1 #------------------------------------------------------------------------------ 2 #* 3 #* Copyright (c) 2006 - 2011, 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 #* start.S 13 #* 14 #* Abstract: 15 #* 16 #------------------------------------------------------------------------------ 17 18 .stack: 19 .486p: 20 .code16 21 22 .equ FAT_DIRECTORY_ENTRY_SIZE, 0x020 23 .equ FAT_DIRECTORY_ENTRY_SHIFT, 5 24 .equ BLOCK_SIZE, 0x0200 25 .equ BLOCK_MASK, 0x01ff 26 .equ BLOCK_SHIFT, 9 27 28 .org 0x0 29 30 .global _start 31 _start: 32 33 Ia32Jump: 34 jmp BootSectorEntryPoint # JMP inst - 3 bytes 35 nop 36 37 OemId: .ascii "INTEL " # OemId - 8 bytes 38 39 SectorSize: .word 0 # Sector Size - 16 bits 40 SectorsPerCluster: .byte 0 # Sector Per Cluster - 8 bits 41 ReservedSectors: .word 0 # Reserved Sectors - 16 bits 42 NoFats: .byte 0 # Number of FATs - 8 bits 43 RootEntries: .word 0 # Root Entries - 16 bits 44 Sectors: .word 0 # Number of Sectors - 16 bits 45 Media: .byte 0 # Media - 8 bits - ignored 46 SectorsPerFat: .word 0 # Sectors Per FAT - 16 bits 47 SectorsPerTrack: .word 0 # Sectors Per Track - 16 bits - ignored 48 Heads: .word 0 # Heads - 16 bits - ignored 49 HiddenSectors: .long 0 # Hidden Sectors - 32 bits - ignored 50 LargeSectors: .long 0 # Large Sectors - 32 bits 51 PhysicalDrive: .byte 0 # PhysicalDriveNumber - 8 bits - ignored 52 CurrentHead: .byte 0 # Current Head - 8 bits 53 Signature: .byte 0 # Signature - 8 bits - ignored 54 VolId: .ascii " " # Volume Serial Number- 4 bytes 55 FatLabel: .ascii " " # Label - 11 bytes 56 SystemId: .ascii "FAT12 " # SystemId - 8 bytes 57 58 BootSectorEntryPoint: 59 #ASSUME ds:@code 60 #ASSUME ss:@code 61 # ds = 1000, es = 2000 + x (size of first cluster >> 4) 62 # cx = Start Cluster of EfiLdr 63 # dx = Start Cluster of Efivar.bin 64 65 # Re use the BPB data stored in Boot Sector 66 movw $0x7c00, %bp 67 68 pushw %cx 69 # Read Efivar.bin 70 # 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already 71 movw $0x1900, %ax 72 movw %ax, %es 73 testw %dx, %dx 74 jnz CheckVarStoreSize 75 76 movb $1, %al 77 NoVarStore: 78 pushw %es 79 # Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl 80 movb %al, %es:(4) 81 jmp SaveVolumeId 82 83 CheckVarStoreSize: 84 movw %dx, %di 85 cmpl $0x4000, %ds:2(%di) 86 movb $2, %al 87 jne NoVarStore 88 89 LoadVarStore: 90 movb $0, %al 91 movb %al, %es:(4) 92 movw (%di), %cx 93 # ES:DI = 1500:0 94 xorw %di, %di 95 pushw %es 96 movw $0x1500, %ax 97 movw %ax, %es 98 call ReadFile 99 SaveVolumeId: 100 popw %es 101 movw VolId(%bp), %ax 102 movw %ax, %es:(0) # Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId 103 movw VolId+2(%bp), %ax 104 movw %ax, %es:(2) 105 106 # Read Efildr 107 popw %cx 108 # cx = Start Cluster of Efildr -> BS.com has filled already 109 # ES:DI = 2000:0, first cluster will be read again 110 xorw %di, %di # di = 0 111 movw $0x2000, %ax 112 movw %ax, %es 113 call ReadFile 114 movw %cs, %ax 115 movw %ax, %cs:JumpSegment 116 117 JumpFarInstruction: 118 .byte 0xea 119 JumpOffset: 120 .word 0x200 121 JumpSegment: 122 .word 0x2000 123 124 125 126 # **************************************************************************** 127 # ReadFile 128 # 129 # Arguments: 130 # CX = Start Cluster of File 131 # ES:DI = Buffer to store file content read from disk 132 # 133 # Return: 134 # (ES << 4 + DI) = end of file content Buffer 135 # 136 # **************************************************************************** 137 ReadFile: 138 # si = NumberOfClusters 139 # cx = ClusterNumber 140 # dx = CachedFatSectorNumber 141 # ds:0000 = CacheFatSectorBuffer 142 # es:di = Buffer to load file 143 # bx = NextClusterNumber 144 pusha 145 movw $1, %si # NumberOfClusters = 1 146 pushw %cx # Push Start Cluster onto stack 147 movw $0xfff, %dx # CachedFatSectorNumber = 0xfff 148 FatChainLoop: 149 movw %cx, %ax # ax = ClusterNumber 150 andw $0xff8, %ax # ax = ax & 0xff8 151 cmpw $0xff8, %ax # See if this is the last cluster 152 je FoundLastCluster # Jump if last cluster found 153 movw %cx, %ax # ax = ClusterNumber 154 shlw %ax # ax = ClusterNumber * 2 155 addw %cx, %ax # ax = ClusterNumber * 2 + ClusterNumber = ClusterNumber * 3 156 shrw %ax # FatOffset = ClusterNumber*3 / 2 157 pushw %si # Save si 158 movw %ax, %si # si = FatOffset 159 shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT 160 addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET) 161 andw $BLOCK_MASK,%si # si = FatOffset & BLOCK_MASK 162 cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber 163 je SkipFatRead 164 movw $2, %bx 165 pushw %es 166 pushw %ds 167 popw %es 168 call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI 169 popw %es 170 movw %ax, %dx # CachedFatSectorNumber = FatSectorNumber 171 SkipFatRead: 172 movw (%si), %bx # bx = NextClusterNumber 173 movw %cx, %ax # ax = ClusterNumber 174 andw $1, %ax # See if this is an odd cluster number 175 je EvenFatEntry 176 shrw $4, %bx # NextClusterNumber = NextClusterNumber >> 4 177 EvenFatEntry: 178 andw $0xfff, %bx # Strip upper 4 bits of NextClusterNumber 179 popw %si # Restore si 180 decw %bx # bx = NextClusterNumber - 1 181 cmpw %cx, %bx # See if (NextClusterNumber-1)==ClusterNumber 182 jne ReadClusters 183 incw %bx # bx = NextClusterNumber 184 incw %si # NumberOfClusters++ 185 movw %bx, %cx # ClusterNumber = NextClusterNumber 186 jmp FatChainLoop 187 ReadClusters: 188 incw %bx 189 popw %ax # ax = StartCluster 190 pushw %bx # StartCluster = NextClusterNumber 191 movw %bx, %cx # ClusterNumber = NextClusterNumber 192 subw $2, %ax # ax = StartCluster - 2 193 xorb %bh, %bh 194 movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster 195 mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster 196 addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster 197 pushw %ax # save start sector 198 movw %si, %ax # ax = NumberOfClusters 199 mulw %bx # ax = NumberOfClusters * SectorsPerCluster 200 movw %ax, %bx # bx = Number of Sectors 201 popw %ax # ax = Start Sector 202 call ReadBlocks 203 movw $1, %si # NumberOfClusters = 1 204 jmp FatChainLoop 205 FoundLastCluster: 206 popw %cx 207 popa 208 ret 209 210 211 # **************************************************************************** 212 # ReadBlocks - Reads a set of blocks from a block device 213 # 214 # AX = Start LBA 215 # BX = Number of Blocks to Read 216 # ES:DI = Buffer to store sectors read from disk 217 # **************************************************************************** 218 219 # cx = Blocks 220 # bx = NumberOfBlocks 221 # si = StartLBA 222 223 ReadBlocks: 224 pusha 225 addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA 226 addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA 227 movl %eax, %esi # esi = Start LBA 228 movw %bx, %cx # cx = Number of blocks to read 229 ReadCylinderLoop: 230 movw $0x7bfc, %bp # bp = 0x7bfc 231 movl %esi, %eax # eax = Start LBA 232 xorl %edx, %edx # edx = 0 233 movzwl (%bp), %ebx # bx = MaxSector 234 divl %ebx # ax = StartLBA / MaxSector 235 incw %dx # dx = (StartLBA % MaxSector) + 1 236 237 movw (%bp), %bx # bx = MaxSector 238 subw %dx, %bx # bx = MaxSector - Sector 239 incw %bx # bx = MaxSector - Sector + 1 240 cmpw %bx, %cx # Compare (Blocks) to (MaxSector - Sector + 1) 241 jg LimitTransfer 242 movw %cx, %bx # bx = Blocks 243 LimitTransfer: 244 pushw %ax # save ax 245 movw %es, %ax # ax = es 246 shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system 247 andw $0x7f, %ax # ax = Number of blocks into current seg 248 addw %bx, %ax # ax = End Block number of transfer 249 cmpw $0x80, %ax # See if it crosses a 64K boundry 250 jle NotCrossing64KBoundry # Branch if not crossing 64K boundry 251 subw $0x80, %ax # ax = Number of blocks past 64K boundry 252 subw %ax, %bx # Decrease transfer size by block overage 253 NotCrossing64KBoundry: 254 popw %ax # restore ax 255 256 pushw %cx 257 movb %dl, %cl # cl = (StartLBA % MaxSector) + 1 = Sector 258 xorw %dx, %dx # dx = 0 259 divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder 260 # dx = ax % (MaxHead + 1) = Head 261 262 pushw %bx # Save number of blocks to transfer 263 movb %dl, %dh # dh = Head 264 movw $0x7c00, %bp # bp = 0x7c00 265 movb PhysicalDrive(%bp), %dl # dl = Drive Number 266 movb %al, %ch # ch = Cylinder 267 movb %bl, %al # al = Blocks 268 movb $2, %ah # ah = Function 2 269 movw %di, %bx # es:bx = Buffer address 270 int $0x13 271 jc DiskError 272 popw %bx 273 popw %cx 274 movzwl %bx, %ebx 275 addl %ebx, %esi # StartLBA = StartLBA + NumberOfBlocks 276 subw %bx, %cx # Blocks = Blocks - NumberOfBlocks 277 movw %es, %ax 278 shlw $(BLOCK_SHIFT-4), %bx 279 addw %bx, %ax 280 movw %ax, %es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE 281 cmpw $0, %cx 282 jne ReadCylinderLoop 283 popa 284 ret 285 286 DiskError: 287 pushw %cs 288 popw %ds 289 leaw ErrorString, %si 290 movw $7, %cx 291 jmp PrintStringAndHalt 292 293 PrintStringAndHalt: 294 movw $0xb800, %ax 295 movw %ax, %es 296 movw $160, %di 297 rep 298 movsw 299 Halt: 300 jmp Halt 301 302 ErrorString: 303 .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!',0x0c 304 305 .org 0x01fa 306 LBAOffsetForBootSector: 307 .long 0x0 308 309 .org 0x01fe 310 .word 0xaa55 311 312 #****************************************************************************** 313 #****************************************************************************** 314 #****************************************************************************** 315 316 .equ DELAY_PORT, 0x0ed # Port to use for 1uS delay 317 .equ KBD_CONTROL_PORT, 0x060 # 8042 control port 318 .equ KBD_STATUS_PORT, 0x064 # 8042 status port 319 .equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port 320 .equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20 321 322 .org 0x200 323 jmp start 324 Em64String: 325 .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 326 327 start: 328 movw %cs, %ax 329 movw %ax, %ds 330 movw %ax, %es 331 movw %ax, %ss 332 movw $MyStack, %sp 333 334 # mov ax,0b800h 335 # mov es,ax 336 # mov byte ptr es:[160],'a' 337 # mov ax,cs 338 # mov es,ax 339 340 movl $0, %ebx 341 leal MemoryMap, %edi 342 MemMapLoop: 343 movl $0xe820, %eax 344 movl $20, %ecx 345 movl $0x534d4150, %edx # SMAP 346 int $0x15 347 jc MemMapDone 348 addl $20, %edi 349 cmpl $0, %ebx 350 je MemMapDone 351 jmp MemMapLoop 352 MemMapDone: 353 leal MemoryMap, %eax 354 subl %eax, %edi # Get the address of the memory map 355 movl %edi, MemoryMapSize # Save the size of the memory map 356 357 xorl %ebx, %ebx 358 movw %cs, %bx # BX=segment 359 shll $4, %ebx # BX="linear" address of segment base 360 leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt 