projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 1efcc4ae | 1 | \r |
| 47fc17d8 | 2 | #include "BaseLibInternals.h"\r |
| f1baef62 | 3 | \r |
| 4 | ;------------------------------------------------------------------------------\r | |
| 5 | ;\r | |
| 48c8b6a2 | 6 | ; Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>\r |
| bb817c56 | 7 | ; This program and the accompanying materials\r |
| f1baef62 | 8 | ; are licensed and made available under the terms and conditions of the BSD License\r |
| 9 | ; which accompanies this distribution. The full text of the license may be found at\r | |
| 2fc59a00 | 10 | ; http://opensource.org/licenses/bsd-license.php.\r |
| f1baef62 | 11 | ;\r |
| 12 | ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
| 13 | ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
| 14 | ;\r | |
| 15 | ; Module Name:\r | |
| 16 | ;\r | |
| 17 | ; Thunk.asm\r | |
| 18 | ;\r | |
| 19 | ; Abstract:\r | |
| 20 | ;\r | |
| 21 | ; Real mode thunk\r | |
| 22 | ;\r | |
| 23 | ;------------------------------------------------------------------------------\r | |
| 24 | \r | |
| 25 | EXTERNDEF m16Start:BYTE\r | |
| 26 | EXTERNDEF m16Size:WORD\r | |
| 27 | EXTERNDEF mThunk16Attr:WORD\r | |
| 28 | EXTERNDEF m16Gdt:WORD\r | |
| 29 | EXTERNDEF m16GdtrBase:WORD\r | |
| 30 | EXTERNDEF mTransition:WORD\r | |
| 31 | \r | |
| 32 | IA32_REGS STRUC 4t\r | |
| 33 | _EDI DD ?\r | |
| 34 | _ESI DD ?\r | |
| 35 | _EBP DD ?\r | |
| 36 | _ESP DD ?\r | |
| 37 | _EBX DD ?\r | |
| 38 | _EDX DD ?\r | |
| 39 | _ECX DD ?\r | |
| 40 | _EAX DD ?\r | |
| 41 | _DS DW ?\r | |
| 42 | _ES DW ?\r | |
| 43 | _FS DW ?\r | |
| 44 | _GS DW ?\r | |
| 45 | _EFLAGS DQ ?\r | |
| 46 | _EIP DD ?\r | |
| 47 | _CS DW ?\r | |
| 48 | _SS DW ?\r | |
| 49 | IA32_REGS ENDS\r | |
| 50 | \r | |
| 51 | .const\r | |
| 52 | \r | |
| 53 | m16Size DW InternalAsmThunk16 - m16Start\r | |
| 54 | mThunk16Attr DW _ThunkAttr - m16Start\r | |
| 55 | m16Gdt DW _NullSeg - m16Start\r | |
| 56 | m16GdtrBase DW _16GdtrBase - m16Start\r | |
| 57 | mTransition DW _EntryPoint - m16Start\r | |
| 58 | \r | |
| 59 | .code\r | |
| 60 | \r | |
| 61 | m16Start LABEL BYTE\r | |
| 62 | \r | |
| 63 | SavedGdt LABEL FWORD\r | |
| 64 | DW ?\r | |
| 65 | DQ ?\r | |
| 66 | \r | |
| 67 | ;------------------------------------------------------------------------------\r | |
| 68 | ; _BackFromUserCode() takes control in real mode after 'retf' has been executed\r | |
| 69 | ; by user code. It will be shadowed to somewhere in memory below 1MB.\r | |
| 70 | ;------------------------------------------------------------------------------\r | |
| 71 | _BackFromUserCode PROC\r | |
| 72 | ;\r | |
| 73 | ; The order of saved registers on the stack matches the order they appears\r | |
| 74 | ; in IA32_REGS structure. This facilitates wrapper function to extract them\r | |
| 75 | ; into that structure.\r | |
| 76 | ;\r | |
| 77 | ; Some instructions for manipulation of segment registers have to be written\r | |
| 78 | ; in opcode since 64-bit MASM prevents accesses to those registers.\r | |
| 79 | ;\r | |
| 80 | DB 16h ; push ss\r | |
| 81 | DB 0eh ; push cs\r | |
| 82 | DB 66h\r | |
