| blob | 55b274b8df59836a695de54cf959a67a2886d17e |
1 #------------------------------------------------------------------------------\r
2 #*\r
3 #* Copyright 2006 - 2007, Intel Corporation \r
4 #* All rights reserved. This program and the accompanying materials \r
5 #* are licensed and made available under the terms and conditions of the BSD License \r
6 #* which accompanies this distribution. The full text of the license may be found at \r
7 #* http://opensource.org/licenses/bsd-license.php \r
8 #* \r
9 #* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
10 #* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
11 #* \r
12 #* start32.asm\r
13 #* \r
14 #* Abstract:\r
15 #*\r
16 #------------------------------------------------------------------------------\r
17 \r
18 #.MODEL small\r
19 .stack: \r
20 .486p: \r
21 .code: \r
22 \r
23 .equ FAT_DIRECTORY_ENTRY_SIZE, 0x020\r
24 .equ FAT_DIRECTORY_ENTRY_SHIFT, 5\r
25 .equ BLOCK_SIZE, 0x0200\r
26 .equ BLOCK_MASK, 0x01ff\r
27 .equ BLOCK_SHIFT, 9\r
28 \r
29 .org 0x0\r
30 \r
31 .global _start\r
32 _start:\r
33 \r
34 Ia32Jump: \r
35 jmp BootSectorEntryPoint # JMP inst - 3 bytes\r
36 nop\r
37 \r
38 OemId: .ascii "INTEL " # OemId - 8 bytes\r
39 SectorSize: .word 0 # Sector Size - 2 bytes\r
40 SectorsPerCluster: .byte 0 # Sector Per Cluster - 1 byte\r
41 ReservedSectors: .word 0 # Reserved Sectors - 2 bytes\r
42 NoFats: .byte 0 # Number of FATs - 1 byte\r
43 RootEntries: .word 0 # Root Entries - 2 bytes\r
44 Sectors: .word 0 # Number of Sectors - 2 bytes\r
45 Media: .byte 0 # Media - 1 byte\r
46 SectorsPerFat16: .word 0 # Sectors Per FAT for FAT12/FAT16 - 2 byte\r
47 SectorsPerTrack: .word 0 # Sectors Per Track - 2 bytes\r
48 Heads: .word 0 # Heads - 2 bytes\r
49 HiddenSectors: .long 0 # Hidden Sectors - 4 bytes\r
50 LargeSectors: .long 0 # Large Sectors - 4 bytes\r
51 \r
52 #******************************************************************************\r
53 #\r
54 #The structure for FAT32 starting at offset 36 of the boot sector. (At this point, \r
55 #the BPB/boot sector for FAT12 and FAT16 differs from the BPB/boot sector for FAT32.)\r
56 #\r
57 #******************************************************************************\r
58 \r
59 SectorsPerFat32: .long 0 # Sectors Per FAT for FAT32 - 4 bytes\r
60 ExtFlags: .word 0 # Mirror Flag - 2 bytes\r
61 FSVersion: .word 0 # File System Version - 2 bytes\r
62 RootCluster: .long 0 # 1st Cluster Number of Root Dir - 4 bytes\r
63 FSInfo: .word 0 # Sector Number of FSINFO - 2 bytes\r
64 BkBootSector: .word 0 # Sector Number of Bk BootSector - 2 bytes\r
65 Reserved: .fill 12,1,0 # Reserved Field - 12 bytes\r
66 PhysicalDrive: .byte 0 # Physical Drive Number - 1 byte\r
67 Reserved1: .byte 0 # Reserved Field - 1 byte\r
68 Signature: .byte 0 # Extended Boot Signature - 1 byte\r
69 VolId: .ascii " " # Volume Serial Number - 4 bytes\r
70 FatLabel: .ascii " " # Volume Label - 11 bytes\r
71 FileSystemType: .ascii "FAT32 " # File System Type - 8 bytes\r
72 \r
73 BootSectorEntryPoint: \r
74 #ASSUME ds:@code\r
75 #ASSUME ss:@code\r
76 # ds = 1000, es = 2000 + x (size of first cluster >> 4)\r
77 # cx = Start Cluster of EfiLdr\r
78 # dx = Start Cluster of Efivar.bin\r
79 \r
80 # Re use the BPB data stored in Boot Sector\r
81 movw $0x7c00, %bp\r
82 \r
83 \r
84 pushw %cx\r
85 # Read Efivar.bin\r
86 # 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already\r
87 movw $0x1900, %ax\r
88 movw %ax, %es\r
89 testw %dx, %dx\r
90 jnz CheckVarStoreSize\r
91 \r
92 movb $1, %al\r
93 NoVarStore: \r
94 pushw %es\r
95 # Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl\r
96 movb %al, %es:4\r
97 jmp SaveVolumeId\r
98 \r
99 CheckVarStoreSize: \r
100 movw %dx, %di\r
101 cmpl $0x4000, %ds:2(%di)\r
