]> git.proxmox.com Git - mirror_edk2.git/blame - DuetPkg/BootSector/start16.S
syntax checked
[mirror_edk2.git] / DuetPkg / BootSector / start16.S
CommitLineData
9be1da06 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#* start16.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, 0x0020\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 0x00\r
30Ia32Jump: \r
31 jmp BootSectorEntryPoint # JMP inst - 3 bytes\r
32 nop\r
33\r
34OemId: .ascii "INTEL " # OemId - 8 bytes\r
35\r
36SectorSize: .word 0 # Sector Size - 16 bits\r
37SectorsPerCluster: .byte 0 # Sector Per Cluster - 8 bits\r
38ReservedSectors: .word 0 # Reserved Sectors - 16 bits\r
39NoFats: .byte 0 # Number of FATs - 8 bits\r
40RootEntries: .word 0 # Root Entries - 16 bits\r
41Sectors: .word 0 # Number of Sectors - 16 bits\r
42Media: .byte 0 # Media - 8 bits - ignored\r
43SectorsPerFat: .word 0 # Sectors Per FAT - 16 bits\r
44SectorsPerTrack: .word 0 # Sectors Per Track - 16 bits - ignored\r
45Heads: .word 0 # Heads - 16 bits - ignored\r
46HiddenSectors: .long 0 # Hidden Sectors - 32 bits - ignored\r
47LargeSectors: .long 0 # Large Sectors - 32 bits \r
48PhysicalDrive: .byte 0 # PhysicalDriveNumber - 8 bits - ignored\r
49CurrentHead: .byte 0 # Current Head - 8 bits\r
50Signature: .byte 0 # Signature - 8 bits - ignored\r
51VolId: .ascii " " # Volume Serial Number- 4 bytes\r
52FatLabel: .ascii " " # Label - 11 bytes\r
53SystemId: .ascii "FAT16 " # SystemId - 8 bytes\r
54\r
55BootSectorEntryPoint: \r
56 #ASSUME ds:@code\r
57 #ASSUME ss:@code\r
58 # ds = 1000, es = 2000 + x (size of first cluster >> 4)\r
59 # cx = Start Cluster of EfiLdr\r
60 # dx = Start Cluster of Efivar.bin\r
61\r
62# Re use the BPB data stored in Boot Sector\r
63 movw $0x7c00, %bp\r
64\r
65 pushw %cx\r
66# Read Efivar.bin\r
67# 1000:dx = DirectoryEntry of Efivar.bin -> BS.com has filled already\r
68 movw $0x1900, %ax\r
69 movw %ax, %es\r
70 testw %dx, %dx\r
71 jnz CheckVarStoreSize\r
72\r
73 movb $1, %al\r
74NoVarStore: \r
75 pushw %es\r
76# Set the 5th byte start @ 0:19000 to non-zero indicating we should init var store header in DxeIpl\r
77 movb %al, %es:($4)\r
78 jmp SaveVolumeId\r
79\r
80CheckVarStoreSize: \r
81 movw %dx, %di\r
82 cmpl $0x4000, %ds:2(%di)\r
83 movb $2, %al\r
84 jne NoVarStore\r
85\r
86LoadVarStore: \r
87 movb $0, %al\r
88 movb %al, %es:($4)\r
89 movw (%di), %cx\r
90# ES:DI = 1500:0\r
91 xorw %di, %di\r
92 pushw %es\r
93 movw $0x1500, %ax\r
94 movw %ax, %es\r
95 call ReadFile\r
96SaveVolumeId: \r
97 popw %es\r
98 movw VolId(%bp), %ax\r
99 movw %ax, %es:($0) # Save Volume Id to 0:19000. we will find the correct volume according to this VolumeId\r
100 movw VolId+2(%bp), %ax\r
101 movw %ax, %es:($2)\r
102\r
103# Read Efildr\r
104 popw %cx\r
105# cx = Start Cluster of Efildr -> BS.com has filled already\r
106# ES:DI = 2000:0, first cluster will be read again\r
107 xorw %di, %di # di = 0\r
108 movw $0x2000, %ax\r
109 movw %ax, %es\r
110 call ReadFile\r
111 movw %cs, %ax\r
112 movw %ax, %cs:JumpSegment\r
113\r
114JumpFarInstruction: \r
115 .byte 0xea\r
116JumpOffset: \r
117 .word 0x200\r
118JumpSegment: \r
119 .word 0x2000\r
120\r
121\r
122\r
123# ****************************************************************************\r
124# ReadFile\r
125#\r
126# Arguments:\r
127# CX = Start Cluster of File\r
128# ES:DI = Buffer to store file content read from disk\r
129#\r
130# Return:\r
131# (ES << 4 + DI) = end of file content Buffer\r
