| 1 |
#define MICRODISC_LOADER |
| 2 |
#include "disk_info.h" |
| 3 |
#include "defines.h" |
| 4 |
|
| 5 |
#define COLOR(color) pha:lda #16+(color&7):sta $bb80+40*27:pla |
| 6 |
#define STOP(color) pha:lda #16+(color&7):sta $bb80+40*27:jmp *:pla |
| 7 |
|
| 8 |
.zero |
| 9 |
|
| 10 |
*=loader_zp_start |
| 11 |
|
| 12 |
retry_counter .dsb 1 ; Number of attempts at loading data (ie: not quite clear what happens when this fails...) |
| 13 |
sectors_to_go .dsb 1 ; How many sectors do we still need to load for this file |
| 14 |
current_track .dsb 1 ; Index of the track being loaded |
| 15 |
current_sector .dsb 1 ; Index of the sector being loaded |
| 16 |
current_side .dsb 1 ; Has the bit 4 set to 0 or 1 to be used as a mask on the Microdisc control register (other bits have to be set to zero) |
| 17 |
irq_save_a .dsb 1 ; To preserve the accumulator value in the IRQ code |
| 18 |
|
| 19 |
; Unpack test |
| 20 |
ptr_source .dsb 2 ; Packed source data adress |
| 21 |
ptr_destination .dsb 2 ; Destination adress where we depack |
| 22 |
ptr_destination_end .dsb 2 ; Point on the end of the depacked stuff |
| 23 |
ptr_source_back .dsb 2 ; Temporary used to hold a pointer on depacked stuff |
| 24 |
offset .dsb 2 |
| 25 |
mask_value .dsb 1 |
| 26 |
nb_dst .dsb 1 |
| 27 |
|
| 28 |
.text |
| 29 |
|
| 30 |
*=location_loader |
| 31 |
|
| 32 |
; |
| 33 |
; This is called from the bootsectors with the X register containing the fdc offset; |
| 34 |
; +$00 = Microdisc |
| 35 |
; +$e4 = Jasmin |
| 36 |
; |
| 37 |
Initialize |
| 38 |
;jmp Initialize |
| 39 |
jmp StartUp |
| 40 |
|
| 41 |
#define LOADER |
| 42 |
|
| 43 |
; This file is generated by the floppy builder |
| 44 |
#include "floppy_description.h" |
| 45 |
|
| 46 |
; Some local variables we need |
| 47 |
fdc_register_offset .dsb 1 |
| 48 |
|
| 49 |
StartUp |
| 50 |
stx fdc_register_offset ; Store the FDC offset value |
| 51 |
|
| 52 |
#ifdef ENABLE_VIP_INTRO |
| 53 |
; Load the intro part |
| 54 |
ldx #LOADER_INTRO |
| 55 |
jsr LoadData |
| 56 |
jsr __auto_execute_address |
| 57 |
#endif |
| 58 |
|
| 59 |
#ifdef ENABLE_TECH_TECH |
| 60 |
; Load the tech tech part |
| 61 |
ldx #LOADER_TECHTECH |
| 62 |
jsr LoadData |
| 63 |
jsr __auto_execute_address |
| 64 |
#endif |
| 65 |
|
| 66 |
; Give control to the application and hope it knows what to do |
| 67 |
__auto_execute_address |
| 68 |
jmp $a000 |
| 69 |
|
| 70 |
|
| 71 |
IrqHandler |
| 72 |
sta irq_save_a |
| 73 |
pla |
| 74 |
pha |
| 75 |
and #%00010000 ; Check the saved B flag to detect a BRK |
| 76 |
bne from_brk |
| 77 |
|
| 78 |
from_irq |
| 79 |
#ifdef LOADER_SHOW_DEBUGINFO |
| 80 |
lda $bfdf |
| 81 |
eor #1 |
| 82 |
ora #16 |
| 83 |
sta $bfdf |
| 84 |
#endif |
| 85 |
lda irq_save_a |
| 86 |
bit $304 |
| 87 |
IrqDoNothing |
| 88 |
rti |
| 89 |
|
| 90 |
from_brk |
| 91 |
lda #16+1 |
| 92 |
sta $bb80+40*27 |
| 93 |
nop |
| 94 |
nop |
| 95 |
nop |
| 96 |
lda #16+2 |
| 97 |
sta $bb80+40*27 |
| 98 |
bne from_brk |
| 99 |
|
| 100 |
|
| 101 |
|
| 102 |
|
| 103 |
; X=File index |
| 104 |
; A=Low |
| 105 |
; Y=High |
| 106 |
SetLoadAddress |
| 107 |
sta FileLoadAdressLow,x |
