DuetPkg/CpuDxe/Ia32/CpuInterrupt.S

   1 #------------------------------------------------------------------------------
   2 #*
   3 #*   Copyright 2006, Intel Corporation
   4 #*   All rights reserved. This program and the accompanying materials
   5 #*   are licensed and made available under the terms and conditions of the BSD License
   6 #*   which accompanies this distribution.  The full text of the license may be found at
   7 #*   http://opensource.org/licenses/bsd-license.php
   8 #*
   9 #*   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 #*   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 #*
  12 #*    CpuInterrupt.S
  13 #*
  14 #*   Abstract:
  15 #*
  16 #------------------------------------------------------------------------------
  17
  18 #PUBLIC SystemTimerHandler
  19 #PUBLIC SystemExceptionHandler
  20 #EXTERNDEF mExceptionCodeSize:DWORD
  21
  22 #EXTERN TimerHandler: NEAR
  23 #EXTERN ExceptionHandler: NEAR
  24 #EXTERN mTimerVector: DWORD
  25
  26         .data
  27         .globl ASM_PFX(mExceptionCodeSize)
  28 ASM_PFX(mExceptionCodeSize): .long  9
  29
  30         .text
  31         .globl ASM_PFX(InitDescriptor)
  32
  33 ASM_PFX(InitDescriptor):
  34         movl    $GDT_BASE,%eax              # EAX=PHYSICAL address of gdt
  35         movl    %eax, gdtr + 2              # Put address of gdt into the gdtr
  36         lgdt    gdtr
  37         movl    $IDT_BASE,%eax              # EAX=PHYSICAL address of idt
  38         movl    %eax, idtr + 2              # Put address of idt into the idtr
  39         lidt    idtr
  40         ret
  41
  42 # VOID
  43 # InstallInterruptHandler (
  44 #     UINTN Vector,
  45 #     VOID  (*Handler)(VOID)
  46 #     )
  47         .globl ASM_PFX(InstallInterruptHandler)
  48 ASM_PFX(InstallInterruptHandler):
  49 #  Vector:DWORD @ 4(%esp)
  50 #  Handler:DWORD @ 8(%esp)
  51
  52         push    %edi
  53         pushf                               # save eflags
  54         cli                                 # turn off interrupts
  55         subl    $6,%esp                     # open some space on the stack
  56         movl    %esp,%edi
  57         sidt    (%edi)                      # get fword address of IDT
  58         movl    2(%edi), %edi               # move offset of IDT into EDI
  59         addl    $6,%esp                     # correct stack
  60         movl    12(%esp),%eax               # Get vector number
  61         shl     $3,%eax                     # multiply by 8 to get offset
  62         addl    %eax,%edi                   # add to IDT base to get entry
  63         movl    16(%esp),%eax               # load new address into IDT entry
  64         movw    %ax,(%edi)                  # write bits 15..0 of offset
  65         shrl    $16,%eax                    # use ax to copy 31..16 to descriptors
  66         movw    %ax,6(%edi)                 # write bits 31..16 of offset
  67         popf                                # restore flags (possible enabling interrupts)
  68         pop     %edi
  69         ret
  70
  71         .macro JmpCommonIdtEntry
  72     # jmp     commonIdtEntry - this must be hand coded to keep the assembler from
  73     #                          using a 8 bit reletive jump when the entries are
  74     #                          within 255 bytes of the common entry.  This must
  75     #                          be done to maintain the consistency of the size
  76     #                          of entry points...
