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AsmReadKr1 is already defined in the baselib
[mirror_edk2.git] / OldMdePkg / Library / BaseLib / X64 / Thunk16.asm
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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
22EXTERNDEF m16Start:BYTE\r
23EXTERNDEF m16Size:WORD\r
24EXTERNDEF mThunk16Attr:WORD\r
25EXTERNDEF m16Gdt:WORD\r
26EXTERNDEF m16GdtrBase:WORD\r
27EXTERNDEF mTransition:WORD\r
28\r
29IA32_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
46IA32_REGS ENDS\r
47\r
48 .const\r
49\r
50m16Size DW InternalAsmThunk16 - m16Start\r
51mThunk16Attr DW _ThunkAttr - m16Start\r
52m16Gdt DW _NullSeg - m16Start\r
53m16GdtrBase DW _16GdtrBase - m16Start\r
54mTransition DW _EntryPoint - m16Start\r
55\r
56 .code\r
57\r
58m16Start LABEL BYTE\r
59\r
60SavedGdt 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 ;\r
70 ; The order of saved registers on the stack matches the order they appears\r
71 ; in IA32_REGS structure. This facilitates wrapper function to extract them\r
72 ; into that structure.\r
73 ;\r
74 ; Some instructions for manipulation of segment registers have to be written\r
75 ; in opcode since 64-bit MASM prevents accesses to those registers.\r
76 ;\r
77 DB 16h ; push ss\r
78 DB 0eh ; push cs\r
79 DB 66h\r
80 call @Base ; push eip\r
81@Base:\r
82 DB 66h\r
83 push 0 ; reserved high order 32 bits of EFlags\r
84 pushf ; pushfd actually\r
85 cli ; disable interrupts\r
86 push gs\r
87 push fs\r
88 DB 6 ; push es\r
89 DB 1eh ; push ds\r
90 DB 66h, 60h ; pushad\r
91 DB 66h, 0bah ; mov edx, imm32\r
92_ThunkAttr DD ?\r
93 test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15\r
94 jz @1\r
95 mov eax, 15cd2401h ; mov ax, 2401h & int 15h\r
96 cli ; disable interrupts\r
97 jnc @2\r
98@1:\r
99 test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL\r
100 jz @2\r
101 in al, 92h\r
102 or al, 2\r
103 out 92h, al ; deactivate A20M#\r
104@2:\r
105 mov eax, ss\r
106 lea bp, [esp + sizeof (IA32_REGS)]\r
107 ;\r
108 ; rsi in the following 2 instructions is indeed bp in 16-bit code\r
109 ;\r
110 mov word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp\r
111 DB 66h\r
112 mov ebx, (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._EIP\r
113 shl ax, 4 ; shl eax, 4\r
114 add bp, ax ; add ebp, eax\r
115 mov ax, cs\r
116 shl ax, 4\r
117 lea ax, [eax + ebx + (@64BitCode - @Base)]\r
118 DB 66h, 2eh, 89h, 87h ; mov cs:[bx + (@64Eip - @Base)], eax\r
119 DW @64Eip - @Base\r
120 DB 66h, 0b8h ; mov eax, imm32\r
121SavedCr4 DD ?\r
122 mov cr4, rax\r
123 ;\r
124 ; rdi in the instruction below is indeed bx in 16-bit code\r
125 ;\r
126 DB 66h, 2eh ; 2eh is "cs:" segment override\r
127 lgdt fword ptr [rdi + (SavedGdt - @Base)]\r
128 DB 66h\r
129 mov ecx, 0c0000080h\r
130 rdmsr\r
131 or ah, 1\r
132 wrmsr\r
133 DB 66h, 0b8h ; mov eax, imm32\r
134SavedCr0 DD ?\r
135 mov cr0, rax\r
136 DB 66h, 0eah ; jmp far cs:@64Bit\r
137@64Eip DD ?\r
138SavedCs DW ?\r
139@64BitCode:\r
140 mov rsp, r8 ; restore stack\r
141 ret\r
142_BackFromUserCode ENDP\r
143\r
144_EntryPoint DD _ToUserCode - m16Start\r
145 DW CODE16\r
146_16Gdtr LABEL FWORD\r
147 DW GDT_SIZE - 1\r
148_16GdtrBase DQ _NullSeg\r
149_16Idtr FWORD (1 SHL 10) - 1\r
150\r
151;------------------------------------------------------------------------------\r
152; _ToUserCode() takes control in real mode before passing control to user code.\r
153; It will be shadowed to somewhere in memory below 1MB.\r
154;------------------------------------------------------------------------------\r
155_ToUserCode PROC\r
156 mov ss, edx ; set new segment selectors\r
157 mov ds, edx\r
158 mov es, edx\r
159 mov fs, edx\r
160 mov gs, edx\r
161 DB 66h\r
162 mov ecx, 0c0000080h\r
163 mov cr0, rax ; real mode starts at next instruction\r
