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 #* start16.asm 13 #* 14 #* Abstract: 15 #* 16 #------------------------------------------------------------------------------ 17 18 #.MODEL small 19 .stack: 20 .486p: 21 .code16 22 23 .equ FAT_DIRECTORY_ENTRY_SIZE, 0x0020 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 0x00 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 40 SectorSize: .word 0 # Sector Size - 16 bits 41 SectorsPerCluster: .byte 0 # Sector Per Cluster - 8 bits 42 ReservedSectors: .word 0 # Reserved Sectors - 16 bits 43 NoFats: .byte 0 # Number of FATs - 8 bits 44 RootEntries: .word 0 # Root Entries - 16 bits 45 Sectors: .word 0 # Number of Sectors - 16 bits 46 Media: .byte 0 # Media - 8 bits - ignored 47 SectorsPerFat: .word 0 # Sectors Per FAT - 16 bits 48 SectorsPerTrack: .word 0 # Sectors Per Track - 16 bits - ignored 49 Heads: .word 0 # Heads - 16 bits - ignored 50 HiddenSectors: .long 0 # Hidden Sectors - 32 bits - ignored 51 LargeSectors: .long 0 # Large Sectors - 32 bits 52 PhysicalDrive: .byte 0 # PhysicalDriveNumber - 8 bits - ignored 53 CurrentHead: .byte 0 # Current Head - 8 bits 54 Signature: .byte 0 # Signature - 8 bits - ignored 55 VolId: .ascii " " # Volume Serial Number- 4 bytes 56 FatLabel: .ascii " " # Label - 11 bytes 57 SystemId: .ascii "FAT16 " # SystemId - 8 bytes 58 59 BootSectorEntryPoint: 60 #ASSUME ds:@code 61 #ASSUME ss:@code 62 # ds = 1000, es = 2000 + x (size of first cluster >> 4) 63 # cx = Start Cluster of EfiLdr 64 # dx = Start Cluster of Efivar.bin 65 66 # Re use the BPB data stored in Boot Sector 67 movw $0x7c00, %bp 68 69 pushw %cx 70 # Read Efivar.bin 71 # 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already 72 movw $0x1900, %ax 73 movw %ax, %es 74 testw %dx, %dx 75 jnz CheckVarStoreSize 76 77 movb $1, %al 78 NoVarStore: 79 pushw %es 80 # Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl 81 movb %al, %es:4 82 jmp SaveVolumeId 83 84 CheckVarStoreSize: 85 movw %dx, %di 86 cmpl $0x4000, %ds:2(%di) 87 movb $2, %al 88 jne NoVarStore 89 90 LoadVarStore: 91 movb $0, %al 92 movb %al, %es:4 93 movw (%di), %cx 94 # ES:DI = 1500:0 95 xorw %di, %di 96 pushw %es 97 movw $0x1500, %ax 98 movw %ax, %es 99 call ReadFile 100 SaveVolumeId: 101 popw %es 102 movw VolId(%bp), %ax 103 movw %ax, %es:0 # Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId 104 movw VolId+2(%bp), %ax 105 movw %ax, %es:2 106 107 # Read Efildr 108 popw %cx 109 # cx = Start Cluster of Efildr -> BS.com has filled already 110 # ES:DI = 2000:0, first cluster will be read again 111 xorw %di, %di # di = 0 112 movw $0x2000, %ax 113 movw %ax, %es 114 call ReadFile 115 movw %cs, %ax 116 movw %ax, %cs:JumpSegment 117 118 JumpFarInstruction: 119 .byte 0xea 120 JumpOffset: 121 .word 0x200 122 JumpSegment: 123 .word 0x2000 124 125 126 127 # **************************************************************************** 128 # ReadFile 129 # 130 # Arguments: 131 # CX = Start Cluster of File 132 # ES:DI = Buffer to store file content read from disk 133 # 134 # Return: 135 # (ES << 4 + DI) = end of file content Buffer 136 # 137 # **************************************************************************** 138 ReadFile: 139 # si = NumberOfClusters 