UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ExceptionHandlerAsm.nasm

   1 ;------------------------------------------------------------------------------ ;
   2 ; Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
   3 ; This program and the accompanying materials
   4 ; are licensed and made available under the terms and conditions of the BSD License
   5 ; which accompanies this distribution.  The full text of the license may be found at
   6 ; http://opensource.org/licenses/bsd-license.php.
   7 ;
   8 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   9 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  10 ;
  11 ; Module Name:
  12 ;
  13 ;   ExceptionHandlerAsm.Asm
  14 ;
  15 ; Abstract:
  16 ;
  17 ;   IA32 CPU Exception Handler
  18 ;
  19 ; Notes:
  20 ;
  21 ;------------------------------------------------------------------------------
  22
  23 ;
  24 ; CommonExceptionHandler()
  25 ;
  26 extern ASM_PFX(CommonExceptionHandler)
  27
  28 SECTION .data
  29
  30 extern ASM_PFX(mErrorCodeFlag)            ; Error code flags for exceptions
  31 extern ASM_PFX(mDoFarReturnFlag)          ; Do far return flag
  32
  33 SECTION .text
  34
  35 ALIGN   8
  36
  37 ;
  38 ; exception handler stub table
  39 ;
  40 AsmIdtVectorBegin:
  41 %rep  32
  42     db      0x6a        ; push  #VectorNum
  43     db      ($ - AsmIdtVectorBegin) / ((AsmIdtVectorEnd - AsmIdtVectorBegin) / 32) ; VectorNum
  44     push    eax
  45     mov     eax, ASM_PFX(CommonInterruptEntry)
  46     jmp     eax
  47 %endrep
  48 AsmIdtVectorEnd:
  49
  50 HookAfterStubBegin:
  51     db      0x6a        ; push
  52 VectorNum:
  53     db      0          ; 0 will be fixed
  54     push    eax
  55     mov     eax, HookAfterStubHeaderEnd
  56     jmp     eax
  57 HookAfterStubHeaderEnd:
  58     pop     eax
  59     sub     esp, 8     ; reserve room for filling exception data later
  60     push    dword [esp + 8]
  61     xchg    ecx, [esp] ; get vector number
  62     bt      [ASM_PFX(mErrorCodeFlag)], ecx
  63     jnc     .0
  64     push    dword [esp]      ; addition push if exception data needed
  65 .0:
  66     xchg    ecx, [esp] ; restore ecx
  67     push    eax
  68
  69 ;----------------------------------------------------------------------------;
  70 ; CommonInterruptEntry                                                               ;
  71 ;----------------------------------------------------------------------------;
  72 ; The follow algorithm is used for the common interrupt routine.
  73 ; Entry from each interrupt with a push eax and eax=interrupt number
  74 ; Stack:
  75 ; +---------------------+
  76 ; +    EFlags           +
  77 ; +---------------------+
  78 ; +    CS               +
  79 ; +---------------------+
  80 ; +    EIP              +
  81 ; +---------------------+
  82 ; +    Error Code       +
  83 ; +---------------------+
  84 ; +    Vector Number    +
  85 ; +---------------------+
  86 ; +    EBP              +
  87 ; +---------------------+ <-- EBP
  88 global ASM_PFX(CommonInterruptEntry)
  89 ASM_PFX(CommonInterruptEntry):
  90     cli
  91     pop    eax
  92     ;
  93     ; All interrupt handlers are invoked through interrupt gates, so
  94     ; IF flag automatically cleared at the entry point
  95     ;
  96
  97     ;
  98     ; Get vector number from top of stack
  99     ;
 100     xchg    ecx, [esp]
 101     and     ecx, 0xFF       ; Vector number should be less than 256
 102     cmp     ecx, 32         ; Intel reserved vector for exceptions?
