\r
\r
SavedGdt    LABEL   FWORD\r
            DW      ?\r
            DQ      ?\r
\r
_BackFromUserCode   PROC\r
    DB      16h                         ; push ss\r
    DB      0eh                         ; push cs\r
    DB      66h\r
    call    @Base                       ; push eip\r
@Base:\r
    DB      66h\r
    push    0                           ; reserved high order 32 bits of EFlags\r
    pushf                               ; pushfd actually\r
    cli                                 ; disable interrupts\r
    push    gs\r
    push    fs\r
    DB      6                           ; push es\r
    DB      1eh                         ; push ds\r
    DB      66h, 60h                    ; pushad\r
    DB      66h, 0bah                   ; mov edx, imm32\r
_ThunkAttr  DD      ?\r
    test    dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15\r
    jz      @1\r
    mov     eax, 15cd2401h              ; mov ax, 2401h & int 15h\r
    cli                                 ; disable interrupts\r
    jnc     @2\r
@1:\r
    test    dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL\r
    jz      @2\r
    in      al, 92h\r
    or      al, 2\r
    out     92h, al                     ; deactivate A20M#\r
@2:\r
    mov     eax, ss\r
    lea     bp, [esp + sizeof (IA32_REGS)]\r
    mov     word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp\r
    mov     ebx, (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._EIP\r
    shl     ax, 4                       ; shl eax, 4\r
    add     bp, ax                      ; add ebp, eax\r
    DB      66h, 0b8h                   ; mov eax, imm32\r
SavedCr4    DD      ?\r
    mov     cr4, rax\r
    DB      66h, 2eh\r
    lgdt    fword ptr [rdi + (SavedGdt - @Base)]\r
    DB      66h\r
    mov     ecx, 0c0000080h\r
    rdmsr\r
    or      ah, 1\r
    wrmsr\r
    DB      66h, 0b8h                   ; mov eax, imm32\r
SavedCr0    DD      ?\r
    mov     cr0, rax\r
    DB      0b8h                        ; mov ax, imm16\r
SavedSs     DW      ?\r
    mov     ss, eax\r
    DB      66h, 0bch                   ; mov esp, imm32\r
SavedEsp    DD      ?\r
    DB      66h\r
    retf                                ; return to protected mode\r
_BackFromUserCode   ENDP\r
\r
_EntryPoint DD      _ToUserCode - m16Start\r
            DW      8h\r
_16Gdtr     LABEL   FWORD\r
            DW      GdtEnd - _NullSegDesc - 1\r
_16GdtrBase DQ      _NullSegDesc\r
_16Idtr     FWORD   (1 SHL 10) - 1\r
\r
_ToUserCode PROC\r
    mov     edi, ss\r
    mov     ss, edx                     ; set new segment selectors\r
    mov     ds, edx\r
    mov     es, edx\r
    mov     fs, edx\r
    mov     gs, edx\r
    DB      66h\r
    mov     ecx, 0c0000080h\r
    mov     cr0, rax                    ; real mode starts at next instruction\r
    rdmsr\r
    and     ah, NOT 1\r
    wrmsr\r
    mov     cr4, rbp\r
    mov     ss, esi                     ; set up 16-bit stack segment\r
    xchg    sp, bx                      ; set up 16-bit stack pointer\r
    DB      66h\r
    call    @Base                       ; push eip\r
@Base:\r
    pop     bp                          ; ebp <- address of @Base\r
    push    [esp + sizeof (IA32_REGS) + 2]\r
    lea     eax, [rsi + (@RealMode - @Base)]\r
    push    rax\r
    retf\r
@RealMode:\r
    DB      2eh                         ; cs:\r
    mov     [rsi + (SavedSs - @Base)], edi\r
    DB      2eh                         ; cs:\r
    mov     [rsi + (SavedEsp - @Base)], bx\r