361 movl %eax, (gdtr + 2) # Put address of gdt into the gdtr 362 leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt 363 movl %eax, (idtr + 2) # Put address of idt into the idtr 364 leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map 365 366 addl $0x1000, %ebx # Source of EFI32 367 movl %ebx, JUMP+2 368 addl $0x1000, %ebx 369 movl %ebx, %esi # Source of EFILDR32 370 371 # mov ax,0b800h 372 # mov es,ax 373 # mov byte ptr es:[162],'b' 374 # mov ax,cs 375 # mov es,ax 376 377 # 378 # Enable A20 Gate 379 # 380 381 movw $0x2401, %ax # Enable A20 Gate 382 int $0x15 383 jnc A20GateEnabled # Jump if it suceeded 384 385 # 386 # If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually. 387 # 388 389 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 390 jnz Timeout8042 # Jump if the 8042 timed out 391 outw %ax, $DELAY_PORT # Delay 1 uS 392 mov $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port 393 out %al, $KBD_STATUS_PORT # Send command to the 8042 394 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 395 jnz Timeout8042 # Jump if the 8042 timed out 396 mov $ENABLE_A20_CMD, %al # gate address bit 20 on 397 out %al, $KBD_CONTROL_PORT # Send command to thre 8042 398 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 399 movw $25, %cx # Delay 25 uS for the command to complete on the 8042 400 Delay25uS: 401 outw %ax, $DELAY_PORT # Delay 1 uS 402 loop Delay25uS 403 Timeout8042: 404 405 406 A20GateEnabled: 407 movw $0x0008, %bx # Flat data descriptor 408 409 # 410 # DISABLE INTERRUPTS - Entering Protected Mode 411 # 412 413 cli 414 415 # mov ax,0b800h 416 # mov es,ax 417 # mov byte ptr es:[164],'c' 418 # mov ax,cs 419 # mov es,ax 420 421 .byte 0x66 422 lgdt gdtr 423 .byte 0x66 424 lidt idtr 425 426 movl %cr0, %eax 427 orb $1, %al 428 movl %eax, %cr0 429 JUMP: 430 # jmp far 0010:00020000 431 .byte 0x66 432 .byte 0xea 433 .long 0x00020000 434 .word 0x0010 435 436 Empty8042InputBuffer: 437 movw $0, %cx 438 Empty8042Loop: 439 outw %ax, $DELAY_PORT # Delay 1us 440 in $KBD_STATUS_PORT, %al # Read the 8042 Status Port 441 andb $0x2, %al # Check the Input Buffer Full Flag 442 loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS 443 ret 444 445 ############################################################################## 446 # data 447 ############################################################################## 448 449 .p2align 1 450 451 gdtr: .long GDT_END - GDT_BASE - 1 # GDT limit 452 .long 0 # (GDT base gets set above) 453 ############################################################################## 454 # global descriptor table (GDT) 455 ############################################################################## 456 457 .p2align 1 458 459 GDT_BASE: 460 # null descriptor 461 .equ NULL_SEL, .-GDT_BASE 462 .word 0 # limit 15:0 463 .word 0 # base 15:0 464 .byte 0 # base 23:16 465 .byte 0 # type 466 .byte 0 # limit 19:16, flags 467 .byte 0 # base 31:24 468 469 # linear data segment descriptor 470 .equ LINEAR_SEL, .-GDT_BASE 471 .word 0xFFFF # limit 0xFFFFF 472 .word 0 # base 0 473 .byte 0 474 .byte 0x92 # present, ring 0, data, expand-up, writable 475 .byte 0xCF # page-granular, 32-bit 476 .byte 0 477 478 # linear code segment descriptor 479 .equ LINEAR_CODE_SEL, .-GDT_BASE 480 .word 0xFFFF # limit 0xFFFFF 481 .word 0 # base 0 482 .byte 0 483 .byte 0x9A # present, ring 0, data, expand-up, writable 484 .byte 0xCF # page-granular, 32-bit 485 .byte 0 486 487 # system data segment descriptor 488 .equ SYS_DATA_SEL, .