1 #------------------------------------------------------------------------------ 2 #* 3 #* Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR> 4 #* 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 #* start32.asm 13 #* 14 #* Abstract: 15 #* 16 #------------------------------------------------------------------------------ 17 18 #.MODEL small 19 .stack: 20 .486p: 21 .code16 22 23 .equ FAT_DIRECTORY_ENTRY_SIZE, 0x020 24 .equ FAT_DIRECTORY_ENTRY_SHIFT, 5 25 .equ BLOCK_SIZE, 0x0200 26 .equ BLOCK_MASK, 0x01ff 27 .equ BLOCK_SHIFT, 9 28 29 .org 0x0 30 31 .global _start 32 _start: 33 34 Ia32Jump: 35 jmp BootSectorEntryPoint # JMP inst - 3 bytes 36 nop 37 38 OemId: .ascii "INTEL " # OemId - 8 bytes 39 SectorSize: .word 0 # Sector Size - 2 bytes 40 SectorsPerCluster: .byte 0 # Sector Per Cluster - 1 byte 41 ReservedSectors: .word 0 # Reserved Sectors - 2 bytes 42 NoFats: .byte 0 # Number of FATs - 1 byte 43 RootEntries: .word 0 # Root Entries - 2 bytes 44 Sectors: .word 0 # Number of Sectors - 2 bytes 45 Media: .byte 0 # Media - 1 byte 46 SectorsPerFat16: .word 0 # Sectors Per FAT for FAT12/FAT16 - 2 byte 47 SectorsPerTrack: .word 0 # Sectors Per Track - 2 bytes 48 Heads: .word 0 # Heads - 2 bytes 49 HiddenSectors: .long 0 # Hidden Sectors - 4 bytes 50 LargeSectors: .long 0 # Large Sectors - 4 bytes 51 52 #****************************************************************************** 53 # 54 #The structure for FAT32 starting at offset 36 of the boot sector. (At this point, 55 #the BPB/boot sector for FAT12 and FAT16 differs from the BPB/boot sector for FAT32.) 56 # 57 #****************************************************************************** 58 59 SectorsPerFat32: .long 0 # Sectors Per FAT for FAT32 - 4 bytes 60 ExtFlags: .word 0 # Mirror Flag - 2 bytes 61 FSVersion: .word 0 # File System Version - 2 bytes 62 RootCluster: .long 0 # 1st Cluster Number of Root Dir - 4 bytes 63 FSInfo: .word 0 # Sector Number of FSINFO - 2 bytes 64 BkBootSector: .word 0 # Sector Number of Bk BootSector - 2 bytes 65 Reserved: .fill 12,1,0 # Reserved Field - 12 bytes 66 PhysicalDrive: .byte 0 # Physical Drive Number - 1 byte 67 Reserved1: .byte 0 # Reserved Field - 1 byte 68 Signature: .byte 0 # Extended Boot Signature - 1 byte 69 VolId: .ascii " " # Volume Serial Number - 4 bytes 70 FatLabel: .ascii " " # Volume Label - 11 bytes 71 FileSystemType: .ascii "FAT32 " # File System Type - 8 bytes 72 73 BootSectorEntryPoint: 74 #ASSUME ds:@code 75 #ASSUME ss:@code 76 # ds = 1000, es = 2000 + x (size of first cluster >> 4) 77 # cx = Start Cluster of EfiLdr 78 # dx = Start Cluster of Efivar.bin 79 80 # Re use the BPB data stored in Boot Sector 81 movw $0x7c00, %bp 82 83 84 pushw %cx 85 # Read Efivar.bin 86 # 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already 87 movw $0x1900, %ax 88 movw %ax, %es 89 testw %dx, %dx 90 jnz CheckVarStoreSize 91 92 movb $1, %al 93 NoVarStore: 94 pushw %es 95 # Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl 96 movb %al, %es:4 97 jmp SaveVolumeId 98 99 CheckVarStoreSize: 100 movw %dx, %di 101 cmpl $0x4000, %ds:2(%di) 102 movb $2, %al 103 jne NoVarStore 104 105 LoadVarStore: 106 movb $0, %al 107 movb %al, %es:4 108 movw (%di), %cx 109 # ES:DI = 1500:0 110 xorw %di, %di 111 pushw %es 112 movw $0x1500, %ax 113 movw %ax, %es 114 call ReadFile 115 SaveVolumeId: 116 popw %es 117 movw VolId(%bp), %ax 118 movw %ax, %es:0 # Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId 119 movw VolId+2(%bp), %ax 120 movw %ax, %es:2 121 122 # Read Efildr 123 popw %cx 124 # cx = Start Cluster of Efildr -> BS.com has filled already 125 # ES:DI = 2000:0, first cluster will be read again 126 xorw %di, %di # di = 0 127 movw $0x2000, %ax 128 movw %ax, %es 129 call ReadFile 130 movw %cs, %ax 131 movw %ax, %cs:JumpSegment 132 JumpFarInstruction: 133 .byte 0xea 134 JumpOffset: 135 .word 0x200 136 JumpSegment: 137 .word 0x2000 138 139 140 141 142 # **************************************************************************** 143 # ReadFile 144 # 145 # Arguments: 146 # CX = Start Cluster of File 147 # ES:DI = Buffer to store file content read from disk 148 # 149 # Return: 150 # (ES << 4 + DI) = end of file content Buffer 151 # 152 # **************************************************************************** 153 ReadFile: 154 # si = NumberOfClusters 155 # cx = ClusterNumber 156 # dx = CachedFatSectorNumber 157 # ds:0000 = CacheFatSectorBuffer 158 # es:di = Buffer to load file 159 # bx = NextClusterNumber 160 pusha 161 movw $1, %si # NumberOfClusters = 1 162 pushw %cx # Push Start Cluster onto stack 163 movw $0xfff, %dx # CachedFatSectorNumber = 0xfff 164 FatChainLoop: 165 movw %cx, %ax # ax = ClusterNumber 166 andw $0xfff8, %ax # ax = ax & 0xfff8 167 cmpw $0xfff8, %ax # See if this is the last cluster 168 je FoundLastCluster # Jump if last cluster found 169 movw %cx, %ax # ax = ClusterNumber 170 shlw $2, %ax # FatOffset = ClusterNumber * 4 171 pushw %si # Save si 172 movw %ax, %si # si = FatOffset 173 shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT 174 addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET) 175 andw $BLOCK_MASK, %si # si = FatOffset & BLOCK_MASK 176 cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber 177 je SkipFatRead 178 movw $2, %bx 179 pushw %es 180 pushw %ds 181 popw %es 182 call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI 183 popw %es 184 movw %ax, %dx # CachedFatSectorNumber = FatSectorNumber 185 SkipFatRead: 186 movw (%si), %bx # bx = NextClusterNumber 187 movw %cx, %ax # ax = ClusterNumber 188 popw %si # Restore si 189 decw %bx # bx = NextClusterNumber - 1 190 cmpw %cx, %bx # See if (NextClusterNumber-1)==ClusterNumber 191 jne ReadClusters 192 incw %bx # bx = NextClusterNumber 193 incw %si # NumberOfClusters++ 194 movw %bx, %cx # ClusterNumber = NextClusterNumber 195 jmp FatChainLoop 196 ReadClusters: 197 incw %bx 198 popw %ax # ax = StartCluster 199 pushw %bx # StartCluster = NextClusterNumber 200 movw %bx, %cx # ClusterNumber = NextClusterNumber 201 subw $2, %ax # ax = StartCluster - 2 202 xorb %bh, %bh 203 movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster 204 mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster 205 addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster 206 pushw %ax # save start sector 207 movw %si, %ax # ax = NumberOfClusters 208 mulw %bx # ax = NumberOfClusters * SectorsPerCluster 209 movw %ax, %bx # bx = Number of Sectors 210 popw %ax # ax = Start Sector 211 call ReadBlocks 212 movw $1, %si # NumberOfClusters = 1 213 jmp FatChainLoop 214 FoundLastCluster: 215 popw %cx 216 popa 217 ret 218 219 220 # **************************************************************************** 221 # ReadBlocks - Reads a set of blocks from a block device 222 # 223 # AX = Start LBA 224 # BX = Number of Blocks to Read 225 # ES:DI = Buffer to store sectors