102 movb $2, %al\r
103 jne NoVarStore\r
104 \r
105 LoadVarStore: \r
106 movb $0, %al\r
107 movb %al, %es:4\r
108 movw (%di), %cx\r
109 # ES:DI = 1500:0\r
110 xorw %di, %di\r
111 pushw %es\r
112 movw $0x1500, %ax\r
113 movw %ax, %es\r
114 call ReadFile\r
115 SaveVolumeId: \r
116 popw %es\r
117 movw VolId(%bp), %ax\r
118 movw %ax, %es:0 # Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId\r
119 movw VolId+2(%bp), %ax\r
120 movw %ax, %es:2\r
121 \r
122 # Read Efildr\r
123 popw %cx\r
124 # cx = Start Cluster of Efildr -> BS.com has filled already\r
125 # ES:DI = 2000:0, first cluster will be read again\r
126 xorw %di, %di # di = 0\r
127 movw $0x2000, %ax\r
128 movw %ax, %es\r
129 call ReadFile\r
130 movw %cs, %ax\r
131 movw %ax, %cs:JumpSegment\r
132 JumpFarInstruction: \r
133 .byte 0xea\r
134 JumpOffset: \r
135 .word 0x200\r
136 JumpSegment: \r
137 .word 0x2000\r
138 \r
139 \r
140 \r
141 \r
142 # ****************************************************************************\r
143 # ReadFile\r
144 #\r
145 # Arguments:\r
146 # CX = Start Cluster of File\r
147 # ES:DI = Buffer to store file content read from disk\r
148 #\r
149 # Return:\r
150 # (ES << 4 + DI) = end of file content Buffer\r
151 #\r
152 # ****************************************************************************\r
153 ReadFile: \r
154 # si = NumberOfClusters\r
155 # cx = ClusterNumber\r
156 # dx = CachedFatSectorNumber\r
157 # ds:0000 = CacheFatSectorBuffer\r
158 # es:di = Buffer to load file\r
159 # bx = NextClusterNumber\r
160 pusha\r
161 movw $1, %si # NumberOfClusters = 1\r
162 pushw %cx # Push Start Cluster onto stack\r
163 movw $0xfff, %dx # CachedFatSectorNumber = 0xfff\r
164 FatChainLoop: \r
165 movw %cx, %ax # ax = ClusterNumber \r
166 andw $0xfff8, %ax # ax = ax & 0xfff8\r
167 cmpw $0xfff8, %ax # See if this is the last cluster\r
168 je FoundLastCluster # Jump if last cluster found\r
169 movw %cx, %ax # ax = ClusterNumber\r
170 shlw $2, %ax # FatOffset = ClusterNumber * 4\r
171 pushw %si # Save si\r
172 movw %ax, %si # si = FatOffset\r
173 shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT\r
174 addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET)\r
175 andw $BLOCK_MASK, %si # si = FatOffset & BLOCK_MASK\r
176 cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber\r
177 je SkipFatRead\r
178 movw $2, %bx\r
179 pushw %es\r
180 pushw %ds\r
181 popw %es\r
182 call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI\r
183 popw %es\r
184 movw %ax, %dx # CachedFatSectorNumber = FatSectorNumber\r
185 SkipFatRead: \r
186 movw (%si), %bx # bx = NextClusterNumber\r
187 movw %cx, %ax # ax = ClusterNumber\r
188 popw %si # Restore si\r
189 decw %bx # bx = NextClusterNumber - 1\r
190 cmpw %cx, %bx # See if (NextClusterNumber-1)==ClusterNumber\r
191 jne ReadClusters\r
192 incw %bx # bx = NextClusterNumber\r
193 incw %si # NumberOfClusters++\r
194 movw %bx, %cx # ClusterNumber = NextClusterNumber\r
195 jmp FatChainLoop\r
196 ReadClusters: \r
197 incw %bx\r
198 popw %ax # ax = StartCluster\r
199 pushw %bx # StartCluster = NextClusterNumber\r
200 movw %bx, %cx # ClusterNumber = NextClusterNumber\r
201 subw $2, %ax # ax = StartCluster - 2\r
202 xorb %bh, %bh\r
203 movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster\r
204 mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster\r
205 addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster\r
206 pushw %ax # save start sector\r
207 movw %si, %ax # ax = NumberOfClusters\r
208 mulw %bx # ax = NumberOfClusters * SectorsPerCluster\r
209 movw %ax, %bx # bx = Number of Sectors\r
210 popw %ax # ax = Start Sector\r
211 call ReadBlocks\r
212 movw $1, %si # NumberOfClusters = 1\r
213 jmp FatChainLoop\r
214 FoundLastCluster: \r
215 popw %cx\r
