avrcpm/avr/dsk_fat16.asm

   1 ;    Various functions for the Interaction with the FAT16 Filesystem
   2 ;
   3 ;    Copyright (C) 2010 Frank Zoll
   4 ;
   5 ;    This file is part of avrcpm.
   6 ;
   7 ;    avrcpm is free software: you can redistribute it and/or modify it
   8 ;    under the terms of the GNU General Public License as published by
   9 ;    the Free Software Foundation, either version 3 of the License, or
  10 ;    (at your option) any later version.
  11 ;
  12 ;    avrcpm is distributed in the hope that it will be useful,
  13 ;    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;    GNU General Public License for more details.
  16 ;
  17 ;    You should have received a copy of the GNU General Public License
  18 ;    along with avrcpm.  If not, see <http://www.gnu.org/licenses/>.
  19 ;
  20 ;    $Id$
  21 ;
  22
  23 ; ===========================================================================
  24 ; Prelimitary !
  25 ; °°°°°°°°°°°°°
  26 ; Size of a Sector is fixed to 512 Bytes by Base - MMC Driver implementation
  27 ; The Functions below therefore assume a fixed Size of 512 Bytes per Sector.
  28 ; ===========================================================================
  29
  30 #if FAT16_SUPPORT
  31
  32
  33 ;-------------------------------- Defines for FAT16 Structures
  34 #define PARTID_FAT16 0x0E
  35
  36 ;#define FAT16_BSO_SECSIZE      0x0b            ; BootSectorOffset to Sectorsize Word
  37 #define FAT16_BSO_CLUSTSZ   0x0d        ; BootSectorOffset to Clustersize Byte
  38 #define FAT16_BSO_RESSECT   0x0e                ; BootSectorOffset to Number of Reserved Sectors
  39 #define FAT16_BSO_VOLPTR    0x1c        ; BootSectorOffset to First VolumeSector
  40 #define FAT16_BSO_SECPERFAT 0x16        ; BootSectorOffset to Number of Sectors per Fat
  41 #define FAT16_BSO_NUMFATCP  0x10                ; BootSectorOffset to Ammount of FAT Copys
  42 #define FAT16_BSO_NUMDIRENT 0x11                ; BootSectorOffset to Max. Root Dir. Entrys
  43
  44 ;-------------------------------- Start of Data Segment
  45
  46         .dseg
  47
  48 fat_partfound:   .byte   1   ; (0= no fat partition found 1=found partition)
  49 fat_parttbl:     .byte   8       ; first fat16 partition entry (start sector, sector count)
  50 ;fat_sectorsize:  .byte   2   ; size of sector in bytes
  51 fat_clustersize: .byte   1   ; sectors per cluster
  52 fat_ressectors:  .byte   2   ; number of reserved sectors
  53 fat_secperfat:   .byte   2   ; number of sectors per fat
  54 fat_numfatcp:    .byte   1   ; Number of FAT Copies
  55 fat_numdirentrys:.byte   2   ; Max. ammount of Directory Entrys within Rootdirektory
  56 fat_ptr2fat:     .byte   4   ; pointer to the first fat sector
  57 fat_ptr2dir:     .byte   4   ; pointer to the first root directory sector
  58 fat_ptr2dat:     .byte   4   ; pointer to the first data sector
  59
  60 fat_last_dsk:     .byte  1   ; number of disk with entry in cache
  61 fat_log_clust:    .byte  2       ; last searched logical cluster
  62 fat_clust_offset: .byte  1   ; offset within the cluster
  63 fat_clust_ptr:    .byte  4;  ; sector of last real cluster
  64 ; ------------------------------- Start of Code Segment
  65         .cseg
  66
  67 ; ====================================================================
  68 ; Function: Does a Disk read/write operation
  69 ; ====================================================================
  70 ; Parameters
  71 ; --------------------------------------------------------------------
  72 ; Registers  : none
  73 ; Variables  : [r] seekdsk              Number of Disk to Read
  74 ;                          [r] seeksec          Sector to read
  75 ;              [r] seektrk              Track  to read
  76 ; --------------------------------------------------------------------
  77 ; Description:
  78 ; ====================================================================
  79 fat_init_partitiontable:
  80
  81         sts fat_partfound,_0
  82
  83         ldiw    y,fat_parttbl
  84         st      y+,_0
  85         st      y+,_0
  86         st      y+,_0
  87         st      y+,_0
  88         st      y+,_0
  89         st      y+,_0
  90         st      y+,_0
  91         st      y+,_0
  92         ldi     yl,0xFF
  93         sts fat_log_clust  ,yl
  94         sts     fat_log_clust+1,yl
  95         sts     fat_last_dsk   ,yl
  96         ret
  97
  98 ; ====================================================================
  99 ; Function: Add's a FAT16 Partition for later Scanning
 100 ; ====================================================================
 101 ; Parameters
 102 ; --------------------------------------------------------------------
 103 ; Registers  :
 104 ; Variables  :
 105 ; --------------------------------------------------------------------
 106 ; Description:
 107 ; This funktion sets the internal Variables to set Start and Size
 108 ; of a given FAT16 Paritition. This Information will be used for a
 109 ; later scanning of the Partition. See Function "fat_scan_partition"
 110 ; for more information.