-GDT_BASE 489 .word 0xFFFF # limit 0xFFFFF 490 .word 0 # base 0 491 .byte 0 492 .byte 0x92 # present, ring 0, data, expand-up, writable 493 .byte 0xCF # page-granular, 32-bit 494 .byte 0 495 496 # system code segment descriptor 497 .equ SYS_CODE_SEL, .-GDT_BASE 498 .word 0xFFFF # limit 0xFFFFF 499 .word 0 # base 0 500 .byte 0 501 .byte 0x9A # present, ring 0, data, expand-up, writable 502 .byte 0xCF # page-granular, 32-bit 503 .byte 0 504 505 # spare segment descriptor 506 .equ SPARE3_SEL, .-GDT_BASE 507 .word 0 # limit 0xFFFFF 508 .word 0 # base 0 509 .byte 0 510 .byte 0 # present, ring 0, data, expand-up, writable 511 .byte 0 # page-granular, 32-bit 512 .byte 0 513 514 # spare segment descriptor 515 .equ SPARE4_SEL, .-GDT_BASE 516 .word 0 # limit 0xFFFFF 517 .word 0 # base 0 518 .byte 0 519 .byte 0 # present, ring 0, data, expand-up, writable 520 .byte 0 # page-granular, 32-bit 521 .byte 0 522 523 # spare segment descriptor 524 .equ SPARE5_SEL, .-GDT_BASE 525 .word 0 # limit 0xFFFFF 526 .word 0 # base 0 527 .byte 0 528 .byte 0 # present, ring 0, data, expand-up, writable 529 .byte 0 # page-granular, 32-bit 530 .byte 0 531 532 GDT_END: 533 534 .p2align 1 535 536 537 538 idtr: .long IDT_END - IDT_BASE - 1 # IDT limit 539 .long 0 # (IDT base gets set above) 540 ############################################################################## 541 # interrupt descriptor table (IDT) 542 # 543 # Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ 544 # mappings. This implementation only uses the system timer and all other 545 # IRQs will remain masked. The descriptors for vectors 33+ are provided 546 # for convenience. 547 ############################################################################## 548 549 #idt_tag db "IDT",0 550 .p2align 1 551 552 IDT_BASE: 553 # divide by zero (INT 0) 554 .equ DIV_ZERO_SEL, .-IDT_BASE 555 .word 0 # offset 15:0 556 .long SYS_CODE_SEL # selector 15:0 557 .byte 0 # 0 for interrupt gate 558 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 559 .word 0 # offset 31:16 560 561 # debug exception (INT 1) 562 .equ DEBUG_EXCEPT_SEL, .-IDT_BASE 563 .word 0 # offset 15:0 564 .long 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 # NMI (INT 2) 570 .equ NMI_SEL, .-IDT_BASE 571 .word 0 # offset 15:0 572 .long 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 # soft breakpoint (INT 3) 578 .equ BREAKPOINT_SEL, .-IDT_BASE 579 .word 0 # offset 15:0 580 .long 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 # overflow (INT 4) 586 .equ OVERFLOW_SEL, .-IDT_BASE 587 .word 0 # offset 15:0 588 .long 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 # bounds check (INT 5) 594 .equ BOUNDS_CHECK_SEL, .-IDT_BASE 595 .word 0 # offset 15:0 596 .long 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 # invalid opcode (INT 6) 602 .equ INVALID_OPCODE_SEL, .-IDT_BASE 603 .word 0 # offset 15:0 604 .long 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 # device not available (INT 7) 610 .equ DEV_NOT_AVAIL_SEL, .-IDT_BASE 611 .word 0 # offset 15:0 612 .long 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 # double fault (INT 8) 618 .equ DOUBLE_FAULT_SEL, .-IDT_BASE 619 .word 0 # offset 15:0 620 .long 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 # Coprocessor segment overrun - reserved (INT 9) 626 .equ RSVD_INTR_SEL1, .-IDT_BASE 627 .word 0 # offset 15:0 628 .long 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 # invalid TSS (INT 0x0a) 634 .equ INVALID_TSS_SEL, .