216 popa\r
217 ret\r
218 \r
219 \r
220 # ****************************************************************************\r
221 # ReadBlocks - Reads a set of blocks from a block device\r
222 #\r
223 # AX = Start LBA\r
224 # BX = Number of Blocks to Read\r
225 # ES:DI = Buffer to store sectors read from disk\r
226 # ****************************************************************************\r
227 \r
228 # cx = Blocks\r
229 # bx = NumberOfBlocks\r
230 # si = StartLBA\r
231 \r
232 ReadBlocks: \r
233 pusha\r
234 addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA\r
235 addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA\r
236 movl %eax, %esi # esi = Start LBA\r
237 movw %bx, %cx # cx = Number of blocks to read\r
238 ReadCylinderLoop: \r
239 movw $0x7bfc, %bp # bp = 0x7bfc\r
240 movl %esi, %eax # eax = Start LBA\r
241 xorl %edx, %edx # edx = 0\r
242 movzwl (%bp), %ebx # bx = MaxSector\r
243 divl %ebx # ax = StartLBA / MaxSector\r
244 incw %dx # dx = (StartLBA % MaxSector) + 1\r
245 \r
246 movw (%bp), %bx # bx = MaxSector\r
247 subw %dx, %bx # bx = MaxSector - Sector\r
248 incw %bx # bx = MaxSector - Sector + 1\r
249 cmpw %bx, %cx # Compare (Blocks) to (MaxSector - Sector + 1)\r
250 jg LimitTransfer\r
251 movw %cx, %bx # bx = Blocks\r
252 LimitTransfer: \r
253 pushw %ax # save ax\r
254 movw %es, %ax # ax = es\r
255 shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system\r
256 andw $0x7f, %ax # ax = Number of blocks into current seg\r
257 addw %bx, %ax # ax = End Block number of transfer\r
258 cmpw $0x80, %ax # See if it crosses a 64K boundry\r
259 jle NotCrossing64KBoundry # Branch if not crossing 64K boundry\r
260 subw $0x80, %ax # ax = Number of blocks past 64K boundry\r
261 subw %ax, %bx # Decrease transfer size by block overage\r
262 NotCrossing64KBoundry: \r
263 popw %ax # restore ax\r
264 \r
265 pushw %cx\r
266 movb %dl, %cl # cl = (StartLBA % MaxSector) + 1 = Sector\r
267 xorw %dx, %dx # dx = 0\r
268 divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder \r
269 # dx = ax % (MaxHead + 1) = Head\r
270 \r
271 pushw %bx # Save number of blocks to transfer\r
272 movb %dl, %dh # dh = Head\r
273 movw $0x7c00, %bp # bp = 0x7c00\r
274 movb PhysicalDrive(%bp), %dl # dl = Drive Number\r
275 movb %al, %ch # ch = Cylinder\r
276 movb %bl, %al # al = Blocks\r
277 movb $2, %ah # ah = Function 2\r
278 movw %di, %bx # es:bx = Buffer address\r
279 int $0x13\r
280 jc DiskError\r
281 popw %bx\r
282 popw %cx\r
283 movzwl %bx, %ebx\r
284 addl %ebx, %esi # StartLBA = StartLBA + NumberOfBlocks\r
285 subw %bx, %cx # Blocks = Blocks - NumberOfBlocks\r
286 movw %es, %ax\r
287 shlw $(BLOCK_SHIFT-4), %bx\r
288 addw %bx, %ax\r
289 movw %ax, %es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE\r
290 cmpw $0, %cx\r
291 jne ReadCylinderLoop\r
292 popa\r
293 ret\r
294 \r
295 DiskError: \r
296 pushw %cs\r
297 popw %ds\r
298 leaw ErrorString, %si\r
299 movw $7, %cx\r
300 jmp PrintStringAndHalt\r
301 \r
302 PrintStringAndHalt: \r
303 movw $0xb800, %ax\r
304 movw %ax, %es\r
305 movw $160, %di\r
306 rep\r
307 movsw\r
308 Halt: \r
309 jmp Halt\r
310 \r
311 ErrorString: \r
312 .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!', 0x0c\r
313 \r
314 # .org 0x01fa # Will cause build break\r
315 LBAOffsetForBootSector: \r
316 .long 0x0\r
317 \r
318 # .org 0x01fe # Will cause build break\r
319 .word 0xaa55\r
320 \r
321 #******************************************************************************\r
322 #******************************************************************************\r
323 #******************************************************************************\r
324 \r
325 .equ DELAY_PORT, 0x0ed # Port to use for 1uS delay\r
326 .equ KBD_CONTROL_PORT, 0x060 # 8042 control port \r
