[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      _NullSeg - 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
;------------------------------------------------------------------------------\r
; _BackFromUserCode() takes control in real mode after 'retf' has been executed\r
; by user code. It will be shadowed to somewhere in memory below 1MB.\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
    ;\r
    ; rsi in the following 2 instructions is indeed bp in 16-bit code\r
    ;\r
    mov     word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp\r
    DB      66h\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
    mov     ax, cs\r
    shl     ax, 4\r
    lea     ax, [eax + ebx + (@64BitCode - @Base)]\r
    DB      66h, 2eh, 89h, 87h          ; mov cs:[bx + (@64Eip - @Base)], eax\r
    DW      @64Eip - @Base\r
    DB      66h, 0b8h                   ; mov eax, imm32\r
SavedCr4    DD      ?\r
    mov     cr4, rax\r
    ;\r
    ; rdi in the instruction below is indeed bx in 16-bit code\r
    ;\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      66h, 0eah                   ; jmp far cs:@64Bit\r
@64Eip      DD      ?\r
SavedCs     DW      ?\r
@64BitCode:\r
    DB      48h, 0b8h                   ; mov rax, imm64\r
SavedRip    DQ      ?\r
    jmp     rax                         ; return to caller\r
_BackFromUserCode   ENDP\r
\r
_EntryPoint DD      _ToUserCode - m16Start\r
            DW      CODE16\r
_16Gdtr     LABEL   FWORD\r
            DW      GDT_SIZE - 1\r
_16GdtrBase DQ      _NullSeg\r
_16Idtr     FWORD   (1 SHL 10) - 1\r
\r
;------------------------------------------------------------------------------\r
; _ToUserCode() takes control in real mode before passing control to user code.\r
; It will be shadowed to somewhere in memory below 1MB.\r
;------------------------------------------------------------------------------\r
_ToUserCode PROC\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
    mov     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      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
CODE16  = _16Code - $\r
DATA16  = _16Data - $\r
DATA32  = _32Data - $\r
\r
_NullSeg    DQ      0\r
_16Code     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
_16Data     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
_32Data     LABEL   QWORD\r
            DW      -1\r
            DW      0\r
            DB      0\r
            DB      93h\r
            DB      0cfh                ; 16-bit segment, 4GB limit\r
            DB      0\r
\r
GDT_SIZE = $ - _NullSeg\r
\r
;------------------------------------------------------------------------------\r
; IA32_REGISTER_SET *\r
; EFIAPI\r
; InternalAsmThunk16 (\r
;   IN      IA32_REGISTER_SET         *RegisterSet,\r
;   IN OUT  VOID                      *Transition\r
;   );\r
;------------------------------------------------------------------------------\r
InternalAsmThunk16  PROC    USES    rbp rbx rsi rdi\r
    mov     r10d, ds\r
    mov     r11d, es\r
    mov     r9d, ss\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     ax, [rdx + (_BackFromUserCode - m16Start)]\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
    DB      6ah, DATA32                 ; push DATA32\r
    pop     rdx                         ; rdx <- 32-bit data segment selector\r
    lgdt    fword ptr [rcx + (_16Gdtr - SavedCr4)]\r
    mov     ss, edx\r
    pushfq\r
    lea     edx, [rdx + DATA16 - DATA32]\r
    lea     r8, @RetFromRealMode\r
    mov     [rcx + (SavedRip - SavedCr4)], r8\r
    mov     r8d, cs\r
    mov     [rcx + (SavedCs - SavedCr4)], r8w\r
    mov     r8, rsp\r
    jmp     fword ptr [rcx + (_EntryPoint - SavedCr4)]\r
@RetFromRealMode:\r
