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#* start64.asm 13#* 14#* Abstract: 15#* 16#------------------------------------------------------------------------------ 17 18 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 34Ia32Jump: 35 jmp BootSectorEntryPoint # JMP inst - 3 bytes 36 nop 37 38OemId: .ascii "INTEL " # OemId - 8 bytes 39 40SectorSize: .word 0 # Sector Size - 16 bits 41SectorsPerCluster: .byte 0 # Sector Per Cluster - 8 bits 42ReservedSectors: .word 0 # Reserved Sectors - 16 bits 43NoFats: .byte 0 # Number of FATs - 8 bits 44RootEntries: .word 0 # Root Entries - 16 bits 45Sectors: .word 0 # Number of Sectors - 16 bits 46Media: .byte 0 # Media - 8 bits - ignored 47SectorsPerFat: .word 0 # Sectors Per FAT - 16 bits 48SectorsPerTrack: .word 0 # Sectors Per Track - 16 bits - ignored 49Heads: .word 0 # Heads - 16 bits - ignored 50HiddenSectors: .long 0 # Hidden Sectors - 32 bits - ignored 51LargeSectors: .long 0 # Large Sectors - 32 bits 52PhysicalDrive: .byte 0 # PhysicalDriveNumber - 8 bits - ignored 53CurrentHead: .byte 0 # Current Head - 8 bits 54Signature: .byte 0 # Signature - 8 bits - ignored 55VolId: .ascii " " # Volume Serial Number- 4 bytes 56FatLabel: .ascii " " # Label - 11 bytes 57SystemId: .ascii "FAT12 " # SystemId - 8 bytes 58 59BootSectorEntryPoint: 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 78NoVarStore: 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 84CheckVarStoreSize: 85 movw %dx,%di 86 cmpl $0x4000, %ds:2(%di) 87 movb $2,%al 88 jne NoVarStore 89 90LoadVarStore: 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 100SaveVolumeId: 101 popw %es 102 movw VolId(%bp), %ax 103 movw %ax, %es:(0) 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 118CheckEm64T: 119 movl $0x80000001,%eax 120# cpuid 121 .word 0xA20F 122 btl $29,%edx 123 jc CheckEm64TPass 124 pushw %cs 125 popw %ds 126 leaw Em64String,%si 127 movw $18,%cx 128 jmp PrintStringAndHalt 129CheckEm64TPass: 130JumpFarInstruction: 131 .byte 0xea 132JumpOffset: 133 .word 0x200 134JumpSegment: 135 .word 0x2000 136 137 138 139# **************************************************************************** 140# ReadFile 141# 142# Arguments: 143# CX = Start Cluster of File 144# ES:DI = Buffer to store file content read from disk 145# 146# Return: 147# (ES << 4 + DI) = end of file content Buffer 148# 149# **************************************************************************** 150ReadFile: 151# si = NumberOfClusters 152# cx = ClusterNumber 153# dx = CachedFatSectorNumber 154# ds:0000 = CacheFatSectorBuffer 155# es:di = Buffer to load file 156# bx = NextClusterNumber 157 pusha 158 movw $1,%si # NumberOfClusters = 1 159 pushw %cx # Push Start Cluster onto stack 160 movw $0xfff,%dx # CachedFatSectorNumber = 0xfff 161FatChainLoop: 162 movw %cx,%ax # ax = ClusterNumber 163 andw $0xff8,%ax # ax = ax & 0xff8 164 cmpw $0xff8,%ax # See if this is the last cluster 165 je FoundLastCluster # Jump if last cluster found 166 movw %cx,%ax # ax = ClusterNumber 167 shlw %ax # ax = ClusterNumber * 2 168 addw %cx,%ax # ax = ClusterNumber * 2 + ClusterNumber = ClusterNumber * 3 169 shrw %ax # FatOffset = ClusterNumber*3 / 2 170 pushw %si # Save si 171 movw %ax,%si # si = FatOffset 172 shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT 173 addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET) 174 andw $BLOCK_MASK, %si # si = FatOffset & BLOCK_MASK 175 cmpw %dx,%ax # Compare FatSectorNumber to CachedFatSectorNumber 176 je SkipFatRead 177 movw $2,%bx 178 pushw %es 179 pushw %ds 180 popw %es 181 call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI 182 popw %es 183 movw %ax,%dx # CachedFatSectorNumber = FatSectorNumber 184SkipFatRead: 185 movw (%si), %bx # bx = NextClusterNumber 186 movw %cx,%ax # ax = ClusterNumber 187 andw $1,%ax # See if this is an odd cluster