 103     jae     NoErrorCode
 104     bt      [ASM_PFX(mErrorCodeFlag)], ecx
 105     jc      HasErrorCode
 106
 107 NoErrorCode:
 108
 109     ;
 110     ; Stack:
 111     ; +---------------------+
 112     ; +    EFlags           +
 113     ; +---------------------+
 114     ; +    CS               +
 115     ; +---------------------+
 116     ; +    EIP              +
 117     ; +---------------------+
 118     ; +    ECX              +
 119     ; +---------------------+ <-- ESP
 120     ;
 121     ; Registers:
 122     ;   ECX - Vector Number
 123     ;
 124
 125     ;
 126     ; Put Vector Number on stack
 127     ;
 128     push    ecx
 129
 130     ;
 131     ; Put 0 (dummy) error code on stack, and restore ECX
 132     ;
 133     xor     ecx, ecx  ; ECX = 0
 134     xchg    ecx, [esp+4]
 135
 136     jmp     ErrorCodeAndVectorOnStack
 137
 138 HasErrorCode:
 139
 140     ;
 141     ; Stack:
 142     ; +---------------------+
 143     ; +    EFlags           +
 144     ; +---------------------+
 145     ; +    CS               +
 146     ; +---------------------+
 147     ; +    EIP              +
 148     ; +---------------------+
 149     ; +    Error Code       +
 150     ; +---------------------+
 151     ; +    ECX              +
 152     ; +---------------------+ <-- ESP
 153     ;
 154     ; Registers:
 155     ;   ECX - Vector Number
 156     ;
 157
 158     ;
 159     ; Put Vector Number on stack and restore ECX
 160     ;
 161     xchg    ecx, [esp]
 162
 163 ErrorCodeAndVectorOnStack:
 164     push    ebp
 165     mov     ebp, esp
 166
 167     ;
 168     ; Stack:
 169     ; +---------------------+
 170     ; +    EFlags           +
 171     ; +---------------------+
 172     ; +    CS               +
 173     ; +---------------------+
 174     ; +    EIP              +
 175     ; +---------------------+
 176     ; +    Error Code       +
 177     ; +---------------------+
 178     ; +    Vector Number    +
 179     ; +---------------------+
 180     ; +    EBP              +
 181     ; +---------------------+ <-- EBP
 182     ;
 183
 184     ;
 185     ; Align stack to make sure that EFI_FX_SAVE_STATE_IA32 of EFI_SYSTEM_CONTEXT_IA32
 186     ; is 16-byte aligned
 187     ;
 188     and     esp, 0xfffffff0
 189     sub     esp, 12
 190
 191     sub     esp, 8
 192     push    0            ; clear EXCEPTION_HANDLER_CONTEXT.OldIdtHandler
 193     push    0            ; clear EXCEPTION_HANDLER_CONTEXT.ExceptionDataFlag
 194
 195 ;; UINT32  Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
 196     push    eax
 197     push    ecx
 198     push    edx
 199     push    ebx
 200     lea     ecx, [ebp + 6 * 4]
 201     push    ecx                          ; ESP
 202     push    dword [ebp]              ; EBP
 203     push    esi
 204     push    edi
 205
 206 ;; UINT32  Gs, Fs, Es, Ds, Cs, Ss;
 207     mov     eax, ss
 208     push    eax
 209     movzx   eax, word [ebp + 4 * 4]
 210     push    eax
 211     mov     eax, ds
 212     push    eax
 213     mov     eax, es
 214     push    eax
 215     mov     eax, fs
 216     push    eax
 217     mov     eax, gs
 218     push    eax
 219
 220 ;; UINT32  Eip;
 221     mov     eax, [ebp + 3 * 4]
 222     push    eax
 223
 224 ;; UINT32  Gdtr[2], Idtr[2];
 225     sub     esp, 8
 226     sidt    [esp]
 227     mov     eax, [esp + 2]
 228     xchg    eax, [esp]
 229     and     eax, 0xFFFF
 230     mov     [esp+4], eax
 231
 232     sub     esp, 8
 233     sgdt    [esp]
 234     mov     eax, [esp + 2]
 235     xchg    eax, [esp]
 236     and     eax, 0xFFFF
 237     mov     [esp+4], eax
 238
 239 ;; UINT32  Ldtr, Tr;
 240     xor     eax, eax
 241     str     ax
 242     push    eax