| 108 |
tya |
| 109 |
sta FileLoadAdressHigh,x |
| 110 |
rts |
| 111 |
|
| 112 |
|
| 113 |
; X=File index |
| 114 |
LoadData |
| 115 |
;STOP(2) |
| 116 |
|
| 117 |
; We have to start somewhere no matter what, compressed or not |
| 118 |
jsr StartReadOperation |
| 119 |
|
| 120 |
; Now at this stage we have to check if the data is compressed or not |
| 121 |
lda FileStoredSizeLow,x |
| 122 |
cmp FileSizeLow,x |
| 123 |
bne LoadCompressedData |
| 124 |
|
| 125 |
lda FileStoredSizeHigh,x |
| 126 |
cmp FileSizeHigh,x |
| 127 |
bne LoadCompressedData |
| 128 |
|
| 129 |
LoadUncompressedData |
| 130 |
|
| 131 |
; |
| 132 |
; Loop to read all the sectors |
| 133 |
; |
| 134 |
read_sectors_loop |
| 135 |
jsr ReadNextSector |
| 136 |
|
| 137 |
; Try to let time to an IRQ to play, and during that time copy the sector to the final location |
| 138 |
cli |
| 139 |
|
| 140 |
ldy #0 |
| 141 |
loop_copy |
| 142 |
lda loader_sector_buffer,y ; Load the byte from the sector buffer |
| 143 |
__auto_write_address |
| 144 |
sta $c000,y ; Store it to the final location |
| 145 |
iny |
| 146 |
bne loop_copy |
| 147 |
|
| 148 |
nop |
| 149 |
nop |
| 150 |
sei |
| 151 |
|
| 152 |
; Next sector |
| 153 |
inc __auto_write_address+2 |
| 154 |
dec sectors_to_go |
| 155 |
bne read_sectors_loop |
| 156 |
|
| 157 |
; Data successfully loaded (we hope), so we restore the interrupts |
| 158 |
cli |
| 159 |
rts |
| 160 |
|
| 161 |
|
| 162 |
LoadCompressedData |
| 163 |
clc |
| 164 |
lda FileLoadAdressLow,x |
| 165 |
sta ptr_destination+0 |
| 166 |
adc FileSizeLow,x |
| 167 |
sta ptr_destination_end+0 |
| 168 |
|
| 169 |
lda FileLoadAdressHigh,x |
| 170 |
sta ptr_destination+1 |
| 171 |
adc FileSizeHigh,x |
| 172 |
sta ptr_destination_end+1 |
| 173 |
|
| 174 |
;STOP(2) |
| 175 |
|
| 176 |
jsr UnpackData |
| 177 |
cli |
| 178 |
rts |
| 179 |
|
| 180 |
|
| 181 |
StartReadOperation |
| 182 |
sei |
| 183 |
|
| 184 |
ldy fdc_register_offset |
| 185 |
|
| 186 |
; Make sure the microdisc IRQ is disabled |
| 187 |
jsr WaitCompletion |
| 188 |
|
| 189 |
lda #%10000100 ; Disable the FDC (Eprom select + FDC Interrupt request) |
| 190 |
sta FDC_flags,y |
| 191 |
|
| 192 |
;jsr WaitCompletion |
| 193 |
|
| 194 |
; |
| 195 |
; Setup, we use the table to find out where the file is located on the floppy, |
| 196 |
; where to write it in memory, and how large it is. |
| 197 |
; |
| 198 |
lda FileLoadAdressHigh,x |
| 199 |
sta __auto_execute_address+2 |
| 200 |
sta __auto_write_address+2 |
| 201 |
|
| 202 |
lda FileLoadAdressLow,x |
| 203 |
sta __auto_execute_address+1 |
| 204 |
sta __auto_write_address+1 |
| 205 |
|
| 206 |
; Starting track |
| 207 |
ldy #%00000000 ; Side 0 |
| 208 |
lda FileStartTrack,x ; If the track id is larger than 128, it means it is on the other side of the floppy |
| 209 |
bpl first_side |
| 210 |
; The file starts on the second side |
| 211 |
ldy #FDC_Flag_DiscSide ; Side 1 |
| 212 |
and #%01111111 ; Mask out the extra bit |
| 213 |
first_side |
| 214 |
sty current_side |
| 215 |
sta current_track |
| 216 |
|
| 217 |
ldy fdc_register_offset |
| 218 |
|
| 219 |
; First sector |