140 # cx = ClusterNumber 141 # dx = CachedFatSectorNumber 142 # ds:0000 = CacheFatSectorBuffer 143 # es:di = Buffer to load file 144 # bx = NextClusterNumber 145 pusha 146 movw $1, %si # NumberOfClusters = 1 147 pushw %cx # Push Start Cluster onto stack 148 movw $0xfff, %dx # CachedFatSectorNumber = 0xfff 149 FatChainLoop: 150 movw %cx, %ax # ax = ClusterNumber 151 andw $0xfff8, %ax # ax = ax & 0xfff8 152 cmpw $0xfff8, %ax # See if this is the last cluster 153 je FoundLastCluster # Jump if last cluster found 154 movw %cx, %ax # ax = ClusterNumber 155 shlw %ax # FatOffset = ClusterNumber * 2 156 pushw %si # Save si 157 movw %ax, %si # si = FatOffset 158 shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT 159 addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET) 160 andw $BLOCK_MASK, %si # si = FatOffset & BLOCK_MASK 161 cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber 162 je SkipFatRead 163 movw $2, %bx 164 pushw %es 165 pushw %ds 166 popw %es 167 call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI 168 popw %es 169 movw %ax, %dx # CachedFatSectorNumber = FatSectorNumber 170 SkipFatRead: 171 movw (%si), %bx # bx = NextClusterNumber 172 movw %cx, %ax # ax = ClusterNumber 173 popw %si # Restore si 174 decw %bx # bx = NextClusterNumber - 1 175 cmpw %cx, %bx # See if (NextClusterNumber-1)==ClusterNumber 176 jne ReadClusters 177 incw %bx # bx = NextClusterNumber 178 incw %si # NumberOfClusters++ 179 movw %bx, %cx # ClusterNumber = NextClusterNumber 180 jmp FatChainLoop 181 ReadClusters: 182 incw %bx 183 popw %ax # ax = StartCluster 184 pushw %bx # StartCluster = NextClusterNumber 185 movw %bx, %cx # ClusterNumber = NextClusterNumber 186 subw $2, %ax # ax = StartCluster - 2 187 xorb %bh, %bh 188 movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster 189 mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster 190 addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster 191 pushw %ax # save start sector 192 movw %si, %ax # ax = NumberOfClusters 193 mulw %bx # ax = NumberOfClusters * SectorsPerCluster 194 movw %ax, %bx # bx = Number of Sectors 195 popw %ax # ax = Start Sector 196 call ReadBlocks 197 movw $1, %si # NumberOfClusters = 1 198 jmp FatChainLoop 199 FoundLastCluster: 200 popw %cx 201 popa 202 ret 203 204 205 # **************************************************************************** 206 # ReadBlocks - Reads a set of blocks from a block device 207 # 208 # AX = Start LBA 209 # BX = Number of Blocks to Read 210 # ES:DI = Buffer to store sectors read from disk 211 # **************************************************************************** 212 213 # cx = Blocks 214 # bx = NumberOfBlocks 215 # si = StartLBA 216 217 ReadBlocks: 218 pusha 219 addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA 220 addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA 221 movl %eax, %esi # esi = Start LBA 222 movw %bx, %cx # cx = Number of blocks to read 223 ReadCylinderLoop: 224 movw $0x7bfc, %bp # bp = 0x7bfc 225 movl %esi, %eax # eax = Start LBA 226 xorl %edx, %edx # edx = 0 227 movzwl (%bp), %ebx # bx = MaxSector 228 divl %ebx # ax = StartLBA / MaxSector 229 incw %dx # dx = (StartLBA % MaxSector) + 1 230 231 movw (%bp), %bx # bx = MaxSector 232 subw %dx, %bx # bx = MaxSector - Sector 233 incw %bx # bx = MaxSector - Sector + 1 234 cmpw %bx, %cx # Compare (Blocks) to (MaxSector - Sector + 1) 235 jg LimitTransfer 236 movw %cx, %bx # bx = Blocks 237 LimitTransfer: 238 pushw %ax # save ax 239 movw %es, %ax # ax = es 240 shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system 241 andw $0x7f, %ax # ax = Number of blocks into current seg 242 addw %bx, %ax # ax = End Block number of transfer 243 cmpw $0x80, %ax # See if it crosses a 64K boundry 244 jle NotCrossing64KBoundry # Branch if not crossing 64K boundry 245 subw $0x80, %ax # ax = Number of blocks past 64K boundry 246 subw %ax, %bx # Decrease transfer size by block overage 247 NotCrossing64KBoundry: 248 popw %ax # restore ax 249 250 pushw %cx 251 movb %dl, %cl # cl = (StartLBA % MaxSector) + 1 = Sector 252 xorw %dx, %dx # dx = 0 253 divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder 254 # dx = ax % (MaxHead + 1) = Head 255 256 pushw %bx # Save number of blocks to transfer 257 movb %dl, %dh # dh = Head 258 movw $0x7c00, %bp # bp = 0x7c00 259 movb PhysicalDrive(%bp), %dl # dl = Drive Number 260 movb %al, %ch # ch = Cylinder 261 movb %bl, %al # al = Blocks 262 movb $2, %ah # ah = Function 2 263 movw %di, %bx # es:bx = Buffer address 264 int $0x13 265 jc DiskError 266 popw %bx 267 popw %cx 268 movzwl %bx, %ebx 269 addl %ebx, %esi # StartLBA = StartLBA + NumberOfBlocks 270 subw %bx, %cx # Blocks = Blocks - NumberOfBlocks 271 movw %es, %ax 272 shlw $(BLOCK_SHIFT-4), %bx 273 addw %bx, %ax 274 movw %ax, %es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE 275 cmpw $0, %cx 276 jne ReadCylinderLoop 277 popa 278 ret 279 280 DiskError: 281 pushw %cs 282 popw %ds 283 leaw ErrorString, %si 284 movw $7, %cx 285 jmp PrintStringAndHalt 286 287 PrintStringAndHalt: 288 movw $0xb800, %ax 289 movw %ax, %es 290 movw $160, %di 291 rep 292 movsw 293 Halt: 294 jmp Halt 295 296 ErrorString: 297 .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!', 0x0c 298 299 # .org 0x01fa # Just for passing build. 300 LBAOffsetForBootSector: 301 .long 0x0 302 303 # .org 0x01fe # Just for passing build. 304 .word 0xaa55 305 306 #****************************************************************************** 307 #****************************************************************************** 308 #****************************************************************************** 309 310 .equ DELAY_PORT, 0x0ed # Port to use for 1uS delay 311 .equ KBD_CONTROL_PORT, 0x060 # 8042 control port 312 .equ KBD_STATUS_PORT, 0x064 # 8042 status port 313 .equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port 314 .equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20 315 316 # .org 0x0200 # Just for passing build. 317 jmp start 318 Em64String: 319 .