 243     sldt    ax
 244     push    eax
 245
 246 ;; UINT32  EFlags;
 247     mov     eax, [ebp + 5 * 4]
 248     push    eax
 249
 250 ;; UINT32  Cr0, Cr1, Cr2, Cr3, Cr4;
 251     mov     eax, 1
 252     push    ebx         ; temporarily save value of ebx on stack
 253     cpuid               ; use CPUID to determine if FXSAVE/FXRESTOR and DE
 254                         ; are supported
 255     pop     ebx         ; retore value of ebx that was overwritten by CPUID
 256     mov     eax, cr4
 257     push    eax         ; push cr4 firstly
 258     test    edx, BIT24  ; Test for FXSAVE/FXRESTOR support
 259     jz      .1
 260     or      eax, BIT9   ; Set CR4.OSFXSR
 261 .1:
 262     test    edx, BIT2   ; Test for Debugging Extensions support
 263     jz      .2
 264     or      eax, BIT3   ; Set CR4.DE
 265 .2:
 266     mov     cr4, eax
 267     mov     eax, cr3
 268     push    eax
 269     mov     eax, cr2
 270     push    eax
 271     xor     eax, eax
 272     push    eax
 273     mov     eax, cr0
 274     push    eax
 275
 276 ;; UINT32  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
 277     mov     eax, dr7
 278     push    eax
 279     mov     eax, dr6
 280     push    eax
 281     mov     eax, dr3
 282     push    eax
 283     mov     eax, dr2
 284     push    eax
 285     mov     eax, dr1
 286     push    eax
 287     mov     eax, dr0
 288     push    eax
 289
 290 ;; FX_SAVE_STATE_IA32 FxSaveState;
 291     sub     esp, 512
 292     mov     edi, esp
 293     test    edx, BIT24  ; Test for FXSAVE/FXRESTOR support.
 294                         ; edx still contains result from CPUID above
 295     jz      .3
 296     db      0xf, 0xae, 0x7 ;fxsave [edi]
 297 .3:
 298
 299 ;; UEFI calling convention for IA32 requires that Direction flag in EFLAGs is clear
 300     cld
 301
 302 ;; UINT32  ExceptionData;
 303     push    dword [ebp + 2 * 4]
 304
 305 ;; Prepare parameter and call
 306     mov     edx, esp
 307     push    edx
 308     mov     edx, dword [ebp + 1 * 4]
 309     push    edx
 310
 311     ;
 312     ; Call External Exception Handler
 313     ;
 314     mov     eax, ASM_PFX(CommonExceptionHandler)
 315     call    eax
 316     add     esp, 8
 317
 318     cli
 319 ;; UINT32  ExceptionData;
 320     add     esp, 4
 321
 322 ;; FX_SAVE_STATE_IA32 FxSaveState;
 323     mov     esi, esp
 324     mov     eax, 1
 325     cpuid               ; use CPUID to determine if FXSAVE/FXRESTOR
 326                         ; are supported
 327     test    edx, BIT24  ; Test for FXSAVE/FXRESTOR support
 328     jz      .4
 329     db      0xf, 0xae, 0xe ; fxrstor [esi]
 330 .4:
 331     add     esp, 512
 332
 333 ;; UINT32  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
 334 ;; Skip restoration of DRx registers to support in-circuit emualators
 335 ;; or debuggers set breakpoint in interrupt/exception context
 336     add     esp, 4 * 6
 337
 338 ;; UINT32  Cr0, Cr1, Cr2, Cr3, Cr4;
 339     pop     eax
 340     mov     cr0, eax
 341     add     esp, 4    ; not for Cr1
 342     pop     eax
 343     mov     cr2, eax
 344     pop     eax
 345     mov     cr3, eax
 346     pop     eax
 347     mov     cr4, eax
 348
 349 ;; UINT32  EFlags;
 350     pop     dword [ebp + 5 * 4]
 351
 352 ;; UINT32  Ldtr, Tr;
 353 ;; UINT32  Gdtr[2], Idtr[2];
 354 ;; Best not let anyone mess with these particular registers...
 355     add     esp, 24
 356
 357 ;; UINT32  Eip;
 358     pop     dword [ebp + 3 * 4]
 359
 360 ;; UINT32  Gs, Fs, Es, Ds, Cs, Ss;
 361 ;; NOTE - modified segment registers could hang the debugger...  We
 362 ;;        could attempt to insulate ourselves against this possibility,
 363 ;;        but that poses risks as well.