number 188 je EvenFatEntry 189 shrw $4,%bx # NextClusterNumber = NextClusterNumber >> 4 190EvenFatEntry: 191 andw $0xfff,%bx # Strip upper 4 bits of NextClusterNumber 192 popw %si # Restore si 193 decw %bx # bx = NextClusterNumber - 1 194 cmpw %cx,%bx # See if (NextClusterNumber-1)==ClusterNumber 195 jne ReadClusters 196 incw %bx # bx = NextClusterNumber 197 incw %si # NumberOfClusters++ 198 movw %bx,%cx # ClusterNumber = NextClusterNumber 199 jmp FatChainLoop 200ReadClusters: 201 incw %bx 202 popw %ax # ax = StartCluster 203 pushw %bx # StartCluster = NextClusterNumber 204 movw %bx,%cx # ClusterNumber = NextClusterNumber 205 subw $2,%ax # ax = StartCluster - 2 206 xorb %bh,%bh 207 movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster 208 mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster 209 addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster 210 pushw %ax # save start sector 211 movw %si,%ax # ax = NumberOfClusters 212 mulw %bx # ax = NumberOfClusters * SectorsPerCluster 213 movw %ax,%bx # bx = Number of Sectors 214 popw %ax # ax = Start Sector 215 call ReadBlocks 216 movw $1,%si # NumberOfClusters = 1 217 jmp FatChainLoop 218FoundLastCluster: 219 popw %cx 220 popa 221 ret 222 223 224# **************************************************************************** 225# ReadBlocks - Reads a set of blocks from a block device 226# 227# AX = Start LBA 228# BX = Number of Blocks to Read 229# ES:DI = Buffer to store sectors read from disk 230# **************************************************************************** 231 232# cx = Blocks 233# bx = NumberOfBlocks 234# si = StartLBA 235 236ReadBlocks: 237 pusha 238 addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA 239 addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA 240 movl %eax,%esi # esi = Start LBA 241 movw %bx,%cx # cx = Number of blocks to read 242ReadCylinderLoop: 243 movw $0x7bfc,%bp # bp = 0x7bfc 244 movl %esi,%eax # eax = Start LBA 245 xorl %edx,%edx # edx = 0 246 movzwl (%bp), %ebx # bx = MaxSector 247 divl %ebx # ax = StartLBA / MaxSector 248 incw %dx # dx = (StartLBA % MaxSector) + 1 249 250 movw (%bp), %bx # bx = MaxSector 251 subw %dx,%bx # bx = MaxSector - Sector 252 incw %bx # bx = MaxSector - Sector + 1 253 cmpw %bx,%cx # Compare (Blocks) to (MaxSector - Sector + 1) 254 jg LimitTransfer 255 movw %cx,%bx # bx = Blocks 256LimitTransfer: 257 pushw %ax # save ax 258 movw %es,%ax # ax = es 259 shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system 260 andw $0x7f,%ax # ax = Number of blocks into current seg 261 addw %bx,%ax # ax = End Block number of transfer 262 cmpw $0x80,%ax # See if it crosses a 64K boundry 263 jle NotCrossing64KBoundry # Branch if not crossing 64K boundry 264 subw $0x80,%ax # ax = Number of blocks past 64K boundry 265 subw %ax,%bx # Decrease transfer size by block overage 266NotCrossing64KBoundry: 267 popw %ax # restore ax 268 269 pushw %cx 270 movb %dl,%cl # cl = (StartLBA % MaxSector) + 1 = Sector 271 xorw %dx,%dx # dx = 0 272 divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder 273 # dx = ax % (MaxHead + 1) = Head 274 275 pushw %bx # Save number of blocks to transfer 276 movb %dl,%dh # dh = Head 277 movw $0x7c00,%bp # bp = 0x7c00 278 movb PhysicalDrive(%bp), %dl # dl = Drive Number 279 movb %al,%ch # ch = Cylinder 280 movb %bl,%al # al = Blocks 281 movb $2,%ah # ah = Function 2 282 movw %di,%bx # es:bx = Buffer address 283 int $0x13 284 jc DiskError 285 popw %bx 286 popw %cx 287 movzwl %bx,%ebx 288 addl %ebx,%esi # StartLBA = StartLBA + NumberOfBlocks 289 subw %bx,%cx # Blocks = Blocks - NumberOfBlocks 290 movw %es,%ax 291 shlw $(BLOCK_SHIFT-4), %bx 292 addw %bx,%ax 293 movw %ax,%es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE 294 cmpw $0,%cx 295 jne ReadCylinderLoop 296 popa 297 ret 298 299DiskError: 300 pushw %cs 301 popw %ds 302 leaw ErrorString,%si 303 movw $7,%cx 304 jmp PrintStringAndHalt 305 306PrintStringAndHalt: 307 movw $0xb800,%ax 308 movw %ax,%es 309 movw $160,%di 310 rep 311 movsw 312Halt: 313 jmp Halt 314 315ErrorString: 316 .