327 .equ KBD_STATUS_PORT, 0x064 # 8042 status port \r
328 .equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port\r
329 .equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20\r
330 \r
331 # .org 0x200 # Will cause build break\r
332 jmp start\r
333 Em64String: \r
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\r
335 \r
336 start: \r
337 movw %cs, %ax\r
338 movw %ax, %ds\r
339 movw %ax, %es\r
340 movw %ax, %ss\r
341 movw $MyStack, %sp\r
342 \r
343 # mov ax,0b800h\r
344 # mov es,ax\r
345 # mov byte ptr es:[160],'a'\r
346 # mov ax,cs\r
347 # mov es,ax\r
348 \r
349 movl $0, %ebx\r
350 leal MemoryMap, %edi\r
351 MemMapLoop: \r
352 movl $0xe820, %eax\r
353 movl $20, %ecx\r
354 movl $0x534d4150, %edx # 0x534d4150 = 'SMAP' \r
355 int $0x15\r
356 jc MemMapDone\r
357 addl $20, %edi\r
358 cmpl $0, %ebx\r
359 je MemMapDone\r
360 jmp MemMapLoop\r
361 MemMapDone: \r
362 leal MemoryMap, %eax\r
363 subl %eax, %edi # Get the address of the memory map\r
364 movl %edi, MemoryMapSize # Save the size of the memory map\r
365 \r
366 xorl %ebx, %ebx\r
367 movw %cs, %bx # BX=segment\r
368 shll $4, %ebx # BX="linear" address of segment base\r
369 leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt\r
370 movl %eax, gdtr + 2 # Put address of gdt into the gdtr\r
371 leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt\r
372 movl %eax, idtr + 2 # Put address of idt into the idtr\r
373 leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map\r
374 \r
375 addl $0x1000, %ebx # Source of EFI32\r
376 movl %ebx, JUMP+2\r
377 addl $0x1000, %ebx\r
378 movl %ebx, %esi # Source of EFILDR32\r
379 \r
380 # mov ax,0b800h\r
381 # mov es,ax\r
382 # mov byte ptr es:[162],'b'\r
383 # mov ax,cs\r
384 # mov es,ax\r
385 \r
386 #\r
387 # Enable A20 Gate \r
388 #\r
389 \r
390 movw $0x2401, %ax # Enable A20 Gate\r
391 int $0x15\r
392 jnc A20GateEnabled # Jump if it suceeded\r
393 \r
394 #\r
395 # If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually.\r
396 #\r
397 \r
398 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller\r
399 jnz Timeout8042 # Jump if the 8042 timed out\r
400 outw %ax, $DELAY_PORT # Delay 1 uS\r
401 movb $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port\r
402 outb %al, $KBD_STATUS_PORT # Send command to the 8042\r
403 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller\r
404 jnz Timeout8042 # Jump if the 8042 timed out\r
405 movb $ENABLE_A20_CMD, %al # gate address bit 20 on\r
406 outb %al, $KBD_CONTROL_PORT # Send command to thre 8042\r
407 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller\r
408 movw $25, %cx # Delay 25 uS for the command to complete on the 8042\r
409 Delay25uS: \r
410 outw %ax, $DELAY_PORT # Delay 1 uS\r
411 loopl Delay25uS\r
412 Timeout8042: \r
413 \r
414 \r
415 A20GateEnabled: \r
416 \r
417 #\r
418 # DISABLE INTERRUPTS - Entering Protected Mode\r
419 #\r
420 \r
421 cli\r
422 \r
423 # mov ax,0b800h\r
424 # mov es,ax\r
425 # mov byte ptr es:[164],'c'\r
426 # mov ax,cs\r
427 # mov es,ax\r
428 \r
429 .byte 0x66\r
430 lgdt gdtr\r
431 .byte 0x66\r
432 lidt idtr\r
433 \r
434 movl %cr0, %eax\r
435 orb $1, %al\r
436 movl %eax, %cr0\r
437 \r
438 movl $0x008, %eax # Flat data descriptor\r
439 movl $0x00400000, %ebp # Destination of EFILDR32\r
440 movl $0x00070000, %ebx # Length of copy\r
441 \r
442 JUMP: \r
443 # jmp far 0010:00020000\r
444 .byte 0x66\r
445 .byte 0xea\r
446 .long 0x00020000\r
447 .word 0x0010\r
448 \r
449 Empty8042InputBuffer: \r
450 movw $0, %cx\r
451 Empty8042Loop: \r
452 outw %ax, $DELAY_PORT # Delay 1us\r
453 inb $KBD_STATUS_PORT, %al # Read the 8042 Status Port\r
454 andb $0x2, %al # Check the Input Buffer Full Flag\r
455 loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS\r
456 ret\r
457 \r