-IDT_BASE 635 .word 0 # offset 15:0 636 .long 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 # segment not present (INT 0x0b) 642 .equ SEG_NOT_PRESENT_SEL, .-IDT_BASE 643 .word 0 # offset 15:0 644 .long 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 # stack fault (INT 0x0c) 650 .equ STACK_FAULT_SEL, .-IDT_BASE 651 .word 0 # offset 15:0 652 .long 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 # general protection (INT 0x0d) 658 .equ GP_FAULT_SEL, .-IDT_BASE 659 .word 0 # offset 15:0 660 .long 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 # page fault (INT 0x0e) 666 .equ PAGE_FAULT_SEL, .-IDT_BASE 667 .word 0 # offset 15:0 668 .long 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 # Intel reserved - do not use (INT 0x0f) 674 .equ RSVD_INTR_SEL2, .-IDT_BASE 675 .word 0 # offset 15:0 676 .long 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 # floating point error (INT 0x10) 682 .equ FLT_POINT_ERR_SEL, .-IDT_BASE 683 .word 0 # offset 15:0 684 .long 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 # alignment check (INT 0x11) 690 .equ ALIGNMENT_CHECK_SEL, .-IDT_BASE 691 .word 0 # offset 15:0 692 .long SYS_CODE_SEL # selector 15:0 693 .byte 0 # 0 for interrupt gate 694 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 695 .word 0 # offset 31:16 696 697 # machine check (INT 0x12) 698 .equ MACHINE_CHECK_SEL, .-IDT_BASE 699 .word 0 # offset 15:0 700 .long SYS_CODE_SEL # selector 15:0 701 .byte 0 # 0 for interrupt gate 702 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 703 .word 0 # offset 31:16 704 705 # SIMD floating-point exception (INT 0x13) 706 .equ SIMD_EXCEPTION_SEL, .-IDT_BASE 707 .word 0 # offset 15:0 708 .long SYS_CODE_SEL # selector 15:0 709 .byte 0 # 0 for interrupt gate 710 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 711 .word 0 # offset 31:16 712 713 # 85 unspecified descriptors, First 12 of them are reserved, the rest are avail 714 .fill 85 * 8, 1, 0 # db (85 * 8) dup(0) 715 716 # IRQ 0 (System timer) - (INT 0x68) 717 .equ IRQ0_SEL, .-IDT_BASE 718 .word 0 # offset 15:0 719 .long SYS_CODE_SEL # selector 15:0 720 .byte 0 # 0 for interrupt gate 721 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 722 .word 0 # offset 31:16 723 724 # IRQ 1 (8042 Keyboard controller) - (INT 0x69) 725 .equ IRQ1_SEL, .-IDT_BASE 726 .word 0 # offset 15:0 727 .long SYS_CODE_SEL # selector 15:0 728 .byte 0 # 0 for interrupt gate 729 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 730 .word 0 # offset 31:16 731 732 # Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 0x6a) 733 .equ IRQ2_SEL, .-IDT_BASE 734 .word 0 # offset 15:0 735 .long SYS_CODE_SEL # selector 15:0 736 .byte 0 # 0 for interrupt gate 737 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 738 .word 0 # offset 31:16 739 740 # IRQ 3 (COM 2) - (INT 0x6b) 741 .equ IRQ3_SEL, .-IDT_BASE 742 .word 0 # offset 15:0 743 .long SYS_CODE_SEL # selector 15:0 744 .byte 0 # 0 for interrupt gate 745 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 746 .word 0 # offset 31:16 747 748 # IRQ 4 (COM 1) - (INT 0x6c) 749 .equ IRQ4_SEL, .-IDT_BASE 750 .word 0 # offset 15:0 751 .long SYS_CODE_SEL # selector 15:0 752 .byte 0 # 0 for interrupt gate 753 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 754 .word 0 # offset 31:16 755 756 # IRQ 5 (LPT 2) - (INT 0x6d) 757 .equ IRQ5_SEL, .-IDT_BASE 758 .word 0 # offset 15:0 759 .long SYS_CODE_SEL # selector 15:0 760 .byte 0 # 0 for interrupt gate 761 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 762 .word 0 # offset 31:16 763 764 # IRQ 6 (Floppy controller) - (INT 0x6e) 765 .equ IRQ6_SEL, .