read from disk 226 # **************************************************************************** 227 228 # cx = Blocks 229 # bx = NumberOfBlocks 230 # si = StartLBA 231 232 ReadBlocks: 233 pusha 234 addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA 235 addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA 236 movl %eax, %esi # esi = Start LBA 237 movw %bx, %cx # cx = Number of blocks to read 238 ReadCylinderLoop: 239 movw $0x7bfc, %bp # bp = 0x7bfc 240 movl %esi, %eax # eax = Start LBA 241 xorl %edx, %edx # edx = 0 242 movzwl (%bp), %ebx # bx = MaxSector 243 divl %ebx # ax = StartLBA / MaxSector 244 incw %dx # dx = (StartLBA % MaxSector) + 1 245 246 movw (%bp), %bx # bx = MaxSector 247 subw %dx, %bx # bx = MaxSector - Sector 248 incw %bx # bx = MaxSector - Sector + 1 249 cmpw %bx, %cx # Compare (Blocks) to (MaxSector - Sector + 1) 250 jg LimitTransfer 251 movw %cx, %bx # bx = Blocks 252 LimitTransfer: 253 pushw %ax # save ax 254 movw %es, %ax # ax = es 255 shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system 256 andw $0x7f, %ax # ax = Number of blocks into current seg 257 addw %bx, %ax # ax = End Block number of transfer 258 cmpw $0x80, %ax # See if it crosses a 64K boundry 259 jle NotCrossing64KBoundry # Branch if not crossing 64K boundry 260 subw $0x80, %ax # ax = Number of blocks past 64K boundry 261 subw %ax, %bx # Decrease transfer size by block overage 262 NotCrossing64KBoundry: 263 popw %ax # restore ax 264 265 pushw %cx 266 movb %dl, %cl # cl = (StartLBA % MaxSector) + 1 = Sector 267 xorw %dx, %dx # dx = 0 268 divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder 269 # dx = ax % (MaxHead + 1) = Head 270 271 pushw %bx # Save number of blocks to transfer 272 movb %dl, %dh # dh = Head 273 movw $0x7c00, %bp # bp = 0x7c00 274 movb PhysicalDrive(%bp), %dl # dl = Drive Number 275 movb %al, %ch # ch = Cylinder 276 movb %bl, %al # al = Blocks 277 movb $2, %ah # ah = Function 2 278 movw %di, %bx # es:bx = Buffer address 279 int $0x13 280 jc DiskError 281 popw %bx 282 popw %cx 283 movzwl %bx, %ebx 284 addl %ebx, %esi # StartLBA = StartLBA + NumberOfBlocks 285 subw %bx, %cx # Blocks = Blocks - NumberOfBlocks 286 movw %es, %ax 287 shlw $(BLOCK_SHIFT-4), %bx 288 addw %bx, %ax 289 movw %ax, %es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE 290 cmpw $0, %cx 291 jne ReadCylinderLoop 292 popa 293 ret 294 295 DiskError: 296 pushw %cs 297 popw %ds 298 leaw ErrorString, %si 299 movw $7, %cx 300 jmp PrintStringAndHalt 301 302 PrintStringAndHalt: 303 movw $0xb800, %ax 304 movw %ax, %es 305 movw $160, %di 306 rep 307 movsw 308 Halt: 309 jmp Halt 310 311 ErrorString: 312 .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!', 0x0c 313 314 .org 0x01fa 315 LBAOffsetForBootSector: 316 .long 0x0 317 318 .org 0x01fe 319 .word 0xaa55 320 321 #****************************************************************************** 322 #****************************************************************************** 323 #****************************************************************************** 324 325 .equ DELAY_PORT, 0x0ed # Port to use for 1uS delay 326 .equ KBD_CONTROL_PORT, 0x060 # 8042 control port 327 .equ KBD_STATUS_PORT, 0x064 # 8042 status port 328 .equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port 329 .equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20 330 331 .org 0x200 332 jmp start 333 Em64String: 334 .byte 'E', 0x0c, 'm', 0x0c, '6', 