 111 ; ====================================================================
 112 fat_add_partition:
 113
 114 .if FAT16_DEBUG > 0
 115         printstring "fat16 part found",0
 116         printnewline
 117 .endif
 118
 119
 120 ;   save variables on stack
 121         push    yl
 122         push    yh
 123
 124 ; set fat16 partition found flag
 125         ldi     yl,1
 126         sts     fat_partfound,yl
 127
 128 ;   save data from first fat16 partition
 129         ldiw    y,fat_parttbl
 130
 131         ldd             temp,z+PART_START
 132         st              y+,temp
 133         ldd             temp,z+PART_START+1
 134         st              y+,temp
 135         ldd             temp,z+PART_START+2
 136         st              y+,temp
 137         ldd             temp,z+PART_START+3
 138         st              y+,temp
 139
 140         ldd             temp,z+PART_SIZE
 141         st              y+,temp
 142         ldd             temp,z+PART_SIZE+1
 143         st              y+,temp
 144         ldd             temp,z+PART_SIZE+2
 145         st              y+,temp
 146         ldd             temp,z+PART_SIZE+3
 147         st              y+,temp
 148
 149
 150 ;   reload variables from stack
 151         pop             yh
 152         pop     yl
 153
 154         ret
 155
 156 ; ---------------------------------------------------------------------------
 157 ; Read and Scann a FAT16 Partition for Imagedatefiles
 158 ; ---------------------------------------------------------------------------
 159 ; This Routine reads the Bootblock and scanns it for a Diskimage
 160 ; Input Registers  : none
 161 ; Output Registers : none
 162 ; Changes Variables: none
 163 ; ---------------------------------------------------------------------------
 164
 165
 166 fat_scan_partition:
 167
 168 .if FAT16_DEBUG > 0
 169         printstring "fat16 scanning",0
 170         printnewline
 171 .endif
 172
 173 ; Check if a FAT16 Partition was realy found
 174         lds             yl,fat_partfound
 175         cpi     yl,1
 176         brne    fat_scan_error
 177
 178
 179 .if FAT16_DEBUG > 0
 180         printstring "free entrys in ptable ?",0
 181         printnewline
 182 .endif
 183
 184 ; Check for free Entrys in Partition table
 185         lds             yl,ndisks
 186         cpi             yl,MAXDISKS
 187         breq    fat_scan_error
 188
 189 .if FAT16_DEBUG > 0
 190         printstring "read fat bootblock.",0
 191         printnewline
 192 .endif
 193
 194 ; Scan partition start
 195         ldiw    z,fat_parttbl
 196         ldd             xl,z+0
 197         ldd             xh,z+1
 198         ldd             yl,z+2
 199         ldd             yh,z+3
 200
 201 ; Load first sector from Partition
 202         rcall   mmcReadSect
 203         tst         temp
 204         breq    fat_bootblock_check
 205
 206 ; Read error: Block not found
 207 fat_scan_error:
 208         clr temp
 209         ret
 210
 211 fat_bootblock_check:
 212
 213 .if FAT16_DEBUG > 0
 214         printstring "fat16 bootblock check",0
 215         printnewline
 216 .endif
 217
 218 ; -> Size of Sectors fixed at 512 Bytes
 219 ;   Get ammount of Bytes per Sector
 220 ;       ldiw    z,hostbuf+FAT16_BSO_SECSIZE
 221 ;       ldiw    y,fat_sectorsize
 222 ;       ld          temp,z
 223 ;       st      y+, temp
 224 ;       ldd         temp2,z+1
 225 ;       st      y , temp2
 226 ;
 227 ;.if FAT16_DEBUG > 0
 228 ;       printstring "Bytes per Sector ",0
 229 ;       rcall printhexw
 230 ;       printnewline
 231 ;.endif
 232
 233 ;   Anzahl der Sectoren pro Cluster lesen
 234         ldiw    z,hostbuf+FAT16_BSO_CLUSTSZ
 235         ld              temp,z
 236         sts     fat_clustersize,temp
 237
 238 .if FAT16_DEBUG > 0
 239         printstring "Sectors per Cluster ",0