  77     .byte     0xe9                        # jmp 16 bit reletive
  78     .long     commonIdtEntry - . - 4      #  offset to jump to
  79         .endm
  80
  81     .align 2
  82         .globl ASM_PFX(SystemExceptionHandler)
  83 ASM_PFX(SystemExceptionHandler):
  84 INT0:
  85     pushl    $0x0      # push error code place holder on the stack
  86     pushl    $0x0
  87     JmpCommonIdtEntry
  88 #    db      0e9h                        # jmp 16 bit reletive
  89 #    dd      commonIdtEntry - $ - 4      #  offset to jump to
  90
  91 INT1:
  92     pushl    $0x0      # push error code place holder on the stack
  93     pushl    $0x1
  94     JmpCommonIdtEntry
  95
  96 INT2:
  97     pushl    $0x0      # push error code place holder on the stack
  98     pushl    $0x2
  99     JmpCommonIdtEntry
 100
 101 INT3:
 102     pushl    $0x0      # push error code place holder on the stack
 103     pushl    $0x3
 104     JmpCommonIdtEntry
 105
 106 INT4:
 107     pushl    $0x0      # push error code place holder on the stack
 108     pushl    $0x4
 109     JmpCommonIdtEntry
 110
 111 INT5:
 112     pushl    $0x0      # push error code place holder on the stack
 113     pushl    $0x5
 114     JmpCommonIdtEntry
 115
 116 INT6:
 117     pushl    $0x0      # push error code place holder on the stack
 118     pushl    $0x6
 119     JmpCommonIdtEntry
 120
 121 INT7:
 122     pushl    $0x0      # push error code place holder on the stack
 123     pushl    $0x7
 124     JmpCommonIdtEntry
 125
 126 INT8:
 127 #   Double fault causes an error code to be pushed so no phony push necessary
 128     nop
 129     nop
 130     pushl    $0x8
 131     JmpCommonIdtEntry
 132
 133 INT9:
 134     pushl    $0x0      # push error code place holder on the stack
 135     pushl    $0x9
 136     JmpCommonIdtEntry
 137
 138 INT10:
 139 #   Invalid TSS causes an error code to be pushed so no phony push necessary
 140     nop
 141     nop
 142     pushl    $10
 143     JmpCommonIdtEntry
 144
 145 INT11:
 146 #   Segment Not Present causes an error code to be pushed so no phony push necessary
 147     nop
 148     nop
 149     pushl    $11
 150     JmpCommonIdtEntry
 151
 152 INT12:
 153 #   Stack fault causes an error code to be pushed so no phony push necessary
 154     nop
 155     nop
 156     pushl    $12
 157     JmpCommonIdtEntry
 158
 159 INT13:
 160 #   GP fault causes an error code to be pushed so no phony push necessary
 161     nop
 162     nop
 163     pushl    $13
 164     JmpCommonIdtEntry
 165
 166 INT14:
 167 #   Page fault causes an error code to be pushed so no phony push necessary
 168     nop
 169     nop
 170     pushl    $14
 171     JmpCommonIdtEntry
 172
 173 INT15:
 174     pushl    $0x0      # push error code place holder on the stack
 175     pushl    $15
 176     JmpCommonIdtEntry
 177
 178 INT16:
 179     pushl    $0x0      # push error code place holder on the stack
 180     pushl    $16
 181     JmpCommonIdtEntry
 182
 183 INT17:
 184 #   Alignment check causes an error code to be pushed so no phony push necessary
 185     nop
 186     nop
 187     pushl    $17
 188     JmpCommonIdtEntry
 189
 190 INT18:
 191     pushl    $0x0      # push error code place holder on the stack
 192     pushl    $18
 193     JmpCommonIdtEntry
 194
 195 INT19:
 196     pushl    $0x0      # push error code place holder on the stack
 197     pushl    $19
 198     JmpCommonIdtEntry
 199
 200 INTUnknown:
 201         .rept (32 - 20)
 202     pushl    $0x0      # push error code place holder on the stack
 203 #    push    xxh     # push vector number
 204     .byte    0x6a
 205     .byte    ( . - INTUnknown - 3 ) / 9 + 20 # vector number
 206     JmpCommonIdtEntry
 207         .endr
 208
 209         .globl ASM_PFX(SystemTimerHandler)
 210 ASM_PFX(SystemTimerHandler):
 211     pushl    $0
 212     pushl    $ASM_PFX(mTimerVector)
 213     JmpCommonIdtEntry
 214
 215 commonIdtEntry:
 216 # +---------------------+
 217 # +    EFlags           +