132#\r
133# ****************************************************************************\r
134ReadFile: \r
135# si = NumberOfClusters\r
136# cx = ClusterNumber\r
137# dx = CachedFatSectorNumber\r
138# ds:0000 = CacheFatSectorBuffer\r
139# es:di = Buffer to load file\r
140# bx = NextClusterNumber\r
141 pusha\r
142 movw $1, %si # NumberOfClusters = 1\r
143 pushw %cx # Push Start Cluster onto stack\r
144 movw $0xfff, %dx # CachedFatSectorNumber = 0xfff\r
145FatChainLoop: \r
146 movw %cx, %ax # ax = ClusterNumber \r
147 andw $0xfff8, %ax # ax = ax & 0xfff8\r
148 cmpw $0xfff8, %ax # See if this is the last cluster\r
149 je FoundLastCluster # Jump if last cluster found\r
150 movw %cx, %ax # ax = ClusterNumber\r
151 shlw %ax # FatOffset = ClusterNumber * 2\r
152 pushw %si # Save si\r
153 movw %ax, %si # si = FatOffset\r
154 shrw $BLOCK_SHIFT, %ax # ax = FatOffset >> BLOCK_SHIFT\r
155 addw ReservedSectors(%bp), %ax # ax = FatSectorNumber = ReservedSectors + (FatOffset >> BLOCK_OFFSET)\r
156 andw $BLOCK_MASK, %si # si = FatOffset & BLOCK_MASK\r
157 cmpw %dx, %ax # Compare FatSectorNumber to CachedFatSectorNumber\r
158 je SkipFatRead\r
159 movw $2, %bx\r
160 pushw %es\r
161 pushw %ds\r
162 popw %es\r
163 call ReadBlocks # Read 2 blocks starting at AX storing at ES:DI\r
164 popw %es\r
165 movw %ax, %dx # CachedFatSectorNumber = FatSectorNumber\r
166SkipFatRead: \r
167 movw (%si), %bx # bx = NextClusterNumber\r
168 movw %cx, %ax # ax = ClusterNumber\r
169 popw %si # Restore si\r
170 decw %bx # bx = NextClusterNumber - 1\r
171 cmpw %cx, %bx # See if (NextClusterNumber-1)==ClusterNumber\r
172 jne ReadClusters\r
173 incw %bx # bx = NextClusterNumber\r
174 incw %si # NumberOfClusters++\r
175 movw %bx, %cx # ClusterNumber = NextClusterNumber\r
176 jmp FatChainLoop\r
177ReadClusters: \r
178 incw %bx\r
179 popw %ax # ax = StartCluster\r
180 pushw %bx # StartCluster = NextClusterNumber\r
181 movw %bx, %cx # ClusterNumber = NextClusterNumber\r
182 subw $2, %ax # ax = StartCluster - 2\r
183 xorb %bh, %bh\r
184 movb SectorsPerCluster(%bp), %bl # bx = SectorsPerCluster\r
185 mulw %bx # ax = (StartCluster - 2) * SectorsPerCluster\r
186 addw (%bp), %ax # ax = FirstClusterLBA + (StartCluster-2)*SectorsPerCluster\r
187 pushw %ax # save start sector\r
188 movw %si, %ax # ax = NumberOfClusters\r
189 mulw %bx # ax = NumberOfClusters * SectorsPerCluster\r
190 movw %ax, %bx # bx = Number of Sectors\r
191 popw %ax # ax = Start Sector\r
192 call ReadBlocks\r
193 movw $1, %si # NumberOfClusters = 1\r
194 jmp FatChainLoop\r
195FoundLastCluster: \r
196 popw %cx\r
197 popa\r
198 ret\r
199\r
200\r
201# ****************************************************************************\r
202# ReadBlocks - Reads a set of blocks from a block device\r
203#\r
204# AX = Start LBA\r
205# BX = Number of Blocks to Read\r
206# ES:DI = Buffer to store sectors read from disk\r
207# ****************************************************************************\r
208\r
209# cx = Blocks\r
210# bx = NumberOfBlocks\r
211# si = StartLBA\r
212\r
213ReadBlocks: \r
214 pusha\r
215 addl LBAOffsetForBootSector(%bp), %eax # Add LBAOffsetForBootSector to Start LBA\r
216 addl HiddenSectors(%bp), %eax # Add HiddenSectors to Start LBA\r
217 movl %eax, %esi # esi = Start LBA\r
218 movw %bx, %cx # cx = Number of blocks to read\r
219ReadCylinderLoop: \r
220 movw $0x7bfc, %bp # bp = 0x7bfc\r
221 movl %esi, %eax # eax = Start LBA\r