 240         rcall printhex
 241         printnewline
 242 .endif
 243
 244 ;   Anzahl der reservierten Sectoren
 245         ldiw    z,hostbuf+FAT16_BSO_RESSECT
 246         ld              temp,z+
 247         sts     fat_ressectors,temp                     ; low byte
 248         ld              temp2,z
 249         sts             fat_ressectors+1,temp2          ; high byte
 250
 251 .if FAT16_DEBUG > 0
 252         printstring "Reserved Sectors__: ",0
 253         rcall printhexw
 254         printnewline
 255 .endif
 256
 257 ;   Anzahl der Sectoren pro FAT
 258         ldiw    z,hostbuf+FAT16_BSO_SECPERFAT
 259         ld              temp,z+
 260         sts     fat_secperfat,temp                      ; low byte
 261         ld              temp2,z
 262         sts             fat_secperfat+1,temp2           ; high byte
 263
 264 .if FAT16_DEBUG > 0
 265         printstring "Sectors per FAT__: ",0
 266         rcall printhexw
 267         printnewline
 268 .endif
 269
 270 ;   Anzahl der FAT kopien
 271         ldiw    z,hostbuf+FAT16_BSO_NUMFATCP
 272         ld              temp,z
 273         sts     fat_numfatcp,temp                       ; low byte
 274
 275 .if FAT16_DEBUG > 0
 276         printstring "Ammount of FAT copies: ",0
 277         rcall printhex
 278         printnewline
 279 .endif
 280
 281 ;   Max. Anzahl der Dir. Enträge im Root Verz.
 282         ldiw    z,hostbuf+FAT16_BSO_NUMDIRENT
 283         ld              temp,z+
 284         sts     fat_numdirentrys,temp                   ; low byte
 285         ld              temp2,z
 286         sts             fat_numdirentrys+1,temp2                ; high byte
 287
 288 .if FAT16_DEBUG > 0
 289         printstring "Max. entrys in Rootdir.: ",0
 290         rcall printhexw
 291         printnewline
 292 .endif
 293
 294 ; Print begin of Volume
 295 .if FAT16_DEBUG > 1
 296
 297         ldiw    z,fat_parttbl
 298         ldd             xl,z+0
 299         ldd             xh,z+1
 300         ldd             yl,z+2
 301         ldd             yh,z+3
 302
 303         printstring "Begin of Volume at: ",0
 304         mov             temp ,yl
 305         mov             temp2,yh
 306         rcall printhexw
 307         mov             temp ,xl
 308         mov             temp2,xh
 309         rcall printhexw
 310         printnewline
 311 .endif
 312
 313 ; Calculate begin of FAT within the Volume
 314         lds             temp ,fat_ressectors
 315         lds             temp2,fat_ressectors+1
 316
 317         ldiw    z,fat_parttbl
 318         ldd             xl,z+0
 319         ldd             xh,z+1
 320         ldd             yl,z+2
 321         ldd             yh,z+3
 322
 323         add             xl,temp
 324         adc     xh,temp2
 325         adc             yl,_0
 326         adc             yh,_0
 327
 328         sts             fat_ptr2fat  ,xl
 329         sts             fat_ptr2fat+1,xh
 330         sts             fat_ptr2fat+2,yl
 331         sts             fat_ptr2fat+3,yh
 332
 333 .if FAT16_DEBUG > 1
 334         printstring "Begin of FAT at___: ",0
 335         mov             temp ,yl
 336         mov             temp2,yh
 337         rcall printhexw
 338         mov             temp ,xl
 339         mov             temp2,xh
 340         rcall printhexw
 341         printnewline
 342 .endif
 343
 344 ; Calculate begin of Root- Directory within the Volume
 345         ldiw    z,fat_ptr2fat
 346         ldd             xl,z+0
 347         ldd             xh,z+1
 348         ldd             yl,z+2
 349         ldd             yh,z+3
 350
 351         lds             temp ,fat_secperfat
 352         lds             temp2,fat_secperfat+1
 353         lds             temp3,fat_numfatcp
 354
 355 fat_calc_dp_loop:
 356         cp              temp3,_0
 357         breq    fat_calc_dp_lend