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!',0x0c 317 318 .org 0x01fa 319LBAOffsetForBootSector: 320 .long 0x0 321 322 .org 0x01fe 323 .word 0xaa55 324 325#****************************************************************************** 326#****************************************************************************** 327#****************************************************************************** 328 329.equ DELAY_PORT, 0x0ed # Port to use for 1uS delay 330.equ KBD_CONTROL_PORT, 0x060 # 8042 control port 331.equ KBD_STATUS_PORT, 0x064 # 8042 status port 332.equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port 333.equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20 334 335 .org 0x200 336 jmp start 337Em64String: 338.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 339 340start: 341 movw %cs,%ax 342 movw %ax,%ds 343 movw %ax,%es 344 movw %ax,%ss 345 movw $MyStack, %sp 346 347# mov ax,0b800h 348# mov es,ax 349# mov byte ptr es:[160],'a' 350# mov ax,cs 351# mov es,ax 352 353 movl $0,%ebx 354 leal MemoryMap, %edi 355MemMapLoop: 356 movl $0xe820,%eax 357 movl $20,%ecx 358 movl $0x534d4150, %edx # SMAP 359 int $0x15 360 jc MemMapDone 361 addl $20,%edi 362 cmpl $0,%ebx 363 je MemMapDone 364 jmp MemMapLoop 365MemMapDone: 366 leal MemoryMap, %eax 367 subl %eax,%edi # Get the address of the memory map 368 movl %edi, MemoryMapSize # Save the size of the memory map 369 370 xorl %ebx,%ebx 371 movw %cs,%bx # BX=segment 372 shll $4,%ebx # BX="linear" address of segment base 373 leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt 374 movl %eax, (gdtr + 2) # Put address of gdt into the gdtr 375 leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt 376 movl %eax, (idtr + 2) # Put address of idt into the idtr 377 leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map 378 379# mov ax,0b800h 380# mov es,ax 381# mov byte ptr es:[162],'b' 382# mov ax,cs 383# mov es,ax 384 385# 386# Enable A20 Gate 387# 388 389 movw $0x2401,%ax # Enable A20 Gate 390 int $0x15 391 jnc A20GateEnabled # Jump if it suceeded 392 393# 394# If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually. 395# 396 397 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 398 jnz Timeout8042 # Jump if the 8042 timed out 399 outw %ax, $DELAY_PORT # Delay 1 uS 400 movb $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port 401 outb %al, $KBD_STATUS_PORT # Send command to the 8042 402 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 403 jnz Timeout8042 # Jump if the 8042 timed out 404 movb $ENABLE_A20_CMD, %al # gate address bit 20 on 405 outb %al, $KBD_CONTROL_PORT # Send command to thre 8042 406 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller 407 movw $25,%cx # Delay 25 uS for the command to complete on the 8042 408Delay25uS: 409 outw %ax, $DELAY_PORT # Delay 1 uS 410 loop Delay25uS 411Timeout8042: 412 413 414A20GateEnabled: 415 416# 417# DISABLE INTERRUPTS - Entering Protected Mode 418# 419 420 cli 421 422# mov ax,0b800h 423# mov es,ax 424# mov byte ptr es:[164],'c' 425# mov ax,cs 426# mov es,ax 427 428 leal OffsetIn32BitProtectedMode, %eax 429 addl $0x20000+0x6,%eax 430 movl %eax, OffsetIn32BitProtectedMode 431 432 leal OffsetInLongMode, %eax 433 addl $0x20000+0x6,%eax 434 movl %eax, OffsetInLongMode 435 436 # 437 # load GDT 438 # 439 .byte 0x66 440 lgdt gdtr 441 442 # 443 # Enable Protect Mode (set CR0.PE=1) 444 # 445 movl %cr0, %eax # Read CR0. 446 orl $0x1,%eax # Set PE=1 447 movl %eax, %cr0 # Write CR0. 