222 xorl %edx, %edx # edx = 0\r
223 movzwl (%bp), %ebx # bx = MaxSector\r
224 divl %ebx # ax = StartLBA / MaxSector\r
225 incw %dx # dx = (StartLBA % MaxSector) + 1\r
226\r
227 movw (%bp), %bx # bx = MaxSector\r
228 subw %dx, %bx # bx = MaxSector - Sector\r
229 incw %bx # bx = MaxSector - Sector + 1\r
230 cmpw %bx, %cx # Compare (Blocks) to (MaxSector - Sector + 1)\r
231 jg LimitTransfer\r
232 movw %cx, %bx # bx = Blocks\r
233LimitTransfer: \r
234 pushw %ax # save ax\r
235 movw %es, %ax # ax = es\r
236 shrw $(BLOCK_SHIFT-4), %ax # ax = Number of blocks into mem system\r
237 andw $0x7f, %ax # ax = Number of blocks into current seg\r
238 addw %bx, %ax # ax = End Block number of transfer\r
239 cmpw $0x80, %ax # See if it crosses a 64K boundry\r
240 jle NotCrossing64KBoundry # Branch if not crossing 64K boundry\r
241 subw $0x80, %ax # ax = Number of blocks past 64K boundry\r
242 subw %ax, %bx # Decrease transfer size by block overage\r
243NotCrossing64KBoundry: \r
244 popw %ax # restore ax\r
245\r
246 pushw %cx\r
247 movb %dl, %cl # cl = (StartLBA % MaxSector) + 1 = Sector\r
248 xorw %dx, %dx # dx = 0\r
249 divw 2(%bp) # ax = ax / (MaxHead + 1) = Cylinder \r
250 # dx = ax % (MaxHead + 1) = Head\r
251\r
252 pushw %bx # Save number of blocks to transfer\r
253 movb %dl, %dh # dh = Head\r
254 movw $0x7c00, %bp # bp = 0x7c00\r
255 movb PhysicalDrive(%bp), %dl # dl = Drive Number\r
256 movb %al, %ch # ch = Cylinder\r
257 movb %bl, %al # al = Blocks\r
258 movb $2, %ah # ah = Function 2\r
259 movw %di, %bx # es:bx = Buffer address\r
260 int $0x13\r
261 jc DiskError\r
262 popw %bx\r
263 popw %cx\r
264 movzwl %bx, %ebx\r
265 addl %ebx, %esi # StartLBA = StartLBA + NumberOfBlocks\r
266 subw %bx, %cx # Blocks = Blocks - NumberOfBlocks\r
267 movw %es, %ax\r
268 shlw $(BLOCK_SHIFT-4), %bx\r
269 addw %bx, %ax\r
270 movw %ax, %es # es:di = es:di + NumberOfBlocks*BLOCK_SIZE\r
271 cmpw $0, %cx\r
272 jne ReadCylinderLoop\r
273 popa\r
274 ret\r
275\r
276DiskError: \r
277 pushw %cs\r
278 popw %ds\r
279 leaw ErrorString, %si\r
280 movw $7, %cx\r
281 jmp PrintStringAndHalt\r
282\r
283PrintStringAndHalt: \r
284 movw $0xb800, %ax\r
285 movw %ax, %es\r
286 movw $160, %di\r
287 rep\r
288 movsw\r
289Halt: \r
290 jmp Halt\r
291\r
292ErrorString: \r
293 .byte 'S', 0x0c, 'E', 0x0c, 'r', 0x0c, 'r', 0x0c, 'o', 0x0c, 'r', 0x0c, '!', 0x0c\r
294\r
295 .org 0x01fa\r
296LBAOffsetForBootSector: \r
297 .long 0x0\r
298\r
299 .org 0x01fe\r
300 .word 0xaa55\r
301\r
302#******************************************************************************\r
303#******************************************************************************\r
304#******************************************************************************\r
305\r
306.equ DELAY_PORT, 0x0ed # Port to use for 1uS delay\r
307.equ KBD_CONTROL_PORT, 0x060 # 8042 control port \r
308.equ KBD_STATUS_PORT, 0x064 # 8042 status port \r
309.equ WRITE_DATA_PORT_CMD, 0x0d1 # 8042 command to write the data port\r
310.equ ENABLE_A20_CMD, 0x0df # 8042 command to enable A20\r
311\r
312 .org 0x0200\r
313 jmp start\r
314Em64String: \r
315 .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
316\r
317start: \r
318 movw %cs, %ax\r
319 movw %ax, %ds\r
320 movw %ax, %es\r
321 movw %ax, %ss\r
322 movw $MyStack, %sp\r
323\r
324# mov ax,0b800h\r
325# mov es,ax\r
326# mov byte ptr es:[160],'a'\r
327# mov ax,cs\r
328# mov es,ax\r
329\r
330 movl $0, %ebx\r
331 leal MemoryMap, %edi\r
332MemMapLoop: \r