 358
 359         add             xl,temp
 360         adc             xh,temp2
 361         adc             yl,_0
 362         adc             yh,_0
 363
 364         dec             temp3
 365
 366         jmp             fat_calc_dp_loop
 367 fat_calc_dp_lend:
 368
 369         sts             fat_ptr2dir  ,xl
 370         sts             fat_ptr2dir+1,xh
 371         sts             fat_ptr2dir+2,yl
 372         sts             fat_ptr2dir+3,yh
 373
 374
 375 .if FAT16_DEBUG > 1
 376         printstring "Begin of DIR at___: ",0
 377         mov             temp ,yl
 378         mov             temp2,yh
 379         rcall printhexw
 380         mov             temp ,xl
 381         mov             temp2,xh
 382         rcall printhexw
 383         printnewline
 384 .endif
 385
 386 ; Calculate begin of DATA Clusters within the Volume
 387 ; Num. Dir.Sektors = (Num. of Dir. Entrys * 32) / Bytes per Sektor
 388
 389 ; Sectorsize is fixed at 512 Bytes, makes 16 Entrys per Sektor
 390
 391         lds     zl,fat_numdirentrys                     ; low byte
 392         lds             zh,fat_numdirentrys+1           ; high byte
 393
 394 ;   Num. Direntrys / 16
 395         lsr             zh
 396         ror             zl
 397         lsr             zh
 398         ror             zl
 399         lsr             zh
 400         ror             zl
 401         lsr             zh
 402         ror             zl
 403
 404         lds             xl,fat_ptr2dir
 405         lds             xh,fat_ptr2dir+1
 406         lds             yl,fat_ptr2dir+2
 407         lds             yh,fat_ptr2dir+3
 408
 409         add             xl,zl
 410         adc             xh,zh
 411         adc             yl,_0
 412         adc             yh,_0
 413
 414         sts             fat_ptr2dat  ,xl
 415         sts             fat_ptr2dat+1,xh
 416         sts             fat_ptr2dat+2,yl
 417         sts             fat_ptr2dat+3,yh
 418
 419 .if FAT16_DEBUG > 1
 420         printstring "Begin of Data at__: ",0
 421         mov             temp ,yl
 422         mov             temp2,yh
 423         rcall printhexw
 424         mov             temp ,xl
 425         mov             temp2,xh
 426         rcall printhexw
 427         printnewline
 428 .endif
 429
 430 ; Here Starts the Scann of the Directory for valid image Files.
 431
 432         lds             xl,fat_ptr2dir
 433         lds             xh,fat_ptr2dir+1
 434         lds             yl,fat_ptr2dir+2
 435         lds             yh,fat_ptr2dir+3
 436
 437 ;  Load first sector from Directory
 438         call    mmcReadSect
 439         tst         temp
 440         breq    fat_look_for_images
 441
 442 ; Read error: Block not found
 443         clr temp
 444         ret
 445
 446 ; Looks at a read directory block for image entrys
 447 fat_look_for_images:
 448
 449         ldiw    z,hostbuf
 450         ldi             temp2,0
 451
 452 fat_look_for_loop:
 453         ldd     temp,z+0
 454         cpi             temp,'C'
 455         brne    fat_look_not_ok
 456
 457         ldd             temp,z+1
 458         cpi             temp,'P'
 459         brne    fat_look_not_ok
 460
 461         ldd             temp,z+2
 462         cpi             temp,'M'
 463         brne    fat_look_not_ok
 464
 465         ldd             temp,z+3
 466         cpi             temp,'D'
 467         brne    fat_look_not_ok
 468
 469         ldd             temp,z+4
 470         cpi             temp,'S'
 471         brne    fat_look_not_ok
 472
 473         ldd             temp,z+5
 474         cpi             temp,'K'
 475         brne    fat_look_not_ok
 476
 477         ldd             temp,z+6
 478         cpi             temp,'_'
 479         brne    fat_look_not_ok
 480
 481         ldd             temp,z+8
 482         cpi             temp,'I'