| 83 | call @Base ; push eip\r | |
| 84 | @Base:\r | |
| 85 | DB 66h\r | |
| 86 | push 0 ; reserved high order 32 bits of EFlags\r | |
| 87 | pushf ; pushfd actually\r | |
| 88 | cli ; disable interrupts\r | |
| 89 | push gs\r | |
| 90 | push fs\r | |
| 91 | DB 6 ; push es\r | |
| 92 | DB 1eh ; push ds\r | |
| 93 | DB 66h, 60h ; pushad\r | |
| 94 | DB 66h, 0bah ; mov edx, imm32\r | |
| 95 | _ThunkAttr DD ?\r | |
| 96 | test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15\r | |
| 97 | jz @1\r | |
| 98 | mov eax, 15cd2401h ; mov ax, 2401h & int 15h\r | |
| 99 | cli ; disable interrupts\r | |
| 100 | jnc @2\r | |
| 101 | @1:\r | |
| 102 | test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL\r | |
| 103 | jz @2\r | |
| 104 | in al, 92h\r | |
| 105 | or al, 2\r | |
| 106 | out 92h, al ; deactivate A20M#\r | |
| 107 | @2:\r | |
| c577049a LG |
108 | xor ax, ax ; xor eax, eax\r |
| 109 | mov eax, ss ; mov ax, ss\r | |
| f1baef62 | 110 | lea bp, [esp + sizeof (IA32_REGS)]\r |
| 111 | ;\r | |
| 112 | ; rsi in the following 2 instructions is indeed bp in 16-bit code\r | |
| 113 | ;\r | |
| 114 | mov word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp\r | |
| 115 | DB 66h\r | |
| 116 | mov ebx, (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._EIP\r | |
| 117 | shl ax, 4 ; shl eax, 4\r | |
| 118 | add bp, ax ; add ebp, eax\r | |
| 119 | mov ax, cs\r | |
| 120 | shl ax, 4\r | |
| 121 | lea ax, [eax + ebx + (@64BitCode - @Base)]\r | |
| 122 | DB 66h, 2eh, 89h, 87h ; mov cs:[bx + (@64Eip - @Base)], eax\r | |
| 123 | DW @64Eip - @Base\r | |
| 124 | DB 66h, 0b8h ; mov eax, imm32\r | |
| 125 | SavedCr4 DD ?\r | |
| 126 | mov cr4, rax\r | |
| 127 | ;\r | |
| 128 | ; rdi in the instruction below is indeed bx in 16-bit code\r | |
| 129 | ;\r | |
| 130 | DB 66h, 2eh ; 2eh is "cs:" segment override\r | |
| 131 | lgdt fword ptr [rdi + (SavedGdt - @Base)]\r | |
| 132 | DB 66h\r | |
| 133 | mov ecx, 0c0000080h\r | |
| 134 | rdmsr\r | |
| 135 | or ah, 1\r | |
| 136 | wrmsr\r | |
| 137 | DB 66h, 0b8h ; mov eax, imm32\r | |
| 138 | SavedCr0 DD ?\r | |
| 139 | mov cr0, rax\r | |
| 140 | DB 66h, 0eah ; jmp far cs:@64Bit\r | |
| 141 | @64Eip DD ?\r | |
| 142 | SavedCs DW ?\r | |
| 143 | @64BitCode:\r | |
| 0fe43214 | 144 | db 090h \r |
| 145 | db 067h, 0bch ; mov esp, imm32\r | |
| 146 | SavedSp DD ? ; restore stack\r | |
| 147 | nop\r | |
| f1baef62 | 148 | ret\r |
| 149 | _BackFromUserCode ENDP\r | |
| 150 | \r | |
| 151 | _EntryPoint DD _ToUserCode - m16Start\r | |
| 152 | DW CODE16\r | |
| 153 | _16Gdtr LABEL FWORD\r | |
| 154 | DW GDT_SIZE - 1\r | |
| 155 | _16GdtrBase DQ _NullSeg\r | |
| 156 | _16Idtr FWORD (1 SHL 10) - 1\r | |
| 157 | \r | |
| 158 | ;------------------------------------------------------------------------------\r | |
| 159 | ; _ToUserCode() takes control in real mode before passing control to user code.\r | |
| 160 | ; It will be shadowed to somewhere in memory below 1MB.\r | |
| 161 | ;------------------------------------------------------------------------------\r | |
| 162 | _ToUserCode PROC\r | |
| 163 | mov ss, edx ; set new segment selectors\r | |
| 164 | mov ds, edx\r | |