| 220 |
lda FileStartSector,x |
| 221 |
sta current_sector |
| 222 |
|
| 223 |
; FileSizeLow/FileSizeHigh |
| 224 |
; Number of sectors to load |
| 225 |
.( |
| 226 |
lda FileStoredSizeHigh,x |
| 227 |
sta sectors_to_go |
| 228 |
lda FileStoredSizeLow,x |
| 229 |
beq skip |
| 230 |
inc sectors_to_go |
| 231 |
skip |
| 232 |
.) |
| 233 |
rts |
| 234 |
|
| 235 |
|
| 236 |
ReadNextSector |
| 237 |
cli |
| 238 |
|
| 239 |
ldy fdc_register_offset |
| 240 |
|
| 241 |
; Check if we have reached the end of the track |
| 242 |
lda current_sector |
| 243 |
cmp #FLOPPY_SECTOR_PER_TRACK+1 |
| 244 |
bne same_track |
| 245 |
|
| 246 |
; Next track |
| 247 |
inc current_track |
| 248 |
lda current_track |
| 249 |
cmp #FLOPPY_TRACK_NUMBER |
| 250 |
bne stay_on_same_side |
| 251 |
|
| 252 |
; Reset to the first track on the other side |
| 253 |
lda #0 |
| 254 |
sta current_track |
| 255 |
|
| 256 |
sei |
| 257 |
|
| 258 |
lda #FDC_Flag_DiscSide |
| 259 |
sta current_side |
| 260 |
stay_on_same_side |
| 261 |
|
| 262 |
|
| 263 |
; Reset the sector position |
| 264 |
lda #1 |
| 265 |
sta current_sector |
| 266 |
same_track |
| 267 |
|
| 268 |
#ifdef LOADER_SHOW_DEBUGINFO |
| 269 |
; Display debug info |
| 270 |
cli |
| 271 |
jsr DisplayPosition |
| 272 |
sei |
| 273 |
#else |
| 274 |
cli |
| 275 |
jsr WaitCommand |
| 276 |
sei |
| 277 |
#endif |
| 278 |
|
| 279 |
lda current_sector |
| 280 |
sta FDC_sector_register,y |
| 281 |
inc current_sector |
| 282 |
|
| 283 |
; Check if the drive is on the correct track |
| 284 |
lda current_track |
| 285 |
cmp FDC_track_register,y |
| 286 |
beq stay_on_the_track |
| 287 |
|
| 288 |
; Set the new track |
| 289 |
sta FDC_data,y |
| 290 |
|
| 291 |
lda #CMD_Seek |
| 292 |
sta FDC_command_register,y |
| 293 |
jsr WaitCompletion |
| 294 |
|
| 295 |
stay_on_the_track |
| 296 |
lda #%10000100 ; on force les le Microdisk en side0, drive A ... Set le bit de données !!! |
| 297 |
ora current_side |
| 298 |
sta FDC_flags,y |
| 299 |
|
| 300 |
lda #CMD_ReadSector |
| 301 |
sta FDC_command_register,y |
| 302 |
|
| 303 |
;cli |
| 304 |
jsr WaitCommand |
| 305 |
;sei |
| 306 |
|
| 307 |
; |
| 308 |
; Read the sector data |
| 309 |
; |
| 310 |
ldx #0 |
| 311 |
microdisc_read_data |
| 312 |
lda $0318 |
| 313 |
bmi microdisc_read_data |
| 314 |
|
| 315 |
lda FDC_data,y |
| 316 |
sta loader_sector_buffer,x ; Store the byte in sector buffer |
| 317 |
inx |
| 318 |
|
| 319 |
bne microdisc_read_data |
| 320 |
|
| 321 |
lda FDC_status_register,y |
| 322 |
and #$1C |
| 323 |
|
| 324 |
jsr WaitCompletion |
| 325 |
cli |
| 326 |
rts |
| 327 |
|
| 328 |
WaitCommand |
| 329 |
ldx #wait_status_floppy |
| 330 |
waitcommand |
| 331 |
nop |
| 332 |
nop |
| 333 |
dex |
| 334 |
bne waitcommand |
| 335 |
rts |
| 336 |
|
| 337 |
WaitCompletion |
| 338 |
txa |
| 339 |
pha |
| 340 |
|
| 341 |
php |
| 342 |
sei |
| 343 |
nop |
| 344 |
nop |
| 345 |
nop |
| 346 |
|
| 347 |
ldx #4 |
| 348 |
r_wait_completion |
| 349 |
dex |
| 350 |
bne r_wait_completion |
| 351 |
plp |
| 352 |
|
| 353 |
r2_wait_completion |
| 354 |
lda FDC_status_register,y |
| 355 |
lsr |
| 356 |