    mov     rsp, r8\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     ss, r9d\r
    mov     es, r11d\r
    mov     ds, r10d\r
    ret\r
InternalAsmThunk16  ENDP\r
\r
    END\r
Commit	Line	Data
	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
	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
	28	\r
	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
	42	_EFLAGS DQ ?\r
	43	_EIP DD ?\r
	44	_CS DW ?\r
	45	_SS DW ?\r
	46	IA32_REGS ENDS\r
	47	\r
	48	.const\r
	49	\r
	50	m16Size DW InternalAsmThunk16 - m16Start\r
	51	mThunk16Attr DW _ThunkAttr - m16Start\r
	52	m16Gdt DW _NullSeg - m16Start\r
	53	m16GdtrBase DW _16GdtrBase - m16Start\r
	54	mTransition DW _EntryPoint - m16Start\r
	55	\r
	56	.code\r
	57	\r
	58	m16Start LABEL BYTE\r
	59	\r
	60	SavedGdt LABEL FWORD\r
	61	DW ?\r
	62	DQ ?\r
	63	\r
	64	;------------------------------------------------------------------------------\r
	65	; _BackFromUserCode() takes control in real mode after 'retf' has been executed\r
	66	; by user code. It will be shadowed to somewhere in memory below 1MB.\r
	67	;------------------------------------------------------------------------------\r
	68	_BackFromUserCode PROC\r
	69	DB 16h ; push ss\r
	70	DB 0eh ; push cs\r
	71	DB 66h\r
	72	call @Base ; push eip\r
	73	@Base:\r
	74	DB 66h\r
	75	push 0 ; reserved high order 32 bits of EFlags\r
	76	pushf ; pushfd actually\r
	77	cli ; disable interrupts\r
	78	push gs\r
	79	push fs\r
	80	DB 6 ; push es\r
	81	DB 1eh ; push ds\r
	82	DB 66h, 60h ; pushad\r
	83	DB 66h, 0bah ; mov edx, imm32\r
	84	_ThunkAttr DD ?\r
	85	test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15\r
	86	jz @1\r
	87	mov eax, 15cd2401h ; mov ax, 2401h & int 15h\r
	88	cli ; disable interrupts\r
	89	jnc @2\r
	90	@1:\r
	91	test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL\r
	92	jz @2\r
	93	in al, 92h\r
	94	or al, 2\r
	95	out 92h, al ; deactivate A20M#\r
	96	@2:\r
	97	mov eax, ss\r
	98	lea bp, [esp + sizeof (IA32_REGS)]\r
	99	;\r
	100	; rsi in the following 2 instructions is indeed bp in 16-bit code\r
	101	;\r
	102	mov word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp\r
	103	DB 66h\r
	104	mov ebx, (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._EIP\r
	105	shl ax, 4 ; shl eax, 4\r
	106	add bp, ax ; add ebp, eax\r
	107	mov ax, cs\r
	108	shl ax, 4\r
	109	lea ax, [eax + ebx + (@64BitCode - @Base)]\r
	110	DB 66h, 2eh, 89h, 87h ; mov cs:[bx + (@64Eip - @Base)], eax\r
	111	DW @64Eip - @Base\r
	112	DB 66h, 0b8h ; mov eax, imm32\r
	113	SavedCr4 DD ?\r
	114	mov cr4, rax\r
	115	;\r
	116	; rdi in the instruction below is indeed bx in 16-bit code\r
	117	;\r
	118	DB 66h, 2eh\r
	119	lgdt fword ptr [rdi + (SavedGdt - @Base)]\r
	120	DB 66h\r
	121	mov ecx, 0c0000080h\r
	122	rdmsr\r
	123	or ah, 1\r
	124	wrmsr\r
	125	DB 66h, 0b8h ; mov eax, imm32\r
	126	SavedCr0 DD ?\r
	127	mov cr0, rax\r
	128	DB 66h, 0eah ; jmp far cs:@64Bit\r
	129	@64Eip DD ?\r
	130	SavedCs DW ?\r
	131	@64BitCode:\r
	132	DB 48h, 0b8h ; mov rax, imm64\r
	133	SavedRip DQ ?\r
	134	jmp rax ; return to caller\r
	135	_BackFromUserCode ENDP\r
	136	\r
	137	_EntryPoint DD _ToUserCode - m16Start\r
	138	DW CODE16\r
	139	_16Gdtr LABEL FWORD\r
	140	DW GDT_SIZE - 1\r
	141	_16GdtrBase DQ _NullSeg\r
	142	_16Idtr FWORD (1 SHL 10) - 1\r
	143	\r
	144	;------------------------------------------------------------------------------\r
	145	; _ToUserCode() takes control in real mode before passing control to user code.\r
	146	; It will be shadowed to somewhere in memory below 1MB.\r
	147	;------------------------------------------------------------------------------\r
	148	_ToUserCode PROC\r
	149	mov ss, edx ; set new segment selectors\r
	150	mov ds, edx\r
	151	mov es, edx\r
	152	mov fs, edx\r