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 320 321 start: 322 movw %cs, %ax 323 movw %ax, %ds 324 movw %ax, %es 325 movw %ax, %ss 326 movw $MyStack, %sp 327 328 # mov ax,0b800h 329 # mov es,ax 330 # mov byte ptr es:[160],'a' 331 # mov ax,cs 332 # mov es,ax 333 334 movl $0, %ebx 335 leal MemoryMap, %edi 336 MemMapLoop: 337 movl $0xe820, %eax 338 movl $20, %ecx 339 movl $0x534d4150, %edx # 0x534d4150 stands for 'SMAP' 340 int $0x15 341 jc MemMapDone 342 addl $20, %edi 343 cmpl $0, %ebx 344 je MemMapDone 345 jmp MemMapLoop 346 MemMapDone: 347 leal MemoryMap, %eax 348 subl %eax, %edi # Get the address of the memory map 349 movl %edi, MemoryMapSize # Save the size of the memory map 350 351 xorl %ebx, %ebx 352 movw %cs, %bx # BX=segment 353 shll $4, %ebx # BX="linear" address of segment base 354 leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt 355 movl %eax, gdtr + 2 # Put address of gdt into the gdtr 356 leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt 357 movl %eax, idtr + 2 # Put address of idt into the idtr 358 leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map 359 360 addl $0x1000, %ebx # Source of EFI32 361 movl %ebx, JUMP+2 362 addl $0x1000, %ebx 363 movl %ebx, %esi # Source of EFILDR32 364 365 # mov ax,0b800h 366 # mov es,ax 367 # mov byte ptr es:[162],'b' 368 # mov ax,cs 369 # mov es,ax 370 371 # 372 # Enable A20 Gate 373 # 374 375 movw $0x2401, %ax # Enable A20 Gate 376 int $0x15 377 jnc A20GateEnabled # Jump if it suceeded 378 379 # 380 # If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually. 381 # 382 383 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 384 jnz Timeout8042 # Jump if the 8042 timed out 385 outw %ax, $DELAY_PORT # Delay 1 uS 386 movb $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port 387 outb %al, $KBD_STATUS_PORT # Send command to the 8042 388 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 389 jnz Timeout8042 # Jump if the 8042 timed out 390 movb $ENABLE_A20_CMD, %al # gate address bit 20 on 391 outb %al, $KBD_CONTROL_PORT # Send command to thre 8042 392 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 393 movw $25, %cx # Delay 25 uS for the command to complete on the 8042 394 Delay25uS: 395 outw %ax, $DELAY_PORT # Delay 1 uS 396 loop Delay25uS 397 Timeout8042: 398 399 400 A20GateEnabled: 401 movw $0x0008, %bx # Flat data descriptor 402 # 403 # DISABLE INTERRUPTS - Entering Protected Mode 404 # 405 406 cli 407 408 # mov ax,0b800h 409 # mov es,ax 410 # mov byte ptr es:[164],'c' 411 # mov ax,cs 412 # mov es,ax 413 414 .byte 0x66 415 lgdt gdtr 416 .byte 0x66 417 lidt idtr 418 419 movl %cr0, %eax 420 orb $1, %al 421 movl %eax, %cr0 422 JUMP: 423 # jmp far 0010:00020000 424 .byte 0x66 425 .byte 0xea 426 .long 0x00020000 427 .word 0x0010 428 429 Empty8042InputBuffer: 430 movw $0, %cx 431 Empty8042Loop: 432 outw %ax, $DELAY_PORT # Delay 1us 433 inb $KBD_STATUS_PORT, %al # Read the 8042 Status Port 434 andb $0x2, %al # Check the Input Buffer Full Flag 435 loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS 436 ret 437 438 ############################################################################## 439 # data 440 ############################################################################## 441 442 .p2align 1 443 444 gdtr: .word GDT_END - GDT_BASE - 1 # GDT limit 445 .long 0 # (GDT base gets set above) 446 ############################################################################## 447 # global descriptor table (GDT) 448 ############################################################################## 449 450 .p2align 1 451 452 GDT_BASE: 453 # null descriptor 454 .equ NULL_SEL, .