 483         brne    fat_look_not_ok
 484
 485         ldd             temp,z+9
 486         cpi             temp,'M'
 487         brne    fat_look_not_ok
 488
 489         ldd             temp,z+10
 490         cpi             temp,'G'
 491         brne    fat_look_not_ok
 492
 493         jmp             fat_store_new_entry
 494
 495 fat_look_not_ok:
 496
 497         //ldi           temp,32
 498         addiw   z,32
 499
 500         inc             temp2
 501         cpi             temp2,16                                ; max entrys/sector
 502         breq    fat_scan_next_sector
 503         jmp     fat_look_for_loop
 504
 505 fat_scan_next_sector:
 506
 507         ret
 508
 509
 510 ;       Create new Partition Entry
 511 fat_store_new_entry:
 512
 513 ;   Found a valid image
 514 .if FAT16_DEBUG > 1
 515         printstring "Found a valid Image ! ",0
 516         printnewline
 517 .endif
 518
 519         ldiw    y,hostparttbl
 520         lds             temp,ndisks
 521
 522 fat_look_store_loop:
 523         cp              temp,_0
 524         breq    fat_look_store
 525
 526         adiw    y,PARTENTRY_SIZE
 527         dec             temp
 528         jmp             fat_look_store_loop
 529
 530 fat_look_store:
 531 ;   Set Type of Partition to FAT16- Fileimage
 532         ldi temp,dskType_FAT
 533         st      y+,temp
 534
 535 ;   Offset to Startcluster + 2
 536         ldd     temp,z+0x1A
 537         st      y+,temp
 538         ldd     temp,z+0x1B
 539         st      y+,temp
 540         ldi     temp,0
 541         st      y+,temp
 542         st      y+,temp
 543
 544 ;   Filesize in Bytes - 2,4,8,16,32,64,128,256,512
 545 ;       ldd     temp,z+0x1C
 546 ;       st      y+,temp
 547 ;       ldd     temp,z+0x1D
 548 ;       st      y+,temp
 549 ;       ldd     temp,z+0x1E
 550 ;       st      y+,temp
 551 ;       ldd     temp,z+0x1F
 552 ;       st      y+,temp
 553
 554 ;   Convert Filesize to ammount of sectors
 555         ldd     xl,z+0x1D
 556         ldd     xh,z+0x1E
 557         ldd     zl,z+0x1F
 558         mov     zh,_0
 559
 560         lsr     zh
 561         ror zl
 562         ror xh
 563         ror xl
 564
 565 ;   store ammount of sectors in partitiontable
 566         st  y+,xl
 567         st  y+,xh
 568         st  y+,zl
 569         st  y+,zh
 570
 571 ; Check for another free entry in partition table
 572         lds     temp,ndisks
 573         inc     temp
 574         sts     ndisks,temp
 575
 576
 577 .if FAT16_DEBUG > 1
 578 ; Test finding of the first sector
 579         ldd     xl,z+0x1A
 580         ldd     xh,z+0x1B
 581         ldi     zl,0
 582
 583         rcall   fat_gethostsec
 584
 585         printstring "Begin of Image at: ",0
 586         mov             temp ,yl
 587         mov             temp2,yh
 588         rcall printhexw
 589         mov             temp ,xl
 590         mov             temp2,xh
 591         rcall printhexw
 592         printnewline
 593
 594 .endif
 595
 596 ;       cp              temp,MAXDISKS
 597 ;       brne    fat_scan_for_more
 598
 599         ret
 600
 601
 602 ; ====================================================================
 603 ; Function: Cluster to HostSector
 604 ; ====================================================================
 605 ; Parameters: [in]      xh,xl                   Cluster Number
 606 ;                         [out] yh,yl,xh,xl             Sector Number on Disk
 607 ; --------------------------------------------------------------------
 608 ; Registers  :
 609 ; Variables  :  [used]  fat_clustersize Ammount of Sectors per Cluster
 610 ;                               [changes] temp
 611 ; --------------------------------------------------------------------
 612 ; Description:
 613 ; ! Only works with Clustersizes 2,4,8,16,32,64,128 !
