[mirror_edk2.git] / EdkCompatibilityPkg / Foundation / Library / Thunk16 / 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   mCode16Size:QWORD\r
\r
    .const\r
\r
mCode16Size     DQ      _Code16End - _Code16Addr\r
\r
    .data\r
\r
NullSegSel      DQ      0\r
_16CsSegSel     LABEL   QWORD\r
                DW      -1\r
                DW      0\r
                DB      0\r
                DB      9bh\r
                DB      8fh             ; 16-bit segment\r
                DB      0\r
_16DsSegSel     LABEL   QWORD\r
                DW      -1\r
                DW      0\r
                DB      0\r
                DB      93h\r
                DB      8fh             ; 16-bit segment\r
                DB      0\r
\r
_16Gdtr         LABEL   FWORD\r
                DW      $ - offset NullSegSel - 1\r
                DQ      offset NullSegSel\r
\r
    .code\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
_RFLAGS     DQ      ?\r
_EIP        DD      ?\r
_CS         DW      ?\r
_SS         DW      ?\r
IA32_REGS   ENDS\r
\r
_STK16      STRUC   1t\r
RetEip      DD      ?\r
RetCs       DW      ?\r
ThunkFlags  DW      ?\r
SavedGdtr   FWORD   ?\r
Resvd1      DW      ?\r
SavedCr0    DD      ?\r
SavedCr4    DD      ?\r
_STK16      ENDS\r
\r
_Thunk16    PROC    USES    rbp rbx rsi rdi r12 r13 r14 r15\r
\r
    push    fs\r
    push    gs\r
\r
    mov     r12d, ds\r
    mov     r13d, es\r
    mov     r14d, ss\r
    mov     r15, rsp\r
    mov     rsi, rcx\r
    movzx   r10, (IA32_REGS ptr [rsi])._SS\r
    xor     rdi, rdi\r
    mov     edi, (IA32_REGS ptr [rsi])._ESP\r
    add     rdi, - sizeof (IA32_REGS) - sizeof (_STK16)\r
    push    rdi\r
    imul    rax, r10, 16\r
    add     rdi, rax\r
    push    sizeof (IA32_REGS) / 4\r
    pop     rcx\r
    rep     movsd\r
    pop     rbx                         ; rbx <- 16-bit stack offset\r
    lea     eax, @F                     ; return offset\r
    stosd\r
    mov     eax, cs                     ; return segment\r
    stosw\r
    mov     eax, edx                    ; THUNK Flags\r
    stosw\r
    sgdt    fword ptr [rsp + 58h]       ; save GDTR\r
    mov     rax, [rsp + 58h]\r
    stosq\r
    mov     rax, cr0                    ; save CR0\r
    mov     esi, eax                    ; esi <- CR0 to set\r
    stosd\r
    mov     rax, cr4                    ; save CR4\r
    stosd\r
    sidt    fword ptr [rsp + 58h]       ; save IDTR\r
    and     esi, 07ffffffeh             ; clear PE & PG bits\r
    mov     rdi, r10                    ; rdi <- 16-bit stack segment\r
\r
    shl     r8, 16\r
    push    r8                          ; far jmp address\r
    lea     eax, @16Bit\r
    push    rax\r
    mov     word ptr [rsp + 4], 8\r
    lgdt    _16Gdtr\r
    retf\r
@16Bit:\r
    DB      66h\r
    mov     ecx, 0c0000080h\r
    mov     cr0, rsi                    ; disable PE & PG\r
    rdmsr\r
    and     ah, NOT 1\r
    wrmsr                               ; clear LME bit\r
    mov     rax, cr4\r
    and     al, NOT 30h                 ; clear PAE & PSE\r
    mov     cr4, rax\r
    retf\r
@@:\r
    xor     rax, rax\r
    mov     eax, ss\r
    shl     eax, 4\r