-GDT_BASE 455 .word 0 # limit 15:0 456 .word 0 # base 15:0 457 .byte 0 # base 23:16 458 .byte 0 # type 459 .byte 0 # limit 19:16, flags 460 .byte 0 # base 31:24 461 462 # linear data segment descriptor 463 .equ LINEAR_SEL, .-GDT_BASE 464 .word 0xFFFF # limit 0xFFFFF 465 .word 0 # base 0 466 .byte 0 467 .byte 0x92 # present, ring 0, data, expand-up, writable 468 .byte 0xCF # page-granular, 32-bit 469 .byte 0 470 471 # linear code segment descriptor 472 .equ LINEAR_CODE_SEL, .-GDT_BASE 473 .word 0xFFFF # limit 0xFFFFF 474 .word 0 # base 0 475 .byte 0 476 .byte 0x9A # present, ring 0, data, expand-up, writable 477 .byte 0xCF # page-granular, 32-bit 478 .byte 0 479 480 # system data segment descriptor 481 .equ SYS_DATA_SEL, .-GDT_BASE 482 .word 0xFFFF # limit 0xFFFFF 483 .word 0 # base 0 484 .byte 0 485 .byte 0x92 # present, ring 0, data, expand-up, writable 486 .byte 0xCF # page-granular, 32-bit 487 .byte 0 488 489 # system code segment descriptor 490 .equ SYS_CODE_SEL, .-GDT_BASE 491 .word 0xFFFF # limit 0xFFFFF 492 .word 0 # base 0 493 .byte 0 494 .byte 0x9A # present, ring 0, data, expand-up, writable 495 .byte 0xCF # page-granular, 32-bit 496 .byte 0 497 498 # spare segment descriptor 499 .equ SPARE3_SEL, .-GDT_BASE 500 .word 0 # limit 0xFFFFF 501 .word 0 # base 0 502 .byte 0 503 .byte 0 # present, ring 0, data, expand-up, writable 504 .byte 0 # page-granular, 32-bit 505 .byte 0 506 507 # spare segment descriptor 508 .equ SPARE4_SEL, .-GDT_BASE 509 .word 0 # limit 0xFFFFF 510 .word 0 # base 0 511 .byte 0 512 .byte 0 # present, ring 0, data, expand-up, writable 513 .byte 0 # page-granular, 32-bit 514 .byte 0 515 516 # spare segment descriptor 517 .equ SPARE5_SEL, .-GDT_BASE 518 .word 0 # limit 0xFFFFF 519 .word 0 # base 0 520 .byte 0 521 .byte 0 # present, ring 0, data, expand-up, writable 522 .byte 0 # page-granular, 32-bit 523 .byte 0 524 525 GDT_END: 526 527 .p2align 1 528 529 530 531 idtr: .word IDT_END - IDT_BASE - 1 # IDT limit 532 .long 0 # (IDT base gets set above) 533 ############################################################################## 534 # interrupt descriptor table (IDT) 535 # 536 # Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ 537 # mappings. This implementation only uses the system timer and all other 538 # IRQs will remain masked. The descriptors for vectors 33+ are provided 539 # for convenience. 540 ############################################################################## 541 542 #idt_tag db "IDT",0 543 .p2align 1 544 545 IDT_BASE: 546 # divide by zero (INT 0) 547 .equ DIV_ZERO_SEL, .-IDT_BASE 548 .word 0 # offset 15:0 549 .word SYS_CODE_SEL # selector 15:0 550 .byte 0 # 0 for interrupt gate 551 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 552 .word 0 # offset 31:16 553 554 # debug exception (INT 1) 555 .equ DEBUG_EXCEPT_SEL, .-IDT_BASE 556 .word 0 # offset 15:0 557 .word SYS_CODE_SEL # selector 15:0 558 .byte 0 # 0 for interrupt gate 559 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 560 .word 0 # offset 31:16 561 562 # NMI (INT 2) 563 .equ NMI_SEL, .-IDT_BASE 564 .word 0 # offset 15:0 565 .word SYS_CODE_SEL # selector 15:0 566 .byte 0 # 0 for interrupt gate 567 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 568 .word 0 # offset 31:16 569 570 # soft breakpoint (INT 3) 571 .equ BREAKPOINT_SEL, .