458 ##############################################################################\r
459 # data\r
460 ##############################################################################\r
461 \r
462 .p2align 1\r
463 \r
464 gdtr: .word GDT_END - GDT_BASE - 1 \r
465 .long 0 # (GDT base gets set above)\r
466 ##############################################################################\r
467 # global descriptor table (GDT)\r
468 ##############################################################################\r
469 \r
470 .p2align 1\r
471 \r
472 GDT_BASE: \r
473 # null descriptor\r
474 .equ NULL_SEL, .-GDT_BASE\r
475 .word 0 # limit 15:0\r
476 .word 0 # base 15:0\r
477 .byte 0 # base 23:16\r
478 .byte 0 # type\r
479 .byte 0 # limit 19:16, flags\r
480 .byte 0 # base 31:24\r
481 \r
482 # linear data segment descriptor\r
483 .equ LINEAR_SEL, .-GDT_BASE\r
484 .word 0xFFFF # limit 0xFFFFF\r
485 .word 0 # base 0\r
486 .byte 0\r
487 .byte 0x92 # present, ring 0, data, expand-up, writable\r
488 .byte 0xCF # page-granular, 32-bit\r
489 .byte 0\r
490 \r
491 # linear code segment descriptor\r
492 .equ LINEAR_CODE_SEL, .-GDT_BASE\r
493 .word 0xFFFF # limit 0xFFFFF\r
494 .word 0 # base 0\r
495 .byte 0\r
496 .byte 0x9A # present, ring 0, data, expand-up, writable\r
497 .byte 0xCF # page-granular, 32-bit\r
498 .byte 0\r
499 \r
500 # system data segment descriptor\r
501 .equ SYS_DATA_SEL, .-GDT_BASE\r
502 .word 0xFFFF # limit 0xFFFFF\r
503 .word 0 # base 0\r
504 .byte 0\r
505 .byte 0x92 # present, ring 0, data, expand-up, writable\r
506 .byte 0xCF # page-granular, 32-bit\r
507 .byte 0\r
508 \r
509 # system code segment descriptor\r
510 .equ SYS_CODE_SEL, .-GDT_BASE\r
511 .word 0xFFFF # limit 0xFFFFF\r
512 .word 0 # base 0\r
513 .byte 0\r
514 .byte 0x9A # present, ring 0, data, expand-up, writable\r
515 .byte 0xCF # page-granular, 32-bit\r
516 .byte 0\r
517 \r
518 # spare segment descriptor\r
519 .equ SPARE3_SEL, .-GDT_BASE\r
520 .word 0 # limit 0xFFFFF\r
521 .word 0 # base 0\r
522 .byte 0\r
523 .byte 0 # present, ring 0, data, expand-up, writable\r
524 .byte 0 # page-granular, 32-bit\r
525 .byte 0\r
526 \r
527 # spare segment descriptor\r
528 .equ SPARE4_SEL, .-GDT_BASE\r
529 .word 0 # limit 0xFFFFF\r
530 .word 0 # base 0\r
531 .byte 0\r
532 .byte 0 # present, ring 0, data, expand-up, writable\r
533 .byte 0 # page-granular, 32-bit\r
534 .byte 0\r
535 \r
536 # spare segment descriptor\r
537 .equ SPARE5_SEL, .-GDT_BASE\r
538 .word 0 # limit 0xFFFFF\r
539 .word 0 # base 0\r
540 .byte 0\r
541 .byte 0 # present, ring 0, data, expand-up, writable\r
542 .byte 0 # page-granular, 32-bit\r
543 .byte 0\r
544 \r
545 GDT_END: \r
546 \r
547 .p2align 1\r
548 \r
549 \r
550 \r
551 idtr: .word IDT_END - IDT_BASE - 1 \r
552 .long 0 # (IDT base gets set above)\r
553 ##############################################################################\r
554 # interrupt descriptor table (IDT)\r
555 #\r
556 # Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ\r
557 # mappings. This implementation only uses the system timer and all other\r
558 # IRQs will remain masked. The descriptors for vectors 33+ are provided\r
559 # for convenience.\r
560 ##############################################################################\r
561 \r
562 #idt_tag db "IDT",0 \r
563 .p2align 1\r
564 \r
565 IDT_BASE: \r
566 # divide by zero (INT 0)\r
567 .equ DIV_ZERO_SEL, .-IDT_BASE\r
568 .word 0 # offset 15:0\r
569 .word SYS_CODE_SEL # selector 15:0\r
570 .byte 0 # 0 for interrupt gate\r
571 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
572 .word 0 # offset 31:16\r
573 \r
574 # debug exception (INT 1)\r
575 .equ DEBUG_EXCEPT_SEL, .-IDT_BASE\r
576 .word 0 # offset 15:0\r
577 .word SYS_CODE_SEL # selector 15:0\r