448 .byte 0x66 449 .byte 0xea # jmp far 16:32 450OffsetIn32BitProtectedMode: 451 .long 0x0000000 # offset $+8 (In32BitProtectedMode) 452 .word 0x10 # selector (flat CS) 453In32BitProtectedMode: 454 455# 456# Entering Long Mode 457# 458 .byte 0x66 459 movw $8,%ax 460 movw %ax,%ds 461 movw %ax,%es 462 movw %ax,%ss 463 464 # 465 # Enable the 64-bit page-translation-table entries by 466 # setting CR4.PAE=1 (this is _required_ before activating 467 # long mode). Paging is not enabled until after long mode 468 # is enabled. 469 # 470 .byte 0xf 471 .byte 0x20 472 .byte 0xe0 473# mov eax, cr4 474 btsl $5,%eax 475 .byte 0xf 476 .byte 0x22 477 .byte 0xe0 478# mov cr4, eax 479 480 # 481 # This is the Trapolean Page Tables that are guarenteed 482 # under 4GB. 483 # 484 # Address Map: 485 # 10000 ~ 12000 - efildr (loaded) 486 # 20000 ~ 21000 - start64.com 487 # 21000 ~ 22000 - efi64.com 488 # 22000 ~ 90000 - efildr 489 # 90000 ~ 96000 - 4G pagetable (will be reload later) 490 # 491 .byte 0xb8 492 .long 0x90000 493# mov eax, 90000h 494 movl %eax, %cr3 495 496 # 497 # Enable long mode (set EFER.LME=1). 498 # 499 .byte 0xb9 500 .long 0xc0000080 501# mov ecx, 0c0000080h ; EFER MSR number. 502 .byte 0xf 503 .byte 0x32 504# rdmsr ; Read EFER. 505 .byte 0xf 506 .byte 0xba 507 .byte 0xe8 508 .byte 0x8 509# bts eax, 8 ; Set LME=1. 510 .byte 0xf 511 .byte 0x30 512# wrmsr ; Write EFER. 513 514 # 515 # Enable paging to activate long mode (set CR0.PG=1) 516 # 517 movl %cr0, %eax # Read CR0. 518 .byte 0xf 519 .byte 0xba 520 .byte 0xe8 521 .byte 0x1f 522# bts eax, 31 ; Set PG=1. 523 movl %eax, %cr0 # Write CR0. 524 jmp GoToLongMode 525GoToLongMode: 526 527 .byte 0x67 528 .byte 0xea # Far Jump $+9:Selector to reload CS 529OffsetInLongMode: 530 .long 00000000 # $+9 Offset is ensuing instruction boundary 531 .word 0x38 # Selector is our code selector, 38h 532 533InLongMode: 534 .byte 0x66 535 movw $0x30,%ax 536 movw %ax,%ds 537 538 .byte 0x66 539 movw $0x18,%ax 540 movw %ax,%es 541 movw %ax,%ss 542 movw %ax,%ds 543 544 .byte 0xbd 545 .long 0x400000 546# mov ebp,000400000h ; Destination of EFILDR32 547 .byte 0xbb 548 .long 0x70000 549# mov ebx,000070000h ; Length of copy 550 551 # 552 # load idt later 553 # 554 .byte 0x48 555 .byte 0x33 556 .byte 0xc0 557# xor rax, rax 558 .byte 0x66 559 movw $idtr, %ax 560 .byte 0x48 561 .byte 0x5 562 .long 0x20000 563# add rax, 20000h 564 565 .byte 0xf 566 .byte 0x1 567 .byte 0x18 568# lidt fword ptr [rax] 569 570 .byte 0x48 571 .byte 0xc7 572 .byte 0xc0 573 .long 0x21000 574# mov rax, 21000h 575 .byte 0x50 576# push rax 577 578# ret 579 .byte 0xc3 580 581Empty8042InputBuffer: 582 movw $0,%cx 583Empty8042Loop: 584 outw %ax, $DELAY_PORT # Delay 1us 585 inb $KBD_STATUS_PORT, %al # Read the 8042 Status Port 586 andb $0x2,%al # Check the Input Buffer Full Flag 587 loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS 588 ret 589 590############################################################################## 591# data 592############################################################################## 593 594 .p2align 1 595 596 gdtr: .long GDT_END - GDT_BASE - 1 # GDT limit 597 .long 0 # (GDT base gets set above) 598############################################################################## 599# global descriptor table (GDT) 600############################################################################## 601 602 .p2align 1 603 604GDT_BASE: 605# null descriptor 606.equ NULL_SEL, .-GDT_BASE # Selector [0x0] 607 .word 0 # limit 15:0 608 .word 0 # base 15:0 609 .byte 0 # base 23:16 610 .byte 0 # type 611 .byte 0 # limit 19:16, flags 612 .byte 0 # base 31:24 613 614# linear data segment descriptor 615.equ LINEAR_SEL, .-GDT_BASE # Selector [0x8] 616 .word 0xFFFF # limit 0xFFFFF 617 .word 0 # base 0 618 .byte 0 619 .byte 0x92 # present, ring 0, data, expand-up, writable 620 .byte 0xCF # page-granular, 32-bit 621 .byte 0 622 623# linear code segment descriptor 624.equ LINEAR_CODE_SEL, .