cbios/mm.180

   1         page    255
   2         .z80
   3
   4
   5         public mmuinit
   6         public bnk2log,bnk2phy,hwl2phy,phy2log
   7         public isv_sw
   8         public b_ld_a,b_ld_hl,b_st_a,b_st_hl
   9
  10
  11         extrn @cbnk
  12         extrn ijphl
  13
  14
  15         maclib z180reg.inc
  16         maclib config.inc
  17
  18
  19 ;----------------------------------------------------------------------
  20 ; Memory Map 1:
  21 ;
  22 ;       Common  CAStart ..     0FFFF
  23 ;       Bank 0    00000 .. CAStart-1
  24 ;       Bank 1    10000 ..
  25 ;       Bank 2
  26 ;
  27 ; Memory Map 2:
  28 ;
  29 ;       Common    18000 .. 1BFFF        BANK1
  30 ;
  31 ;       Bank 0    00000 .. 0BFFF        0
  32 ;       Bank 1    0C000 .. 17FFF        1*BNK_SIZE
  33 ;       Bank 2    1C000 .. 27FFF        2*BNK_SIZE + CMN_SIZE
  34 ;       Bank 3    28000 .. 33FFF        3*BNK_SIZE + CMN_SIZE
  35 ;       Bank n                          n*BNK_SIZE + (n < 2) ? 0 : CMN_SIZE
  36 ;
  37 ;----------------------------------------------------------------------
  38
  39         cseg
  40
  41 mmuinit:
  42         ld      a,USR$CBAR
  43         out0    (cbar),a
  44         ret
  45
  46 ;--------------------------------------------------------------------
  47 ; Return the BBR value for the given bank number
  48 ;
  49 ; in  a: Bank number
  50 ; out a: bbr value
  51
  52    if 0 ; Memory Map 1
  53
  54 bnk2log:
  55         or      a               ;
  56         ret     z               ; Bank 0 is at physical address 0
  57
  58         dec     a               ;
  59         push    bc              ;
  60         ld      c,a             ;
  61         ld      b,BNK_SIZE      ;
  62         mlt     bc              ; bank size * bank number
  63         ld      a,c             ;
  64         add     a,10h           ; add bank0 + common
  65         pop     bc              ;
  66         ret                     ;
  67
  68    else ; Memory Map 2
  69
  70 bnk2log:
  71         or      a
  72         ret     z               ; Bank 0 is at physical address 0
  73
  74         push    bc
  75         ld      c,a             ;
  76         ld      b,BNK_SIZE      ;
  77         mlt     bc              ; bank size * bank number
  78         cp      2               ;
  79         ld      a,c             ;
  80         pop     bc
  81         ret     c
  82         add     a,CMN_SIZE
  83         ret
  84
  85     endif
  86
  87     if 0 ; table version
  88
  89         push    hl
  90         ld      hl,bnk_table    ;
  91         add     a,l             ;
  92         ld      l,a             ;
  93         jr      nc,$+3          ;
  94         inc     h               ;
  95         ld      a,(hl)          ;
  96         pop     hl
  97         ret
  98
  99     endif
 100
 101 ;--------------------------------------------------------------
 102
 103 ;in  hl: Log. Address
 104 ;     a: Bank number
 105 ;
 106 ;out ahl: Phys. (linear) Address
 107
 108
 109 bnk2phy:
 110         push    bc
 111         ld      c,a
 112         ld      a,h
 113         and     a,0f0h
 114         cp      CA*16
 115         ld      a,c