-IDT_BASE 572 .word 0 # offset 15:0 573 .word SYS_CODE_SEL # selector 15:0 574 .byte 0 # 0 for interrupt gate 575 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 576 .word 0 # offset 31:16 577 578 # overflow (INT 4) 579 .equ OVERFLOW_SEL, .-IDT_BASE 580 .word 0 # offset 15:0 581 .word SYS_CODE_SEL # selector 15:0 582 .byte 0 # 0 for interrupt gate 583 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 584 .word 0 # offset 31:16 585 586 # bounds check (INT 5) 587 .equ BOUNDS_CHECK_SEL, .-IDT_BASE 588 .word 0 # offset 15:0 589 .word SYS_CODE_SEL # selector 15:0 590 .byte 0 # 0 for interrupt gate 591 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 592 .word 0 # offset 31:16 593 594 # invalid opcode (INT 6) 595 .equ INVALID_OPCODE_SEL, .-IDT_BASE 596 .word 0 # offset 15:0 597 .word SYS_CODE_SEL # selector 15:0 598 .byte 0 # 0 for interrupt gate 599 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 600 .word 0 # offset 31:16 601 602 # device not available (INT 7) 603 .equ DEV_NOT_AVAIL_SEL, .-IDT_BASE 604 .word 0 # offset 15:0 605 .word SYS_CODE_SEL # selector 15:0 606 .byte 0 # 0 for interrupt gate 607 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 608 .word 0 # offset 31:16 609 610 # double fault (INT 8) 611 .equ DOUBLE_FAULT_SEL, .-IDT_BASE 612 .word 0 # offset 15:0 613 .word SYS_CODE_SEL # selector 15:0 614 .byte 0 # 0 for interrupt gate 615 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 616 .word 0 # offset 31:16 617 618 # Coprocessor segment overrun - reserved (INT 9) 619 .equ RSVD_INTR_SEL1, .-IDT_BASE 620 .word 0 # offset 15:0 621 .word SYS_CODE_SEL # selector 15:0 622 .byte 0 # 0 for interrupt gate 623 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 624 .word 0 # offset 31:16 625 626 # invalid TSS (INT 0ah) 627 .equ INVALID_TSS_SEL, .-IDT_BASE 628 .word 0 # offset 15:0 629 .word SYS_CODE_SEL # selector 15:0 630 .byte 0 # 0 for interrupt gate 631 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 632 .word 0 # offset 31:16 633 634 # segment not present (INT 0bh) 635 .equ SEG_NOT_PRESENT_SEL, .-IDT_BASE 636 .word 0 # offset 15:0 637 .word SYS_CODE_SEL # selector 15:0 638 .byte 0 # 0 for interrupt gate 639 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 640 .word 0 # offset 31:16 641 642 # stack fault (INT 0ch) 643 .equ STACK_FAULT_SEL, .-IDT_BASE 644 .word 0 # offset 15:0 645 .word SYS_CODE_SEL # selector 15:0 646 .byte 0 # 0 for interrupt gate 647 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 648 .word 0 # offset 31:16 649 650 # general protection (INT 0dh) 651 .equ GP_FAULT_SEL, .-IDT_BASE 652 .word 0 # offset 15:0 653 .word SYS_CODE_SEL # selector 15:0 654 .byte 0 # 0 for interrupt gate 655 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 656 .word 0 # offset 31:16 657 658 # page fault (INT 0eh) 659 .equ PAGE_FAULT_SEL, .-IDT_BASE 660 .word 0 # offset 15:0 661 .word SYS_CODE_SEL # selector 15:0 662 .byte 0 # 0 for interrupt gate 663 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 664 .word 0 # offset 31:16 665 666 # Intel reserved - do not use (INT 0fh) 667 .equ RSVD_INTR_SEL2, .