578 .byte 0 # 0 for interrupt gate\r
579 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
580 .word 0 # offset 31:16\r
581 \r
582 # NMI (INT 2)\r
583 .equ NMI_SEL, .-IDT_BASE\r
584 .word 0 # offset 15:0\r
585 .word SYS_CODE_SEL # selector 15:0\r
586 .byte 0 # 0 for interrupt gate\r
587 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
588 .word 0 # offset 31:16\r
589 \r
590 # soft breakpoint (INT 3)\r
591 .equ BREAKPOINT_SEL, .-IDT_BASE\r
592 .word 0 # offset 15:0\r
593 .word SYS_CODE_SEL # selector 15:0\r
594 .byte 0 # 0 for interrupt gate\r
595 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
596 .word 0 # offset 31:16\r
597 \r
598 # overflow (INT 4)\r
599 .equ OVERFLOW_SEL, .-IDT_BASE\r
600 .word 0 # offset 15:0\r
601 .word SYS_CODE_SEL # selector 15:0\r
602 .byte 0 # 0 for interrupt gate\r
603 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
604 .word 0 # offset 31:16\r
605 \r
606 # bounds check (INT 5)\r
607 .equ BOUNDS_CHECK_SEL, .-IDT_BASE\r
608 .word 0 # offset 15:0\r
609 .word SYS_CODE_SEL # selector 15:0\r
610 .byte 0 # 0 for interrupt gate\r
611 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
612 .word 0 # offset 31:16\r
613 \r
614 # invalid opcode (INT 6)\r
615 .equ INVALID_OPCODE_SEL, .-IDT_BASE\r
616 .word 0 # offset 15:0\r
617 .word SYS_CODE_SEL # selector 15:0\r
618 .byte 0 # 0 for interrupt gate\r
619 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
620 .word 0 # offset 31:16\r
621 \r
622 # device not available (INT 7)\r
623 .equ DEV_NOT_AVAIL_SEL, .-IDT_BASE\r
624 .word 0 # offset 15:0\r
625 .word SYS_CODE_SEL # selector 15:0\r
626 .byte 0 # 0 for interrupt gate\r
627 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
628 .word 0 # offset 31:16\r
629 \r
630 # double fault (INT 8)\r
631 .equ DOUBLE_FAULT_SEL, .-IDT_BASE\r
632 .word 0 # offset 15:0\r
633 .word SYS_CODE_SEL # selector 15:0\r
634 .byte 0 # 0 for interrupt gate\r
635 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
636 .word 0 # offset 31:16\r
637 \r
638 # Coprocessor segment overrun - reserved (INT 9)\r
639 .equ RSVD_INTR_SEL1, .-IDT_BASE\r
640 .word 0 # offset 15:0\r
641 .word SYS_CODE_SEL # selector 15:0\r
642 .byte 0 # 0 for interrupt gate\r
643 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
644 .word 0 # offset 31:16\r
645 \r
646 # invalid TSS (INT 0ah)\r
647 .equ INVALID_TSS_SEL, .-IDT_BASE\r
648 .word 0 # offset 15:0\r
649 .word SYS_CODE_SEL # selector 15:0\r
650 .byte 0 # 0 for interrupt gate\r
651 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
652 .word 0 # offset 31:16\r
653 \r
654 # segment not present (INT 0bh)\r
655 .equ SEG_NOT_PRESENT_SEL, .-IDT_BASE\r
656 .word 0 # offset 15:0\r
657 .word SYS_CODE_SEL # selector 15:0\r
658 .byte 0 # 0 for interrupt gate\r
659 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
660 .word 0 # offset 31:16\r
661 \r
662 # stack fault (INT 0ch)\r
663 .equ STACK_FAULT_SEL, .-IDT_BASE\r
664 .word 0 # offset 15:0\r
665 .word SYS_CODE_SEL # selector 15:0\r
666 .byte 0 # 0 for interrupt gate\r
667 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
668 .word 0 # offset 31:16\r
669 \r
670 # general protection (INT 0dh)\r
671 .equ GP_FAULT_SEL, .-IDT_BASE\r
672 .word 0 # offset 15:0\r
673 .word SYS_CODE_SEL # selector 15:0\r
674 .byte 0 # 0 for interrupt gate\r
675 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
676 .word 0 # offset 31:16\r
677 \r
678 # page fault (INT 0eh)\r
679 .equ PAGE_FAULT_SEL, .-IDT_BASE\r
680 .word 0 # offset 15:0\r
681 .word SYS_CODE_SEL # selector 15:0\r
682 .byte 0 # 0 for interrupt gate\r
683 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
684 .word 0 # offset 31:16\r
685 \r
686 # Intel reserved - do not use (INT 0fh)\r
687 .equ RSVD_INTR_SEL2, .-IDT_BASE\r