 116         pop     bc
 117         jr      c,b2p_banked
 118                                 ; address is in common
 119     if 0 ; Memory Map 1
 120         ld      a,0             ; base is 0
 121     else ; Memory Map 2
 122         ld      a,1             ; same as bank1
 123     endif
 124
 125 b2p_banked:
 126         call    bnk2log         ; get address base
 127
 128         ; fall thru
 129
 130 ;--------------------------------------------------------------
 131 ;
 132 ; hl: Log. Address
 133 ;  a: Bank base (bbr)
 134 ;
 135 ;            2           0       0
 136 ;            0   6       8       0
 137 ; hl              hhhhhhhhllllllll
 138 ;  a    +     bbbbbbbb
 139 ;
 140 ; OP: ahl = (a<<12) + (h<<8) + l
 141 ;
 142 ;out ahl: Phys. (linear) Address
 143
 144 log2phy:
 145         push    bc              ;
 146 l2p_i:
 147         ld      c,a             ;
 148         ld      b,16            ;
 149         mlt     bc              ; bc = a<<4
 150         ld      a,c             ;
 151         add     a,h             ;
 152         ld      h,a             ;
 153         ld      a,b             ;
 154         adc     a,0             ;
 155         pop     bc              ;
 156         ret                     ;
 157
 158 ;--------------------------------------------------------------
 159 ;
 160 ; hl: Log. Address
 161 ;
 162 ;
 163 ; OP: ahl = (bankbase<<12) + (h<<8) + l
 164 ;
 165 ;out ahl: Phys. (linear) Address
 166
 167
 168 hwl2phy:
 169         push    bc              ;
 170         in0     c,(cbar)        ;
 171         ld      a,h             ;
 172         or      00fh            ; log. addr in common1?
 173         cp      c
 174         jr      c,hlp_1
 175
 176         in0     a,(cbr)         ; yes, cbr is address base
 177         jr      hl2p_x
 178 hlp_1:
 179         ld      b,16            ; log. address in baked area?
 180         mlt     bc
 181         ld      a,h
 182         cp      c
 183         jr      c,hlp_2
 184         in0     a,(bbr)         ; yes, bbr is address base
 185         jr      hl2p_x
 186 hlp_2:
 187         xor     a               ; common1
 188 hl2p_x:
 189         jr      nz,l2p_i
 190
 191         pop     bc              ; bank part is 0, no translation
 192         ret                     ;
 193
 194
 195 ;--------------------------------------------------------------
 196 ; return logical bank 0 address for given physical address.
 197 ;
 198 ; in: ahl: pyhsical addres (20 bit)
 199 ; out  hl: logical address.
 200 ;          logical address is in bank 0 or common, no bank number returned
 201 ;
 202
 203 phy2log:
 204         or      a
 205         ret     z
 206
 207         push    bc
 208         push    hl
 209         ld      l,h
 210         ld      h,0
 211         ld      bc,-16*SYS$CBR
 212         add     hl,bc
 213         ld      h,l
 214         pop     bc
 215         ld      l,c
 216         pop     bc
 217         ret
 218
 219 ;--------------------------------------------------------------
 220 ; Trampoline for routines in banked ram.
 221 ; Switch stack pointer to "system" stack in top ram
 222 ; Save cbar
 223 ;
 224         extrn   bs$stack
 225
 226         cseg    ; common!