 614 ; ====================================================================
 615 fat_gethostsec:
 616
 617 ;       Get Offset into Data area of Disk
 618         rcall   fat_clusttosec
 619
 620
 621 ;       add begin of data area to offset
 622         lds             temp,fat_ptr2dat+0
 623         add             xl,temp
 624         lds             temp,fat_ptr2dat+1
 625         adc             xh,temp
 626         lds             temp,fat_ptr2dat+2
 627         adc             yl,temp
 628         lds             temp,fat_ptr2dat+3
 629         adc             yh,temp
 630         ret
 631
 632 ; ====================================================================
 633 ; Function: Cluster to Sector
 634 ; ====================================================================
 635 ; Parameters: [in]      xl,xh                   Cluster Number
 636 ;                         [out] xl,xh,yl,yh             Sector Number
 637 ; --------------------------------------------------------------------
 638 ; Registers  :
 639 ; Variables  :  [used]  fat_clustersize Ammount of Sectors per Cluster
 640 ;                               [changes] temp
 641 ; --------------------------------------------------------------------
 642 ; Description:
 643 ; ! Only works with Clustersizes 2,4,8,16,32,64,128 !
 644 ; ====================================================================
 645 fat_clusttosec:
 646         clr     yl
 647         clr             yh
 648
 649         ldi             temp,2
 650         sub             xl,temp         ; Substract the 2 reserved clusters
 651         sbc             xh,_0
 652
 653         lds             temp,fat_clustersize
 654
 655 fat_c2s_loop:
 656         tst             temp
 657         breq    fat_c2s_end
 658         lsr             temp
 659
 660         lsl             xl
 661         rol             xh
 662         rol             yl
 663         rol             yh
 664         rjmp    fat_c2s_loop
 665
 666 fat_c2s_end:
 667         ret
 668
 669 ; ====================================================================
 670 ; Function: Searches a physical Cluster, given the logical Cluster
 671 ; ====================================================================
 672 ; Parameters
 673 ; --------------------------------------------------------------------
 674 ; Registers  : [r] xh,xl                logical- Cluster
 675 ;                          [w] yh,yl            physical- Cluster
 676 ; --------------------------------------------------------------------
 677 ; Description:
 678 ; ====================================================================
 679 fat_find_phsy_clust:
 680         mov     temp2,xl
 681         lds             xl,hostdsk
 682
 683         rcall   dsk_getpartentry        ; get partition entry
 684         mov     xl,temp2
 685
 686 ;       Get First FAT- Cluster Number of Diskimage
 687
 688         ldd             xl,z+1
 689         ldd             xh,z+2
 690
 691 fat_next_phsy_clust:
 692         cp              xl,_0
 693         cpc             xh,_0
 694         breq    fat_found_phsy_clust
 695 ;       Get Next Cluster from Fat
 696
 697 ; Trick: 512 Bytes Per Sector equals to 256 FAT- Entrys per Sector
 698 ; so given:  yl is the Offset within the FAT Sector
 699 ;            yh is the number off se FAT sector to Read
 700
 701 ;       in      zh,zl:          Pointer to Word within the Sector to read
 702 ;   in  yh..xl: Start sector number (LBA)
 703 ;       out     zh,zl   : word thats been read
 704         push xl
 705         push xh
 706
 707 ;   Create FAT Offset Value
 708         clr     zh
 709         mov zl,yl
 710         lsl     zl
 711         rol zh
 712 ;   Get FAT Start
 713         mov temp,yh
 714         lds xl,fat_ptr2fat
 715         lds xh,fat_ptr2fat+1
 716         lds yl,fat_ptr2fat+2
 717         lds yh,fat_ptr2fat+3
 718 ;   Add Sector offset
 719         add     xl,temp
 720         adc     xh,_0
 721         adc yl,_0
 722         adc yh,_0
 723         call mmcReadWord
 724
 725         pop xh
 726         pop xl
 727
 728         mov yl,zl
 729         mov yh,zh
 730
 731 ;       Check next logical Cluster
 732         ldi             zl,1
 733         sub             xl,zl
 734         sbc             xh,_0
 735         rjmp    fat_next_phsy_clust
 736
 737 ; Found the physical cluster
 738 fat_found_phsy_clust:
 739         ret
 740
 741 ; ====================================================================
 742 ; Function: Does a Disk write operation
 743 ; ====================================================================