	153	mov gs, edx\r
	154	DB 66h\r
	155	mov ecx, 0c0000080h\r
	156	mov cr0, rax ; real mode starts at next instruction\r
	157	rdmsr\r
	158	and ah, NOT 1\r
	159	wrmsr\r
	160	mov cr4, rbp\r
	161	mov ss, esi ; set up 16-bit stack segment\r
	162	mov sp, bx ; set up 16-bit stack pointer\r
	163	DB 66h\r
	164	call @Base ; push eip\r
	165	@Base:\r
	166	pop bp ; ebp <- address of @Base\r
	167	push [esp + sizeof (IA32_REGS) + 2]\r
	168	lea eax, [rsi + (@RealMode - @Base)]\r
	169	push rax\r
	170	retf\r
	171	@RealMode:\r
	172	DB 66h, 2eh ; CS and operand size override\r
	173	lidt fword ptr [rsi + (_16Idtr - @Base)]\r
	174	DB 66h, 61h ; popad\r
	175	DB 1fh ; pop ds\r
	176	DB 07h ; pop es\r
	177	pop fs\r
	178	pop gs\r
	179	popf ; popfd\r
	180	lea sp, [esp + 4] ; skip high order 32 bits of EFlags\r
	181	DB 66h\r
	182	retf ; transfer control to user code\r
	183	_ToUserCode ENDP\r
	184	\r
	185	CODE16 = _16Code - $\r
	186	DATA16 = _16Data - $\r
	187	DATA32 = _32Data - $\r
	188	\r
	189	_NullSeg DQ 0\r
	190	_16Code LABEL QWORD\r
	191	DW -1\r
	192	DW 0\r
	193	DB 0\r
	194	DB 9bh\r
	195	DB 8fh ; 16-bit segment, 4GB limit\r
	196	DB 0\r
	197	_16Data LABEL QWORD\r
	198	DW -1\r
	199	DW 0\r
	200	DB 0\r
	201	DB 93h\r
	202	DB 8fh ; 16-bit segment, 4GB limit\r
	203	DB 0\r
	204	_32Data LABEL QWORD\r
	205	DW -1\r
	206	DW 0\r
	207	DB 0\r
	208	DB 93h\r
	209	DB 0cfh ; 16-bit segment, 4GB limit\r
	210	DB 0\r
	211	\r
	212	GDT_SIZE = $ - _NullSeg\r
	213	\r
	214	;------------------------------------------------------------------------------\r
	215	; IA32_REGISTER_SET *\r
	216	; EFIAPI\r
	217	; InternalAsmThunk16 (\r
	218	; IN IA32_REGISTER_SET *RegisterSet,\r
	219	; IN OUT VOID *Transition\r
	220	; );\r
	221	;------------------------------------------------------------------------------\r
	222	InternalAsmThunk16 PROC USES rbp rbx rsi rdi\r
	223	mov r10d, ds\r
	224	mov r11d, es\r
	225	mov r9d, ss\r
	226	push fs\r
	227	push gs\r
	228	mov rsi, rcx\r
	229	movzx r8d, (IA32_REGS ptr [rsi])._SS\r
	230	mov edi, (IA32_REGS ptr [rsi])._ESP\r
	231	lea rdi, [edi - (sizeof (IA32_REGS) + 4)]\r
	232	imul eax, r8d, 16 ; eax <- r8d(stack segment) * 16\r
	233	mov ebx, edi ; ebx <- stack for 16-bit code\r
	234	push sizeof (IA32_REGS) / 4\r
	235	add edi, eax ; edi <- linear address of 16-bit stack\r
	236	pop rcx\r
	237	rep movsd ; copy RegSet\r
	238	lea ecx, [rdx + (SavedCr4 - m16Start)]\r
	239	mov eax, edx ; eax <- transition code address\r
	240	and edx, 0fh\r
	241	shl eax, 12\r
	242	lea ax, [rdx + (_BackFromUserCode - m16Start)]\r
	243	stosd ; [edi] <- return address of user code\r
	244	sgdt fword ptr [rcx + (SavedGdt - SavedCr4)]\r
	245	sidt fword ptr [rsp + 38h] ; save IDT stack in argument space\r
	246	mov rax, cr0\r
	247	mov [rcx + (SavedCr0 - SavedCr4)], eax\r
	248	and eax, 7ffffffeh ; clear PE, PG bits\r
	249	mov rbp, cr4\r
	250	mov [rcx], ebp ; save CR4 in SavedCr4\r
	251	and ebp, 300h ; clear all but PCE and OSFXSR bits\r
	252	mov esi, r8d ; esi <- 16-bit stack segment\r
	253	DB 6ah, DATA32 ; push DATA32\r
	254	pop rdx ; rdx <- 32-bit data segment selector\r
	255	lgdt fword ptr [rcx + (_16Gdtr - SavedCr4)]\r
	256	mov ss, edx\r
	257	pushfq\r
	258	lea edx, [rdx + DATA16 - DATA32]\r
	259	lea r8, @RetFromRealMode\r
	260	mov [rcx + (SavedRip - SavedCr4)], r8\r
	261	mov r8d, cs\r
	262	mov [rcx + (SavedCs - SavedCr4)], r8w\r
	263	mov r8, rsp\r
	264	jmp fword ptr [rcx + (_EntryPoint - SavedCr4)]\r
	265	@RetFromRealMode:\r
	266	mov rsp, r8\r
	267	popfq\r
	268	lidt fword ptr [rsp + 38h] ; restore protected mode IDTR\r
	269	lea eax, [rbp - sizeof (IA32_REGS)]\r
	270	pop gs\r
	271	pop fs\r
	272	mov ss, r9d\r
	273	mov es, r11d\r
	274	mov ds, r10d\r
	275	ret\r
	276	InternalAsmThunk16 ENDP\r
	277	\r
	278	END\r