    DB      66h, 2eh                    ; CS and operand size override\r
    lidt    fword ptr [rsi + (_16Idtr - @Base)]\r
    DB      66h, 61h                    ; popad\r
    DB      1fh                         ; pop ds\r
    DB      07h                         ; pop es\r
    pop     fs\r
    pop     gs\r
    popf                                ; popfd\r
    lea     sp, [esp + 4]               ; skip high order 32 bits of EFlags\r
    DB      66h\r
    retf                                ; transfer control to user code\r
_ToUserCode ENDP\r
\r
_NullSegDesc    DQ      0\r
_16CsDesc       LABEL   QWORD\r
                DW      -1\r
                DW      0\r
                DB      0\r
                DB      9bh\r
                DB      8fh             ; 16-bit segment, 4GB limit\r
                DB      0\r
_16DsDesc       LABEL   QWORD\r
                DW      -1\r
                DW      0\r
                DB      0\r
                DB      93h\r
                DB      8fh             ; 16-bit segment, 4GB limit\r
                DB      0\r
GdtEnd          LABEL   QWORD\r
\r
;\r
;   @param  RegSet  Pointer to a IA32_DWORD_REGS structure\r
;   @param  Transition  Pointer to the transition code\r
;   @return The address of the 16-bit stack after returning from user code\r
;\r
InternalAsmThunk16  PROC    USES    rbp rbx rsi rdi\r
    mov     r10d, ds\r
    mov     r11d, es\r
    push    fs\r
    push    gs\r
    mov     rsi, rcx\r
    movzx   r8d, (IA32_REGS ptr [rsi])._SS\r
    mov     edi, (IA32_REGS ptr [rsi])._ESP\r
    lea     rdi, [edi - (sizeof (IA32_REGS) + 4)]\r
    imul    eax, r8d, 16                ; eax <- r8d(stack segment) * 16\r
    mov     ebx, edi                    ; ebx <- stack for 16-bit code\r
    push    sizeof (IA32_REGS) / 4\r
    add     edi, eax                    ; edi <- linear address of 16-bit stack\r
    pop     rcx\r
    rep     movsd                       ; copy RegSet\r
    lea     ecx, [rdx + (SavedCr4 - m16Start)]\r
    mov     eax, edx                    ; eax <- transition code address\r
    and     edx, 0fh\r
    shl     eax, 12\r
    lea     edx, [rdx + (_BackFromUserCode - m16Start)]\r
    mov     ax, dx\r
    stosd                               ; [edi] <- return address of user code\r
    sgdt    fword ptr [rcx + (SavedGdt - SavedCr4)]\r
    sidt    fword ptr [rsp + 38h]       ; save IDT stack in argument space\r
    mov     rax, cr0\r
    mov     [rcx + (SavedCr0 - SavedCr4)], eax\r
    and     eax, 7ffffffeh              ; clear PE, PG bits\r
    mov     rbp, cr4\r
    mov     [rcx], ebp                  ; save CR4 in SavedCr4\r
    and     ebp, 300h                   ; clear all but PCE and OSFXSR bits\r
    mov     esi, r8d                    ; esi <- 16-bit stack segment\r
    push    10h\r
    pop     rdx                         ; rdx <- selector for data segments\r
    lgdt    fword ptr [rcx + (_16Gdtr - SavedCr4)]\r
    pushfq\r
    call    fword ptr [rcx + (_EntryPoint - SavedCr4)]\r
    popfq\r
    lidt    fword ptr [rsp + 38h]       ; restore protected mode IDTR\r
    lea     eax, [rbp - sizeof (IA32_REGS)]\r
    pop     gs\r
    pop     fs\r
    mov     es, r11d\r
    mov     ds, r10d\r
    ret\r
InternalAsmThunk16  ENDP\r
\r
    END\r
Commit	Line	Data
878ddf1f	1	;------------------------------------------------------------------------------\r
	2	;\r
	3	; Copyright (c) 2006, Intel Corporation\r
	4	; All rights reserved. This program and the accompanying materials\r