164 rdmsr\r
165 and ah, NOT 1\r
166 wrmsr\r
167 mov cr4, rbp\r
168 mov ss, esi ; set up 16-bit stack segment\r
169 mov sp, bx ; set up 16-bit stack pointer\r
170 DB 66h ; make the following call 32-bit\r
171 call @Base ; push eip\r
172@Base:\r
173 pop bp ; ebp <- address of @Base\r
174 push [esp + sizeof (IA32_REGS) + 2]\r
175 lea eax, [rsi + (@RealMode - @Base)] ; rsi is "bp" in 16-bit code\r
176 push rax\r
177 retf ; execution begins at next instruction\r
178@RealMode:\r
179 DB 66h, 2eh ; CS and operand size override\r
180 lidt fword ptr [rsi + (_16Idtr - @Base)]\r
181 DB 66h, 61h ; popad\r
182 DB 1fh ; pop ds\r
183 DB 07h ; pop es\r
184 pop fs\r
185 pop gs\r
186 popf ; popfd\r
187 lea sp, [esp + 4] ; skip high order 32 bits of EFlags\r
188 DB 66h ; make the following retf 32-bit\r
189 retf ; transfer control to user code\r
190_ToUserCode ENDP\r
191\r
192CODE16 = _16Code - $\r
193DATA16 = _16Data - $\r
194DATA32 = _32Data - $\r
195\r
196_NullSeg DQ 0\r
197_16Code LABEL QWORD\r
198 DW -1\r
199 DW 0\r
200 DB 0\r
201 DB 9bh\r
202 DB 8fh ; 16-bit segment, 4GB limit\r
203 DB 0\r
204_16Data LABEL QWORD\r
205 DW -1\r
206 DW 0\r
207 DB 0\r
208 DB 93h\r
209 DB 8fh ; 16-bit segment, 4GB limit\r
210 DB 0\r
211_32Data LABEL QWORD\r
212 DW -1\r
213 DW 0\r
214 DB 0\r
215 DB 93h\r
216 DB 0cfh ; 16-bit segment, 4GB limit\r
217 DB 0\r
218\r
219GDT_SIZE = $ - _NullSeg\r
220\r
221;------------------------------------------------------------------------------\r
222; IA32_REGISTER_SET *\r
223; EFIAPI\r
224; InternalAsmThunk16 (\r
225; IN IA32_REGISTER_SET *RegisterSet,\r
226; IN OUT VOID *Transition\r
227; );\r
228;------------------------------------------------------------------------------\r
229InternalAsmThunk16 PROC USES rbp rbx rsi rdi\r
230 mov r10d, ds ; r9 ~ r11 are not accessible in 16-bit\r
231 mov r11d, es ; so use them for saving seg registers\r
232 mov r9d, ss\r
233 push fs\r
234 push gs\r
235 mov rsi, rcx\r
236 movzx r8d, (IA32_REGS ptr [rsi])._SS\r
237 mov edi, (IA32_REGS ptr [rsi])._ESP\r
238 lea rdi, [edi - (sizeof (IA32_REGS) + 4)]\r
239 imul eax, r8d, 16 ; eax <- r8d(stack segment) * 16\r
240 mov ebx, edi ; ebx <- stack for 16-bit code\r
241 push sizeof (IA32_REGS) / 4\r
242 add edi, eax ; edi <- linear address of 16-bit stack\r
243 pop rcx\r
244 rep movsd ; copy RegSet\r
245 lea ecx, [rdx + (SavedCr4 - m16Start)]\r
246 mov eax, edx ; eax <- transition code address\r
247 and edx, 0fh\r
248 shl eax, 12 ; segment address in high order 16 bits\r
249 lea ax, [rdx + (_BackFromUserCode - m16Start)] ; offset address\r
250 stosd ; [edi] <- return address of user code\r
251 sgdt fword ptr [rcx + (SavedGdt - SavedCr4)]\r
252 sidt fword ptr [rsp + 38h] ; save IDT stack in argument space\r
253 mov rax, cr0\r
254 mov [rcx + (SavedCr0 - SavedCr4)], eax\r
255 and eax, 7ffffffeh ; clear PE, PG bits\r
256 mov rbp, cr4\r
257 mov [rcx], ebp ; save CR4 in SavedCr4\r
258 and ebp, 300h ; clear all but PCE and OSFXSR bits\r
259 mov esi, r8d ; esi <- 16-bit stack segment\r
260 DB 6ah, DATA32 ; push DATA32\r
261 pop rdx ; rdx <- 32-bit data segment selector\r
262 lgdt fword ptr [rcx + (_16Gdtr - SavedCr4)]\r
263 mov ss, edx\r
264 pushfq\r
265 lea edx, [rdx + DATA16 - DATA32]\r
266 lea r8, @RetFromRealMode\r
267 push r8\r
268 mov r8d, cs\r
269 mov [rcx + (SavedCs - SavedCr4)], r8w\r
270 mov r8, rsp\r
271 jmp fword ptr [rcx + (_EntryPoint - SavedCr4)]\r
272@RetFromRealMode:\r
273 popfq\r
274 lidt fword ptr [rsp + 38h] ; restore protected mode IDTR\r
275 lea eax, [rbp - sizeof (IA32_REGS)]\r
276 pop gs\r
277 pop fs\r
278 mov ss, r9d\r
279 mov es, r11d\r
280 mov ds, r10d\r
281 ret\r
282InternalAsmThunk16 ENDP\r
283\r
284 END\r
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