333 movl $0xe820, %eax\r
334 movl $20, %ecx\r
9ffd16fb 335 movl $0x534d4150, %edx # 0x534d4150 stands for 'SMAP'\r
9be1da06 336 int $0x15\r
337 jc MemMapDone\r
338 addl $20, %edi\r
339 cmpl $0, %ebx\r
340 je MemMapDone\r
341 jmp MemMapLoop\r
342MemMapDone: \r
343 leal MemoryMap, %eax\r
344 subl %eax, %edi # Get the address of the memory map\r
345 movl %edi, MemoryMapSize # Save the size of the memory map\r
346\r
347 xorl %ebx, %ebx\r
348 movw %cs, %bx # BX=segment\r
349 shll $4, %ebx # BX="linear" address of segment base\r
350 leal GDT_BASE(%ebx), %eax # EAX=PHYSICAL address of gdt\r
351 movl %eax, gdtr + 2 # Put address of gdt into the gdtr\r
352 leal IDT_BASE(%ebx), %eax # EAX=PHYSICAL address of idt\r
353 movl %eax, idtr + 2 # Put address of idt into the idtr\r
354 leal MemoryMapSize(%ebx), %edx # Physical base address of the memory map\r
355\r
356 addl $0x1000, %ebx # Source of EFI32\r
357 movl %ebx, JUMP+2\r
358 addl $0x1000, %ebx\r
359 movl %ebx, %esi # Source of EFILDR32\r
360\r
361# mov ax,0b800h\r
362# mov es,ax\r
363# mov byte ptr es:[162],'b'\r
364# mov ax,cs\r
365# mov es,ax\r
366\r
367#\r
368# Enable A20 Gate \r
369#\r
370\r
371 movw $0x2401, %ax # Enable A20 Gate\r
372 int $0x15\r
373 jnc A20GateEnabled # Jump if it suceeded\r
374\r
375#\r
376# If INT 15 Function 2401 is not supported, then attempt to Enable A20 manually.\r
377#\r
378\r
379 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller\r
380 jnz Timeout8042 # Jump if the 8042 timed out\r
381 outw %ax, $DELAY_PORT # Delay 1 uS\r
382 movb $WRITE_DATA_PORT_CMD, %al # 8042 cmd to write output port\r
383 outb %al, $KBD_STATUS_PORT # Send command to the 8042\r
384 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller\r
385 jnz Timeout8042 # Jump if the 8042 timed out\r
386 movb $ENABLE_A20_CMD, %al # gate address bit 20 on\r
387 outb %al, $KBD_CONTROL_PORT # Send command to thre 8042\r
388 call Empty8042InputBuffer # Empty the Input Buffer on the 8042 controller\r
389 movw $25, %cx # Delay 25 uS for the command to complete on the 8042\r
390Delay25uS: \r
391 outw %ax, $DELAY_PORT # Delay 1 uS\r
392 loop Delay25uS\r
393Timeout8042: \r
394\r
395\r
396A20GateEnabled: \r
397\r
398#\r
399# DISABLE INTERRUPTS - Entering Protected Mode\r
400#\r
401\r
402 cli\r
403\r
404# mov ax,0b800h\r
405# mov es,ax\r
406# mov byte ptr es:[164],'c'\r
407# mov ax,cs\r
408# mov es,ax\r
409\r
410 .byte 0x66\r
411 lgdt gdtr\r
412 .byte 0x66\r
413 lidt idtr\r
414\r
415 movl %cr0, %eax\r
416 orb $1, %al\r
417 movl %eax, %cr0\r
418\r
419 movl $0x008, %eax # Flat data descriptor\r
420 movl $0x00400000, %ebp # Destination of EFILDR32\r
421 movl $0x00070000, %ebx # Length of copy\r
422\r
423JUMP: \r
424# jmp far 0010:00020000\r
425 .byte 0x66\r
426 .byte 0xea\r
427 .long 0x00020000\r
428 .word 0x0010\r
429\r
430Empty8042InputBuffer: \r
431 movw $0, %cx\r
432Empty8042Loop: \r
433 outw %ax, $DELAY_PORT # Delay 1us\r
434 inb $KBD_STATUS_PORT, %al # Read the 8042 Status Port\r
435 andb $0x2, %al # Check the Input Buffer Full Flag\r
436 loopnz Empty8042Loop # Loop until the input buffer is empty or a timout of 65536 uS\r
437 ret\r
438\r
439##############################################################################\r
440# data\r
441##############################################################################\r
442\r
443 .align 0x2\r
444\r
445gdtr: .word GDT_END - GDT_BASE - 1 # GDT limit\r
446 .long 0 # (GDT base gets set above)\r