-GDT_BASE # Selector [0x10] 625 .word 0xFFFF # limit 0xFFFFF 626 .word 0 # base 0 627 .byte 0 628 .byte 0x9A # present, ring 0, data, expand-up, writable 629 .byte 0xCF # page-granular, 32-bit 630 .byte 0 631 632# system data segment descriptor 633.equ SYS_DATA_SEL, .-GDT_BASE # Selector [0x18] 634 .word 0xFFFF # limit 0xFFFFF 635 .word 0 # base 0 636 .byte 0 637 .byte 0x92 # present, ring 0, data, expand-up, writable 638 .byte 0xCF # page-granular, 32-bit 639 .byte 0 640 641# system code segment descriptor 642.equ SYS_CODE_SEL, .-GDT_BASE # Selector [0x20] 643 .word 0xFFFF # limit 0xFFFFF 644 .word 0 # base 0 645 .byte 0 646 .byte 0x9A # present, ring 0, data, expand-up, writable 647 .byte 0xCF # page-granular, 32-bit 648 .byte 0 649 650# spare segment descriptor 651.equ SPARE3_SEL, .-GDT_BASE # Selector [0x28] 652 .word 0 # limit 0xFFFFF 653 .word 0 # base 0 654 .byte 0 655 .byte 0 # present, ring 0, data, expand-up, writable 656 .byte 0 # page-granular, 32-bit 657 .byte 0 658 659# 660# system data segment descriptor 661# 662.equ SYS_DATA64_SEL, .-GDT_BASE # Selector [0x30] 663 .word 0xFFFF # limit 0xFFFFF 664 .word 0 # base 0 665 .byte 0 666 .byte 0x92 # P | DPL [1..2] | 1 | 1 | C | R | A 667 .byte 0xCF # G | D | L | AVL | Segment [19..16] 668 .byte 0 669 670# 671# system code segment descriptor 672# 673.equ SYS_CODE64_SEL, .-GDT_BASE # Selector [0x38] 674 .word 0xFFFF # limit 0xFFFFF 675 .word 0 # base 0 676 .byte 0 677 .byte 0x9A # P | DPL [1..2] | 1 | 1 | C | R | A 678 .byte 0xAF # G | D | L | AVL | Segment [19..16] 679 .byte 0 680 681# spare segment descriptor 682.equ SPARE4_SEL, .-GDT_BASE # Selector [0x40] 683 .word 0 # limit 0xFFFFF 684 .word 0 # base 0 685 .byte 0 686 .byte 0 # present, ring 0, data, expand-up, writable 687 .byte 0 # page-granular, 32-bit 688 .byte 0 689 690GDT_END: 691 692 .p2align 1 693 694 695 696idtr: .long IDT_END - IDT_BASE - 1 # IDT limit 697 .quad 0 # (IDT base gets set above) 698 699############################################################################## 700# interrupt descriptor table (IDT) 701# 702# Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ 703# mappings. This implementation only uses the system timer and all other 704# IRQs will remain masked. The descriptors for vectors 33+ are provided 705# for convenience. 706############################################################################## 707 708#idt_tag db "IDT",0 709 .p2align 1 710 711 712IDT_BASE: 713# divide by zero (INT 0) 714.equ DIV_ZERO_SEL, .-IDT_BASE 715 .word 0 # offset 15:0 716 .long SYS_CODE64_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 .long 0 # offset 63:32 721 .long 0 # 0 for reserved 722 723# debug exception (INT 1) 724.equ DEBUG_EXCEPT_SEL, .-IDT_BASE 725 .word 0 # offset 15:0 726 .long SYS_CODE64_SEL # selector 15:0 727 .byte 0 # 0 for interrupt gate 728 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 729 .word 0 # offset 31:16 730 .long 0 # offset 63:32 731 .long 0 # 0 for reserved 732 733# NMI (INT 2) 734.equ NMI_SEL, .-IDT_BASE 735 .word 0 # offset 15:0 736 .long SYS_CODE64_SEL # selector 15:0 737 .byte 0 # 0 for interrupt gate 738 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 739 .word 0 # offset 31:16 740 .long 0 # offset 63:32 741 .long 0 # 0 for reserved 742 743# soft breakpoint (INT 3) 744.equ BREAKPOINT_SEL, .-IDT_BASE 745 .word 0 # offset 15:0 746 .long SYS_CODE64_SEL # selector 15:0 747 .byte 0 # 0 for interrupt gate 748 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 749 .word 0 # offset 31:16 750 .long 0 # offset 63:32 751 .long 0 # 0 for reserved 752 753# overflow (INT 4) 754.equ OVERFLOW_SEL, .-IDT_BASE 755 .word 0 # offset 15:0 756 .long SYS_CODE64_SEL # selector 15:0 757 .byte 0 # 0 for interrupt gate 758 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 759 .word 0 # offset 31:16 760 .long 0 # offset 63:32 761 .long 0 # 0 for reserved 762 763# bounds check (INT 5) 764.equ BOUNDS_CHECK_SEL, .