1 ; **************************************************************************** 2 ; TRDOS386.ASM (TRDOS 386 Kernel) - v2.0.0 - trfs1_bs.s - TRFS1 BOOT SECTOR 3 ; ---------------------------------------------------------------------------- 4 ; Turkish Rational SINGLIX File System 1 (Hard Disk) Boot Sector Source Code 5 ; ---------------------------------------------------------------------------- 6 ; Last Update: 04/01/2018 7 ; ---------------------------------------------------------------------------- 8 ; Beginning: 03/01/2018 9 ; ---------------------------------------------------------------------------- 10 ; Assembler: NASM version 2.11 11 ; ---------------------------------------------------------------------------- 12 ; ((nasm trfs1_bs.s -l trfs1_bs.lst -o TRFS1_BS.BIN)) 13 ; ---------------------------------------------------------------------------- 14 ; Turkish Rational DOS 15 ; Operating System Project v2.0 by ERDOGAN TAN (Beginning: 04/01/2016) 16 ; 17 ; Derived from 'fat32_bs.s' TRDOS 386 (v2) FAT32 boot sector source code 18 ; by Erdogan Tan (25/12/2017). 19 ; 20 ; Derived from 'FS1_HDBS.ASM' TRDOS 8086 (v1) Singlix FS1 boot sector 21 ; source code by Erdogan Tan (21/02/2010). 22 ; **************************************************************************** 23 ; incbin "TRFS1_BS.BIN" (in 'hdimage.s' & 'hdformat.s') 24 25 rts_segment equ 1000h 26 27 ; FDT equalities 28 ; 03-01-2018 [ TRFS Issue 2, Revision 14 ] 29 30 FDT_Sign equ 0 ; 'FDT' 31 FDT_SectorSize equ 4 ; 512 32 FDT_Number equ 6 ; FDT sequence number 33 FDT_FileNumber equ 8 ; 1st FDT address (offset) 34 FDT_NextFDTNum equ 12 ; Next FDT address 35 FDT_SectorCount equ 16 ; Sector count in section 36 FDT_ParentDir equ 20 ; Parent directory address 37 FDT_PDirSerial equ 24 ; Parent directory serial number 38 FDT_FileSize equ 28 ; File Size lower 4 bytes 39 FDT_FileSizeHW equ 32 ; File Size higher 2 bytes 40 41 [BITS 16] 42 [ORG 7C00h] 43 bsjmpBoot: 44 00000000 EB40 jmp short loc_42 ; jmp short start 45 bsjmpBoot_nop: 46 00000002 90 nop 47 48 49 ; TR-SINGLIX FS1 BootSector Identification (Data) Block 50 ; 03-01-2018 FS1 HD Partition Boot Sector 51 ; 02-01-2018 [ TRFS Issue 1, Revision 14 ] 52 53 00000003 4653 bsFSystemID: db 'FS' ; bp+3 54 00000005 00 db 0 55 00000006 0002 bsBytesPerSec: dw 512 ; bp+6 56 00000008 01 bsMediaAttrib: db 1 ; bp+8 57 00000009 A1 bsPartitionID: db 0A1h ; bp+9 58 0000000A 01 bsFSVersionMaj: db 01h ; bp+10 59 0000000B 00 bsFSVersionMin: db 0 ; bp+11 60 0000000C 00000000 bsBeginSector: dd 0 ; bp+12 61 00000010 00000000 bsVolumeSize: dd 0 ; bp+16 62 00000014 00000000 bsStartupFDT: dd 0 ; bp+20 63 00000018 02000000 bsMATLocation: dd 2 ; bp+24 64 0000001C 00000000 bsRootDirDT: dd 0 ; bp+28 65 00000020 00000000 bsSysConfFDT: dd 0 ; bp+32 66 00000024 00000000 bsSwapFD: dd 0 ; bp+36 67 00000028 00000000 