bcs r2_wait_completion |
| 357 |
|
| 358 |
;asl |
| 359 |
pla |
| 360 |
tax |
| 361 |
rts |
| 362 |
|
| 363 |
#ifdef LOADER_SHOW_DEBUGINFO |
| 364 |
HexData .byt "0123456789ABCDEF" |
| 365 |
|
| 366 |
DisplayPosition |
| 367 |
.( |
| 368 |
lda current_side |
| 369 |
lsr |
| 370 |
lsr |
| 371 |
lsr |
| 372 |
lsr |
| 373 |
tax |
| 374 |
lda HexData,x |
| 375 |
sta $bb80+40*27+0 |
| 376 |
|
| 377 |
lda #3 |
| 378 |
sta $bb80+40*27+1 |
| 379 |
|
| 380 |
lda current_track |
| 381 |
lsr |
| 382 |
lsr |
| 383 |
lsr |
| 384 |
lsr |
| 385 |
tax |
| 386 |
lda HexData,x |
| 387 |
sta $bb80+40*27+2 |
| 388 |
|
| 389 |
lda current_track |
| 390 |
and #15 |
| 391 |
tax |
| 392 |
lda HexData,x |
| 393 |
sta $bb80+40*27+3 |
| 394 |
|
| 395 |
lda #2 |
| 396 |
sta $bb80+40*27+4 |
| 397 |
|
| 398 |
lda current_sector |
| 399 |
lsr |
| 400 |
lsr |
| 401 |
lsr |
| 402 |
lsr |
| 403 |
tax |
| 404 |
lda HexData,x |
| 405 |
sta $bb80+40*27+5 |
| 406 |
|
| 407 |
lda current_sector |
| 408 |
and #15 |
| 409 |
tax |
| 410 |
lda HexData,x |
| 411 |
sta $bb80+40*27+6 |
| 412 |
|
| 413 |
;jsr WaitLoop |
| 414 |
rts |
| 415 |
.) |
| 416 |
#endif |
| 417 |
|
| 418 |
|
| 419 |
GetNextByte |
| 420 |
php |
| 421 |
lda __fetchByte+1 |
| 422 |
bne __fetchByte |
| 423 |
nop |
| 424 |
nop |
| 425 |
nop |
| 426 |
nop |
| 427 |
sei |
| 428 |
jsr ReadNextSector |
| 429 |
nop |
| 430 |
nop |
| 431 |
nop |
| 432 |
nop |
| 433 |
cli |
| 434 |
ldx #0 |
| 435 |
ldy #0 |
| 436 |
__fetchByte |
| 437 |
lda $200 |
| 438 |
inc __fetchByte+1 |
| 439 |
plp |
| 440 |
rts |
| 441 |
|
| 442 |
|
| 443 |
|
| 444 |
; void file_unpack(void *ptr_dst,void *ptr_src) |
| 445 |
|
| 446 |
; Need to be called with valid values in: |
| 447 |
; ptr_destination |
| 448 |
; ptr_source |
| 449 |
; ptr_destination_end (Destination + size) |
| 450 |
UnpackData |
| 451 |
;jmp UnpackData |
| 452 |
.( |
| 453 |
cli |
| 454 |
|
| 455 |
; Initialise variables |
| 456 |
; We try to keep "y" null during all the code, |
| 457 |
; so the block copy routine has to be sure that |
| 458 |
; y is null on exit |
| 459 |
ldy #0 |
| 460 |
sty __fetchByte+1 |
| 461 |
lda #1 |
| 462 |
sta mask_value |
| 463 |
|
| 464 |
unpack_loop |
| 465 |
; Handle bit mask |
| 466 |
lsr mask_value |
| 467 |
bne end_reload_mask |
| 468 |
|
| 469 |
jsr GetNextByte ; Read from source stream |
| 470 |
|
| 471 |
ror |
| 472 |
sta mask_value |
| 473 |
end_reload_mask |
| 474 |
bcc back_copy |
| 475 |
|
| 476 |
write_byte |
| 477 |
; Copy one byte from the source stream |
| 478 |
jsr GetNextByte ; Read from source stream |
| 479 |
sta (ptr_destination),y |
| 480 |
|
| 481 |
lda #1 |
| 482 |
sta nb_dst |
| 483 |
|
| 484 |
|
| 485 |
|
| 486 |
_UnpackEndLoop |
| 487 |
;// We increase the current destination pointer, |
| 488 |
;// by a given value, white checking if we reach |
| 489 |
;// the end of the buffer. |
| 490 |
clc |
| 491 |
lda ptr_destination |
| 492 |
adc nb_dst |
| 493 |
sta ptr_destination |
| 494 |
|
| 495 |
.( |
| 496 |
bcc skip |
| 497 |
inc ptr_destination+1 |
| 498 |
skip |
| 499 |
.) |
| 500 |
cmp ptr_destination_end |
| 501 |
lda ptr_destination+1 |