0x0c, '4', 0x0c, 'T', 0x0c, ' ', 0x0c, 'U', 0x0c, 'n', 0x0c, 's', 0x0c, 'u', 0x0c, 'p', 0x0c, 'p', 0x0c, 'o', 0x0c, 'r', 0x0c, 't', 0x0c, 'e', 0x0c, 'd', 0x0c, '!', 0x0c 335 336 start: 337 movw %cs, %ax 338 movw %ax, %ds 339 movw %ax, %es 340 movw %ax, %ss 341 movw $MyStack, %sp 342 343 # mov ax,0b800h 344 # mov es,ax 345 # mov byte ptr es:[160],'a' 346 # mov ax,cs 347 # mov es,ax 348 349 movl $0, %ebx 350 leal MemoryMap, %edi 351 MemMapLoop: 352 movl $0xe820, %eax 353 movl $20, %ecx 354 movl $0x534d4150, %edx # 0x534d4150 = 'SMAP' 355 int $0x15 356 jc MemMapDone 357 addl $20, %edi 358 cmpl $0, %ebx 359 je MemMapDone 360 jmp MemMapLoop 361 MemMapDone: 362 leal MemoryMap, %eax 363 subl %eax, %edi # Get the address of the memory map 364 movl %edi, MemoryMapSize # Save the size of the memory map 365 366 xorl %ebx, %ebx 367 movw %cs, %bx # BX=segment 368 shll $4, %ebx # BX="linear" address of segment base 369 leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt 370 movl %eax, gdtr + 2 # Put address of gdt into the gdtr 371 leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt 372 movl %eax, idtr + 2 # Put address of idt into the idtr 373 leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map 374 375 addl $0x1000, %ebx # Source of EFI32 376 movl %ebx, JUMP+2 377 addl $0x1000, %ebx 378 movl %ebx, %esi # Source of EFILDR32 379 380 # mov ax,0b800h 381 # mov es,ax 382 # mov byte ptr es:[162],'b' 383 # mov ax,cs 384 # mov es,ax 385 386 # 387 # Enable A20 Gate 388 # 389 390 movw $0x2401, %ax # Enable A20 Gate 391 int $0x15 392 jnc A20GateEnabled # Jump if it suceeded 393 394 # 395 # If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually. 396 # 397 398 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 399 jnz Timeout8042 # Jump if the 8042 timed out 400 outw %ax, $DELAY_PORT # Delay 1 uS 401 movb $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port 402 outb %al, $KBD_STATUS_PORT # Send command to the 8042 403 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 404 jnz Timeout8042 # Jump if the 8042 timed out 405 movb $ENABLE_A20_CMD, %al # gate address bit 20 on 406 outb %al, $KBD_CONTROL_PORT # Send command to thre 8042 407 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 408 movw $25, %cx # Delay 25 uS for the command to complete on the 8042 409 Delay25uS: 410 outw %ax, $DELAY_PORT # Delay 1 uS 411 loopl Delay25uS 412 Timeout8042: 413 414 415 A20GateEnabled: 416 movw $0x0008, %bx # Flat data descriptor 417 # 418 # DISABLE INTERRUPTS - Entering Protected Mode 419 # 420 421 cli 422 423 # mov ax,0b800h 424 # mov es,ax 425 # mov byte ptr es:[164],'c' 426 # mov ax,cs 427 # mov es,ax 428 429 .byte 0x66 430 lgdt gdtr 431 .byte 0x66 432 lidt idtr 433 434 movl %cr0, %eax 435 orb $1, %al 436 movl %eax, %cr0 437 JUMP: 438 # jmp far 0010:00020000 439 .byte 0x66 440 .byte 0xea 441 .long 0x00020000 442 .word 0x0010 443 444 Empty8042InputBuffer: 445 movw $0, %cx 446 Empty8042Loop: 447 outw %ax, $DELAY_PORT # Delay 1us 448 inb $KBD_STATUS_PORT, %al # Read the 8042 Status Port 449 andb $0x2, %al # Check the Input Buffer Full Flag 450 loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS 451 ret 452 453 ############################################################################## 454 # data 455 ############################################################################## 456 457 .p2align 1 458 459 gdtr: .word GDT_END - GDT_BASE - 1 460 .long 0 # (GDT base gets set above) 461 ############################################################################## 462 # global descriptor table (GDT) 463 ############################################################################## 464 465 .p2align 1 466 467 GDT_BASE: 468 # null descriptor 469 .equ NULL_SEL, .