bsUndelDirDT: dd 0 ; bp+40 68 0000002C 00 bsDriveNumber: db 0 ; bp+44 69 0000002D 01 bs_LBA_Ready: db 01h ; bp+45 70 bsMagicWord: 71 bs_Disk_SecPerTrack: 72 0000002E A1 db 0A1h ; bp+46 73 bs_Disk_Heads: 74 0000002F 01 db 01h ; bp+47 75 bsOperationSys: 76 ; db 'TR-SINGLIX v1.0b' ; bp+48 77 00000030 54522D444F53203338- db 'TR-DOS 386 TRFS1' 77 00000039 36205452465331 78 00000040 00 terminator: db 0 79 80 start: 81 00000041 90 nop 82 loc_42: 83 00000042 BD007C mov bp, 7C00h 84 85 00000045 3DA101 cmp ax, 417 ; If AX=417, the masterboot sector 86 ; has a SINGLIX FS (& TRDOS 386) 87 ; masterboot code; and... 88 ; DX=ES=SS=0, BP=7C00h 89 ; SP=7C00h ... masterboot sector has 90 ; been loaded at 0:600h, it has 91 ; CHS parameters at offset 600h+420. 92 ; (There is a 01A1h in offset 600h+417) 93 94 00000048 740F je short bs_01 ; no need to following assignments ! 95 96 0000004A 31C0 xor ax, ax 97 0000004C 8ED8 mov ds, ax 98 0000004E 8EC0 mov es, ax 99 00000050 FA cli 100 00000051 8ED0 mov ss, ax 101 00000053 89EC mov sp, bp 102 00000055 FB sti 103 00000056 8A562C mov dl, [bp+44] ; [bsDriveNumber] 104 bs_01: 105 00000059 8936[CE01] mov [bsReserved1], si ; Partition entry address.. 106 ; 24/12/2017 ; (from Singlix FS MBR) 107 ; (7BEh,7CEh,7DEh,7EEh) 108 109 ; Check File System ID value 110 0000005D 817E034653 cmp word [bp+3], 'FS' ; [bsFSystemID] 111 00000062 7570 jne invalid_system_disk 112 113 ; Check Bytes/Sector value 114 ; It must be 512 !? (at least, for TRDOS386) 115 00000064 817E060002 cmp word [bp+6], 512 ; [bsBytesPerSec] 116 00000069 7569 jne invalid_system_disk 117 118 ; overwrite hd drive number ! 119 ;mov [bsDriveNumber], dl ; drive number from INT 19h 120 0000006B 88562C mov [bp+44], dl 121 122 ; reset SINGLIX FS1 reading pointers and set SP to 7BF4h 123 0000006E 6631C9 xor ecx, ecx ; * 124 ;sub ecx, ecx ; * 125 00000071 6651 push ecx ; [bp-4] = 0 ; CHS limit (8.4GB) 126 00000073 6651 push ecx ; [bp-8] = 0 ; Startup File (FDT) Address 127 00000075 6651 push ecx ; [bp-12] = 0 ; Remain sectors to read 128 129 ; SP = 7BF4h 130 131 ; check for ROMBIOS INT 13h extensions 132 00000077 B441 mov ah, 41h 133 ;mov ebx, 55AAh 134 00000079 BBAA55 mov bx, 55AAh 135 ;mov dl, [bsDriveNumber] 136 ;mov dl, [bp+44] 137 0000007C CD13 int 13h 138 0000007E 7213 jc short bs_02 139 00000080 81FB55AA cmp bx, 0AA55h 140 00000084 750D jne short bs_02 141 00000086 F6C101 test cl, 1 142 00000089 7408 jz short bs_02 143 0000008B C6460242 mov byte [bp+2], 42h ; LBA ready 144 0000008F 80462D41 add byte [bp+45], 41h 145 bs_02: 146 ; ..CHS limit setup.. 