 227
 228         public  _b0call
 229
 230    if 0
 231
 232 _b0call:
 233         push    af
 234         in0     a,(bbr)
 235         jr      nz,b0c_doit
 236         pop     af
 237
 238         ex      (sp),hl                 ;16
 239         push    de
 240         ld      e,(hl)
 241         inc     hl
 242         ld      d,(hl)
 243         inc     hl
 244         ld      (b0c_fast_go),de
 245         pop     de
 246         ex      (sp),hl                 ;16
 247 b0c_fast_go equ $+1
 248         jp      0
 249
 250 b0c_doit:
 251         ld      (b0_save_hl),hl
 252         ld      (b0_save_de),de
 253         pop     hl
 254         ld      (b0_save_af),hl
 255
 256         pop     de                      ;get ptr to 'function address' in de
 257         ld      hl,2
 258         add     hl,de
 259         push    hl                      ;put return address on stack
 260
 261    if 0 ; link80
 262
 263         ld      hl,0
 264         add     hl,sp                   ;
 265         ld      a,h
 266         cp      high (bs$stack-bs$stack$size) ;link80 can't process this
 267         jr      nc,$ + 5                ;skip if stack allready in common bios ram
 268
 269    else
 270
 271         ld      hl,bs$stack-bs$stack$size
 272         ld      a,h
 273         dec     a
 274         ld      hl,0
 275         add     hl,sp                   ;
 276         cp      h
 277         jr      c,$ + 5                 ;skip if stack allready in common bios ram
 278    endif
 279         ld      sp,bs$stack             ;
 280
 281         push    hl                      ;save   user stack pointer
 282
 283         in0     h,(bbr)                 ;
 284         push    hl                      ;
 285         ld      hl,b0c_ret
 286         push    hl
 287         xor     a
 288         out0    (bbr),a                 ;
 289         ex      de,hl                   ;ptr
 290         ld      e,(hl)                  ;get 'function address'
 291         inc     hl                      ;
 292         ld      d,(hl)                  ;
 293         push    de                      ;put on (switched) stack
 294
 295         ld      hl,(b0_save_af)         ;get back users registers
 296         push    hl
 297         pop     af
 298         ld      de,(b0_save_de)
 299         ld      hl,(b0_save_hl)
 300         ret                             ;go to function
 301 b0c_ret:
 302         ld      (b0_save_hl),hl
 303
 304         pop     hl                      ;
 305         out0    (bbr),h                 ;
 306         pop     hl                      ;
 307         ld      sp,hl                   ;
 308         ld      hl,(b0_save_hl)
 309         ret                             ;
 310    else
 311
 312 _b0call:
 313         push    af
 314         ld      (b0_save_hl),hl
 315         ld      (b0_save_de),de
 316         pop     hl
 317         ld      (b0_save_af),hl
 318
 319         pop     de                      ;get ptr to 'function address' in de
 320         ld      hl,2
 321         add     hl,de
 322         push    hl                      ;put return address on stack
 323
 324    if 0 ; link80
 325
 326         ld      hl,0
 327         add     hl,sp                   ;
 328         ld      a,h
 329         cp      high (bs$stack-bs$stack$size) ;link80 can't process this
 330         jr      nc,$ + 5                ;skip if stack allready in common bios ram
 331
 332    else
 333
 334         ld      hl,bs$stack-bs$stack$size
 335         ld      a,h
 336         dec     a
 337         ld      hl,0
 338         add     hl,sp                   ;
 339         cp      h
 340         jr      c,$ + 5                 ;skip if stack allready in common bios ram
 341    endif
 342         ld      sp,bs$stack             ;
 343
 344         push    hl                      ;save   user stack pointer
 345
 346         in0     h,(bbr)                 ;
 347         push    hl                      ;
 348         ld      hl,b0c_ret
 349         push    hl
 350         xor     a
 351         out0    (bbr),a                 ;
 352         ex      de,hl                   ;ptr
 353         ld      e,(hl)                  ;get 'function address'
 354         inc     hl                      ;
 355         ld      d,(hl)                  ;
 356         push    de                      ;put on (switched) stack
 357
 358         ld      hl,(b0_save_af)         ;get back users registers
 359         push    hl
 360         pop     af
 361         ld      de,(b0_save_de)
 362         ld      hl,(b0_save_hl)
 363         ret                             ;go to function
 364 b0c_ret:
 365         ld      (b0_save_hl),hl
 366
 367         pop     hl                      ;
 368         out0    (bbr),h                 ;
 369         pop     hl                      ;
 370         ld      sp,hl                   ;
 371         ld      hl,(b0_save_hl)
 372         ret                             ;
 373    endif
 374
 375 b0_save_hl: dw  0
 376 b0_save_de: dw  0
 377 b0_save_af: dw  0
 378
 379
 380 ;--------------------------------------------------------------------
 381 ; Trampoline for interrupt routines in banked ram.