 218 # +---------------------+
 219 # +    CS               +
 220 # +---------------------+
 221 # +    EIP              +
 222 # +---------------------+
 223 # +    Error Code       +
 224 # +---------------------+
 225 # +    Vector Number    +
 226 # +---------------------+
 227 # +    EBP              +
 228 # +---------------------+ <-- EBP
 229
 230   cli
 231   push %ebp
 232   movl %esp,%ebp
 233
 234   #
 235   # Align stack to make sure that EFI_FX_SAVE_STATE_IA32 of EFI_SYSTEM_CONTEXT_IA32
 236   # is 16-byte aligned
 237   #
 238   andl    $0xfffffff0,%esp
 239   subl    $12,%esp
 240
 241 ## UINT32  Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax#
 242   push    %eax
 243   push    %ecx
 244   push    %edx
 245   push    %ebx
 246   leal    6*4(%ebp),%ecx
 247   push    %ecx                          # ESP
 248   push    (%ebp)                        # EBP
 249   push    %esi
 250   push    %edi
 251
 252 ## UINT32  Gs, Fs, Es, Ds, Cs, Ss#
 253   movw  %ss,%ax
 254   push  %eax
 255   movzx 4*4(%ebp),%eax
 256   push %eax
 257   movw  %ds,%ax
 258   push %eax
 259   movw  %es,%ax
 260   push %eax
 261   movw %fs,%ax
 262   push %eax
 263   movw %gs,%ax
 264   push %eax
 265
 266 ## UINT32  Eip#
 267   pushl   3*4(%ebp)
 268
 269 ## UINT32  Gdtr[2], Idtr[2]#
 270   subl  $8,%esp
 271   sidt (%esp)
 272   subl  $8,%esp
 273   sgdt (%esp)
 274
 275 ## UINT32  Ldtr, Tr#
 276   xorl  %eax, %eax
 277   str  %ax
 278   push %eax
 279   sldt %eax
 280   push %eax
 281
 282 ## UINT32  EFlags#
 283   pushl  5*4(%ebp)
 284
 285 ## UINT32  Cr0, Cr1, Cr2, Cr3, Cr4#
 286   mov  %cr4,%eax
 287   orl  $0x208,%eax
 288   mov  %eax,%cr4
 289   push %eax
 290   mov  %cr3,%eax
 291   push %eax
 292   mov  %cr2,%eax
 293   push %eax
 294   xor  %eax, %eax
 295   push %eax
 296   mov  %cr0,%eax
 297   push %eax
 298
 299 ## UINT32  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7#
 300   mov     %dr7,%eax
 301   push    %eax
 302 ## clear Dr7 while executing debugger itself
 303   xor     %eax, %eax
 304   mov     %eax,%dr7
 305
 306   mov     %dr6,%eax
 307   push    %eax
 308 ## insure all status bits in dr6 are clear...
 309   xor     %eax, %eax
 310   mov     %eax,%dr6
 311
 312   mov     %dr3,%eax
 313   push    %eax
 314   mov     %dr2,%eax
 315   push    %eax
 316   mov     %dr1,%eax
 317   push    %eax
 318   mov     %dr0,%eax
 319   push    %eax
 320
 321 ## FX_SAVE_STATE_IA32 FxSaveState;
 322   sub     $512,%esp
 323   mov     %esp,%edi
 324   fxsave (%edi)
 325
 326 ## UINT32  ExceptionData;
 327   pushl    2*4(%ebp)
 328
 329 ## Prepare parameter and call
 330   mov     %esp,%edx
 331   push    %edx
 332   mov     1*4(%ebp),%eax
 333   push    %eax
 334   cmpl    $32,%eax
 335   jb      CallException
 336   call    ASM_PFX(TimerHandler)
 337   jmp     ExceptionDone
 338 CallException:
 339   call    ASM_PFX(ExceptionHandler)
 340 ExceptionDone:
 341   addl    $8,%esp
 342
 343   cli
 344 ## UINT32  ExceptionData;
 345   addl     $4,%esp
 346
 347 ## FX_SAVE_STATE_IA32 FxSaveState;
 348   mov      %esp,%esi
 349   fxrstor  (%esi)
 350   addl     $512,%esp
 351
 352 #; UINT32  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
 353   pop     %eax
 354   mov     %eax,%dr0
 355   pop     %eax
 356   mov     %eax,%dr1
 357   pop     %eax
 358   mov     %eax,%dr2
 359   pop     %eax
 360   mov     %eax,%dr3
 361 ## skip restore of dr6.  We cleared dr6 during the context save.
 362   addl    $4,%esp
 363   pop     %eax
 364   mov     %eax,%dr7
 365
 366 ## UINT32  Cr0, Cr1, Cr2, Cr3, Cr4;
 367   pop     %eax
 368   mov     %eax,%cr0
 369   addl    $4,%esp    # not for Cr1
 370   pop     %eax
 371   mov     %eax,%cr2
 372   pop     %eax
 373   mov     %eax,%cr3
 374   pop     %eax
 375   mov     %eax,%cr4
 376
 377 ## UINT32  EFlags;
 378   popl     5*4(%ebp)
 379
 380 ## UINT32  Ldtr, Tr;
 381 ## UINT32  Gdtr[2], Idtr[2];
 382 ## Best not let anyone mess with these particular registers...