-GDT_BASE 470 .word 0 # limit 15:0 471 .word 0 # base 15:0 472 .byte 0 # base 23:16 473 .byte 0 # type 474 .byte 0 # limit 19:16, flags 475 .byte 0 # base 31:24 476 477 # linear data segment descriptor 478 .equ LINEAR_SEL, .-GDT_BASE 479 .word 0xFFFF # limit 0xFFFFF 480 .word 0 # base 0 481 .byte 0 482 .byte 0x92 # present, ring 0, data, expand-up, writable 483 .byte 0xCF # page-granular, 32-bit 484 .byte 0 485 486 # linear code segment descriptor 487 .equ LINEAR_CODE_SEL, .-GDT_BASE 488 .word 0xFFFF # limit 0xFFFFF 489 .word 0 # base 0 490 .byte 0 491 .byte 0x9A # present, ring 0, data, expand-up, writable 492 .byte 0xCF # page-granular, 32-bit 493 .byte 0 494 495 # system data segment descriptor 496 .equ SYS_DATA_SEL, .-GDT_BASE 497 .word 0xFFFF # limit 0xFFFFF 498 .word 0 # base 0 499 .byte 0 500 .byte 0x92 # present, ring 0, data, expand-up, writable 501 .byte 0xCF # page-granular, 32-bit 502 .byte 0 503 504 # system code segment descriptor 505 .equ SYS_CODE_SEL, .-GDT_BASE 506 .word 0xFFFF # limit 0xFFFFF 507 .word 0 # base 0 508 .byte 0 509 .byte 0x9A # present, ring 0, data, expand-up, writable 510 .byte 0xCF # page-granular, 32-bit 511 .byte 0 512 513 # spare segment descriptor 514 .equ SPARE3_SEL, .-GDT_BASE 515 .word 0 # limit 0xFFFFF 516 .word 0 # base 0 517 .byte 0 518 .byte 0 # present, ring 0, data, expand-up, writable 519 .byte 0 # page-granular, 32-bit 520 .byte 0 521 522 # spare segment descriptor 523 .equ SPARE4_SEL, .-GDT_BASE 524 .word 0 # limit 0xFFFFF 525 .word 0 # base 0 526 .byte 0 527 .byte 0 # present, ring 0, data, expand-up, writable 528 .byte 0 # page-granular, 32-bit 529 .byte 0 530 531 # spare segment descriptor 532 .equ SPARE5_SEL, .-GDT_BASE 533 .word 0 # limit 0xFFFFF 534 .word 0 # base 0 535 .byte 0 536 .byte 0 # present, ring 0, data, expand-up, writable 537 .byte 0 # page-granular, 32-bit 538 .byte 0 539 540 GDT_END: 541 542 .p2align 1 543 544 545 546 idtr: .word IDT_END - IDT_BASE - 1 547 .long 0 # (IDT base gets set above) 548 ############################################################################## 549 # interrupt descriptor table (IDT) 550 # 551 # Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ 552 # mappings. This implementation only uses the system timer and all other 553 # IRQs will remain masked. The descriptors for vectors 33+ are provided 554 # for convenience. 555 ############################################################################## 556 557 #idt_tag db "IDT",0 558 .p2align 1 559 560 IDT_BASE: 561 # divide by zero (INT 0) 562 .equ DIV_ZERO_SEL, .-IDT_BASE 563 .word 0 # offset 15:0 564 .word SYS_CODE_SEL # selector 15:0 565 .byte 0 # 0 for interrupt gate 566 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 567 .word 0 # offset 31:16 568 569 # debug exception (INT 1) 570 .equ DEBUG_EXCEPT_SEL, .-IDT_BASE 571 .word 0 # offset 15:0 572 .word SYS_CODE_SEL # selector 15:0 573 .byte 0 # 0 for interrupt gate 574 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 575 .word 0 # offset 31:16 576 577 # NMI (INT 2) 578 .equ NMI_SEL, .