447##############################################################################\r
448# global descriptor table (GDT)\r
449##############################################################################\r
450\r
451 .align 0x2\r
452\r
453.global GDT_BASE\r
454GDT_BASE: \r
455# null descriptor\r
456.equ NULL_SEL, .-GDT_BASE\r
457 .word 0 # limit 15:0\r
458 .word 0 # base 15:0\r
459 .byte 0 # base 23:16\r
460 .byte 0 # type\r
461 .byte 0 # limit 19:16, flags\r
462 .byte 0 # base 31:24\r
463\r
464# linear data segment descriptor\r
465.equ LINEAR_SEL, .-GDT_BASE\r
466 .word 0xFFFF # limit 0xFFFFF\r
467 .word 0 # base 0\r
468 .byte 0\r
469 .byte 0x92 # present, ring 0, data, expand-up, writable\r
470 .byte 0xCF # page-granular, 32-bit\r
471 .byte 0\r
472\r
473# linear code segment descriptor\r
474.equ LINEAR_CODE_SEL, .-GDT_BASE\r
475 .word 0xFFFF # limit 0xFFFFF\r
476 .word 0 # base 0\r
477 .byte 0\r
478 .byte 0x9A # present, ring 0, data, expand-up, writable\r
479 .byte 0xCF # page-granular, 32-bit\r
480 .byte 0\r
481\r
482# system data segment descriptor\r
483.equ SYS_DATA_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# system code segment descriptor\r
492.equ SYS_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# spare segment descriptor\r
501.equ SPARE3_SEL, .-GDT_BASE\r
502 .word 0 # limit 0xFFFFF\r
503 .word 0 # base 0\r
504 .byte 0\r
505 .byte 0 # present, ring 0, data, expand-up, writable\r
506 .byte 0 # page-granular, 32-bit\r
507 .byte 0\r
508\r
509# spare segment descriptor\r
510.equ SPARE4_SEL, .-GDT_BASE\r
511 .word 0 # limit 0xFFFFF\r
512 .word 0 # base 0\r
513 .byte 0\r
514 .byte 0 # present, ring 0, data, expand-up, writable\r
515 .byte 0 # page-granular, 32-bit\r
516 .byte 0\r
517\r
518# spare segment descriptor\r
519.equ SPARE5_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
527GDT_END: \r
528\r
529 .align 0x2\r
530\r
531\r
532\r
533idtr: .word IDT_END - IDT_BASE - 1 # IDT limit\r
534 .long 0 # (IDT base gets set above)\r
535##############################################################################\r
536# interrupt descriptor table (IDT)\r
537#\r
538# Note: The hardware IRQ's specified in this table are the normal PC/AT IRQ\r
539# mappings. This implementation only uses the system timer and all other\r
540# IRQs will remain masked. The descriptors for vectors 33+ are provided\r
541# for convenience.\r
542##############################################################################\r
543\r
544#idt_tag db "IDT",0 \r
545 .align 0x2\r
546\r
547.global IDT_BASE\r
548IDT_BASE: \r
549# divide by zero (INT 0)\r
550.equ DIV_ZERO_SEL, .-IDT_BASE\r
551 .word 0 # offset 15:0\r
552 .word SYS_CODE_SEL # selector 15:0\r
553 .byte 0 # 0 for interrupt gate\r
554 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
555 .word 0 # offset 31:16\r
556\r
557# debug exception (INT 1)\r
558.equ DEBUG_EXCEPT_SEL, .-IDT_BASE\r
559 .word 0 # offset 15:0\r
560 .word SYS_CODE_SEL # selector 15:0\r
561 .byte 0 # 0 for interrupt gate\r
562 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
563 .word 0 # offset 31:16\r
564\r
565# NMI (INT 2)\r
566.equ NMI_SEL, .-IDT_BASE\r
567 .word 0 # offset 15:0\r
568 .word SYS_CODE_SEL # selector 15:0\r
569 .byte 0 # 0 for interrupt gate\r
570 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
571 .word 0 # offset 31:16\r
572\r
573# soft breakpoint (INT 3)\r
574.equ BREAKPOINT_SEL, .-IDT_BASE\r
575 .word 0 # offset 15:0\r