 383   addl     $24,%esp
 384
 385 ## UINT32  Eip;
 386   popl     3*4(%ebp)
 387
 388 ## UINT32  Gs, Fs, Es, Ds, Cs, Ss;
 389 ## NOTE - modified segment registers could hang the debugger...  We
 390 ##        could attempt to insulate ourselves against this possibility,
 391 ##        but that poses risks as well.
 392 ##
 393   pop     %gs
 394   pop     %fs
 395   pop     %es
 396   pop     %ds
 397   popl    4*4(%ebp)
 398   pop     %ss
 399
 400 ## UINT32  Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
 401   pop     %edi
 402   pop     %esi
 403   addl    $4,%esp   # not for ebp
 404   addl    $4,%esp   # not for esp
 405   pop     %ebx
 406   pop     %edx
 407   pop     %ecx
 408   pop     %eax
 409
 410   mov     %ebp,%esp
 411   pop     %ebp
 412   addl    $8,%esp
 413   iret
 414
 415
 416 #;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 417 # data
 418 #;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 419
 420         .data
 421         .align 4
 422
 423 gdtr:   .short GDT_END - GDT_BASE - 1   # GDT limit
 424         .long 0                         # (GDT base gets set above)
 425 #;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 426 #   global descriptor table (GDT)
 427 #;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 428
 429         .align 4
 430
 431 GDT_BASE:
 432 # null descriptor
 433 NULL_SEL            = .-GDT_BASE
 434         .short 0            # limit 15:0
 435         .short 0            # base 15:0
 436         .byte 0             # base 23:16
 437         .byte 0             # type
 438         .byte 0             # limit 19:16, flags
 439         .byte 0             # base 31:24
 440
 441 # linear data segment descriptor
 442 LINEAR_SEL      = .-GDT_BASE
 443         .short 0x0FFFF       # limit 0xFFFFF
 444         .short 0             # base 0
 445         .byte 0
 446         .byte 0x092          # present, ring 0, data, expand-up, writable
 447         .byte 0x0CF          # page-granular, 32-bit
 448         .byte 0
 449
 450 # linear code segment descriptor
 451 LINEAR_CODE_SEL = .-GDT_BASE
 452         .short 0x0FFFF       # limit 0xFFFFF
 453         .short 0             # base 0
 454         .byte 0
 455         .byte 0x09A          # present, ring 0, data, expand-up, writable
 456         .byte 0x0CF          # page-granular, 32-bit
 457         .byte 0
 458
 459 # system data segment descriptor
 460 SYS_DATA_SEL    = .-GDT_BASE
 461         .short 0x0FFFF       # limit 0xFFFFF
 462         .short 0             # base 0
 463         .byte 0
 464         .byte 0x092          # present, ring 0, data, expand-up, writable
 465         .byte 0x0CF          # page-granular, 32-bit
 466         .byte 0
 467
 468 # system code segment descriptor
 469 SYS_CODE_SEL    = .-GDT_BASE
 470         .short 0x0FFFF       # limit 0xFFFFF
 471         .short 0             # base 0
 472         .byte 0
 473         .byte 0x09A          # present, ring 0, data, expand-up, writable
 474         .byte 0x0CF          # page-granular, 32-bit
 475         .byte 0
 476
 477 # spare segment descriptor
 478 SPARE3_SEL  = .-GDT_BASE
 479         .short 0            # limit 0xFFFFF
 480         .short 0            # base 0
 481         .byte 0
 482         .byte 0             # present, ring 0, data, expand-up, writable
 483         .byte 0             # page-granular, 32-bit
 484         .byte 0
 485
 486 # spare segment descriptor
 487 SPARE4_SEL  = .-GDT_BASE
 488         .short 0            # limit 0xFFFFF
 489         .short 0            # base 0
 490         .byte 0
 491         .byte 0             # present, ring 0, data, expand-up, writable
 492         .byte 0             # page-granular, 32-bit
 493         .byte 0
 494
 495 # spare segment descriptor
 496 SPARE5_SEL  = .-GDT_BASE
 497         .short 0            # limit 0xFFFFF
 498         .short 0            # base 0
 499         .byte 0
 500         .byte 0             # present, ring 0, data, expand-up, writable
 501         .byte 0             # page-granular, 32-bit
 502         .byte 0
 503
 504 GDT_END:
 505
 506         .align 4
 507
 508
 509
 510 idtr:   .short IDT_END - IDT_BASE - 1   # IDT limit
 511         .long 0                         # (IDT base gets set above)
 512 #;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 513 #   interrupt descriptor table (IDT)
 514 #
 515 #   Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ
 516 #       mappings.  This implementation only uses the system timer and all other
 517 #       IRQs will remain masked.  The descriptors for vectors 33+ are provided
 518 #       for convenience.
