[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      offset InternalAsmThunk16 - offset m16Start\r
mThunk16Attr    DW      offset _ThunkAttr - offset m16Start\r
m16Gdt          DW      offset _NullSegDesc - offset m16Start\r
m16GdtrBase     DW      offset _16GdtrBase - offset m16Start\r
mTransition     DW      offset _EntryPoint - offset 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 + (offset SavedGdt - offset @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      offset _ToUserCode - offset m16Start\r
                DW      8h\r
_16Gdtr         LABEL   FWORD\r
                DW      offset GdtEnd - offset _NullSegDesc - 1\r
_16GdtrBase     DQ      offset _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 <- offset @Base\r
    push    [esp + sizeof (IA32_REGS) + 2]\r
    lea     eax, [rsi + (offset @RealMode - offset @Base)]\r
    push    rax\r
    retf\r
@RealMode:\r
    DB      2eh                         ; cs:\r
    mov     [rsi + (offset SavedSs - offset @Base)], edi\r
    DB      2eh                         ; cs:\r
    mov     [rsi + (offset SavedEsp - offset @Base)], bx\r
    DB      66h, 2eh                    ; CS and operand size override\r
    lidt    fword ptr [rsi + (offset _16Idtr - offset @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 offset 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 + (offset SavedCr4 - offset m16Start)]\r
    mov     eax, edx                    ; eax <- transition code address\r
    and     edx, 0fh\r
    shl     eax, 12\r
    lea     edx, [rdx + (offset _BackFromUserCode - offset m16Start)]\r
    mov     ax, dx\r
    stosd                               ; [edi] <- return address of user code\r
    sgdt    fword ptr [rcx + (offset SavedGdt - offset SavedCr4)]\r
    sidt    fword ptr [rsp + 38h]       ; save IDT stack in argument space\r
    mov     rax, cr0\r
    mov     [rcx + (offset SavedCr0 - offset 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 + (offset _16Gdtr - offset SavedCr4)]\r
    pushfq\r
    call    fword ptr [rcx + (offset _EntryPoint - offset 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
	49	\r
	50	m16Size DW offset InternalAsmThunk16 - offset m16Start\r
	51	mThunk16Attr DW offset _ThunkAttr - offset m16Start\r
	52	m16Gdt DW offset _NullSegDesc - offset m16Start\r
	53	m16GdtrBase DW offset _16GdtrBase - offset m16Start\r
	54	mTransition DW offset _EntryPoint - offset 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	_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
	103	lgdt fword ptr [rdi + (offset SavedGdt - offset @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
	121	_EntryPoint DD offset _ToUserCode - offset m16Start\r
	122	DW 8h\r
	123	_16Gdtr LABEL FWORD\r
	124	DW offset GdtEnd - offset _NullSegDesc - 1\r
	125	_16GdtrBase DQ offset _NullSegDesc\r
	126	_16Idtr FWORD (1 SHL 10) - 1\r
	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
	146	@Base:\r
	147	pop bp ; ebp <- offset @Base\r
18c319ae	148	push [esp + sizeof (IA32_REGS) + 2]\r
	149	lea eax, [rsi + (offset @RealMode - offset @Base)]\r
	150	push rax\r
	151	retf\r
	152	@RealMode:\r
97d92bda	153	DB 2eh ; cs:\r
	154	mov [rsi + (offset SavedSs - offset @Base)], edi\r
	155	DB 2eh ; cs:\r
	156	mov [rsi + (offset SavedEsp - offset @Base)], bx\r
	157	DB 66h, 2eh ; CS and operand size override\r
	158	lidt fword ptr [rsi + (offset _16Idtr - offset @Base)]\r
	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
	202	mov ebx, edi ; ebx <- stack offset for 16-bit code\r
	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
	207	lea ecx, [rdx + (offset SavedCr4 - offset m16Start)]\r
	208	mov eax, edx ; eax <- transition code address\r
	209	and edx, 0fh\r
	210	shl eax, 12\r
	211	lea edx, [rdx + (offset _BackFromUserCode - offset m16Start)]\r
	212	mov ax, dx\r
	213	stosd ; [edi] <- return address of user code\r
	214	sgdt fword ptr [rcx + (offset SavedGdt - offset SavedCr4)]\r
	215	sidt fword ptr [rsp + 38h] ; save IDT stack in argument space\r
	216	mov rax, cr0\r
	217	mov [rcx + (offset SavedCr0 - offset SavedCr4)], eax\r
	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
	225	lgdt fword ptr [rcx + (offset _16Gdtr - offset SavedCr4)]\r
18c319ae	226	pushfq\r
97d92bda	227	call fword ptr [rcx + (offset _EntryPoint - offset 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