 744 ; Parameters
 745 ; --------------------------------------------------------------------
 746 ; Registers  : none
 747 ; Variables  : [r] seekdsk              Number of Disk to Read
 748 ;                          [r] seeksec          Sector to read
 749 ;              [r] seektrk              Track  to read
 750 ; hostdsk = host disk #,  (partition #)
 751 ; hostlba = host block #, relative to partition start
 752 ; Read/Write "hostsize" bytes to/from hostbuf
 753 ; --------------------------------------------------------------------
 754 ; Description:
 755 ; ====================================================================
 756
 757 fat_hostparam:
 758         lds             xl,hostdsk
 759
 760 .if HOSTRW_DEBUG
 761         mov     temp,xl
 762         subi    temp,-('A')
 763         rcall   uartputc
 764         printstring ": "
 765 .endif
 766
 767         rcall dsk_getpartentry  ; get partition entry
 768
 769 fat_hostlend:
 770         lds             temp ,hostlba
 771         lds             temp2,hostlba+1
 772         lds             temp3,hostlba+2
 773
 774 .if HOSTRW_DEBUG
 775         printstring "lba: "
 776         clr             temp4
 777         rcall   print_ultoa
 778 .endif
 779
 780         ldd             xl,z+5                  ; get size of disk in sectors
 781         ldd             xh,z+6
 782         ldd             yl,z+7
 783
 784         cp              temp,xl                 ; check given sector against disksize
 785         cpc             temp2,xh
 786         cpc             temp3,yl
 787         brcs    fat_hp1
 788
 789 .if HOSTRW_DEBUG
 790         printstring ", max: "
 791         push    temp4
 792         push    temp3
 793         push    temp2
 794         push    temp
 795         movw    temp,x
 796         mov             temp3,yl
 797         clr             temp4
 798         rcall   print_ultoa
 799         pop             temp
 800         pop             temp2
 801         pop             temp3
 802         pop             temp4
 803         printstring " "
 804 .endif
 805
 806         clr             temp
 807         ret
 808
 809 fat_hp1:
 810 ; ################# Get logical Number of Cluster within the imagefile
 811 ;       printstring "calc log sector"
 812 ; Get logical Sectornumber from temp
 813         mov     xl,temp
 814         mov     xh,temp2
 815         mov     yl,temp3
 816         mov     yh,_0
 817 ; Divide logical Sectornumber by size of Cluster in sectors
 818         lds             zl,     fat_clustersize
 819 fat_search_clst_lp:
 820         tst             zl
 821         breq    fat_found_clst
 822
 823         lsr             yh
 824         ror             yl
 825         ror             xh
 826         ror             xl
 827
 828         lsr             zl
 829
 830         rjmp    fat_search_clst_lp
 831 fat_found_clst:
 832 ; at this point xh and xl are carying the logical cluster number
 833 ;       printstring "find subsector"
 834 ; ################# Get Subsector within the logical Cluster for later use
 835         mov             yl,xl
 836         lds             zl,     fat_clustersize
 837 fat_search_clst_lp2:
 838         tst             zl
 839         breq    fat_found_subsec
 840         lsl             yl
 841
 842         lsr             zl
 843         rjmp    fat_search_clst_lp2
 844
 845 fat_found_subsec:
 846         mov             zl,temp
 847         sub             zl,yl
 848         sts             fat_clust_offset,zl
 849
 850 ; Check against last HOSTDISK searched
 851         lds             yl,fat_last_dsk
 852         lds             yh,hostdsk
 853         cp              yl,yh
 854         brne    fat_wrong_cache_clst
 855
 856 ; Check against last Cluster searched
 857         lds             yl,fat_log_clust
 858         lds             yh,fat_log_clust+1
 859
 860         cp              yl,xl
 861         brne    fat_wrong_cache_clst
 862         cp              yh,xh
 863         brne    fat_wrong_cache_clst
 864
 865 ;   Last Cluster = searched Cluster -> get Sectornumber from cache
 866         lds             xl,fat_clust_ptr
 867         lds             xh,fat_clust_ptr+1
 868         lds             yl,fat_clust_ptr+2
 869         lds             yh,fat_clust_ptr+3
 870
 871         rjmp    fat_add_offset
 872
 873 ; ################# Cluster is not in cache, so we must search for it
 874 fat_wrong_cache_clst:
 875         lds             yl,hostdsk
 876         sts             fat_last_dsk,yl
 877         sts             fat_log_clust,xl
 878         sts             fat_log_clust+1,xh