 519 #;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 520
 521 #idt_tag .byte "IDT",0
 522         .align 4
 523
 524 IDT_BASE:
 525 # divide by zero (INT 0)
 526 DIV_ZERO_SEL        = .-IDT_BASE
 527         .short 0            # offset 15:0
 528         .short SYS_CODE_SEL # selector 15:0
 529         .byte 0             # 0 for interrupt gate
 530         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 531         .short 0            # offset 31:16
 532
 533 # debug exception (INT 1)
 534 DEBUG_EXCEPT_SEL    = .-IDT_BASE
 535         .short 0            # offset 15:0
 536         .short SYS_CODE_SEL # selector 15:0
 537         .byte 0             # 0 for interrupt gate
 538         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 539         .short 0            # offset 31:16
 540
 541 # NMI (INT 2)
 542 NMI_SEL             = .-IDT_BASE
 543         .short 0            # offset 15:0
 544         .short SYS_CODE_SEL # selector 15:0
 545         .byte 0             # 0 for interrupt gate
 546         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 547         .short 0            # offset 31:16
 548
 549 # soft breakpoint (INT 3)
 550 BREAKPOINT_SEL      = .-IDT_BASE
 551         .short 0            # offset 15:0
 552         .short SYS_CODE_SEL # selector 15:0
 553         .byte 0             # 0 for interrupt gate
 554         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 555         .short 0            # offset 31:16
 556
 557 # overflow (INT 4)
 558 OVERFLOW_SEL        = .-IDT_BASE
 559         .short 0            # offset 15:0
 560         .short SYS_CODE_SEL # selector 15:0
 561         .byte 0             # 0 for interrupt gate
 562         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 563         .short 0            # offset 31:16
 564
 565 # bounds check (INT 5)
 566 BOUNDS_CHECK_SEL    = .-IDT_BASE
 567         .short 0            # offset 15:0
 568         .short SYS_CODE_SEL # selector 15:0
 569         .byte 0             # 0 for interrupt gate
 570         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 571         .short 0            # offset 31:16
 572
 573 # invalid opcode (INT 6)
 574 INVALID_OPCODE_SEL  = .-IDT_BASE
 575         .short 0            # offset 15:0
 576         .short SYS_CODE_SEL # selector 15:0
 577         .byte 0             # 0 for interrupt gate
 578         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 579         .short 0            # offset 31:16
 580
 581 # device not available (INT 7)
 582 DEV_NOT_AVAIL_SEL   = .-IDT_BASE
 583         .short 0            # offset 15:0
 584         .short SYS_CODE_SEL # selector 15:0
 585         .byte 0             # 0 for interrupt gate
 586         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 587         .short 0            # offset 31:16
 588
 589 # double fault (INT 8)
 590 DOUBLE_FAULT_SEL    = .-IDT_BASE
 591         .short 0            # offset 15:0
 592         .short SYS_CODE_SEL # selector 15:0
 593         .byte 0             # 0 for interrupt gate
 594         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 595         .short 0            # offset 31:16
 596
 597 # Coprocessor segment overrun - reserved (INT 9)
 598 RSVD_INTR_SEL1      = .-IDT_BASE
 599         .short 0            # offset 15:0
 600         .short SYS_CODE_SEL # selector 15:0
 601         .byte 0             # 0 for interrupt gate
 602         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 603         .short 0            # offset 31:16
 604
 605 # invalid TSS (INT 0ah)
 606 INVALID_TSS_SEL     = .-IDT_BASE
 607         .short 0            # offset 15:0
 608         .short SYS_CODE_SEL # selector 15:0
 609         .byte 0             # 0 for interrupt gate
 610         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 611         .short 0            # offset 31:16
 612
 613 # segment not present (INT 0bh)
 614 SEG_NOT_PRESENT_SEL = .-IDT_BASE
 615         .short 0            # offset 15:0
 616         .short SYS_CODE_SEL # selector 15:0
 617         .byte 0             # 0 for interrupt gate
 618         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 619         .short 0            # offset 31:16
 620
 621 # stack fault (INT 0ch)
 622 STACK_FAULT_SEL     = .-IDT_BASE
 623         .short 0            # offset 15:0
 624         .short SYS_CODE_SEL # selector 15:0