688 .word 0 # offset 15:0\r
689 .word SYS_CODE_SEL # selector 15:0\r
690 .byte 0 # 0 for interrupt gate\r
691 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
692 .word 0 # offset 31:16\r
693 \r
694 # floating point error (INT 10h)\r
695 .equ FLT_POINT_ERR_SEL, .-IDT_BASE\r
696 .word 0 # offset 15:0\r
697 .word SYS_CODE_SEL # selector 15:0\r
698 .byte 0 # 0 for interrupt gate\r
699 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
700 .word 0 # offset 31:16\r
701 \r
702 # alignment check (INT 11h)\r
703 .equ ALIGNMENT_CHECK_SEL, .-IDT_BASE\r
704 .word 0 # offset 15:0\r
705 .word SYS_CODE_SEL # selector 15:0\r
706 .byte 0 # 0 for interrupt gate\r
707 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
708 .word 0 # offset 31:16\r
709 \r
710 # machine check (INT 12h)\r
711 .equ MACHINE_CHECK_SEL, .-IDT_BASE\r
712 .word 0 # offset 15:0\r
713 .word SYS_CODE_SEL # selector 15:0\r
714 .byte 0 # 0 for interrupt gate\r
715 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
716 .word 0 # offset 31:16\r
717 \r
718 # SIMD floating-point exception (INT 13h)\r
719 .equ SIMD_EXCEPTION_SEL, .-IDT_BASE\r
720 .word 0 # offset 15:0\r
721 .word SYS_CODE_SEL # selector 15:0\r
722 .byte 0 # 0 for interrupt gate\r
723 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
724 .word 0 # offset 31:16\r
725 \r
726 # 85 unspecified descriptors, First 12 of them are reserved, the rest are avail\r
727 .fill 85 * 8, 1, 0\r
728 \r
729 # IRQ 0 (System timer) - (INT 68h)\r
730 .equ IRQ0_SEL, .-IDT_BASE\r
731 .word 0 # offset 15:0\r
732 .word SYS_CODE_SEL # selector 15:0\r
733 .byte 0 # 0 for interrupt gate\r
734 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
735 .word 0 # offset 31:16\r
736 \r
737 # IRQ 1 (8042 Keyboard controller) - (INT 69h)\r
738 .equ IRQ1_SEL, .-IDT_BASE\r
739 .word 0 # offset 15:0\r
740 .word SYS_CODE_SEL # selector 15:0\r
741 .byte 0 # 0 for interrupt gate\r
742 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
743 .word 0 # offset 31:16\r
744 \r
745 # Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah)\r
746 .equ IRQ2_SEL, .-IDT_BASE\r
747 .word 0 # offset 15:0\r
748 .word SYS_CODE_SEL # selector 15:0\r
749 .byte 0 # 0 for interrupt gate\r
750 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
751 .word 0 # offset 31:16\r
752 \r
753 # IRQ 3 (COM 2) - (INT 6bh)\r
754 .equ IRQ3_SEL, .-IDT_BASE\r
755 .word 0 # offset 15:0\r
756 .word SYS_CODE_SEL # selector 15:0\r
757 .byte 0 # 0 for interrupt gate\r
758 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
759 .word 0 # offset 31:16\r
760 \r
761 # IRQ 4 (COM 1) - (INT 6ch)\r
762 .equ IRQ4_SEL, .-IDT_BASE\r
763 .word 0 # offset 15:0\r
764 .word SYS_CODE_SEL # selector 15:0\r
765 .byte 0 # 0 for interrupt gate\r
766 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
767 .word 0 # offset 31:16\r
768 \r
769 # IRQ 5 (LPT 2) - (INT 6dh)\r
770 .equ IRQ5_SEL, .-IDT_BASE\r
771 .word 0 # offset 15:0\r
772 .word SYS_CODE_SEL # selector 15:0\r
773 .byte 0 # 0 for interrupt gate\r
774 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
775 .word 0 # offset 31:16\r
776 \r
777 # IRQ 6 (Floppy controller) - (INT 6eh)\r
778 .equ IRQ6_SEL, .-IDT_BASE\r
779 .word 0 # offset 15:0\r
780 .word SYS_CODE_SEL # selector 15:0\r
781 .byte 0 # 0 for interrupt gate\r
782 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
783 .word 0 # offset 31:16\r
784 \r
785 # IRQ 7 (LPT 1) - (INT 6fh)\r
786 .equ IRQ7_SEL, .-IDT_BASE\r
787 .word 0 # offset 15:0\r
788 .word SYS_CODE_SEL # selector 15:0\r
789 .byte 0 # 0 for interrupt gate\r
790 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
791 .word 0 # offset 31:16\r
792 \r
793 # IRQ 8 (RTC Alarm) - (INT 70h)\r
794 .equ IRQ8_SEL, .-IDT_BASE\r
795 .word 0 # offset 15:0\r