147 148 ; Get drive parameters (CHS parameters) 149 ;mov dl, [bsDriveNumber] 150 ;mov dl, [bp+44] 151 00000093 B408 mov ah, 08h 152 00000095 CD13 int 13h 153 00000097 7247 jc disk_io_error 154 155 ; CX = maximum value for cylinder and sector 156 ; DH = maximum value for head 157 ; DL = number of harddisks on first controller 158 ; ES:DI = address of hard disk parameters table 159 ; (Bits 6&7 of CL is high 2 bits of 10 bit clinder value 160 ; which is low 8 bits are in CH.) 161 162 00000099 1E push ds 163 0000009A 07 pop es 164 165 ; convert CHS values to CHS limit (as LBA) 166 0000009B 660FB6C6 movzx eax, dh 167 0000009F 40 inc ax 168 000000A0 88462F mov [bp+47], al ; [bs_Disk_Heads] 169 ;movzx edx, cl 170 000000A3 88CA mov dl, cl 171 ;and dl, 3Fh 172 000000A5 83E23F and dx, 3Fh 173 000000A8 88562E mov [bp+46], dl ; [bs_Disk_SecPerTrack] 174 000000AB F7E2 mul dx 175 000000AD C0E906 shr cl, 6 176 000000B0 86CD xchg cl, ch 177 000000B2 41 inc cx 178 ;movzx ecx, cx ; * 179 000000B3 66F7E1 mul ecx 180 000000B6 668946FC mov [bp-4], eax ; dword [7BFCh] ; CHS limit 181 182 ; Load the second half (remain bytes) of this boot code 183 ; at 7E00h. 184 185 000000BA 668B460C mov eax, [bp+12] ; [bsBeginSector] 186 000000BE 6683C002 add eax, 2 ; Second half of boot code is in BS 2 187 ;mov ebx, 7E00h 188 000000C2 BB007E mov bx, 7E00h 189 ;mov cx, 1 190 ;call disk_read 191 000000C5 E83500 call read_sector ; (Read 1 sector) 192 000000C8 7216 jc short disk_io_error 193 194 ; Boot sector 2 validation check 195 000000CA 813EA17FA101 cmp word [7FA1h], 417 ; The magic word ! 196 000000D0 0F842E01 je check_startup_file_address 197 198 invalid_system_disk: 199 000000D4 BE[8001] mov si, Inv_disk_Msg 200 000000D7 E81400 call print_msg 201 getchar_reboot: 202 ; Wait for a keystroke just before reboot 203 000000DA 30E4 xor ah, ah 204 000000DC CD16 int 16h 205 206 000000DE CD19 int 19h ; disk boot 207 ; causes reboot of disk system 208 disk_io_error: 209 000000E0 BE[6F01] mov si, Diskio_err_Msg 210 000000E3 E80800 call print_msg 211 ;replace_disk: 212 ; mov si, Replace_Msg 213 replace_disk: 214 000000E6 BE[9501] mov si, Disk_err_replace_Msg 215 000000E9 E80200 call print_msg 216 000000EC EBEC jmp getchar_reboot 217 218 print_msg: 219 ; DS:SI = Error message address (ASCIIZ string) 220 000000EE B40E mov ah, 0Eh 221 000000F0 BB0700 mov bx, 7 222 bs_03: 223 000000F3 AC lodsb 224 000000F4 84C0 test al, al 225 000000F6 7404 jz short bs_04 226 000000F8 CD10 int 10h 227 000000FA EBF7 jmp short bs_03 228 bs_04: 229 000000FC C3 retn 230 231 232 read_sector: ; 25/12/2017 (Read 1 sector) 233 000000FD B90100 mov cx, 1 234 disk_read: 235 ;mov byte [bp+retry_count-7C00h], 4 236 00000100 B204 mov dl, 4 ; retry count 237 disk_read_0: 238 00000102 6660 pushad 239 00000104 B242 mov dl, 42h 240 00000106 38562D cmp [bp+45], dl ; 42h ; TRFS1 LBA partition & LBA ready 241 00000109 740D je short lba_read 242 ; Jump to lba_read if sector addr overs CHS limit 243 0000010B 663B46FC cmp eax, [bp-4] ; CHS limit ([7BFCh]) 244 0000010F 721F jb short chs_read 245 ; Disk I/O error if Int 13h LBA read func is not usable 246 ; byte [bsjmpBoot+2] = 'LBA read function is ready' sign 247 ;cmp byte [bsjmpBoot+2], 42h ; LBA availability 248 ;cmp byte [bp+2], 42h 249 00000111 385602 cmp [bp+2], dl ; 42h ; is LBA mode ready ? 