-IDT_BASE 579 .word 0 # offset 15:0 580 .word SYS_CODE_SEL # selector 15:0 581 .byte 0 # 0 for interrupt gate 582 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 583 .word 0 # offset 31:16 584 585 # soft breakpoint (INT 3) 586 .equ BREAKPOINT_SEL, .-IDT_BASE 587 .word 0 # offset 15:0 588 .word SYS_CODE_SEL # selector 15:0 589 .byte 0 # 0 for interrupt gate 590 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 591 .word 0 # offset 31:16 592 593 # overflow (INT 4) 594 .equ OVERFLOW_SEL, .-IDT_BASE 595 .word 0 # offset 15:0 596 .word SYS_CODE_SEL # selector 15:0 597 .byte 0 # 0 for interrupt gate 598 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 599 .word 0 # offset 31:16 600 601 # bounds check (INT 5) 602 .equ BOUNDS_CHECK_SEL, .-IDT_BASE 603 .word 0 # offset 15:0 604 .word SYS_CODE_SEL # selector 15:0 605 .byte 0 # 0 for interrupt gate 606 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 607 .word 0 # offset 31:16 608 609 # invalid opcode (INT 6) 610 .equ INVALID_OPCODE_SEL, .-IDT_BASE 611 .word 0 # offset 15:0 612 .word SYS_CODE_SEL # selector 15:0 613 .byte 0 # 0 for interrupt gate 614 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 615 .word 0 # offset 31:16 616 617 # device not available (INT 7) 618 .equ DEV_NOT_AVAIL_SEL, .-IDT_BASE 619 .word 0 # offset 15:0 620 .word SYS_CODE_SEL # selector 15:0 621 .byte 0 # 0 for interrupt gate 622 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 623 .word 0 # offset 31:16 624 625 # double fault (INT 8) 626 .equ DOUBLE_FAULT_SEL, .-IDT_BASE 627 .word 0 # offset 15:0 628 .word SYS_CODE_SEL # selector 15:0 629 .byte 0 # 0 for interrupt gate 630 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 631 .word 0 # offset 31:16 632 633 # Coprocessor segment overrun - reserved (INT 9) 634 .equ RSVD_INTR_SEL1, .-IDT_BASE 635 .word 0 # offset 15:0 636 .word SYS_CODE_SEL # selector 15:0 637 .byte 0 # 0 for interrupt gate 638 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 639 .word 0 # offset 31:16 640 641 # invalid TSS (INT 0ah) 642 .equ INVALID_TSS_SEL, .-IDT_BASE 643 .word 0 # offset 15:0 644 .word SYS_CODE_SEL # selector 15:0 645 .byte 0 # 0 for interrupt gate 646 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 647 .word 0 # offset 31:16 648 649 # segment not present (INT 0bh) 650 .equ SEG_NOT_PRESENT_SEL, .-IDT_BASE 651 .word 0 # offset 15:0 652 .word SYS_CODE_SEL # selector 15:0 653 .byte 0 # 0 for interrupt gate 654 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 655 .word 0 # offset 31:16 656 657 # stack fault (INT 0ch) 658 .equ STACK_FAULT_SEL, .-IDT_BASE 659 .word 0 # offset 15:0 660 .word SYS_CODE_SEL # selector 15:0 661 .byte 0 # 0 for interrupt gate 662 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 663 .word 0 # offset 31:16 664 665 # general protection (INT 0dh) 666 .equ GP_FAULT_SEL, .-IDT_BASE 667 .word 0 # offset 15:0 668 .word SYS_CODE_SEL # selector 15:0 669 .byte 0 # 0 for interrupt gate 670 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 671 .word 0 # offset 31:16 672 673 # page fault (INT 0eh) 674 .equ PAGE_FAULT_SEL, .-IDT_BASE 675 .word 0 # offset 15:0 676 .word SYS_CODE_SEL # selector 15:0 677 .byte 0 # 0 for interrupt gate 678 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 679 .word 0 # offset 31:16 680 681 # Intel reserved - do not use (INT 0fh) 682 .equ RSVD_INTR_SEL2, .-IDT_BASE 683 .word 0 # offset 15:0 684 .word SYS_CODE_SEL # selector 15:0 685 .byte 0 # 0 for interrupt gate 686 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 687 .word 0 # offset 31:16 688 689 # floating point error (INT 10h) 690 .equ FLT_POINT_ERR_SEL, .