 382 ; Switch stack pointer to "system" stack in top ram
 383 ; Save bbr
 384
 385         cseg
 386
 387    if 0
 388
 389 isv_sw:                                 ;
 390         ex      (sp),hl                 ;save hl, 'return adr' in hl
 391         push    de                      ;
 392         push    af                      ;
 393         ex      de,hl                   ;'return address' in de
 394
 395   if 0
 396    if 0 ; link80
 397
 398         ld      hl,0
 399         add     hl,sp                   ;
 400         ld      a,h
 401         cp      high (bs$stack-bs$stack$size) ;link80 can't process this
 402         jr      nc,$ + 5                ;skip if stack allready in common bios ram
 403
 404    else
 405
 406         ld      hl,bs$stack-bs$stack$size
 407         ld      a,h
 408         dec     a
 409         ld      hl,0
 410         add     hl,sp                   ;
 411         cp      h
 412         jr      c,$ + 5                 ;skip if stack allready in common bios ram
 413    endif
 414         ld      sp,bs$stack             ;
 415   else
 416         ld      hl,0
 417         add     hl,sp
 418         ld      sp,istack
 419   endif
 420         push    hl                      ;save user stack pointer
 421         in0     h,(bbr)                 ;
 422         push    hl                      ;
 423         xor     a                       ;
 424         out0    (bbr),a                 ;
 425         ex      de,hl                   ;
 426         ld      e,(hl)                  ;
 427         inc     hl                      ;
 428         ld      d,(hl)                  ;
 429         ex      de,hl                   ;
 430         push    bc                      ;
 431         call    ijphl                   ;
 432
 433         pop     bc                      ;
 434         pop     hl                      ;
 435         out0    (bbr),h                 ;
 436         pop     hl                      ;
 437         ld      sp,hl                   ;
 438         pop     af                      ;
 439         pop     de                      ;
 440         pop     hl                      ;
 441         ei                              ;
 442         ret                             ;
 443
 444    else
 445
 446 isv_sw:                                 ;
 447         ex      (sp),hl                 ;save hl, 'return adr' in hl
 448
 449         ld      (istack),sp             ;save user stack pointer
 450         ld      sp,istack
 451         push    de                      ;
 452         push    bc                      ;
 453         push    af                      ;
 454         in0     a,(bbr)                 ;
 455         push    af                      ;
 456         xor     a                       ;
 457         out0    (bbr),a                 ;
 458         ld      e,(hl)                  ;
 459         inc     hl                      ;
 460         ld      d,(hl)                  ;
 461         ex      de,hl                   ;
 462         call    ijphl                   ;
 463
 464         pop     af                      ;
 465         out0    (bbr),a                 ;
 466         pop     af                      ;
 467         pop     bc                      ;
 468         pop     de                      ;
 469         ld      sp,(istack)             ;
 470         pop     hl                      ;
 471         ei                              ;
 472         ret                             ;
 473
 474    endif
 475         ds      24
 476 istack:
 477         dw      0
 478
 479         dseg
 480
 481 ;--------------------------------------------------------------------
 482 ; Load byte/word from user ram
 483 ;
 484 ;   de:  src address in users bank
 485 ; return
 486 ;    a:  value (byte)
 487 ;   hl:  value (word)
 488
 489 b_ld_a:
 490         push    hl
 491         or      a               ; clear carry == byte store
 492         jr      $+3
 493 b_ld_hl:
 494         scf                     ; set carry == word store
 495         push    af              ; save flag
 496         push    hl              ; make space on stack
 497
 498         ld      a,(@cbnk)
 499         ld      b,a             ; b = src bank
 500
 501         ld      hl,0
 502         ld      a,l
 503         ld      c,l             ; c = dst bank (0)
 504         add     hl,sp           ; hl = dst
 505         adc     a,1             ; a = count
