BCOS 80x86 SourceProject Map
80x86 OS Installation Boot CD Image
File: 80x86/bootcd/0index.asm
 

Copyright © Brendan Trotter 2008

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Overview

This source code creates a default boot CD image (mainly intended for installing the operating system).


Notes

"d-characters" are ASCII characters with values 0x30 to 0x39 (numerical digits 0 to 9), 0x41 to 0x5A (upper case letters from A to Z), and 0x5F (underscore). This means no space characters(?).

"a-characters" are ASCII characters with values 0x20 to 0x22 (space, exclamation mark, double quote), 0x25 to 0x3F (characters "%&'()*+,-./0123456789:;<=>?", 0x41 to 0x5A (upper case letters from A to Z), and 0x5F (underscore).


Macros

 27: ;Misc. macros
 28: 
 29: %ifdef __UTC_DATE_NUM__
 30:  %ifdef __UTC_TIME_NUM__
 31:   %define USE_UTC
 32:  %endif
 33:  %endif
 34: 
 35: 
 36: %ifdef USE_UTC
 37:  %defstr CURRENT_DATE_STRING __UTC_DATE_NUM__
 38:  %defstr CURRENT_TIME_STRING __UTC_TIME_NUM__
 39: %else
 40:  %defstr CURRENT_DATE_STRING __DATE_NUM__
 41:  %defstr CURRENT_TIME_STRING __TIME_NUM__
 42: %endif
 43: 
 44: 
 45: %macro NULL_TIME 0
 46:       times 16 db '0'
 47:       db 0
 48: %endmacro
 49: 
 50: 
 51: %macro CURRENT_TIME 0
 52:       db CURRENT_DATE_STRING
 53:       db CURRENT_TIME_STRING
 54:       db '00'                 ;Hundreths of a second
 55:       db 3                    ;Offset from "Greenwich Mean Time"
 56: %endmacro
 57: 
 58: 
 59: %macro BIG_ENDIAN_WORD 1
 60:       db (%1) >> 8                                                ;Big endian word (first byte/high byte)
 61:       db (%1) & 0xFF                                              ;Big endian word (second byte/low byte)
 62: %endmacro
 63: 
 64: 
 65: %macro BIG_ENDIAN_DWORD 1
 66:       db ((%1) >> 24) & 0xFF                                      ;Big endian dword (first byte/high byte)
 67:       db ((%1) >> 16) & 0xFF                                      ;Big endian dword (second byte)
 68:       db ((%1) >> 8) & 0xFF                                       ;Big endian dword (third byte)
 69:       db (%1) & 0xFF                                              ;Big endian dword (fourth byte/low byte)
 70: %endmacro
 71: 
 72: 
 73: %macro MIXED_ENDIAN_WORD 1
 74:       dw %1                                                       ;Little endian word
 75:       db (%1) >> 8                                                ;Big endian word (first byte/high byte)
 76:       db (%1) & 0xFF                                              ;Big endian word (second byte/low byte)
 77: %endmacro
 78: 
 79: 
 80: %macro MIXED_ENDIAN_DWORD 1
 81:       dd %1                                                       ;Little endian dword
 82:       db ((%1) >> 24) & 0xFF                                      ;Big endian dword (first byte/high byte)
 83:       db ((%1) >> 16) & 0xFF                                      ;Big endian dword (second byte)
 84:       db ((%1) >> 8) & 0xFF                                       ;Big endian dword (third byte)
 85:       db (%1) & 0xFF                                              ;Big endian dword (fourth byte/low byte)
 86: %endmacro
 87: 
 88: 
 89: 
 90: ;Path table macros
 91: 
 92: %macro PATH_TABLE 1
 93:  %ifidni %1, L
 94:   %push PATH_L
 95:  %else
 96:   %push PATH_M
 97:  %endif
 98: %endmacro
 99: 
100: 
101: %macro PATH_ENTRY 3+
102:       db %%l2 - %%l1                                              ;Length of directory identifier
103:       db 0                                                        ;Length of extended data
104:  %ifctx PATH_L
105:       dd (%1 - IMAGE_START) / 2048                                ;Starting sector