| 165 | mov es, edx\r | |
| 166 | mov fs, edx\r | |
| 167 | mov gs, edx\r | |
| 168 | DB 66h\r | |
| 169 | mov ecx, 0c0000080h\r | |
| 170 | mov cr0, rax ; real mode starts at next instruction\r | |
| 171 | rdmsr\r | |
| 172 | and ah, NOT 1\r | |
| 173 | wrmsr\r | |
| 174 | mov cr4, rbp\r | |
| 175 | mov ss, esi ; set up 16-bit stack segment\r | |
| 176 | mov sp, bx ; set up 16-bit stack pointer\r | |
| 177 | DB 66h ; make the following call 32-bit\r | |
| 178 | call @Base ; push eip\r | |
| 179 | @Base:\r | |
| 180 | pop bp ; ebp <- address of @Base\r | |
| 181 | push [esp + sizeof (IA32_REGS) + 2]\r | |
| 182 | lea eax, [rsi + (@RealMode - @Base)] ; rsi is "bp" in 16-bit code\r | |
| 183 | push rax\r | |
| 184 | retf ; execution begins at next instruction\r | |
| 185 | @RealMode:\r | |
| 186 | DB 66h, 2eh ; CS and operand size override\r | |
| 187 | lidt fword ptr [rsi + (_16Idtr - @Base)]\r | |
| 188 | DB 66h, 61h ; popad\r | |
| 189 | DB 1fh ; pop ds\r | |
| 190 | DB 07h ; pop es\r | |
| 191 | pop fs\r | |
| 192 | pop gs\r | |
| 193 | popf ; popfd\r | |
| 194 | lea sp, [esp + 4] ; skip high order 32 bits of EFlags\r | |
| 195 | DB 66h ; make the following retf 32-bit\r | |
| 196 | retf ; transfer control to user code\r | |
| 197 | _ToUserCode ENDP\r | |
| 198 | \r | |
| 199 | CODE16 = _16Code - $\r | |
| 200 | DATA16 = _16Data - $\r | |
| 201 | DATA32 = _32Data - $\r | |
| 202 | \r | |
| 203 | _NullSeg DQ 0\r | |
| 204 | _16Code LABEL QWORD\r | |
| 205 | DW -1\r | |
| 206 | DW 0\r | |
| 207 | DB 0\r | |
| 208 | DB 9bh\r | |
| 209 | DB 8fh ; 16-bit segment, 4GB limit\r | |
| 210 | DB 0\r | |
| 211 | _16Data LABEL QWORD\r | |
| 212 | DW -1\r | |
| 213 | DW 0\r | |
| 214 | DB 0\r | |
| 215 | DB 93h\r | |
| 216 | DB 8fh ; 16-bit segment, 4GB limit\r | |
| 217 | DB 0\r | |
| 218 | _32Data LABEL QWORD\r | |
| 219 | DW -1\r | |
| 220 | DW 0\r | |
| 221 | DB 0\r | |
| 222 | DB 93h\r | |
| 223 | DB 0cfh ; 16-bit segment, 4GB limit\r | |
| 224 | DB 0\r | |
| 225 | \r | |
| 226 | GDT_SIZE = $ - _NullSeg\r | |
| 227 | \r | |
| 228 | ;------------------------------------------------------------------------------\r | |
| 229 | ; IA32_REGISTER_SET *\r | |
| 230 | ; EFIAPI\r | |
| 231 | ; InternalAsmThunk16 (\r | |
| 232 | ; IN IA32_REGISTER_SET *RegisterSet,\r | |
| 233 | ; IN OUT VOID *Transition\r | |
| 234 | ; );\r | |
| 235 | ;------------------------------------------------------------------------------\r | |
| 236 | InternalAsmThunk16 PROC USES rbp rbx rsi rdi\r | |
| 0fe43214 | 237 | mov rbx, ds\r |
| 238 | push rbx ; Save ds segment register on the stack\r | |
| 239 | mov rbx, es\r | |
| 240 | push rbx ; Save es segment register on the stack\r | |
| 241 | mov rbx, ss\r | |
| 242 | push rbx ; Save ss segment register on the stack\r | |
| 243 | \r | |
| f1baef62 | 244 | push fs\r |
| 245 | push gs\r | |
| 246 | mov rsi, rcx\r | |
| 247 | movzx r8d, (IA32_REGS ptr [rsi])._SS\r | |
| 248 | mov edi, (IA32_REGS ptr [rsi])._ESP\r | |
| 249 | lea rdi, [edi - (sizeof (IA32_REGS) + 4)]\r | |
| 250 | imul eax, r8d, 16 ; eax <- r8d(stack segment) * 16\r | |
| 251 | mov ebx, edi ; ebx <- stack for 16-bit code\r | |