    add     eax, esp                    ; rax <- address of 16-bit stack\r
    mov     rsp, r15\r
    lidt    fword ptr [rsp + 58h]       ; restore IDTR\r
    mov     ds, r12d\r
    mov     es, r13d\r
    mov     ss, r14d\r
    pop     gs\r
    pop     fs\r
    ret\r
_Thunk16    ENDP\r
\r
    ALIGN   10h\r
\r
_Code16Addr PROC\r
_Code16Addr ENDP\r
\r
RealMode    PROC\r
    mov     ss, edi\r
    mov     sp, bx                      ; set up 16-bit stack\r
    DB      2eh, 0fh, 1, 1eh\r
    DW      _16Idtr - _Code16Addr       ; lidt _16Idtr\r
    DB      66h, 61h                    ; popad\r
    DB      1fh                         ; pop ds\r
    DB      7                           ; pop es\r
    pop     fs\r
    pop     gs\r
\r
    add     esp, 8                      ; skip RFLAGS\r
    DB      67h, 0f7h, 44h, 24h, 0eh, 1, 0  ; test [esp + 0eh], 1\r
    jz      @F\r
    pushfq                              ; pushf, actually\r
@@:\r
    DB      0eh                         ; push cs\r
    DB      68h                         ; push /iw\r
    DW      @FarCallRet - _Code16Addr\r
    jz      @F\r
    DB      66h\r
    jmp     fword ptr [esp + 6]\r
@@:\r
    DB      66h\r
    jmp     fword ptr [esp + 4]\r
@FarCallRet:\r
    DB      66h\r
    push    0                           ; push a dword of zero\r
    pushf                               ; pushfd, actually\r
    push    gs\r
    push    fs\r
    DB      6                           ; push es\r
    DB      1eh                         ; push ds\r
    DB      66h, 60h                    ; pushad\r
    cli\r
\r
    DB      66h\r
    lgdt    (_STK16 ptr [esp + sizeof(IA32_REGS)]).SavedGdtr\r
    DB      66h\r
    mov     eax, (_STK16 ptr [esp + sizeof(IA32_REGS)]).SavedCr4\r
    mov     cr4, rax\r
    DB      66h\r
    mov     ecx, 0c0000080h\r
    rdmsr\r
    or      ah, 1\r
    wrmsr                               ; set LME\r
    DB      66h\r
    mov     eax, (_STK16 ptr [esp + sizeof(IA32_REGS)]).SavedCr0\r
    mov     cr0, rax\r
    DB      66h\r
    jmp     fword ptr (_STK16 ptr [esp + sizeof(IA32_REGS)]).RetEip\r
\r
RealMode    ENDP\r
\r
_16Idtr     FWORD   (1 SHL 10) - 1\r
\r
_Code16End:\r
\r
    END\r
Commit	Line	Data
3eb9473e	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 mCode16Size:QWORD\r
	23	\r
	24	.const\r
	25	\r
	26	mCode16Size DQ _Code16End - _Code16Addr\r
	27	\r
	28	.data\r
	29	\r
	30	NullSegSel DQ 0\r
	31	_16CsSegSel LABEL QWORD\r
	32	DW -1\r
	33	DW 0\r
	34	DB 0\r
	35	DB 9bh\r
	36	DB 8fh ; 16-bit segment\r
	37	DB 0\r
	38	_16DsSegSel LABEL QWORD\r
	39	DW -1\r
	40	DW 0\r
	41	DB 0\r
	42	DB 93h\r
	43	DB 8fh ; 16-bit segment\r
	44	DB 0\r
	45	\r
	46	_16Gdtr LABEL FWORD\r
	47	DW $ - offset NullSegSel - 1\r
	48	DQ offset NullSegSel\r
	49	\r
	50	.code\r
	51	\r
	52	IA32_REGS STRUC 4t\r
	53	_EDI DD ?\r
	54	_ESI DD ?\r
	55	_EBP DD ?\r
	56	_ESP DD ?\r
	57	_EBX DD ?\r
	58	_EDX DD ?\r
	59	_ECX DD ?\r
	60	_EAX DD ?\r
	61	_DS DW ?\r
	62	_ES DW ?\r
	63	_FS DW ?\r
	64	_GS DW ?\r
65	_RFLAGS DQ ?\r
66	_EIP DD ?\r
67	_CS DW ?\r
68	_SS DW ?\r
69	IA32_REGS ENDS\r
70	\r
71	_STK16 STRUC 1t\r
72	RetEip DD ?\r
73	RetCs DW ?\r
74	ThunkFlags DW ?\r
75	SavedGdtr FWORD ?\r
76	Resvd1 DW ?\r