250 00000114 7402 je short lba_read ; LBA mode is usable/available 251 00000116 F9 stc ; cf = 1 252 00000117 C3 retn 253 lba_read: 254 ;pushad 255 256 ;mov di, sp 257 258 00000118 666A00 push dword 0 259 0000011B 6650 push eax 260 0000011D 06 push es 261 0000011E 53 push bx 262 0000011F 6A01 push byte 1 263 00000121 6A10 push byte 16 ; 10h 264 00000123 B442 mov ah, 42h 265 ;mov dl, [bsDriveNumber] 266 00000125 8A562C mov dl, [bp+44] 267 00000128 89E6 mov si, sp 268 0000012A CD13 int 13h 269 270 ;pop eax 271 ;pop eax 272 ;pop eax 273 ;pop eax 274 ;mov sp, di 275 276 0000012C 61 popa 277 0000012D 61 popa 278 0000012E EB2C jmp short disk_read_1 279 chs_read: 280 ;pushad 281 282 ; Convert LBA to CHS 283 00000130 6631D2 xor edx, edx 284 ;movzx ecx, byte [bs_Disk_SecPerTrack] ; [bp+46] 285 ; sectors per track (17 or 63) 286 00000133 660FB64E2E movzx ecx, byte [bp+46] 287 00000138 66F7F1 div ecx 288 0000013B FEC2 inc dl ; sector number (1 based) 289 0000013D 52 push dx 290 0000013E 6689C2 mov edx, eax ; (heads * cylinder) + head number 291 00000141 66C1EA10 shr edx, 16 ; high word in DX, low word in AX 292 ;mov cl, [bs_Disk_Heads] ; [bp+47] 293 00000145 8A4E2F mov cl, [bp+47] ; number of heads (2 to 255) 294 00000148 F7F1 div cx 295 ; AX = cylinder (0 to 1023) 296 ; DX = head number (in DL) 297 0000014A 88D6 mov dh, dl ; head number in DH 298 ;mov dl, [bsDriveNumber] ; [bp+2Ch] ; Drive number (80h) 299 0000014C 8A562C mov dl, [bp+44] 300 0000014F 59 pop cx 301 00000150 88C5 mov ch, al ; Low 8 bits of cylinder number (0 to 7) 302 00000152 C0E406 shl ah, 6 ; High 2 bits of cylinder is in bit 7&8 303 00000155 08E1 or cl, ah ; High two bits of CL is cylinder bits 8&9 304 00000157 B80102 mov ax, 201h ; Read 1 sector 305 0000015A CD13 int 13h 306 disk_read_1: 307 0000015C 6661 popad 308 0000015E 7305 jnc short disk_read_2 309 ; cf = 1 310 ;dec byte [retry_count] 311 ;dec byte [bp+retry_count-7C00h] 312 00000160 FECA dec dl ; Retry count 313 00000162 759E jnz short disk_read_0 ; Retry 314 ; cf = 1 315 00000164 C3 retn 316 disk_read_2: 317 ;add bx, [bp+6] ; [bsBytesPerSec] ; 512 318 ;add bx, 512 319 00000165 80C702 add bh, 2 ; ** 320 00000168 6640 inc eax 321 0000016A 49 dec cx 322 0000016B 7593 jnz short disk_read 323 ;clc ; ** (128 sectors/cluster!?) 324 0000016D C3 retn 325 326 0000016E 07 db 07h 327 Diskio_err_Msg: 328 0000016F 0D0A db 0Dh, 0Ah 329 00000171 4469736B20492F4F20- db 'Disk I/O error' 329 0000017A 6572726F72 330 ;db '!' 331 0000017F 00 db 0 332 Inv_disk_Msg: 333 00000180 0D0A db 0Dh, 0Ah 334 00000182 496E76616C69642073- db 'Invalid system disk' 334 0000018B 797374656D20646973- 334 00000194 6B 335 Disk_err_replace_Msg: 336 00000195 21 db '!' 