 879
 880 ; ################# Map Logical Cluster-Number to "Physical" Cluster Number using the FAT
 881         rcall   fat_find_phsy_clust
 882
 883 ; ################# Get StartSector of "physical" Cluster
 884         mov     xl,yl
 885         mov             xh,yh
 886         rcall   fat_gethostsec
 887
 888 ;   Save the found Sector for later use into cache
 889         sts             fat_clust_ptr  ,xl
 890         sts             fat_clust_ptr+1,xh
 891         sts             fat_clust_ptr+2,yl
 892         sts             fat_clust_ptr+3,yh
 893
 894 ;   Add- Subsector to Startsector
 895 fat_add_offset:
 896         lds             zl,fat_clust_offset
 897         add             xl,zl
 898         adc             xh,_0
 899         adc             yl,_0
 900         adc             yh,_0
 901
 902 .if HOSTRW_DEBUG
 903         printstring ", abs:"
 904         push    temp4
 905         push    temp3
 906         push    temp2
 907         push    temp
 908         movw    temp,x
 909         movw    temp3,y
 910         rcall   print_ultoa
 911         pop             temp
 912         pop             temp2
 913         pop             temp3
 914         pop             temp4
 915         printstring " "
 916 .endif
 917
 918         ori             temp,255
 919 fat_hpex:
 920         ret
 921
 922 ; ====================================================================
 923 ; Function: Does a Disk write operation
 924 ; ====================================================================
 925 ; Parameters
 926 ; --------------------------------------------------------------------
 927 ; Registers  : none
 928 ; Variables  : [r] seekdsk              Number of Disk to Read
 929 ;                          [r] seeksec          Sector to read
 930 ;              [r] seektrk              Track  to read
 931 ; --------------------------------------------------------------------
 932 ; Description:
 933 ; ====================================================================
 934
 935 fat_writehost:
 936 .if HOSTRW_DEBUG
 937         printnewline
 938         printstring "host write "
 939 .endif
 940         rcall   fat_hostparam
 941         breq    fat_rdwr_err
 942
 943         ;call   mmcWriteSect    ; disabled till read is functioning
 944         tst             temp
 945         breq    fat_rdwr_ok
 946
 947         rcall   mgr_init_partitions
 948         cbr             temp,0x80
 949         breq    fat_rdwr_err
 950
 951         rcall   fat_hostparam
 952         breq    fat_rdwr_err
 953         ;call   mmcWriteSect    ; disabled till read is functioning
 954         tst             temp
 955         brne    fat_rdwr_err
 956         rjmp    fat_rdwr_ok
 957
 958 ; ====================================================================
 959 ; Function: Does a Disk read operation
 960 ; ====================================================================
 961 ; Parameters
 962 ; --------------------------------------------------------------------
 963 ; Registers  : none
 964 ; Variables  : [r] seekdsk              Number of Disk to Read
 965 ;                          [r] seeksec          Sector to read
 966 ;              [r] seektrk              Track  to read
 967 ; --------------------------------------------------------------------
 968 ; Description:
 969 ; ====================================================================
 970
 971 fat_readhost:
 972 .if HOSTRW_DEBUG
 973         printnewline
 974         printstring "host read  "
 975 .endif
 976
 977         rcall   fat_hostparam
 978         breq    fat_rdwr_err
 979
 980
 981         printstring "Read Image Sector:"
 982         push    temp4
 983         push    temp3
 984         push    temp2
 985         push    temp
 986         movw    temp,x
 987         movw    temp3,y
 988         rcall   print_ultoa
 989         pop             temp
 990         pop             temp2
 991         pop             temp3
 992         pop             temp4
 993         printstring " "
 994
 995         call    mmcReadSect
 996         tst             temp
 997         breq    fat_rdwr_ok
 998
 999         rcall   mgr_init_partitions
1000         cbr             temp,0x80
1001         breq    fat_rdwr_err
1002
1003         rcall   fat_hostparam
1004         breq    fat_rdwr_err
1005         call    mmcReadSect
1006         tst             temp
1007         brne    fat_rdwr_err
1008
1009 fat_rdwr_ok:
1010         sts             erflag,_0
1011         ret
1012
1013 fat_rdwr_err:
1014         sts             erflag,_255
1015         ret
1016 #endif
1017