-IDT_BASE 668 .word 0 # offset 15:0 669 .word SYS_CODE_SEL # selector 15:0 670 .byte 0 # 0 for interrupt gate 671 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 672 .word 0 # offset 31:16 673 674 # floating point error (INT 10h) 675 .equ FLT_POINT_ERR_SEL, .-IDT_BASE 676 .word 0 # offset 15:0 677 .word SYS_CODE_SEL # selector 15:0 678 .byte 0 # 0 for interrupt gate 679 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 680 .word 0 # offset 31:16 681 682 # alignment check (INT 11h) 683 .equ ALIGNMENT_CHECK_SEL, .-IDT_BASE 684 .word 0 # offset 15:0 685 .word SYS_CODE_SEL # selector 15:0 686 .byte 0 # 0 for interrupt gate 687 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 688 .word 0 # offset 31:16 689 690 # machine check (INT 12h) 691 .equ MACHINE_CHECK_SEL, .-IDT_BASE 692 .word 0 # offset 15:0 693 .word SYS_CODE_SEL # selector 15:0 694 .byte 0 # 0 for interrupt gate 695 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 696 .word 0 # offset 31:16 697 698 # SIMD floating-point exception (INT 13h) 699 .equ SIMD_EXCEPTION_SEL, .-IDT_BASE 700 .word 0 # offset 15:0 701 .word SYS_CODE_SEL # selector 15:0 702 .byte 0 # 0 for interrupt gate 703 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 704 .word 0 # offset 31:16 705 706 # 85 unspecified descriptors, First 12 of them are reserved, the rest are avail 707 .fill 85 * 8, 1, 0 708 709 # IRQ 0 (System timer) - (INT 68h) 710 .equ IRQ0_SEL, .-IDT_BASE 711 .word 0 # offset 15:0 712 .word SYS_CODE_SEL # selector 15:0 713 .byte 0 # 0 for interrupt gate 714 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 715 .word 0 # offset 31:16 716 717 # IRQ 1 (8042 Keyboard controller) - (INT 69h) 718 .equ IRQ1_SEL, .-IDT_BASE 719 .word 0 # offset 15:0 720 .word SYS_CODE_SEL # selector 15:0 721 .byte 0 # 0 for interrupt gate 722 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 723 .word 0 # offset 31:16 724 725 # Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah) 726 .equ IRQ2_SEL, .-IDT_BASE 727 .word 0 # offset 15:0 728 .word SYS_CODE_SEL # selector 15:0 729 .byte 0 # 0 for interrupt gate 730 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 731 .word 0 # offset 31:16 732 733 # IRQ 3 (COM 2) - (INT 6bh) 734 .equ IRQ3_SEL, .-IDT_BASE 735 .word 0 # offset 15:0 736 .word SYS_CODE_SEL # selector 15:0 737 .byte 0 # 0 for interrupt gate 738 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 739 .word 0 # offset 31:16 740 741 # IRQ 4 (COM 1) - (INT 6ch) 742 .equ IRQ4_SEL, .-IDT_BASE 743 .word 0 # offset 15:0 744 .word SYS_CODE_SEL # selector 15:0 745 .byte 0 # 0 for interrupt gate 746 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 747 .word 0 # offset 31:16 748 749 # IRQ 5 (LPT 2) - (INT 6dh) 750 .equ IRQ5_SEL, .-IDT_BASE 751 .word 0 # offset 15:0 752 .word SYS_CODE_SEL # selector 15:0 753 .byte 0 # 0 for interrupt gate 754 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 755 .word 0 # offset 31:16 756 757 # IRQ 6 (Floppy controller) - (INT 6eh) 758 .equ IRQ6_SEL, .-IDT_BASE 759 .word 0 # offset 15:0 760 .word SYS_CODE_SEL # selector 15:0 761 .byte 0 # 0 for interrupt gate 762 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 763 .word 0 # offset 31:16 764 765 # IRQ 7 (LPT 1) - (INT 6fh) 766 .equ IRQ7_SEL, .