	5	; are licensed and made available under the terms and conditions of the BSD License\r
	6	; which accompanies this distribution. The full text of the license may be found at\r
	7	; http://opensource.org/licenses/bsd-license.php\r
	8	;\r
	9	; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	10	; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	11	;\r
	12	; Module Name:\r
	13	;\r
	14	; Thunk.asm\r
	15	;\r
	16	; Abstract:\r
	17	;\r
	18	; Real mode thunk\r
	19	;\r
	20	;------------------------------------------------------------------------------\r
	21	\r
97d92bda	22	EXTERNDEF m16Start:BYTE\r
	23	EXTERNDEF m16Size:WORD\r
	24	EXTERNDEF mThunk16Attr:WORD\r
	25	EXTERNDEF m16Gdt:WORD\r
	26	EXTERNDEF m16GdtrBase:WORD\r
	27	EXTERNDEF mTransition:WORD\r
878ddf1f	28	\r
878ddf1f	29	IA32_REGS STRUC 4t\r
	30	_EDI DD ?\r
	31	_ESI DD ?\r
	32	_EBP DD ?\r
	33	_ESP DD ?\r
	34	_EBX DD ?\r
	35	_EDX DD ?\r
	36	_ECX DD ?\r
	37	_EAX DD ?\r
	38	_DS DW ?\r
	39	_ES DW ?\r
	40	_FS DW ?\r
	41	_GS DW ?\r
97d92bda	42	_EFLAGS DQ ?\r
878ddf1f	43	_EIP DD ?\r
	44	_CS DW ?\r
	45	_SS DW ?\r
	46	IA32_REGS ENDS\r
	47	\r
97d92bda	48	.const\r
97d92bda	49	\r
bbe4ba81	50	m16Size DW InternalAsmThunk16 - m16Start\r
	51	mThunk16Attr DW _ThunkAttr - m16Start\r
	52	m16Gdt DW _NullSegDesc - m16Start\r
	53	m16GdtrBase DW _16GdtrBase - m16Start\r
	54	mTransition DW _EntryPoint - m16Start\r
97d92bda	55	\r
	56	.code\r
	57	\r
	58	m16Start LABEL BYTE\r
	59	\r
bbe4ba81	60	SavedGdt LABEL FWORD\r
	61	DW ?\r
	62	DQ ?\r
97d92bda	63	\r
	64	_BackFromUserCode PROC\r
	65	DB 16h ; push ss\r
	66	DB 0eh ; push cs\r
878ddf1f	67	DB 66h\r
97d92bda	68	call @Base ; push eip\r
97d92bda	69	@Base:\r
878ddf1f	70	DB 66h\r
97d92bda	71	push 0 ; reserved high order 32 bits of EFlags\r
878ddf1f	72	pushf ; pushfd actually\r
97d92bda	73	cli ; disable interrupts\r
878ddf1f	74	push gs\r
	75	push fs\r
	76	DB 6 ; push es\r
	77	DB 1eh ; push ds\r
	78	DB 66h, 60h ; pushad\r
97d92bda	79	DB 66h, 0bah ; mov edx, imm32\r
	80	_ThunkAttr DD ?\r
	81	test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15\r
	82	jz @1\r
	83	mov eax, 15cd2401h ; mov ax, 2401h & int 15h\r
	84	cli ; disable interrupts\r
	85	jnc @2\r
	86	@1:\r
	87	test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL\r
	88	jz @2\r
	89	in al, 92h\r
	90	or al, 2\r
	91	out 92h, al ; deactivate A20M#\r
	92	@2:\r
	93	mov eax, ss\r
	94	lea bp, [esp + sizeof (IA32_REGS)]\r
	95	mov word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp\r
	96	mov ebx, (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._EIP\r
	97	shl ax, 4 ; shl eax, 4\r
	98	add bp, ax ; add ebp, eax\r
	99	DB 66h, 0b8h ; mov eax, imm32\r
	100	SavedCr4 DD ?\r
	101	mov cr4, rax\r
	102	DB 66h, 2eh\r
bbe4ba81	103	lgdt fword ptr [rdi + (SavedGdt - @Base)]\r
878ddf1f	104	DB 66h\r
	105	mov ecx, 0c0000080h\r
	106	rdmsr\r
97d92bda	107	or ah, 1\r
878ddf1f	108	wrmsr\r
97d92bda	109	DB 66h, 0b8h ; mov eax, imm32\r
	110	SavedCr0 DD ?\r
	111	mov cr0, rax\r
	112	DB 0b8h ; mov ax, imm16\r
	113	SavedSs DW ?\r
	114	mov ss, eax\r
	115	DB 66h, 0bch ; mov esp, imm32\r
	116	SavedEsp DD ?\r
878ddf1f	117	DB 66h\r
97d92bda	118	retf ; return to protected mode\r
	119	_BackFromUserCode ENDP\r
	120	\r
bbe4ba81	121	_EntryPoint DD _ToUserCode - m16Start\r
	122	DW 8h\r
	123	_16Gdtr LABEL FWORD\r
	124	DW GdtEnd - _NullSegDesc - 1\r
	125	_16GdtrBase DQ _NullSegDesc\r
	126	_16Idtr FWORD (1 SHL 10) - 1\r
97d92bda	127	\r
	128	_ToUserCode PROC\r
	129	mov edi, ss\r
	130	mov ss, edx ; set new segment selectors\r
	131	mov ds, edx\r
	132	mov es, edx\r
	133	mov fs, edx\r