106:       dw %2                                                       ;Parent directory number
107:  %else
108:       BIG_ENDIAN_DWORD (%1 - IMAGE_START) / 2048                  ;Starting sector
109:       BIG_ENDIAN_WORD %2                                          ;Parent directory number
110:  %endif
111: %%l1:
112:       db %3                                                       ;Directory identifier
113: %%l2:
114:       times (%%l2 - %%l1) & 1 db 0                                ;Padding byte (only if directory identifer length is odd)
115: %endmacro
116: 
117: 
118: %macro PATH_TABLE_END 0
119:  %ifctx PATH_L
120:   %pop
121:  %endif
122:  %ifctx PATH_M
123:   %pop
124:  %endif
125: .end:
126:       align 2048, db 0
127: %endmacro
128: 
129: 
130: ;Directory entry macros
131: 
132: %macro DIR_ENTRY 3+
133: %%l1:
134:       db %%l4 - %%l1                                              ;Length of directory entry
135:       db 0                                                        ;Length of extended data
136:       MIXED_ENDIAN_DWORD (%1 - IMAGE_START) / 2048                ;Starting sector
137:       MIXED_ENDIAN_DWORD %{1}.end - %1                            ;Number of bytes of data
138:  %ifdef USE_UTC
139:       db (__UTC_DATE_NUM__ / 10000) - 1900                        ;Years since 1900
140:       db (__UTC_DATE_NUM__ / 100) % 100                           ;Month
141:       db __UTC_DATE_NUM__  % 100                                  ;Day of month
142:       db (__UTC_TIME_NUM__ / 10000) - 1900                        ;Hour
143:       db (__UTC_TIME_NUM__ / 100) % 100                           ;Minute
144:       db __UTC_TIME_NUM__  % 100                                  ;Second
145:  %else
146:       db (__DATE_NUM__ / 10000) - 1900                            ;Years since 1900
147:       db (__DATE_NUM__ / 100) % 100                               ;Month
148:       db __DATE_NUM__  % 100                                      ;Day of month
149:       db (__DATE_NUM__ / 10000) - 1900                            ;Hour
150:       db (__DATE_NUM__ / 100) % 100                               ;Minute
151:       db __DATE_NUM__  % 100                                      ;Second
152:  %endif
153:       db 3                                                        ;Offset from "Greenwich Mean Time"
154:       db %2                                                       ;File flags
155:       db 0                                                        ;File unit size (zero if file doesn't used interleaved mode)
156:       db 0                                                        ;Interleave gap size (zero if file doesn't used interleaved mode)
157:       MIXED_ENDIAN_WORD 1                                         ;Volume sequence number
158:       db %%l3 - %%l2                                              ;File identifier length
159: %%l2:
160:       db %3                                                       ;File identifier
161: %%l3:
162:       times ~(%%l3 - %%l2) & 1 db 0                               ;Padding byte (only if file identifer length is even)
163: %%l4:
164: %endmacro
165: 
166: %define F_HIDDEN        0x01
167: %define F_DIRECTORY     0x02
168: %define SELF            0x00
169: %define PARENT          0x01
170: 
171: 
172: %macro DIR_START 2
173:       DIR_ENTRY %1, F_DIRECTORY, SELF
174:       DIR_ENTRY %2, F_DIRECTORY, PARENT
175: %endmacro
176: 
177: %macro DIR_END 0
178:       align 2048, db 0
179: .end:
180: %endmacro
181: 
182: 
183: ;File macros
184: 
185: %macro ADD_FILE_END 0
186: .end:
187:       align 2048, db 0
188: %endmacro