576 .word SYS_CODE_SEL # selector 15:0\r
577 .byte 0 # 0 for interrupt gate\r
578 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
579 .word 0 # offset 31:16\r
580\r
581# overflow (INT 4)\r
582.equ OVERFLOW_SEL, .-IDT_BASE\r
583 .word 0 # offset 15:0\r
584 .word SYS_CODE_SEL # selector 15:0\r
585 .byte 0 # 0 for interrupt gate\r
586 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
587 .word 0 # offset 31:16\r
588\r
589# bounds check (INT 5)\r
590.equ BOUNDS_CHECK_SEL, .-IDT_BASE\r
591 .word 0 # offset 15:0\r
592 .word SYS_CODE_SEL # selector 15:0\r
593 .byte 0 # 0 for interrupt gate\r
594 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
595 .word 0 # offset 31:16\r
596\r
597# invalid opcode (INT 6)\r
598.equ INVALID_OPCODE_SEL, .-IDT_BASE\r
599 .word 0 # offset 15:0\r
600 .word SYS_CODE_SEL # selector 15:0\r
601 .byte 0 # 0 for interrupt gate\r
602 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
603 .word 0 # offset 31:16\r
604\r
605# device not available (INT 7)\r
606.equ DEV_NOT_AVAIL_SEL, .-IDT_BASE\r
607 .word 0 # offset 15:0\r
608 .word SYS_CODE_SEL # selector 15:0\r
609 .byte 0 # 0 for interrupt gate\r
610 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
611 .word 0 # offset 31:16\r
612\r
613# double fault (INT 8)\r
614.equ DOUBLE_FAULT_SEL, .-IDT_BASE\r
615 .word 0 # offset 15:0\r
616 .word SYS_CODE_SEL # selector 15:0\r
617 .byte 0 # 0 for interrupt gate\r
618 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
619 .word 0 # offset 31:16\r
620\r
621# Coprocessor segment overrun - reserved (INT 9)\r
622.equ RSVD_INTR_SEL1, .-IDT_BASE\r
623 .word 0 # offset 15:0\r
624 .word SYS_CODE_SEL # selector 15:0\r
625 .byte 0 # 0 for interrupt gate\r
626 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
627 .word 0 # offset 31:16\r
628\r
629# invalid TSS (INT 0ah)\r
630.equ INVALID_TSS_SEL, .-IDT_BASE\r
631 .word 0 # offset 15:0\r
632 .word SYS_CODE_SEL # selector 15:0\r
633 .byte 0 # 0 for interrupt gate\r
634 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
635 .word 0 # offset 31:16\r
636\r
637# segment not present (INT 0bh)\r
638.equ SEG_NOT_PRESENT_SEL, .-IDT_BASE\r
639 .word 0 # offset 15:0\r
640 .word SYS_CODE_SEL # selector 15:0\r
641 .byte 0 # 0 for interrupt gate\r
642 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
643 .word 0 # offset 31:16\r
644\r
645# stack fault (INT 0ch)\r
646.equ STACK_FAULT_SEL, .-IDT_BASE\r
647 .word 0 # offset 15:0\r
648 .word SYS_CODE_SEL # selector 15:0\r
649 .byte 0 # 0 for interrupt gate\r
650 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
651 .word 0 # offset 31:16\r
652\r
653# general protection (INT 0dh)\r
654.equ GP_FAULT_SEL, .-IDT_BASE\r
655 .word 0 # offset 15:0\r
656 .word SYS_CODE_SEL # selector 15:0\r
657 .byte 0 # 0 for interrupt gate\r
658 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
659 .word 0 # offset 31:16\r
660\r
661# page fault (INT 0eh)\r
662.equ PAGE_FAULT_SEL, .-IDT_BASE\r
663 .word 0 # offset 15:0\r
664 .word SYS_CODE_SEL # selector 15:0\r
665 .byte 0 # 0 for interrupt gate\r
666 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
667 .word 0 # offset 31:16\r
668\r
669# Intel reserved - do not use (INT 0fh)\r
670.equ RSVD_INTR_SEL2, .-IDT_BASE\r
671 .word 0 # offset 15:0\r
672 .word SYS_CODE_SEL # selector 15:0\r
673 .byte 0 # 0 for interrupt gate\r
674 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
675 .word 0 # offset 31:16\r
676\r