 506         ex      de,hl
 507         call    dma_move
 508         ex      de,hl
 509         pop     hl
 510         pop     af
 511         ret     c
 512         ld      a,l
 513         pop     hl
 514         ret
 515
 516 ;--------------------------------------------------------------------
 517 ; Store byte/word to user ram
 518 ;
 519 ;   de:  dst address in users bank
 520 ;    a:  value (byte)
 521 ;   hl:  value (word)
 522
 523 b_st_a:
 524         push    hl
 525         ld      l,a
 526         or      a               ; clear carry == byte store
 527         jr      $+3
 528 b_st_hl:
 529         scf                     ; set carry == word store
 530         push    af              ; save flag
 531         push    hl              ; put value on stack
 532
 533         ld      a,(@cbnk)       ;
 534         ld      c,a             ; c = dst bank
 535         ld      a,0
 536         ld      l,a
 537         ld      h,a
 538         ld      b,a             ; b = src bank (0)
 539         add     hl,sp           ; hl = src
 540         adc     a,1             ; a = count
 541
 542         call    dma_move
 543
 544         pop     hl              ; restore value
 545         pop     af              ; carry
 546         ret     c
 547         pop     hl
 548         ret
 549
 550 ;--------------------------------------------------------------------
 551 ;
 552 ;    hl: src
 553 ;    de: dst
 554 ;     b: src bank
 555 ;     c: dst bank
 556 ;     a: count
 557
 558 dma_move:
 559         out0    (bcr0l),a       ; setup DMA count
 560         xor     a
 561         out0    (bcr0h),a
 562
 563         push    hl
 564         ld      a,b
 565         call    bnk2phy
 566         out0    (sar0l),l       ; setup DMA src address
 567         out0    (sar0h),h
 568         out0    (sar0b),a
 569
 570         ld      l,e
 571         ld      h,d
 572         ld      a,c
 573         call    bnk2phy
 574         out0    (dar0l),l       ; setup DMA dst address
 575         out0    (dar0h),h
 576         out0    (dar0b),a
 577
 578         ld      a,M_MMOD        ; DMA burst mode
 579         out0    (dmode),a
 580         ld      a,M_DE0+M_NDWE1 ; enable DMA0
 581         out0    (dstat),a       ; move ...
 582         pop     hl
 583         ret
 584
 585
 586 ;====================================================================
 587
 588         cseg
 589
 590   if 0
 591
 592 ;--------------------------------------------------------------------
 593 ; Return the BBR value for the given bank number
 594
 595 bnk2bbr:
 596         or      a               ; 4
 597         ret     z               ; 5/10 | 11             14
 598
 599         push    bc              ;11 | 11
 600         ld      b,a             ; 4
 601         ld      c,CA            ; 6
 602         mlt     bc              ;17                         >45
 603         ld      a,c             ; 4
 604         add     a,10h           ; 6
 605         pop     bc              ; 9 | 10
 606         ret                     ; 9 | 10                76
 607
 608         push    ix              ;2 / 14 | 15
 609         ld      ix,bnktbl       ;4 / 12 | 14
 610         ld      ($+3+2),a       ;3 / 15 | 19
 611         ld      a,(ix+0)        ;3 / 14 | 19
 612         pop     ix              ;2 / 12 | 14
 613         ret                     ;1 /  9 | 10            15 / 76|91
 614
 615         push    hl              ;1 / 11 | 11
 616         ld      hl,bnktbl       ;3 /  9 | 10
 617         add     a,l             ;1 /  4 | 4
 618         ld      l,a             ;1 /  4 | 4
 619         ld      a,0             ;1 /  6 | 7
 620         adc     a,h             ;1 /  4 | 4
 621         ld      h,a             ;1 /  4 | 4
 622         ld      a,(hl)          ;1 /  6 | 7
 623         pop     hl              ;1 /  9 | 10
 624         ret                     ;1 /  9 | 10            12 / 66|71
 625
 626         push    hl              ;1 / 11 | 11
 627         add     a,low bnktbl    ;2 /  6 | 7
 628         ld      l,a             ;1 /  4 | 4
 629         ld      a,0             ;1 /  6 | 7
 630         adc     a,high bnktbl   ;2 /  6 | 7
 631         ld      h,a             ;1 /  4 | 4
 632         ld      a,(hl)          ;1 /  6 | 7
 633         pop     hl              ;1 /  9 | 10
 634         ret                     ;1 /  9 | 10            11 / 61|67
 635
 636   endif
 637
 638
 639         end