Assembler Setup

194:       ORG 0
195: IMAGE_START:


Data


(Sectors 0 to 15) System Area

204: ;This is 16 sectors (sector 0 to sector 15) that are reserved for system use.
205: 
206:       times 2048*16 db 0


(Sector 16) Primary Volume Descriptor

212:       db 1                                                        ;Volume descriptor type
213:       db "CD001"                                                  ;Standard identifier
214:       db 1                                                        ;Volume descriptor version
215:       db 0                                                        ;unused
216:       db "BCOS                            "                       ;System identifier ("a-characters")
217:       db "VOLUME_IDENTIFIER_0000000000001A"                       ;Volume identifier ("d-characters")
218:       db 0,0,0,0,0,0,0,0                                          ;unused
219:       MIXED_ENDIAN_DWORD (IMAGE_END - IMAGE_START + 2047)/2048    ;Volume space size (in logical blocks)
220:       times 32 db 0                                               ;unused
221:       MIXED_ENDIAN_WORD 1                                         ;Volume set size
222:       MIXED_ENDIAN_WORD 1                                         ;Volume sequence number (first volume of a one volume set)
223:       MIXED_ENDIAN_WORD 2048                                      ;Logical block size in bytes
224:       MIXED_ENDIAN_DWORD PATH_TABLE_L.end - PATH_TABLE_L          ;Path table size
225:       dd (PATH_TABLE_L - IMAGE_START) / 2048                      ;Location of Type L Path Table
226:       dd 0                                                        ;Location of optional Type L Path Table
227:       BIG_ENDIAN_DWORD (PATH_TABLE_M - IMAGE_START) / 2048        ;Location of Type M Path Table
228:       dd 0                                                        ;Location of optional Type M Path Table
229:       DIR_ENTRY ROOT_DIR, F_DIRECTORY, SELF                       ;Directory record for root directory
230:       db "________________________________"                       ;Volume set identifier, part 1 ("d-characters")
231:       db "________________________________"                       ;Volume set identifier, part 2 ("d-characters")
232:       db "________________________________"                       ;Volume set identifier, part 3 ("d-characters")
233:       db "________________________________"                       ;Volume set identifier, part 4 ("d-characters")
234:       db "BRENDAN TROTTER                 "                       ;Publisher identifier, part 1 ("a-characters")
235:       db "                                "                       ;Publisher identifier, part 2 ("a-characters")
236:       db "                                "                       ;Publisher identifier, part 3 ("a-characters")
237:       db "                                "                       ;Publisher identifier, part 4 ("a-characters")
238:       db "BRENDAN TROTTER                 "                       ;Data preparer identifier, part 1 ("a-characters")
239:       db "                                "                       ;Data preparer identifier, part 2 ("a-characters")
240:       db "                                "                       ;Data preparer identifier, part 3 ("a-characters")
241:       db "                                "                       ;Data preparer identifier, part 4 ("a-characters")
242:       db "CUSTOM ASSEMBLY LANGUAGE        "                       ;Application identifier, part 1 ("a-characters")
243:       db "                                "                       ;Application identifier, part 2 ("a-characters")
244:       db "                                "                       ;Application identifier, part 3 ("a-characters")
245:       db "                                "                       ;Application identifier, part 4 ("a-characters")
246:       times 37 db ' '                                             ;Copyright file identifier (none)
247:       times 37 db ' '                                             ;Abstract file identifier (none)
248:       times 37 db ' '                                             ;Bibliographic file identifier (none)
249:       CURRENT_TIME                                                ;Volume creation date and time
250:       CURRENT_TIME                                                ;Volume modification date and time
251:       NULL_TIME                                                   ;Volume expiration date and time
252:       NULL_TIME                                                   ;Volume effective date and time
253:       db 1                                                        ;File structure version
254:       db 0                                                        ;Reserved/unused
255:       times 512 db 0                                              ;Application use
256:       times 653 db 0                                              ;Reserved/unused


(Sector 17) Boot Record Volume Descriptor

262: ;WARNING: The El Torito specification directly contradicts the ECMA-119 Standard
263: ;         for the format of the "a-character" fields. This data reluctantly
264: ;         follows the El Torito specification's use of zeros in "a-character"
265: ;         fields.
266: 
267:       db 0                                                        ;Volume descriptor type
268:       db "CD001"                                                  ;Standard identifier
269:       db 1                                                        ;Volume descriptor version
270:       db "EL TORITO SPECIFICATION",0,0,0,0,0,0,0,0,0              ;Boot system identifier ("a-characters", sort of)
271:       db "                                "                       ;Boot identifier ("a-characters")
272:       dd (BOOT_CATALOGUE - IMAGE_START) / 2048                    ;Absolute pointer to first sector of boot catalogue (this is a sector number)
273:       times 1973 db 0                                             ;Unused


(Sector 18) Set Terminator Volume Descriptor

279:       db 255                                                      ;Volume descriptor type
280:       db "CD001"                                                  ;Standard identifier
281:       db 1                                                        ;Volume descriptor version
282:       times 2041 db 0                                             ;Reserved/unused