-IDT_BASE 765 .word 0 # offset 15:0 766 .long SYS_CODE64_SEL # selector 15:0 767 .byte 0 # 0 for interrupt gate 768 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 769 .word 0 # offset 31:16 770 .long 0 # offset 63:32 771 .long 0 # 0 for reserved 772 773# invalid opcode (INT 6) 774.equ INVALID_OPCODE_SEL, .-IDT_BASE 775 .word 0 # offset 15:0 776 .long SYS_CODE64_SEL # selector 15:0 777 .byte 0 # 0 for interrupt gate 778 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 779 .word 0 # offset 31:16 780 .long 0 # offset 63:32 781 .long 0 # 0 for reserved 782 783# device not available (INT 7) 784.equ DEV_NOT_AVAIL_SEL, .-IDT_BASE 785 .word 0 # offset 15:0 786 .long SYS_CODE64_SEL # selector 15:0 787 .byte 0 # 0 for interrupt gate 788 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 789 .word 0 # offset 31:16 790 .long 0 # offset 63:32 791 .long 0 # 0 for reserved 792 793# double fault (INT 8) 794.equ DOUBLE_FAULT_SEL, .-IDT_BASE 795 .word 0 # offset 15:0 796 .long SYS_CODE64_SEL # selector 15:0 797 .byte 0 # 0 for interrupt gate 798 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 799 .word 0 # offset 31:16 800 .long 0 # offset 63:32 801 .long 0 # 0 for reserved 802 803# Coprocessor segment overrun - reserved (INT 9) 804.equ RSVD_INTR_SEL1, .-IDT_BASE 805 .word 0 # offset 15:0 806 .long SYS_CODE64_SEL # selector 15:0 807 .byte 0 # 0 for interrupt gate 808 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 809 .word 0 # offset 31:16 810 .long 0 # offset 63:32 811 .long 0 # 0 for reserved 812 813# invalid TSS (INT 0ah) 814.equ INVALID_TSS_SEL, .-IDT_BASE 815 .word 0 # offset 15:0 816 .long SYS_CODE64_SEL # selector 15:0 817 .byte 0 # 0 for interrupt gate 818 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 819 .word 0 # offset 31:16 820 .long 0 # offset 63:32 821 .long 0 # 0 for reserved 822 823# segment not present (INT 0bh) 824.equ SEG_NOT_PRESENT_SEL, .-IDT_BASE 825 .word 0 # offset 15:0 826 .long SYS_CODE64_SEL # selector 15:0 827 .byte 0 # 0 for interrupt gate 828 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 829 .word 0 # offset 31:16 830 .long 0 # offset 63:32 831 .long 0 # 0 for reserved 832 833# stack fault (INT 0ch) 834.equ STACK_FAULT_SEL, .-IDT_BASE 835 .word 0 # offset 15:0 836 .long SYS_CODE64_SEL # selector 15:0 837 .byte 0 # 0 for interrupt gate 838 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 839 .word 0 # offset 31:16 840 .long 0 # offset 63:32 841 .long 0 # 0 for reserved 842 843# general protection (INT 0dh) 844.equ GP_FAULT_SEL, .-IDT_BASE 845 .word 0 # offset 15:0 846 .long SYS_CODE64_SEL # selector 15:0 847 .byte 0 # 0 for interrupt gate 848 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 849 .word 0 # offset 31:16 850 .long 0 # offset 63:32 851 .long 0 # 0 for reserved 852 853# page fault (INT 0eh) 854.equ PAGE_FAULT_SEL, .-IDT_BASE 855 .word 0 # offset 15:0 856 .long SYS_CODE64_SEL # selector 15:0 857 .byte 0 # 0 for interrupt gate 858 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 859 .word 0 # offset 31:16 860 .long 0 # offset 63:32 861 .long 0 # 0 for reserved 862 863# Intel reserved - do not use (INT 0fh) 864.equ RSVD_INTR_SEL2, .-IDT_BASE 865 .word 0 # offset 15:0 866 .long SYS_CODE64_SEL # selector 15:0 867 .byte 0 # 0 for interrupt gate 868 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 869 .word 0 # offset 31:16 870 .long 0 # offset 63:32 871 .long 0 # 0 for reserved 872 873# floating point error (INT 10h) 874.equ FLT_POINT_ERR_SEL, .-IDT_BASE 875 .word 0 # offset 15:0 876 .long SYS_CODE64_SEL # selector 15:0 877 .byte 0 # 0 for interrupt gate 878 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 879 .word 0 # offset 31:16 880 .long 0 # offset 63:32 881 .long 0 # 0 for reserved 882 883# alignment check (INT 11h) 884.equ ALIGNMENT_CHECK_SEL, .