-IDT_BASE 691 .word 0 # offset 15:0 692 .word SYS_CODE_SEL # selector 15:0 693 .byte 0 # 0 for interrupt gate 694 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 695 .word 0 # offset 31:16 696 697 # alignment check (INT 11h) 698 .equ ALIGNMENT_CHECK_SEL, .-IDT_BASE 699 .word 0 # offset 15:0 700 .word SYS_CODE_SEL # selector 15:0 701 .byte 0 # 0 for interrupt gate 702 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 703 .word 0 # offset 31:16 704 705 # machine check (INT 12h) 706 .equ MACHINE_CHECK_SEL, .-IDT_BASE 707 .word 0 # offset 15:0 708 .word SYS_CODE_SEL # selector 15:0 709 .byte 0 # 0 for interrupt gate 710 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 711 .word 0 # offset 31:16 712 713 # SIMD floating-point exception (INT 13h) 714 .equ SIMD_EXCEPTION_SEL, .-IDT_BASE 715 .word 0 # offset 15:0 716 .word SYS_CODE_SEL # selector 15:0 717 .byte 0 # 0 for interrupt gate 718 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 719 .word 0 # offset 31:16 720 721 # 85 unspecified descriptors, First 12 of them are reserved, the rest are avail 722 .fill 85 * 8, 1, 0 723 724 # IRQ 0 (System timer) - (INT 68h) 725 .equ IRQ0_SEL, .-IDT_BASE 726 .word 0 # offset 15:0 727 .word SYS_CODE_SEL # selector 15:0 728 .byte 0 # 0 for interrupt gate 729 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 730 .word 0 # offset 31:16 731 732 # IRQ 1 (8042 Keyboard controller) - (INT 69h) 733 .equ IRQ1_SEL, .-IDT_BASE 734 .word 0 # offset 15:0 735 .word SYS_CODE_SEL # selector 15:0 736 .byte 0 # 0 for interrupt gate 737 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 738 .word 0 # offset 31:16 739 740 # Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah) 741 .equ IRQ2_SEL, .-IDT_BASE 742 .word 0 # offset 15:0 743 .word SYS_CODE_SEL # selector 15:0 744 .byte 0 # 0 for interrupt gate 745 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 746 .word 0 # offset 31:16 747 748 # IRQ 3 (COM 2) - (INT 6bh) 749 .equ IRQ3_SEL, .-IDT_BASE 750 .word 0 # offset 15:0 751 .word SYS_CODE_SEL # selector 15:0 752 .byte 0 # 0 for interrupt gate 753 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 754 .word 0 # offset 31:16 755 756 # IRQ 4 (COM 1) - (INT 6ch) 757 .equ IRQ4_SEL, .-IDT_BASE 758 .word 0 # offset 15:0 759 .word SYS_CODE_SEL # selector 15:0 760 .byte 0 # 0 for interrupt gate 761 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 762 .word 0 # offset 31:16 763 764 # IRQ 5 (LPT 2) - (INT 6dh) 765 .equ IRQ5_SEL, .-IDT_BASE 766 .word 0 # offset 15:0 767 .word SYS_CODE_SEL # selector 15:0 768 .byte 0 # 0 for interrupt gate 769 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 770 .word 0 # offset 31:16 771 772 # IRQ 6 (Floppy controller) - (INT 6eh) 773 .equ IRQ6_SEL, .-IDT_BASE 774 .word 0 # offset 15:0 775 .word SYS_CODE_SEL # selector 15:0 776 .byte 0 # 0 for interrupt gate 777 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 778 .word 0 # offset 31:16 779 780 # IRQ 7 (LPT 1) - (INT 6fh) 781 .equ IRQ7_SEL, .-IDT_BASE 782 .word 0 # offset 15:0 783 .word SYS_CODE_SEL # selector 15:0 784 .byte 0 # 0 for interrupt gate 785 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 786 .word 0 # offset 31:16 787 788 # IRQ 8 (RTC Alarm) - (INT 70h) 789 .equ IRQ8_SEL, .