-IDT_BASE 766 .word 0 # offset 15:0 767 .long SYS_CODE_SEL # selector 15:0 768 .byte 0 # 0 for interrupt gate 769 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 770 .word 0 # offset 31:16 771 772 # IRQ 7 (LPT 1) - (INT 0x6f) 773 .equ IRQ7_SEL, .-IDT_BASE 774 .word 0 # offset 15:0 775 .long SYS_CODE_SEL # selector 15:0 776 .byte 0 # 0 for interrupt gate 777 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 778 .word 0 # offset 31:16 779 780 # IRQ 8 (RTC Alarm) - (INT 0x70) 781 .equ IRQ8_SEL, .-IDT_BASE 782 .word 0 # offset 15:0 783 .long SYS_CODE_SEL # selector 15:0 784 .byte 0 # 0 for interrupt gate 785 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 786 .word 0 # offset 31:16 787 788 # IRQ 9 - (INT 0x71) 789 .equ IRQ9_SEL, .-IDT_BASE 790 .word 0 # offset 15:0 791 .long SYS_CODE_SEL # selector 15:0 792 .byte 0 # 0 for interrupt gate 793 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 794 .word 0 # offset 31:16 795 796 # IRQ 10 - (INT 0x72) 797 .equ IRQ10_SEL, .-IDT_BASE 798 .word 0 # offset 15:0 799 .long SYS_CODE_SEL # selector 15:0 800 .byte 0 # 0 for interrupt gate 801 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 802 .word 0 # offset 31:16 803 804 # IRQ 11 - (INT 0x73) 805 .equ IRQ11_SEL, .-IDT_BASE 806 .word 0 # offset 15:0 807 .long SYS_CODE_SEL # selector 15:0 808 .byte 0 # 0 for interrupt gate 809 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 810 .word 0 # offset 31:16 811 812 # IRQ 12 (PS/2 mouse) - (INT 0x74) 813 .equ IRQ12_SEL, .-IDT_BASE 814 .word 0 # offset 15:0 815 .long SYS_CODE_SEL # selector 15:0 816 .byte 0 # 0 for interrupt gate 817 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 818 .word 0 # offset 31:16 819 820 # IRQ 13 (Floating point error) - (INT 0x75) 821 .equ IRQ13_SEL, .-IDT_BASE 822 .word 0 # offset 15:0 823 .long SYS_CODE_SEL # selector 15:0 824 .byte 0 # 0 for interrupt gate 825 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 826 .word 0 # offset 31:16 827 828 # IRQ 14 (Secondary IDE) - (INT 0x76) 829 .equ IRQ14_SEL, .-IDT_BASE 830 .word 0 # offset 15:0 831 .long SYS_CODE_SEL # selector 15:0 832 .byte 0 # 0 for interrupt gate 833 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 834 .word 0 # offset 31:16 835 836 # IRQ 15 (Primary IDE) - (INT 0x77) 837 .equ IRQ15_SEL, .-IDT_BASE 838 .word 0 # offset 15:0 839 .long SYS_CODE_SEL # selector 15:0 840 .byte 0 # 0 for interrupt gate 841 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 842 .word 0 # offset 31:16 843 844 IDT_END: 845 846 .p2align 1 847 848 MemoryMapSize: .long 0 849 MemoryMap: .long 0,0,0,0,0,0,0,0 850 .long 0,0,0,0,0,0,0,0 851 .long 0,0,0,0,0,0,0,0 852 .long 0,0,0,0,0,0,0,0 853 .long 0,0,0,0,0,0,0,0 854 .long 0,0,0,0,0,0,0,0 855 .long 0,0,0,0,0,0,0,0 856 .long 0,0,0,0,0,0,0,0 857 .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 0,0,0,0,0,0,0,0 879 880 .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 881 .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 882 883 .org 0x0fe0 884 MyStack: 885 # below is the pieces of the IVT that is used to redirect INT 68h - 6fh 886 # back to INT 08h - 0fh when in real mode... It is 'org'ed to a 887 # known low address (20f00) so it can be set up by PlMapIrqToVect in 888 # 8259.c 889 890 int $8 891 iret 892 893 int $9 894 iret 895 896 int $10 897 iret 898 899 int $11 900 iret 901 902 int $12 903 iret 904 905 int $13 906 iret 907 908 int $14 909 iret 910 911 int $15 912 iret 913 914 915 .org 0x0ffe 916 BlockSignature: 917 .word 0xaa55 918 919 920