677# floating point error (INT 10h)\r
678.equ FLT_POINT_ERR_SEL, .-IDT_BASE\r
679 .word 0 # offset 15:0\r
680 .word SYS_CODE_SEL # selector 15:0\r
681 .byte 0 # 0 for interrupt gate\r
682 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
683 .word 0 # offset 31:16\r
684\r
685# alignment check (INT 11h)\r
686.equ ALIGNMENT_CHECK_SEL, .-IDT_BASE\r
687 .word 0 # offset 15:0\r
688 .word SYS_CODE_SEL # selector 15:0\r
689 .byte 0 # 0 for interrupt gate\r
690 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
691 .word 0 # offset 31:16\r
692\r
693# machine check (INT 12h)\r
694.equ MACHINE_CHECK_SEL, .-IDT_BASE\r
695 .word 0 # offset 15:0\r
696 .word SYS_CODE_SEL # selector 15:0\r
697 .byte 0 # 0 for interrupt gate\r
698 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
699 .word 0 # offset 31:16\r
700\r
701# SIMD floating-point exception (INT 13h)\r
702.equ SIMD_EXCEPTION_SEL, .-IDT_BASE\r
703 .word 0 # offset 15:0\r
704 .word SYS_CODE_SEL # selector 15:0\r
705 .byte 0 # 0 for interrupt gate\r
706 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
707 .word 0 # offset 31:16\r
708\r
709# 85 unspecified descriptors, First 12 of them are reserved, the rest are avail\r
710 .fill 85 * 8, 1, 0\r
711\r
712# IRQ 0 (System timer) - (INT 68h)\r
713.equ IRQ0_SEL, .-IDT_BASE\r
714 .word 0 # offset 15:0\r
715 .word SYS_CODE_SEL # selector 15:0\r
716 .byte 0 # 0 for interrupt gate\r
717 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
718 .word 0 # offset 31:16\r
719\r
720# IRQ 1 (8042 Keyboard controller) - (INT 69h)\r
721.equ IRQ1_SEL, .-IDT_BASE\r
722 .word 0 # offset 15:0\r
723 .word SYS_CODE_SEL # selector 15:0\r
724 .byte 0 # 0 for interrupt gate\r
725 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
726 .word 0 # offset 31:16\r
727\r
728# Reserved - IRQ 2 redirect (IRQ 2) - DO NOT USE!!! - (INT 6ah)\r
729.equ IRQ2_SEL, .-IDT_BASE\r
730 .word 0 # offset 15:0\r
731 .word SYS_CODE_SEL # selector 15:0\r
732 .byte 0 # 0 for interrupt gate\r
733 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
734 .word 0 # offset 31:16\r
735\r
736# IRQ 3 (COM 2) - (INT 6bh)\r
737.equ IRQ3_SEL, .-IDT_BASE\r
738 .word 0 # offset 15:0\r
739 .word SYS_CODE_SEL # selector 15:0\r
740 .byte 0 # 0 for interrupt gate\r
741 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
742 .word 0 # offset 31:16\r
743\r
744# IRQ 4 (COM 1) - (INT 6ch)\r
745.equ IRQ4_SEL, .-IDT_BASE\r
746 .word 0 # offset 15:0\r
747 .word SYS_CODE_SEL # selector 15:0\r
748 .byte 0 # 0 for interrupt gate\r
749 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
750 .word 0 # offset 31:16\r
751\r
752# IRQ 5 (LPT 2) - (INT 6dh)\r
753.equ IRQ5_SEL, .-IDT_BASE\r
754 .word 0 # offset 15:0\r
755 .word SYS_CODE_SEL # selector 15:0\r
756 .byte 0 # 0 for interrupt gate\r
757 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
758 .word 0 # offset 31:16\r
759\r
760# IRQ 6 (Floppy controller) - (INT 6eh)\r
761.equ IRQ6_SEL, .-IDT_BASE\r
762 .word 0 # offset 15:0\r
763 .word SYS_CODE_SEL # selector 15:0\r
764 .byte 0 # 0 for interrupt gate\r
765 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
766 .word 0 # offset 31:16\r
767\r
768# IRQ 7 (LPT 1) - (INT 6fh)\r
769.equ IRQ7_SEL, .-IDT_BASE\r
770 .word 0 # offset 15:0\r
771 .word SYS_CODE_SEL # selector 15:0\r
772 .byte 0 # 0 for interrupt gate\r
773 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
774 .word 0 # offset 31:16\r
775\r
776# IRQ 8 (RTC Alarm) - (INT 70h)\r