-IDT_BASE 767 .word 0 # offset 15:0 768 .word SYS_CODE_SEL # selector 15:0 769 .byte 0 # 0 for interrupt gate 770 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 771 .word 0 # offset 31:16 772 773 # IRQ 8 (RTC Alarm) - (INT 70h) 774 .equ IRQ8_SEL, .-IDT_BASE 775 .word 0 # offset 15:0 776 .word SYS_CODE_SEL # selector 15:0 777 .byte 0 # 0 for interrupt gate 778 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 779 .word 0 # offset 31:16 780 781 # IRQ 9 - (INT 71h) 782 .equ IRQ9_SEL, .-IDT_BASE 783 .word 0 # offset 15:0 784 .word SYS_CODE_SEL # selector 15:0 785 .byte 0 # 0 for interrupt gate 786 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 787 .word 0 # offset 31:16 788 789 # IRQ 10 - (INT 72h) 790 .equ IRQ10_SEL, .-IDT_BASE 791 .word 0 # offset 15:0 792 .word SYS_CODE_SEL # selector 15:0 793 .byte 0 # 0 for interrupt gate 794 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 795 .word 0 # offset 31:16 796 797 # IRQ 11 - (INT 73h) 798 .equ IRQ11_SEL, .-IDT_BASE 799 .word 0 # offset 15:0 800 .word SYS_CODE_SEL # selector 15:0 801 .byte 0 # 0 for interrupt gate 802 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 803 .word 0 # offset 31:16 804 805 # IRQ 12 (PS/2 mouse) - (INT 74h) 806 .equ IRQ12_SEL, .-IDT_BASE 807 .word 0 # offset 15:0 808 .word SYS_CODE_SEL # selector 15:0 809 .byte 0 # 0 for interrupt gate 810 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 811 .word 0 # offset 31:16 812 813 # IRQ 13 (Floating point error) - (INT 75h) 814 .equ IRQ13_SEL, .-IDT_BASE 815 .word 0 # offset 15:0 816 .word SYS_CODE_SEL # selector 15:0 817 .byte 0 # 0 for interrupt gate 818 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 819 .word 0 # offset 31:16 820 821 # IRQ 14 (Secondary IDE) - (INT 76h) 822 .equ IRQ14_SEL, .-IDT_BASE 823 .word 0 # offset 15:0 824 .word SYS_CODE_SEL # selector 15:0 825 .byte 0 # 0 for interrupt gate 826 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 827 .word 0 # offset 31:16 828 829 # IRQ 15 (Primary IDE) - (INT 77h) 830 .equ IRQ15_SEL, .-IDT_BASE 831 .word 0 # offset 15:0 832 .word SYS_CODE_SEL # selector 15:0 833 .byte 0 # 0 for interrupt gate 834 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present 835 .word 0 # offset 31:16 836 837 IDT_END: 838 839 .p2align 1 840 841 MemoryMapSize: .long 0 842 MemoryMap: .long 0,0,0,0,0,0,0,0 843 .long 0,0,0,0,0,0,0,0 844 .long 0,0,0,0,0,0,0,0 845 .long 0,0,0,0,0,0,0,0 846 .long 0,0,0,0,0,0,0,0 847 .long 0,0,0,0,0,0,0,0 848 .long 0,0,0,0,0,0,0,0 849 .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 0,0,0,0,0,0,0,0 872 873 .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 874 .long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 875 876 .org 0x0fe0 877 MyStack: 878 # below is the pieces of the IVT that is used to redirect INT 68h - 6fh 879 # back to INT 08h - 0fh when in real mode... It is 'org'ed to a 880 # known low address (20f00) so it can be set up by PlMapIrqToVect in 881 # 8259.c 882 883 int $8 884 iret 885 886 int $9 887 iret 888 889 int $10 890 iret 891 892 int $11 893 iret 894 895 int $12 896 iret 897 898 int $13 899 iret 900 901 int $14 902 iret 903 904 int $15 905 iret 906 907 908 .org 0x0ffe 909 BlockSignature: 910 .word 0xaa55 911