| 252 | push sizeof (IA32_REGS) / 4\r | |
| 253 | add edi, eax ; edi <- linear address of 16-bit stack\r | |
| 254 | pop rcx\r | |
| 255 | rep movsd ; copy RegSet\r | |
| 256 | lea ecx, [rdx + (SavedCr4 - m16Start)]\r | |
| 257 | mov eax, edx ; eax <- transition code address\r | |
| 258 | and edx, 0fh\r | |
| 259 | shl eax, 12 ; segment address in high order 16 bits\r | |
| 260 | lea ax, [rdx + (_BackFromUserCode - m16Start)] ; offset address\r | |
| 261 | stosd ; [edi] <- return address of user code\r | |
| a1487801 | 262 | \r |
| 263 | sgdt fword ptr [rsp + 60h] ; save GDT stack in argument space\r | |
| 264 | movzx r10, word ptr [rsp + 60h] ; r10 <- GDT limit \r | |
| 265 | lea r11, [rcx + (InternalAsmThunk16 - SavedCr4) + 0xf]\r | |
| 266 | and r11, 0xfffffff0 ; r11 <- 16-byte aligned shadowed GDT table in real mode buffer\r | |
| 267 | \r | |
| 268 | mov word ptr [rcx + (SavedGdt - SavedCr4)], r10w ; save the limit of shadowed GDT table\r | |
| 269 | mov qword ptr [rcx + (SavedGdt - SavedCr4) + 2], r11 ; save the base address of shadowed GDT table\r | |
| 270 | \r | |
| 271 | mov rsi, qword ptr [rsp + 62h] ; rsi <- the original GDT base address\r | |
| 272 | xchg rcx, r10 ; save rcx to r10 and initialize rcx to be the limit of GDT table\r | |
| 273 | inc rcx ; rcx <- the size of memory to copy\r | |
| 274 | xchg rdi, r11 ; save rdi to r11 and initialize rdi to the base address of shadowed GDT table\r | |
| 275 | rep movsb ; perform memory copy to shadow GDT table\r | |
| 276 | mov rcx, r10 ; restore the orignal rcx before memory copy\r | |
| 277 | mov rdi, r11 ; restore the original rdi before memory copy\r | |
| 278 | \r | |
| 0fe43214 | 279 | sidt fword ptr [rsp + 50h] ; save IDT stack in argument space\r |
| f1baef62 | 280 | mov rax, cr0\r |
| 281 | mov [rcx + (SavedCr0 - SavedCr4)], eax\r | |
| 282 | and eax, 7ffffffeh ; clear PE, PG bits\r | |
| 283 | mov rbp, cr4\r | |
| 284 | mov [rcx], ebp ; save CR4 in SavedCr4\r | |
| 48c8b6a2 | 285 | and ebp, NOT 30h ; clear PAE, PSE bits\r |
| f1baef62 | 286 | mov esi, r8d ; esi <- 16-bit stack segment\r |
| 287 | DB 6ah, DATA32 ; push DATA32\r | |
| 288 | pop rdx ; rdx <- 32-bit data segment selector\r | |
| 289 | lgdt fword ptr [rcx + (_16Gdtr - SavedCr4)]\r | |
| 290 | mov ss, edx\r | |
| 291 | pushfq\r | |
| 292 | lea edx, [rdx + DATA16 - DATA32]\r | |
| 293 | lea r8, @RetFromRealMode\r | |
| 294 | push r8\r | |
| 295 | mov r8d, cs\r | |
| 296 | mov [rcx + (SavedCs - SavedCr4)], r8w\r | |
| 0fe43214 | 297 | mov [rcx + (SavedSp - SavedCr4)], esp\r |
| f1baef62 | 298 | jmp fword ptr [rcx + (_EntryPoint - SavedCr4)]\r |
| 299 | @RetFromRealMode:\r | |
| 300 | popfq\r | |
| a1487801 | 301 | lgdt fword ptr [rsp + 60h] ; restore protected mode GDTR\r |
| 0fe43214 | 302 | lidt fword ptr [rsp + 50h] ; restore protected mode IDTR\r |
| f1baef62 | 303 | lea eax, [rbp - sizeof (IA32_REGS)]\r |
| 304 | pop gs\r | |
| 305 | pop fs\r | |
| 0fe43214 | 306 | pop rbx\r |
| 307 | mov ss, rbx\r | |
| 308 | pop rbx\r | |
| 309 | mov es, rbx\r | |
| 310 | pop rbx\r | |
| 311 | mov ds, rbx\r | |
| f1baef62 | 312 | ret\r |
| 313 | InternalAsmThunk16 ENDP\r | |
| 314 | \r | |
| 315 | END\r |