777.equ IRQ8_SEL, .-IDT_BASE\r
778 .word 0 # offset 15:0\r
779 .word SYS_CODE_SEL # selector 15:0\r
780 .byte 0 # 0 for interrupt gate\r
781 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
782 .word 0 # offset 31:16\r
783\r
784# IRQ 9 - (INT 71h)\r
785.equ IRQ9_SEL, .-IDT_BASE\r
786 .word 0 # offset 15:0\r
787 .word SYS_CODE_SEL # selector 15:0\r
788 .byte 0 # 0 for interrupt gate\r
789 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
790 .word 0 # offset 31:16\r
791\r
792# IRQ 10 - (INT 72h)\r
793.equ IRQ10_SEL, .-IDT_BASE\r
794 .word 0 # offset 15:0\r
795 .word SYS_CODE_SEL # selector 15:0\r
796 .byte 0 # 0 for interrupt gate\r
797 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
798 .word 0 # offset 31:16\r
799\r
800# IRQ 11 - (INT 73h)\r
801.equ IRQ11_SEL, .-IDT_BASE\r
802 .word 0 # offset 15:0\r
803 .word SYS_CODE_SEL # selector 15:0\r
804 .byte 0 # 0 for interrupt gate\r
805 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
806 .word 0 # offset 31:16\r
807\r
808# IRQ 12 (PS/2 mouse) - (INT 74h)\r
809.equ IRQ12_SEL, .-IDT_BASE\r
810 .word 0 # offset 15:0\r
811 .word SYS_CODE_SEL # selector 15:0\r
812 .byte 0 # 0 for interrupt gate\r
813 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
814 .word 0 # offset 31:16\r
815\r
816# IRQ 13 (Floating point error) - (INT 75h)\r
817.equ IRQ13_SEL, .-IDT_BASE\r
818 .word 0 # offset 15:0\r
819 .word SYS_CODE_SEL # selector 15:0\r
820 .byte 0 # 0 for interrupt gate\r
821 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
822 .word 0 # offset 31:16\r
823\r
824# IRQ 14 (Secondary IDE) - (INT 76h)\r
825.equ IRQ14_SEL, .-IDT_BASE\r
826 .word 0 # offset 15:0\r
827 .word SYS_CODE_SEL # selector 15:0\r
828 .byte 0 # 0 for interrupt gate\r
829 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
830 .word 0 # offset 31:16\r
831\r
832# IRQ 15 (Primary IDE) - (INT 77h)\r
833.equ IRQ15_SEL, .-IDT_BASE\r
834 .word 0 # offset 15:0\r
835 .word SYS_CODE_SEL # selector 15:0\r
836 .byte 0 # 0 for interrupt gate\r
837 .byte 0x0e | 0x80 # (10001110)type = 386 interrupt gate, present\r
838 .word 0 # offset 31:16\r
839\r
840IDT_END: \r
841\r
842 .align 0x2\r
843\r
844MemoryMapSize: .long 0\r
845MemoryMap: .long 0,0,0,0,0,0,0,0\r
846 .long 0,0,0,0,0,0,0,0\r
847 .long 0,0,0,0,0,0,0,0\r
848 .long 0,0,0,0,0,0,0,0\r
849 .long 0,0,0,0,0,0,0,0\r
850 .long 0,0,0,0,0,0,0,0\r
851 .long 0,0,0,0,0,0,0,0\r
852 .long 0,0,0,0,0,0,0,0\r
853 .long 0,0,0,0,0,0,0,0\r
854 .long 0,0,0,0,0,0,0,0\r
855 .long 0,0,0,0,0,0,0,0\r
856 .long 0,0,0,0,0,0,0,0\r
857 .long 0,0,0,0,0,0,0,0\r
858 .long 0,0,0,0,0,0,0,0\r
859 .long 0,0,0,0,0,0,0,0\r
860 .long 0,0,0,0,0,0,0,0\r
861 .long 0,0,0,0,0,0,0,0\r
862 .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\r
876 .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
877 .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
878\r
879 .org 0x0fe0\r
880MyStack: \r
881 # below is the pieces of the IVT that is used to redirect INT 68h - 6fh\r
882 # back to INT 08h - 0fh when in real mode... It is 'org'ed to a\r
883 # known low address (20f00) so it can be set up by PlMapIrqToVect in\r
884 # 8259.c\r
885\r
886 int $8\r
887 iret\r
888\r
889 int $9\r
890 iret\r
891\r
892 int $10\r
893 iret\r
894\r
895 int $11\r
896 iret\r
897\r
898 int $12\r
899 iret\r
900\r
901 int $13\r
902 iret\r
903\r
904 int $14\r
905 iret\r
906\r
907 int $15\r
908 iret\r
909\r
910\r
911 .org 0x0ffe\r
912BlockSignature: \r
913 .word 0xaa55\r