-IDT_BASE 790 .word 0 # offset 15:0 791 .word SYS_CODE_SEL # selector 15:0 792 .byte 0 # 0 for interrupt gate 793 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 794 .word 0 # offset 31:16 795 796 # IRQ 9 - (INT 71h) 797 .equ IRQ9_SEL, .-IDT_BASE 798 .word 0 # offset 15:0 799 .word SYS_CODE_SEL # selector 15:0 800 .byte 0 # 0 for interrupt gate 801 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 802 .word 0 # offset 31:16 803 804 # IRQ 10 - (INT 72h) 805 .equ IRQ10_SEL, .-IDT_BASE 806 .word 0 # offset 15:0 807 .word SYS_CODE_SEL # selector 15:0 808 .byte 0 # 0 for interrupt gate 809 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 810 .word 0 # offset 31:16 811 812 # IRQ 11 - (INT 73h) 813 .equ IRQ11_SEL, .-IDT_BASE 814 .word 0 # offset 15:0 815 .word SYS_CODE_SEL # selector 15:0 816 .byte 0 # 0 for interrupt gate 817 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 818 .word 0 # offset 31:16 819 820 # IRQ 12 (PS/2 mouse) - (INT 74h) 821 .equ IRQ12_SEL, .-IDT_BASE 822 .word 0 # offset 15:0 823 .word SYS_CODE_SEL # selector 15:0 824 .byte 0 # 0 for interrupt gate 825 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 826 .word 0 # offset 31:16 827 828 # IRQ 13 (Floating point error) - (INT 75h) 829 .equ IRQ13_SEL, .-IDT_BASE 830 .word 0 # offset 15:0 831 .word SYS_CODE_SEL # selector 15:0 832 .byte 0 # 0 for interrupt gate 833 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 834 .word 0 # offset 31:16 835 836 # IRQ 14 (Secondary IDE) - (INT 76h) 837 .equ IRQ14_SEL, .-IDT_BASE 838 .word 0 # offset 15:0 839 .word SYS_CODE_SEL # selector 15:0 840 .byte 0 # 0 for interrupt gate 841 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 842 .word 0 # offset 31:16 843 844 # IRQ 15 (Primary IDE) - (INT 77h) 845 .equ IRQ15_SEL, .-IDT_BASE 846 .word 0 # offset 15:0 847 .word SYS_CODE_SEL # selector 15:0 848 .byte 0 # 0 for interrupt gate 849 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 850 .word 0 # offset 31:16 851 852 IDT_END: 853 854 .p2align 1 855 856 MemoryMapSize: .long 0 857 MemoryMap: .long 0,0,0,0,0,0,0,0 858 .long 0,0,0,0,0,0,0,0 859 .long 0,0,0,0,0,0,0,0 860 .long 0,0,0,0,0,0,0,0 861 .long 0,0,0,0,0,0,0,0 862 .long 0,0,0,0,0,0,0,0 863 .long 0,0,0,0,0,0,0,0 864 .long 0,0,0,0,0,0,0,0 865 .long 0,0,0,0,0,0,0,0 866 .long 0,0,0,0,0,0,0,0 867 .long 0,0,0,0,0,0,0,0 868 .long 0,0,0,0,0,0,0,0 869 .long 0,0,0,0,0,0,0,0 870 .long 0,0,0,0,0,0,0,0 871 .long 0,0,0,0,0,0,0,0 872 .long 0,0,0,0,0,0,0,0 873 .long 0,0,0,0,0,0,0,0 874 .long 0,0,0,0,0,0,0,0 875 .long 0,0,0,0,0,0,0,0 876 .long 0,0,0,0,0,0,0,0 877 .long 0,0,0,0,0,0,0,0 878 .long 0,0,0,0,0,0,0,0 879 .long 0,0,0,0,0,0,0,0 880 .long 0,0,0,0,0,0,0,0 881 .long 0,0,0,0,0,0,0,0 882 .long 0,0,0,0,0,0,0,0 883 .long 0,0,0,0,0,0,0,0 884 .long 0,0,0,0,0,0,0,0 885 .long 0,0,0,0,0,0,0,0 886 .long 0,0,0,0,0,0,0,0 887 888 .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 889 .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 890 891 .org 0x0fe0 892 MyStack: 893 # below is the pieces of the IVT that is used to redirect INT 68h - 6fh 894 # back to INT 08h - 0fh when in real mode... It is 'org'ed to a 895 # known low address (20f00) so it can be set up by PlMapIrqToVect in 896 # 8259.c 897 898 int $8 899 iret 900 901 int $9 902 iret 903 904 int $10 905 iret 906 907 int $11 908 iret 909 910 int $12 911 iret 912 913 int $13 914 iret 915 916 int $14 917 iret 918 919 int $15 920 iret 921 922 923 .org 0x0ffe 924 BlockSignature: 925 .word 0xaa55 926 927 928