-IDT_BASE 885 .word 0 # offset 15:0 886 .long SYS_CODE64_SEL # selector 15:0 887 .byte 0 # 0 for interrupt gate 888 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 889 .word 0 # offset 31:16 890 .long 0 # offset 63:32 891 .long 0 # 0 for reserved 892 893# machine check (INT 12h) 894.equ MACHINE_CHECK_SEL, .-IDT_BASE 895 .word 0 # offset 15:0 896 .long SYS_CODE64_SEL # selector 15:0 897 .byte 0 # 0 for interrupt gate 898 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 899 .word 0 # offset 31:16 900 .long 0 # offset 63:32 901 .long 0 # 0 for reserved 902 903# SIMD floating-point exception (INT 13h) 904.equ SIMD_EXCEPTION_SEL, .-IDT_BASE 905 .word 0 # offset 15:0 906 .long SYS_CODE64_SEL # selector 15:0 907 .byte 0 # 0 for interrupt gate 908 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 909 .word 0 # offset 31:16 910 .long 0 # offset 63:32 911 .long 0 # 0 for reserved 912 913# 85 unspecified descriptors, First 12 of them are reserved, the rest are avail 914 .fill 85 * 16, 1, 0 # db (85 * 16) dup(0) 915 916# IRQ 0 (System timer) - (INT 68h) 917.equ IRQ0_SEL, .-IDT_BASE 918 .word 0 # offset 15:0 919 .long SYS_CODE64_SEL # selector 15:0 920 .byte 0 # 0 for interrupt gate 921 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 922 .word 0 # offset 31:16 923 .long 0 # offset 63:32 924 .long 0 # 0 for reserved 925 926# IRQ 1 (8042 Keyboard controller) - (INT 69h) 927.equ IRQ1_SEL, .-IDT_BASE 928 .word 0 # offset 15:0 929 .long SYS_CODE64_SEL # selector 15:0 930 .byte 0 # 0 for interrupt gate 931 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 932 .word 0 # offset 31:16 933 .long 0 # offset 63:32 934 .long 0 # 0 for reserved 935 936# Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah) 937.equ IRQ2_SEL, .-IDT_BASE 938 .word 0 # offset 15:0 939 .long SYS_CODE64_SEL # selector 15:0 940 .byte 0 # 0 for interrupt gate 941 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 942 .word 0 # offset 31:16 943 .long 0 # offset 63:32 944 .long 0 # 0 for reserved 945 946# IRQ 3 (COM 2) - (INT 6bh) 947.equ IRQ3_SEL, .-IDT_BASE 948 .word 0 # offset 15:0 949 .long SYS_CODE64_SEL # selector 15:0 950 .byte 0 # 0 for interrupt gate 951 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 952 .word 0 # offset 31:16 953 .long 0 # offset 63:32 954 .long 0 # 0 for reserved 955 956# IRQ 4 (COM 1) - (INT 6ch) 957.equ IRQ4_SEL, .-IDT_BASE 958 .word 0 # offset 15:0 959 .long SYS_CODE64_SEL # selector 15:0 960 .byte 0 # 0 for interrupt gate 961 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 962 .word 0 # offset 31:16 963 .long 0 # offset 63:32 964 .long 0 # 0 for reserved 965 966# IRQ 5 (LPT 2) - (INT 6dh) 967.equ IRQ5_SEL, .-IDT_BASE 968 .word 0 # offset 15:0 969 .long SYS_CODE64_SEL # selector 15:0 970 .byte 0 # 0 for interrupt gate 971 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 972 .word 0 # offset 31:16 973 .long 0 # offset 63:32 974 .long 0 # 0 for reserved 975 976# IRQ 6 (Floppy controller) - (INT 6eh) 977.equ IRQ6_SEL, .-IDT_BASE 978 .word 0 # offset 15:0 979 .long SYS_CODE64_SEL # selector 15:0 980 .byte 0 # 0 for interrupt gate 981 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 982 .word 0 # offset 31:16 983 .long 0 # offset 63:32 984 .long 0 # 0 for reserved 985 986# IRQ 7 (LPT 1) - (INT 6fh) 987.equ IRQ7_SEL, .-IDT_BASE 988 .word 0 # offset 15:0 989 .long SYS_CODE64_SEL # selector 15:0 990 .byte 0 # 0 for interrupt gate 991 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 992 .word 0 # offset 31:16 993 .long 0 # offset 63:32 994 .long 0 # 0 for reserved 995 996# IRQ 8 (RTC Alarm) - (INT 70h) 997.equ IRQ8_SEL, .-IDT_BASE 998 .word 0 # offset 15:0 999 .long SYS_CODE64_SEL # selector 15:0 1000 .byte 0 # 0 for interrupt gate 1001 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1002 .word 0 # offset 31:16 1003 .long 0 # offset 63:32 1004 .long 0 # 0 for reserved 1005 1006# IRQ 9 - (INT 71h) 1007.equ IRQ9_SEL, .