	134	mov gs, edx\r
878ddf1f	135	DB 66h\r
97d92bda	136	mov ecx, 0c0000080h\r
	137	mov cr0, rax ; real mode starts at next instruction\r
	138	rdmsr\r
	139	and ah, NOT 1\r
	140	wrmsr\r
	141	mov cr4, rbp\r
	142	mov ss, esi ; set up 16-bit stack segment\r
	143	xchg sp, bx ; set up 16-bit stack pointer\r
878ddf1f	144	DB 66h\r
97d92bda	145	call @Base ; push eip\r
97d92bda	146	@Base:\r
bbe4ba81	147	pop bp ; ebp <- address of @Base\r
18c319ae	148	push [esp + sizeof (IA32_REGS) + 2]\r
bbe4ba81	149	lea eax, [rsi + (@RealMode - @Base)]\r
18c319ae	150	push rax\r
	151	retf\r
	152	@RealMode:\r
97d92bda	153	DB 2eh ; cs:\r
bbe4ba81	154	mov [rsi + (SavedSs - @Base)], edi\r
97d92bda	155	DB 2eh ; cs:\r
bbe4ba81	156	mov [rsi + (SavedEsp - @Base)], bx\r
97d92bda	157	DB 66h, 2eh ; CS and operand size override\r
bbe4ba81	158	lidt fword ptr [rsi + (_16Idtr - @Base)]\r
97d92bda	159	DB 66h, 61h ; popad\r
	160	DB 1fh ; pop ds\r
	161	DB 07h ; pop es\r
	162	pop fs\r
	163	pop gs\r
	164	popf ; popfd\r
	165	lea sp, [esp + 4] ; skip high order 32 bits of EFlags\r
878ddf1f	166	DB 66h\r
97d92bda	167	retf ; transfer control to user code\r
	168	_ToUserCode ENDP\r
	169	\r
	170	_NullSegDesc DQ 0\r
	171	_16CsDesc LABEL QWORD\r
	172	DW -1\r
	173	DW 0\r
	174	DB 0\r
	175	DB 9bh\r
	176	DB 8fh ; 16-bit segment, 4GB limit\r
	177	DB 0\r
	178	_16DsDesc LABEL QWORD\r
	179	DW -1\r
	180	DW 0\r
	181	DB 0\r
	182	DB 93h\r
	183	DB 8fh ; 16-bit segment, 4GB limit\r
	184	DB 0\r
	185	GdtEnd LABEL QWORD\r
	186	\r
	187	;\r
	188	; @param RegSet Pointer to a IA32_DWORD_REGS structure\r
	189	; @param Transition Pointer to the transition code\r
	190	; @return The address of the 16-bit stack after returning from user code\r
	191	;\r
	192	InternalAsmThunk16 PROC USES rbp rbx rsi rdi\r
	193	mov r10d, ds\r
	194	mov r11d, es\r
	195	push fs\r
	196	push gs\r
	197	mov rsi, rcx\r
	198	movzx r8d, (IA32_REGS ptr [rsi])._SS\r
	199	mov edi, (IA32_REGS ptr [rsi])._ESP\r
	200	lea rdi, [edi - (sizeof (IA32_REGS) + 4)]\r
	201	imul eax, r8d, 16 ; eax <- r8d(stack segment) * 16\r
bbe4ba81	202	mov ebx, edi ; ebx <- stack for 16-bit code\r
97d92bda	203	push sizeof (IA32_REGS) / 4\r
	204	add edi, eax ; edi <- linear address of 16-bit stack\r
	205	pop rcx\r
	206	rep movsd ; copy RegSet\r
bbe4ba81	207	lea ecx, [rdx + (SavedCr4 - m16Start)]\r
97d92bda	208	mov eax, edx ; eax <- transition code address\r
	209	and edx, 0fh\r
	210	shl eax, 12\r
bbe4ba81	211	lea edx, [rdx + (_BackFromUserCode - m16Start)]\r
97d92bda	212	mov ax, dx\r
97d92bda	213	stosd ; [edi] <- return address of user code\r
bbe4ba81	214	sgdt fword ptr [rcx + (SavedGdt - SavedCr4)]\r
97d92bda	215	sidt fword ptr [rsp + 38h] ; save IDT stack in argument space\r
97d92bda	216	mov rax, cr0\r
bbe4ba81	217	mov [rcx + (SavedCr0 - SavedCr4)], eax\r
97d92bda	218	and eax, 7ffffffeh ; clear PE, PG bits\r
	219	mov rbp, cr4\r
	220	mov [rcx], ebp ; save CR4 in SavedCr4\r
	221	and ebp, 300h ; clear all but PCE and OSFXSR bits\r
	222	mov esi, r8d ; esi <- 16-bit stack segment\r
	223	push 10h\r
	224	pop rdx ; rdx <- selector for data segments\r
bbe4ba81	225	lgdt fword ptr [rcx + (_16Gdtr - SavedCr4)]\r
18c319ae	226	pushfq\r
bbe4ba81	227	call fword ptr [rcx + (_EntryPoint - SavedCr4)]\r
18c319ae	228	popfq\r
97d92bda	229	lidt fword ptr [rsp + 38h] ; restore protected mode IDTR\r
97d92bda	230	lea eax, [rbp - sizeof (IA32_REGS)]\r
878ddf1f	231	pop gs\r
878ddf1f	232	pop fs\r
97d92bda	233	mov es, r11d\r
97d92bda	234	mov ds, r10d\r
878ddf1f	235	ret\r
	236	InternalAsmThunk16 ENDP\r
	237	\r
	238	END\r