 625         .byte 0             # 0 for interrupt gate
 626         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 627         .short 0            # offset 31:16
 628
 629 # general protection (INT 0dh)
 630 GP_FAULT_SEL        = .-IDT_BASE
 631         .short 0            # offset 15:0
 632         .short SYS_CODE_SEL # selector 15:0
 633         .byte 0             # 0 for interrupt gate
 634         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 635         .short 0            # offset 31:16
 636
 637 # page fault (INT 0eh)
 638 PAGE_FAULT_SEL      = .-IDT_BASE
 639         .short 0            # offset 15:0
 640         .short SYS_CODE_SEL # selector 15:0
 641         .byte 0             # 0 for interrupt gate
 642         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 643         .short 0            # offset 31:16
 644
 645 # Intel reserved - do not use (INT 0fh)
 646 RSVD_INTR_SEL2      = .-IDT_BASE
 647         .short 0            # offset 15:0
 648         .short SYS_CODE_SEL # selector 15:0
 649         .byte 0             # 0 for interrupt gate
 650         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 651         .short 0            # offset 31:16
 652
 653 # floating point error (INT 0x10)
 654 FLT_POINT_ERR_SEL   = .-IDT_BASE
 655         .short 0            # offset 15:0
 656         .short SYS_CODE_SEL # selector 15:0
 657         .byte 0             # 0 for interrupt gate
 658         .byte 0x0e | 0x80   # type = 386 interrupt gate, present
 659         .short 0            # offset 31:16
 660
 661 # alignment check (INT 0x11)
 662 ALIGNMENT_CHECK_SEL = .-IDT_BASE
 663         .short 0            # offset 15:0
 664         .short SYS_CODE_SEL # selector 15:0
 665         .byte 0             # 0 for interrupt gate
 666         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 667         .short 0            # offset 31:16
 668
 669 # machine check (INT 0x12)
 670 MACHINE_CHECK_SEL   = .-IDT_BASE
 671         .short 0            # offset 15:0
 672         .short SYS_CODE_SEL # selector 15:0
 673         .byte 0             # 0 for interrupt gate
 674         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 675         .short 0            # offset 31:16
 676
 677 # SIMD floating-point exception (INT 0x13)
 678 SIMD_EXCEPTION_SEL  = .-IDT_BASE
 679         .short 0            # offset 15:0
 680         .short SYS_CODE_SEL # selector 15:0
 681         .byte 0             # 0 for interrupt gate
 682         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 683         .short 0            # offset 31:16
 684
 685         .rept  (32 - 20)
 686         .short 0            # offset 15:0
 687         .short SYS_CODE_SEL # selector 15:0
 688         .byte 0             # 0 for interrupt gate
 689         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 690         .short 0            # offset 31:16
 691         .endr
 692
 693 # 72 unspecified descriptors
 694         .rept 72 * 8
 695         .byte 0
 696         .endr
 697
 698 # IRQ 0 (System timer) - (INT 0x68)
 699 IRQ0_SEL            = .-IDT_BASE
 700         .short 0            # offset 15:0
 701         .short SYS_CODE_SEL # selector 15:0
 702         .byte 0             # 0 for interrupt gate
 703         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 704         .short 0            # offset 31:16
 705
 706 # IRQ 1 (8042 Keyboard controller) - (INT 0x69)
 707 IRQ1_SEL            = .-IDT_BASE
 708         .short 0            # offset 15:0
 709         .short SYS_CODE_SEL # selector 15:0
 710         .byte 0             # 0 for interrupt gate
 711         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 712         .short 0            # offset 31:16
 713
 714 # Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah)
 715 IRQ2_SEL            = .-IDT_BASE
 716         .short 0            # offset 15:0
 717         .short SYS_CODE_SEL # selector 15:0
 718         .byte 0             # 0 for interrupt gate
 719         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 720         .short 0            # offset 31:16
 721
 722 # IRQ 3 (COM 2) - (INT 6bh)
 723 IRQ3_SEL            = .-IDT_BASE
 724         .short 0            # offset 15:0
 725         .short SYS_CODE_SEL # selector 15:0
 726         .byte 0             # 0 for interrupt gate