(Sector 19) Boot Catalogue

288: ;WARNING: The El Torito specification doesn't say which characters are allowed
289: ;         in character strings, and the only thing it does say is "All character
290: ;         strings are padded to their full length with hex zeros.". I've assumed
291: ;         that all characters are "a-characters". I'm still trying to figure out the
292: ;         difference between "hex zeros" and other types of zeros, and have assumed
293: ;         they won't mind if I use "decimal zeros" instead... :-)
294: 
295: BOOT_CATALOGUE:
296: 
297: ;Validation entry
298: 
299:       db 1                                                        ;Header ID
300:       db 0                                                        ;Platform ID (80x86)
301:       dw 0                                                        ;Reserved/unused
302:       db "BRENDAN TROTTER",0,0,0,0,0,0,0,0,0                      ;ID string
303:       dw -(0x0001 + "BR" + "EN" + "DA" + "N " + "TR" + "OT" + "TE" + "R" + 0xAA55)              ;Checksum
304:       dw 0xAA55                                                   ;Key bytes
305: 
306: ;Initial/Default Entry
307: 
308:       db 0x88                                                     ;Boot indicator
309:       db 0x00                                                     ;Media type (0x00 = "no emulation")
310:       dw 0x07C0                                                   ;Load segment
311:       db 0                                                        ;Partition type (assumed to be unused for "no emulation")
312:       db 0                                                        ;Unused, must be 0
313:       dw (BOOT_LOADER.end - BOOT_LOADER + 511) / 512              ;Sector count (virtual 512-byte sectors)
314:       dd (BOOT_LOADER - IMAGE_START) / 2048                       ;First sector number for boot loader
315:       times 20 db 0                                               ;Unused, must be zero
316: 
317: ;Padding
318: 
319:       times 62*32 db 0                                            ;62 unused entries


(Sector 20 to Sector ?) Boot Loader

325: BOOT_LOADER:
326:       incbin "../sys_src/bin/bootcd.bin"
327:       ADD_FILE_END


Type L Path Table

333: PATH_TABLE_L:
334:       PATH_TABLE L
335:       PATH_ENTRY ROOT_DIR, 1, 0
336:       PATH_ENTRY BOOT_DIR, 1, "BOOT"
337:       PATH_ENTRY FLOPPY_DIR, 1, "FLOPPY"
338:       PATH_TABLE_END


Type M Path Table

344: PATH_TABLE_M:
345:       PATH_TABLE M
346:       PATH_ENTRY ROOT_DIR, 1, 0
347:       PATH_ENTRY BOOT_DIR, 1, "BOOT"
348:       PATH_ENTRY FLOPPY_DIR, 1, "FLOPPY"
349:       PATH_TABLE_END


Root Directory

355: ROOT_DIR:
356:       DIR_START ROOT_DIR, ROOT_DIR
357:       DIR_ENTRY BOOT_DIR, F_DIRECTORY, "BOOT"
358:       DIR_ENTRY FLOPPY_DIR, F_DIRECTORY, "FLOPPY"
359:       DIR_END


"BOOT" Directory

366: BOOT_DIR:
367:       DIR_START BOOT_DIR, ROOT_DIR
368:       DIR_ENTRY BOOT_IMAGE_FILE, 0, "BOOT.BIM;1"
369:       DIR_ENTRY BOOT_SCRIPT_FILE, 0, "BOOT.BSC;1"
370:       DIR_ENTRY BOOT_FRL_FILE, 0, "BOOT.FRL;1"
371:       DIR_ENTRY COMMONPC_FILE, 0, "COMMONPC.BIN;1"
372:       DIR_END
373: 
374: BOOT_IMAGE_FILE:
375:       incbin "../bin/install.sbi"
376:       ADD_FILE_END
377: 
378: BOOT_SCRIPT_FILE:
379:       incbin "../bin/default.bsc"
380:       ADD_FILE_END
381: 
382: BOOT_FRL_FILE:
383:       incbin "../bin/default.frl"
384:       ADD_FILE_END
385: 
386: COMMONPC_FILE:
387:       incbin "../sys_src/bin/commonpc.bin"
388:       ADD_FILE_END


"FLOPPY" Directory

394: FLOPPY_DIR:
395:       DIR_START FLOPPY_DIR, ROOT_DIR
396:       DIR_ENTRY FLOPPY1200_FILE, 0, "FLOP1200.IMG;1"
397:       DIR_ENTRY FLOPPY1440_FILE, 0, "FLOP1440.IMG;1"
398:       DIR_ENTRY FLOPPY2880_FILE, 0, "FLOP2880.IMG;1"
399:       DIR_END
400: 
401: FLOPPY1200_FILE:
402:       incbin "../../www/ftp/flop1200.img"
403:       ADD_FILE_END
404: 
405: FLOPPY1440_FILE:
406:       incbin "../../www/ftp/flop1440.img"
407:       ADD_FILE_END
408: 
409: FLOPPY2880_FILE:
410:       incbin "../../www/ftp/flop2880.img"
411:       ADD_FILE_END


The End

417:       align 32 * 1024, db 0
418: IMAGE_END:

Generated on Thu Sep 17 04:38:58 2009