-IDT_BASE 1008 .word 0 # offset 15:0 1009 .long SYS_CODE64_SEL # selector 15:0 1010 .byte 0 # 0 for interrupt gate 1011 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1012 .word 0 # offset 31:16 1013 .long 0 # offset 63:32 1014 .long 0 # 0 for reserved 1015 1016# IRQ 10 - (INT 72h) 1017.equ IRQ10_SEL, .-IDT_BASE 1018 .word 0 # offset 15:0 1019 .long SYS_CODE64_SEL # selector 15:0 1020 .byte 0 # 0 for interrupt gate 1021 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1022 .word 0 # offset 31:16 1023 .long 0 # offset 63:32 1024 .long 0 # 0 for reserved 1025 1026# IRQ 11 - (INT 73h) 1027.equ IRQ11_SEL, .-IDT_BASE 1028 .word 0 # offset 15:0 1029 .long SYS_CODE64_SEL # selector 15:0 1030 .byte 0 # 0 for interrupt gate 1031 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1032 .word 0 # offset 31:16 1033 .long 0 # offset 63:32 1034 .long 0 # 0 for reserved 1035 1036# IRQ 12 (PS/2 mouse) - (INT 74h) 1037.equ IRQ12_SEL, .-IDT_BASE 1038 .word 0 # offset 15:0 1039 .long SYS_CODE64_SEL # selector 15:0 1040 .byte 0 # 0 for interrupt gate 1041 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1042 .word 0 # offset 31:16 1043 .long 0 # offset 63:32 1044 .long 0 # 0 for reserved 1045 1046# IRQ 13 (Floating point error) - (INT 75h) 1047.equ IRQ13_SEL, .-IDT_BASE 1048 .word 0 # offset 15:0 1049 .long SYS_CODE64_SEL # selector 15:0 1050 .byte 0 # 0 for interrupt gate 1051 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1052 .word 0 # offset 31:16 1053 .long 0 # offset 63:32 1054 .long 0 # 0 for reserved 1055 1056# IRQ 14 (Secondary IDE) - (INT 76h) 1057.equ IRQ14_SEL, .-IDT_BASE 1058 .word 0 # offset 15:0 1059 .long SYS_CODE64_SEL # selector 15:0 1060 .byte 0 # 0 for interrupt gate 1061 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1062 .word 0 # offset 31:16 1063 .long 0 # offset 63:32 1064 .long 0 # 0 for reserved 1065 1066# IRQ 15 (Primary IDE) - (INT 77h) 1067.equ IRQ15_SEL, .-IDT_BASE 1068 .word 0 # offset 15:0 1069 .long SYS_CODE64_SEL # selector 15:0 1070 .byte 0 # 0 for interrupt gate 1071 .byte 0x0e | 0x80 # type = 386 interrupt gate, present 1072 .word 0 # offset 31:16 1073 .long 0 # offset 63:32 1074 .long 0 # 0 for reserved 1075 1076IDT_END: 1077 1078 .p2align 1 1079 1080MemoryMapSize: .long 0 1081MemoryMap: .long 0,0,0,0,0,0,0,0 1082 .long 0,0,0,0,0,0,0,0 1083 .long 0,0,0,0,0,0,0,0 1084 .long 0,0,0,0,0,0,0,0 1085 .long 0,0,0,0,0,0,0,0 1086 .long 0,0,0,0,0,0,0,0 1087 .long 0,0,0,0,0,0,0,0 1088 .long 0,0,0,0,0,0,0,0 1089 .long 0,0,0,0,0,0,0,0 1090 .long 0,0,0,0,0,0,0,0 1091 .long 0,0,0,0,0,0,0,0 1092 .long 0,0,0,0,0,0,0,0 1093 .long 0,0,0,0,0,0,0,0 1094 .long 0,0,0,0,0,0,0,0 1095 .long 0,0,0,0,0,0,0,0 1096 .long 0,0,0,0,0,0,0,0 1097 .long 0,0,0,0,0,0,0,0 1098 .long 0,0,0,0,0,0,0,0 1099 .long 0,0,0,0,0,0,0,0 1100 .long 0,0,0,0,0,0,0,0 1101 .long 0,0,0,0,0,0,0,0 1102 .long 0,0,0,0,0,0,0,0 1103 .long 0,0,0,0,0,0,0,0 1104 .long 0,0,0,0,0,0,0,0 1105 .long 0,0,0,0,0,0,0,0 1106 .long 0,0,0,0,0,0,0,0 1107 .long 0,0,0,0,0,0,0,0 1108 .long 0,0,0,0,0,0,0,0 1109 .long 0,0,0,0,0,0,0,0 1110 .long 0,0,0,0,0,0,0,0 1111 1112 .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 1113 1114 .org 0x0fe0 1115MyStack: 1116 # below is the pieces of the IVT that is used to redirect INT 68h - 6fh 1117 # back to INT 08h - 0fh when in real mode... It is 'org'ed to a 1118 # known low address (20f00) so it can be set up by PlMapIrqToVect in 1119 # 8259.c 1120 1121 int $8 1122 iret 1123 1124 int $9 1125 iret 1126 1127 int $10 1128 iret 1129 1130 int $11 1131 iret 1132 1133 int $12 1134 iret 1135 1136 int $13 1137 iret 1138 1139 int $14 1140 iret 1141 1142 int $15 1143 iret 1144 1145 1146 .org 0x0ffe 1147BlockSignature: 1148 .word 0xaa55 1149 1150