337 Replace_Msg: 338 00000196 0D0A db 0Dh, 0Ah 339 00000198 5265706C6163652074- db 'Replace the disk and press any key to reboot.' 339 000001A1 6865206469736B2061- 339 000001AA 6E6420707265737320- 339 000001B3 616E79206B65792074- 339 000001BC 6F207265626F6F742E 340 000001C5 0D0A00 db 0Dh, 0Ah, 0 341 342 ; Boot sector code writing date (by Erdogan Tan) 343 000001C8 04 db 4 344 000001C9 01 db 1 345 000001CA 32303138 db '2018' 346 bsReserved1: 347 000001CE 0000 dw 0 348 349 ; TRDOS 386 TRFS1 boot sector code version 350 000001D0 5475726B6973682052- db 'Turkish Rational Singlix FS v1' 350 000001D9 6174696F6E616C2053- 350 000001E2 696E676C6978204653- 350 000001EB 207631 351 000001EE 0000 dw 0 352 000001F0 424F4F542053454354- db 'BOOT SECTOR' 352 000001F9 4F52 353 000001FB 00 db 0 354 000001FC 00 times 510 - ($ - $$) db 0 355 bootsignature1: 356 000001FE 55AA db 55h, 0AAh 357 358 bsReserved2: 359 00000200 5254 db 'RT' ; 'Turkish Rational DOS' feature identifier 360 361 362 check_startup_file_address: 363 00000202 668B4614 mov eax, [bp+20] ; [bsStartupFDT] 364 00000206 6621C0 and eax, eax 365 00000209 0F84C7FE jz invalid_system_disk 366 367 368 0000020D 663B4610 cmp eax, [bp+16] ; [bsVolumeSize] 369 00000211 0F83BFFE jnb invalid_system_disk 370 371 00000215 6603460C add eax, [bp+12] ; [bsBeginSector] 372 00000219 668946F8 mov [bp-8], eax 373 374 0000021D BB0080 mov bx, 8000h ; FDT Buffer address 375 00000220 89DE mov si, bx 376 377 00000222 E8D8FE call read_sector 378 00000225 0F82B7FE jc disk_io_error 379 380 ; BX = 8200h 381 382 check_startup_file_fdt: 383 ; Check FDT signature 384 00000229 AD lodsw 385 0000022A 3D4644 cmp ax, 'FD' 386 0000022D 0F85A3FE jne invalid_system_disk ; not a valid FDT! 387 00000231 AC lodsb 388 00000232 3C54 cmp al, 'T' 389 00000234 0F859CFE jne invalid_system_disk ; not a valid FDT! 390 00000238 83C605 add si, 5 391 0000023B 66AD lodsd ; FDT_FileNumber 392 0000023D 668B7E0C mov edi, [bp+12] ; [bsBeginSector] 393 00000241 668B56F8 mov edx, [bp-8] ; Current FDT address (LBA) 394 00000245 6601C7 add edi, eax 395 00000248 6639D7 cmp edi, edx 396 0000024B 0F8585FE jne invalid_system_disk 397 0000024F 66AD lodsd ; FDT_NextFDTNum 398 00000251 6601D0 add eax, edx 399 00000254 668946F8 mov [bp-8], eax ; Next FDT address (LBA) 400 ; EDI = Current FDT address 401 00000258 66AD lodsd ; FDT_SectorCount 402 0000025A 6609C0 or eax, eax 403 0000025D 0F8473FE jz invalid_system_disk ; not a valid FDT! 404 00000261 6650 push eax ; * 405 00000263 83C608 add si, 8 406 00000266 66AD lodsd ; FDT_FileSize 407 00000268 6689C2 mov edx, eax 408 0000026B AD lodsw ; FDT_FileSizeHW 409 0000026C 660FB7C0 movzx eax, ax 410 00000270 6689D1 mov ecx, edx 411 00000273 6609C1 or ecx, eax 412 00000276 0F845AFE jz invalid_system_disk ; not a valid FDT! 413 0000027A 6692 