796 .word SYS_CODE_SEL # selector 15:0\r
797 .byte 0 # 0 for interrupt gate\r
798 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
799 .word 0 # offset 31:16\r
800 \r
801 # IRQ 9 - (INT 71h)\r
802 .equ IRQ9_SEL, .-IDT_BASE\r
803 .word 0 # offset 15:0\r
804 .word SYS_CODE_SEL # selector 15:0\r
805 .byte 0 # 0 for interrupt gate\r
806 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
807 .word 0 # offset 31:16\r
808 \r
809 # IRQ 10 - (INT 72h)\r
810 .equ IRQ10_SEL, .-IDT_BASE\r
811 .word 0 # offset 15:0\r
812 .word SYS_CODE_SEL # selector 15:0\r
813 .byte 0 # 0 for interrupt gate\r
814 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
815 .word 0 # offset 31:16\r
816 \r
817 # IRQ 11 - (INT 73h)\r
818 .equ IRQ11_SEL, .-IDT_BASE\r
819 .word 0 # offset 15:0\r
820 .word SYS_CODE_SEL # selector 15:0\r
821 .byte 0 # 0 for interrupt gate\r
822 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
823 .word 0 # offset 31:16\r
824 \r
825 # IRQ 12 (PS/2 mouse) - (INT 74h)\r
826 .equ IRQ12_SEL, .-IDT_BASE\r
827 .word 0 # offset 15:0\r
828 .word SYS_CODE_SEL # selector 15:0\r
829 .byte 0 # 0 for interrupt gate\r
830 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
831 .word 0 # offset 31:16\r
832 \r
833 # IRQ 13 (Floating point error) - (INT 75h)\r
834 .equ IRQ13_SEL, .-IDT_BASE\r
835 .word 0 # offset 15:0\r
836 .word SYS_CODE_SEL # selector 15:0\r
837 .byte 0 # 0 for interrupt gate\r
838 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
839 .word 0 # offset 31:16\r
840 \r
841 # IRQ 14 (Secondary IDE) - (INT 76h)\r
842 .equ IRQ14_SEL, .-IDT_BASE\r
843 .word 0 # offset 15:0\r
844 .word SYS_CODE_SEL # selector 15:0\r
845 .byte 0 # 0 for interrupt gate\r
846 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
847 .word 0 # offset 31:16\r
848 \r
849 # IRQ 15 (Primary IDE) - (INT 77h)\r
850 .equ IRQ15_SEL, .-IDT_BASE\r
851 .word 0 # offset 15:0\r
852 .word SYS_CODE_SEL # selector 15:0\r
853 .byte 0 # 0 for interrupt gate\r
854 .byte 0x0e | 0x80 # type = 386 interrupt gate, present\r
855 .word 0 # offset 31:16\r
856 \r
857 IDT_END: \r
858 \r
859 .p2align 1\r
860 \r
861 MemoryMapSize: .long 0\r
862 MemoryMap: .long 0,0,0,0,0,0,0,0\r
863 .long 0,0,0,0,0,0,0,0\r
864 .long 0,0,0,0,0,0,0,0\r
865 .long 0,0,0,0,0,0,0,0\r
866 .long 0,0,0,0,0,0,0,0\r
867 .long 0,0,0,0,0,0,0,0\r
868 .long 0,0,0,0,0,0,0,0\r
869 .long 0,0,0,0,0,0,0,0\r
870 .long 0,0,0,0,0,0,0,0\r
871 .long 0,0,0,0,0,0,0,0\r
872 .long 0,0,0,0,0,0,0,0\r
873 .long 0,0,0,0,0,0,0,0\r
874 .long 0,0,0,0,0,0,0,0\r
875 .long 0,0,0,0,0,0,0,0\r
876 .long 0,0,0,0,0,0,0,0\r
877 .long 0,0,0,0,0,0,0,0\r
878 .long 0,0,0,0,0,0,0,0\r
879 .long 0,0,0,0,0,0,0,0\r
880 .long 0,0,0,0,0,0,0,0\r
881 .long 0,0,0,0,0,0,0,0\r
882 .long 0,0,0,0,0,0,0,0\r
883 .long 0,0,0,0,0,0,0,0\r
884 .long 0,0,0,0,0,0,0,0\r
885 .long 0,0,0,0,0,0,0,0\r
886 .long 0,0,0,0,0,0,0,0\r
887 .long 0,0,0,0,0,0,0,0\r
888 .long 0,0,0,0,0,0,0,0\r
889 .long 0,0,0,0,0,0,0,0\r
890 .long 0,0,0,0,0,0,0,0\r
891 .long 0,0,0,0,0,0,0,0\r
892 \r
893 .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\r
894 .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\r
895 \r
896 .org 0x0fe0\r
897 MyStack: \r
898 # below is the pieces of the IVT that is used to redirect INT 68h - 6fh\r
899 # back to INT 08h - 0fh when in real mode... It is 'org'ed to a\r
900 # known low address (20f00) so it can be set up by PlMapIrqToVect in\r
901 # 8259.c\r
902 \r
903 int $8\r
904 iret\r
905 \r
906 int $9\r
907 iret\r
908 \r
909 int $10\r
910 iret\r
911 \r
912 int $11\r
913 iret\r
914 \r
915 int $12\r
916 iret\r
917 \r
918 int $13\r
919 iret\r
920 \r
921 int $14\r
922 iret\r
923 \r
924 int $15\r
925 iret\r
926 \r
927 \r
928 .org 0x0ffe\r
929 BlockSignature: \r
930 .word 0xaa55\r
931 \r
932 \r