 727         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 728         .short 0            # offset 31:16
 729
 730 # IRQ 4 (COM 1) - (INT 6ch)
 731 IRQ4_SEL            = .-IDT_BASE
 732         .short 0            # offset 15:0
 733         .short SYS_CODE_SEL # selector 15:0
 734         .byte 0             # 0 for interrupt gate
 735         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 736         .short 0            # offset 31:16
 737
 738 # IRQ 5 (LPT 2) - (INT 6dh)
 739 IRQ5_SEL            = .-IDT_BASE
 740         .short 0            # offset 15:0
 741         .short SYS_CODE_SEL # selector 15:0
 742         .byte 0             # 0 for interrupt gate
 743         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 744         .short 0            # offset 31:16
 745
 746 # IRQ 6 (Floppy controller) - (INT 6eh)
 747 IRQ6_SEL            = .-IDT_BASE
 748         .short 0            # offset 15:0
 749         .short SYS_CODE_SEL # selector 15:0
 750         .byte 0             # 0 for interrupt gate
 751         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 752         .short 0            # offset 31:16
 753
 754 # IRQ 7 (LPT 1) - (INT 6fh)
 755 IRQ7_SEL            = .-IDT_BASE
 756         .short 0            # offset 15:0
 757         .short SYS_CODE_SEL # selector 15:0
 758         .byte 0             # 0 for interrupt gate
 759         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 760         .short 0            # offset 31:16
 761
 762 # IRQ 8 (RTC Alarm) - (INT 0x70)
 763 IRQ8_SEL            = .-IDT_BASE
 764         .short 0            # offset 15:0
 765         .short SYS_CODE_SEL # selector 15:0
 766         .byte 0             # 0 for interrupt gate
 767         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 768         .short 0            # offset 31:16
 769
 770 # IRQ 9 - (INT 0x71)
 771 IRQ9_SEL            = .-IDT_BASE
 772         .short 0            # offset 15:0
 773         .short SYS_CODE_SEL # selector 15:0
 774         .byte 0             # 0 for interrupt gate
 775         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 776         .short 0            # offset 31:16
 777
 778 # IRQ 10 - (INT 0x72)
 779 IRQ10_SEL            = .-IDT_BASE
 780         .short 0            # offset 15:0
 781         .short SYS_CODE_SEL # selector 15:0
 782         .byte 0             # 0 for interrupt gate
 783         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 784         .short 0            # offset 31:16
 785
 786 # IRQ 11 - (INT 0x73)
 787 IRQ11_SEL            = .-IDT_BASE
 788         .short 0            # offset 15:0
 789         .short SYS_CODE_SEL # selector 15:0
 790         .byte 0             # 0 for interrupt gate
 791         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 792         .short 0            # offset 31:16
 793
 794 # IRQ 12 (PS/2 mouse) - (INT 0x74)
 795 IRQ12_SEL            = .-IDT_BASE
 796         .short 0            # offset 15:0
 797         .short SYS_CODE_SEL # selector 15:0
 798         .byte 0             # 0 for interrupt gate
 799         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 800         .short 0            # offset 31:16
 801
 802 # IRQ 13 (Floating point error) - (INT 0x75)
 803 IRQ13_SEL            = .-IDT_BASE
 804         .short 0            # offset 15:0
 805         .short SYS_CODE_SEL # selector 15:0
 806         .byte 0             # 0 for interrupt gate
 807         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 808         .short 0            # offset 31:16
 809
 810 # IRQ 14 (Secondary IDE) - (INT 0x76)
 811 IRQ14_SEL            = .-IDT_BASE
 812         .short 0            # offset 15:0
 813         .short SYS_CODE_SEL # selector 15:0
 814         .byte 0             # 0 for interrupt gate
 815         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 816         .short 0            # offset 31:16
 817
 818 # IRQ 15 (Primary IDE) - (INT 0x77)
 819 IRQ15_SEL            = .-IDT_BASE
 820         .short 0            # offset 15:0
 821         .short SYS_CODE_SEL # selector 15:0
 822         .byte 0             # 0 for interrupt gate
 823         .byte 0x0e | 0x80   # (10001110)type = 386 interrupt gate, present
 824         .short 0            # offset 31:16
 825
 826         .rept 1 * 8
 827         .byte 0
 828         .endr
 829
 830 IDT_END:
 831