xchg eax, edx 414 0000027C 66B9FF010000 mov ecx, 511 415 00000282 6601C8 add eax, ecx 416 00000285 6683D200 adc edx, 0 417 00000289 6641 inc ecx 418 0000028B 66F7F1 div ecx 419 0000028E B97F04 mov cx, 1151 420 00000291 6639C8 cmp eax, ecx ; Maximum 1151 sectors 421 ; (Segment 1000h to 9FE0h) 422 ; ((512 bytes must be reserved for 423 ; stack just before segment A000h)) 424 00000294 7603 jna short bs_05 425 00000296 6689C8 mov eax, ecx 426 bs_05: 427 ; Load RTS (Kernel) file 428 00000299 6650 push eax 429 ; "Loading ..." message 430 0000029B BE[3203] mov si, Loading_Msg 431 0000029E E84DFE call print_msg 432 ; "TRDOS386.SYS ..." 433 000002A1 BE4080 mov si, 8000h+40h ; FS1 File Name (<= 64 bytes) 434 000002A4 C6444000 mov byte [si+64], 0 ; Force max. 64 bytes file name. 435 000002A8 E843FE call print_msg 436 000002AB BE[8603] mov si, tridot ; " ..." 437 000002AE E83DFE call print_msg 438 000002B1 6658 pop eax 439 000002B3 6659 pop ecx ; * ; sector count (in section) 440 load_startup_file: 441 000002B5 6639C8 cmp eax, ecx 442 000002B8 7303 jnb short bs_06 443 000002BA 6689C1 mov ecx, eax ; sector count (in section) 444 ; must not be greater 445 ; remain sectors (for file) to read 446 bs_06: 447 000002BD 6629C8 sub eax, ecx 448 000002C0 668946F4 mov [bp-12], eax ; Remain sector count (for next read) 449 000002C4 6689F8 mov eax, edi ; FDT address 450 000002C7 6640 inc eax ; +1 (section data) 451 ; CX = Sector count (<= 1151) in section 452 000002C9 8B1E[AA03] mov bx, [next_segment] 453 000002CD 06 push es 454 000002CE 8EC3 mov es, bx ; segment = 1000h + 455 000002D0 31DB xor bx, bx ; offset = 0 456 ; CX = num of sectors to read (= sectors/cluster) 457 000002D2 E82BFE call disk_read 458 000002D5 07 pop es 459 ;jc diskio_error 460 000002D6 7251 jc short trdos_loading_error 461 000002D8 C1EB04 shr bx, 4 ; from byte count to paragraph count 462 000002DB 011E[AA03] add [next_segment], bx 463 464 000002DF 668B7EF4 mov edi, [bp-12] 465 000002E3 6609FF or edi, edi 466 000002E6 0F84A100 jz bs_07 467 468 000002EA 668B46F8 mov eax, [bp-8] ; Next FDT address 469 000002EE BB0080 mov bx, 8000h ; FDT Buffer address 470 000002F1 89DE mov si, bx 471 472 000002F3 E807FE call read_sector 473 ;jc diskio_error 474 000002F6 7231 jc short trdos_loading_error 475 476 000002F8 AD lodsw 477 000002F9 3D4644 cmp ax, 'FD' 478 000002FC 0F85D4FD jne invalid_system_disk ; not a valid FDT! 479 00000300 AC lodsb 480 00000301 3C54 cmp al, 'T' 481 00000303 0F85CDFD jne invalid_system_disk ; not a valid FDT! 482 00000307 83C609 add si, 9 483 0000030A 66AD lodsd ; FDT_NextFDTNum 484 0000030C 6603460C add eax, [bp+12] ; [bsBeginSector] 485 00000310 668946F8 mov [bp-8], eax ; Next FDT address (LBA) 486 00000314 6689C2 mov edx, eax 487 00000317 66AD lodsd ; FDT_SectorCount 488 00000319 6609C0 or eax, eax 489 0000031C 0F84B4FD jz invalid_system_disk ; not a valid FDT! 490 ;mov ecx, eax ; sector count (in section) 491 00000320 6691 xchg ecx, eax 492 ;mov eax, edi ; [bp-12] ; remain sectors to read 493 00000322 6697 xchg eax, edi 494 00000324 6689D7 mov edi, edx 495 ; EDI = Current FDT address 496 00000327 EB8C jmp short load_startup_file 497 498 trdos_loading_error: 499 00000329 BE[4203] mov si, Load_err_Msg 500 0000032C E8BFFD call print_msg 501 0000032F E9B4FD jmp replace_disk 502 503 00000332 0D0A Loading_Msg: db 0Dh, 0Ah 504 00000334 4C6F6164696E67202E- db 'Loading ...' 504 0000033D 2E2E 505 0000033F 0D0A00 db 0Dh, 0Ah, 0 506 507 Load_err_Msg: 508 00000342 0D0A db 0Dh, 0Ah 509 00000344 537461727475702046- db 'Startup File Loading Error' 509 0000034D 696C65204C6F616469- 509 00000356 6E67204572726F72 510 ;db '!' 511 0000035E 00 db 0 512 513 0000035F 07 db 07h ; Filler 514 515 ; TRDOS 386 TRFS1 boot sector code version 516 00000360 5475726B6973682052- db 'Turkish Rational Singlix File System 1' 516 00000369 6174696F6E616C2053- 516 00000372 696E676C6978204669- 516 0000037B 6C652053797374656D- 516 00000384 2031 517 tridot: 518 00000386 202E2E2E00 db ' ...', 0 519 520 bs_07: 521 ; Set TRDOS 386 kernel specific parameters (& signs) 522 ; and 523 ; Launch TRDOS 386 Kernel (Startup/RTS file) 524 525 ;mov dl, [bsDriveNumber] 526 0000038B 8B562C mov dx, [bp+44] ; DL = Drive number, DH = 41h (CHS) 527 ; DH = 42h (LBA) 528 529 0000038E A1[AA03] mov ax, [next_segment] ; 16 paragraphs after the 530 ; start of the last segment 531 ; of the kernel file loading 532 ; space. 533 ; So, (top of) stack will have 534 ; 256 bytes or more distance 535 ; from the last byte 536 ; of the kernel file. 537 ; (This will be enough for 538 ; TRDOS 386 kernel before 539 ; entering protected mode.) 540 00000391 FA cli 541 00000392 8ED0 mov ss, ax 542 00000394 BCFEFF mov sp, 0FFFEh 543 00000397 FB sti 544 545 00000398 BB0010 mov bx, rts_segment ; 1000h 546 0000039B 8EDB mov ds, bx 547 0000039D 8EC3 mov es, bx 548 ;mov fs, bx 549 ;mov gs, bx 550 551 ;xor ebx, ebx 552 ;xor ecx, ecx 553 ;xor edx, edx 554 ;xor esi, esi 555 ;xor edi, edi 556 ;xor ebp, ebp 557 558 ; bp = 7C00h 559 560 ; NOTE: Offset 417 in boot sector 2 (the 2nd half of VBR) 561 ; is also TRFS1 boot record validation check address and 562 ; boot sector 2 must have 417 here for boot sector 1 code 563 ; (the 1st half of volume boot record). 564 ; ((So, 'mov eax, 417' has double meaning here.)) 565 loc_39F: 566 0000039F 66B8A1010000 mov eax, 417 ; TRDOS boot sector sign for TRDOS386.SYS 567 568 000003A5 EA00000010 jmp rts_segment:0 569 570 next_segment: 571 000003AA 0010 dw rts_segment 572 573 000003AC 5452465331 db 'TRFS1' 574 575 000003B1 00 times 1020 - ($ - $$) db 0 576 bsReserved3: 577 000003FC 5452 db 'TR' ; 'Turkish Rational DOS' feature identifier. 578 bootsignature2: 579 000003FE 55AA db 55h, 0AAh