| 502 |
sbc ptr_destination_end+1 |
| 503 |
bcc unpack_loop |
| 504 |
rts |
| 505 |
|
| 506 |
|
| 507 |
back_copy |
| 508 |
;BreakPoint jmp BreakPoint |
| 509 |
; Copy a number of bytes from the already unpacked stream |
| 510 |
; Here we know that y is null. So no need for clearing it. |
| 511 |
; Just be sure it's still null at the end. |
| 512 |
; At this point, the source pointer points to a two byte value that actually contains a 4 bits counter, and a 12 bit offset to point back into the depacked stream. |
| 513 |
; The counter is in the 4 high order bits. |
| 514 |
;clc <== No need, since we access this routie from a BCC |
| 515 |
jsr GetNextByte ; Read from source stream |
| 516 |
adc #1 |
| 517 |
sta offset |
| 518 |
jsr GetNextByte ; Read from source stream |
| 519 |
tax |
| 520 |
and #$0f |
| 521 |
adc #0 |
| 522 |
sta offset+1 |
| 523 |
|
| 524 |
txa |
| 525 |
lsr |
| 526 |
lsr |
| 527 |
lsr |
| 528 |
lsr |
| 529 |
clc |
| 530 |
adc #3 |
| 531 |
sta nb_dst |
| 532 |
|
| 533 |
sec |
| 534 |
lda ptr_destination |
| 535 |
sbc offset |
| 536 |
sta ptr_source_back |
| 537 |
lda ptr_destination+1 |
| 538 |
sbc offset+1 |
| 539 |
sta ptr_source_back+1 |
| 540 |
|
| 541 |
; Beware, in that loop, the direction is important |
| 542 |
; since RLE like depacking is done by recopying the |
| 543 |
; very same byte just copied... Do not make it a |
| 544 |
; reverse loop to achieve some speed gain... |
| 545 |
.( |
| 546 |
copy_loop |
| 547 |
lda (ptr_source_back),y ; Read from already unpacked stream |
| 548 |
sta (ptr_destination),y ; Write to destination buffer |
| 549 |
iny |
| 550 |
cpy nb_dst |
| 551 |
bne copy_loop |
| 552 |
.) |
| 553 |
ldy #0 |
| 554 |
beq _UnpackEndLoop |
| 555 |
rts |
| 556 |
.) |
| 557 |
|
| 558 |
_EndLoaderCode |
| 559 |
|
| 560 |
; |
| 561 |
; This is free memory that can be used, when it reaches zero then the loader start address should be changed |
| 562 |
; |
| 563 |
|
| 564 |
.dsb $FFF4 - _EndLoaderCode |
| 565 |
|
| 566 |
_Vectors |
| 567 |
|
| 568 |
#if ( _Vectors <> $FFF4 ) |
| 569 |
#error - Vector address is incorrect, loader will crash |
| 570 |
#else |
| 571 |
|
| 572 |
; |
| 573 |
; Here are the functions that the user can call from his own application |
| 574 |
; |
| 575 |
_ApiSetLoadAddress .byt $4c,<SetLoadAddress,>SetLoadAddress ; $FFF4 |
| 576 |
_ApiSetLoadData .byt $4c,<LoadData,>LoadData ; $FFF7 |
| 577 |
|
| 578 |
; |
| 579 |
; These three HAVE to be at these precise adresses, they map to hardware registers |
| 580 |
; |
| 581 |
_VectorNMI .word IrqDoNothing ; FFFA-FFFB - NMI Vector (Usually points to $0247) |
| 582 |
_VectorReset .word IrqDoNothing ; FFFC-FFFD - RESET Vector (Usually points to $F88F) |
| 583 |
_VectorIRQ .word IrqHandler ; FFFE-FFFF - IRQ Vector (Normally points to $0244) |
| 584 |
|
| 585 |
#echo Remaining space in the loader code: |
| 586 |
#print (_Vectors - _EndLoaderCode) |
| 587 |
|
| 588 |
#endif |
| 589 |
|
| 590 |
; End of the loader - Nothing should come after because it's out of the addressable memory range :) |
| 591 |
|
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