 364 ;;
 365     pop     gs
 366     pop     fs
 367     pop     es
 368     pop     ds
 369     pop     dword [ebp + 4 * 4]
 370     pop     ss
 371
 372 ;; UINT32  Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
 373     pop     edi
 374     pop     esi
 375     add     esp, 4   ; not for ebp
 376     add     esp, 4   ; not for esp
 377     pop     ebx
 378     pop     edx
 379     pop     ecx
 380     pop     eax
 381
 382     pop     dword [ebp - 8]
 383     pop     dword [ebp - 4]
 384     mov     esp, ebp
 385     pop     ebp
 386
 387 ; Enable TF bit after page fault handler runs
 388     cmp     dword [esp], 14       ; #PF?
 389     jne     .5
 390     bts     dword [esp + 16], 8   ; EFLAGS
 391
 392 .5:
 393     add     esp, 8
 394     cmp     dword [esp - 16], 0   ; check EXCEPTION_HANDLER_CONTEXT.OldIdtHandler
 395     jz      DoReturn
 396     cmp     dword [esp - 20], 1   ; check EXCEPTION_HANDLER_CONTEXT.ExceptionDataFlag
 397     jz      ErrorCode
 398     jmp     dword [esp - 16]
 399 ErrorCode:
 400     sub     esp, 4
 401     jmp     dword [esp - 12]
 402
 403 DoReturn:
 404     cmp     dword [ASM_PFX(mDoFarReturnFlag)], 0   ; Check if need to do far return instead of IRET
 405     jz      DoIret
 406     push    dword [esp + 8]    ; save EFLAGS
 407     add     esp, 16
 408     push    dword [esp - 8]    ; save CS in new location
 409     push    dword [esp - 8]    ; save EIP in new location
 410     push    dword [esp - 8]    ; save EFLAGS in new location
 411     popfd                ; restore EFLAGS
 412     retf                 ; far return
 413
 414 DoIret:
 415     iretd
 416
 417 ;---------------------------------------;
 418 ; _AsmGetTemplateAddressMap                  ;
 419 ;----------------------------------------------------------------------------;
 420 ;
 421 ; Protocol prototype
 422 ;   AsmGetTemplateAddressMap (
 423 ;     EXCEPTION_HANDLER_TEMPLATE_MAP *AddressMap
 424 ;   );
 425 ;
 426 ; Routine Description:
 427 ;
 428 ;  Return address map of interrupt handler template so that C code can generate
 429 ;  interrupt table.
 430 ;
 431 ; Arguments:
 432 ;
 433 ;
 434 ; Returns:
 435 ;
 436 ;   Nothing
 437 ;
 438 ;
 439 ; Input:  [ebp][0]  = Original ebp
 440 ;         [ebp][4]  = Return address
 441 ;
 442 ; Output: Nothing
 443 ;
 444 ; Destroys: Nothing
 445 ;-----------------------------------------------------------------------------;
 446 global ASM_PFX(AsmGetTemplateAddressMap)
 447 ASM_PFX(AsmGetTemplateAddressMap):
 448     push    ebp                 ; C prolog
 449     mov     ebp, esp
 450     pushad
 451
 452     mov ebx, dword [ebp + 0x8]
 453     mov dword [ebx],      AsmIdtVectorBegin
 454     mov dword [ebx + 0x4], (AsmIdtVectorEnd - AsmIdtVectorBegin) / 32
 455     mov dword [ebx + 0x8], HookAfterStubBegin
 456
 457     popad
 458     pop     ebp
 459     ret
 460
 461 ;-------------------------------------------------------------------------------------
 462 ;  AsmVectorNumFixup (*NewVectorAddr, VectorNum, *OldVectorAddr);
 463 ;-------------------------------------------------------------------------------------
 464 global ASM_PFX(AsmVectorNumFixup)
 465 ASM_PFX(AsmVectorNumFixup):
 466     mov     eax, dword [esp + 8]
 467     mov     ecx, [esp + 4]
 468     mov     [ecx + (VectorNum - HookAfterStubBegin)], al
 469     ret