77	SavedCr0 DD ?\r
78	SavedCr4 DD ?\r
79	_STK16 ENDS\r
80	\r
81	_Thunk16 PROC USES rbp rbx rsi rdi r12 r13 r14 r15\r
82	\r
83	push fs\r
84	push gs\r
85	\r
86	mov r12d, ds\r
87	mov r13d, es\r
88	mov r14d, ss\r
89	mov r15, rsp\r
90	mov rsi, rcx\r
91	movzx r10, (IA32_REGS ptr [rsi])._SS\r
92	xor rdi, rdi\r
93	mov edi, (IA32_REGS ptr [rsi])._ESP\r
94	add rdi, - sizeof (IA32_REGS) - sizeof (_STK16)\r
95	push rdi\r
96	imul rax, r10, 16\r
97	add rdi, rax\r
98	push sizeof (IA32_REGS) / 4\r
99	pop rcx\r
100	rep movsd\r
101	pop rbx ; rbx <- 16-bit stack offset\r
102	lea eax, @F ; return offset\r
103	stosd\r
104	mov eax, cs ; return segment\r
105	stosw\r
106	mov eax, edx ; THUNK Flags\r
107	stosw\r
108	sgdt fword ptr [rsp + 58h] ; save GDTR\r
109	mov rax, [rsp + 58h]\r
110	stosq\r
111	mov rax, cr0 ; save CR0\r
112	mov esi, eax ; esi <- CR0 to set\r
113	stosd\r
114	mov rax, cr4 ; save CR4\r
115	stosd\r
116	sidt fword ptr [rsp + 58h] ; save IDTR\r
117	and esi, 07ffffffeh ; clear PE & PG bits\r
118	mov rdi, r10 ; rdi <- 16-bit stack segment\r
119	\r
120	shl r8, 16\r
121	push r8 ; far jmp address\r
122	lea eax, @16Bit\r
123	push rax\r
124	mov word ptr [rsp + 4], 8\r
125	lgdt _16Gdtr\r
126	retf\r
127	@16Bit:\r
128	DB 66h\r
129	mov ecx, 0c0000080h\r
130	mov cr0, rsi ; disable PE & PG\r
131	rdmsr\r
132	and ah, NOT 1\r
133	wrmsr ; clear LME bit\r
134	mov rax, cr4\r
135	and al, NOT 30h ; clear PAE & PSE\r
136	mov cr4, rax\r
137	retf\r
138	@@:\r
139	xor rax, rax\r
140	mov eax, ss\r
141	shl eax, 4\r
142	add eax, esp ; rax <- address of 16-bit stack\r
143	mov rsp, r15\r
144	lidt fword ptr [rsp + 58h] ; restore IDTR\r
145	mov ds, r12d\r
146	mov es, r13d\r
147	mov ss, r14d\r
148	pop gs\r
149	pop fs\r
150	ret\r
151	_Thunk16 ENDP\r
152	\r
153	ALIGN 10h\r
154	\r
155	_Code16Addr PROC\r
156	_Code16Addr ENDP\r
157	\r
158	RealMode PROC\r
159	mov ss, edi\r
160	mov sp, bx ; set up 16-bit stack\r
161	DB 2eh, 0fh, 1, 1eh\r
162	DW _16Idtr - _Code16Addr ; lidt _16Idtr\r
163	DB 66h, 61h ; popad\r
164	DB 1fh ; pop ds\r
165	DB 7 ; pop es\r
166	pop fs\r
167	pop gs\r
168	\r
169	add esp, 8 ; skip RFLAGS\r
170	DB 67h, 0f7h, 44h, 24h, 0eh, 1, 0 ; test [esp + 0eh], 1\r
171	jz @F\r
172	pushfq ; pushf, actually\r
173	@@:\r
174	DB 0eh ; push cs\r
175	DB 68h ; push /iw\r
176	DW @FarCallRet - _Code16Addr\r
177	jz @F\r
178	DB 66h\r
179	jmp fword ptr [esp + 6]\r
180	@@:\r
181	DB 66h\r
182	jmp fword ptr [esp + 4]\r
183	@FarCallRet:\r
184	DB 66h\r
185	push 0 ; push a dword of zero\r
186	pushf ; pushfd, actually\r
187	push gs\r
188	push fs\r
189	DB 6 ; push es\r
190	DB 1eh ; push ds\r
191	DB 66h, 60h ; pushad\r
192	cli\r
193	\r
194	DB 66h\r
195	lgdt (_STK16 ptr [esp + sizeof(IA32_REGS)]).SavedGdtr\r
196	DB 66h\r
197	mov eax, (_STK16 ptr [esp + sizeof(IA32_REGS)]).SavedCr4\r
198	mov cr4, rax\r
199	DB 66h\r
200	mov ecx, 0c0000080h\r
201	rdmsr\r
202	or ah, 1\r
203	wrmsr ; set LME\r
204	DB 66h\r
205	mov eax, (_STK16 ptr [esp + sizeof(IA32_REGS)]).SavedCr0\r
206	mov cr0, rax\r
207	DB 66h\r
208	jmp fword ptr (_STK16 ptr [esp + sizeof(IA32_REGS)]).RetEip\r
209	\r
210	RealMode ENDP\r
211	\r
212	_16Idtr FWORD (1 SHL 10) - 1\r
213	\r
214	_Code16End:\r
215	\r
216	END\r