v4.0/src/DEV/XMA2EMS/ROMSCAN.INC

   1
   2         page
   3 ;-------------------------------------------------------------------
   4 ;
   5 ;       This file contains the code to do a pseudo-rom scan looking
   6 ;       for possible EMS holes
   7 ;
   8 ;-------------------------------------------------------------------
   9
  10
  11
  12 romscan proc    near
  13
  14         push    ax
  15         push    dx
  16         push    cx
  17         push    di
  18
  19         push    cs                      ; make es and ds point to segment where messages are
  20         pop     es
  21
  22         push    cs
  23         pop     ds
  24
  25 ;       must do rom scan with interrupts disabled
  26
  27         cli
  28
  29 ;------------------------
  30
  31         cmp     map_count,0             ; no segments specified, do rom scan
  32         je      no_pages_spec
  33
  34         mov     cx,map_count            ; number of segments to check
  35         xor     di,di                   ; use di as pointer into table
  36
  37 check_segs:
  38         mov     ax,map_table.phys_page_segment[di]
  39
  40         call    CHK_FREE_SEGMENT        ; check a 16K block
  41         jnc     segment_ok
  42
  43 ;       display the error
  44
  45         mov     segment_error,1         ; set segment error flag
  46
  47
  48 ;       display conflict message
  49
  50         push    ax                      ; save some regs
  51         push    dx
  52         push    di
  53
  54         MOV     DI,OFFSET confl_address ; ascii string page frame
  55         CALL    CNVHEXAT
  56
  57         MOV     DX,OFFSET conflict_msg  ; start of message
  58         MOV     AH,9                    ; dos prt string
  59         INT     21H                     ;
  60
  61         pop     di                      ; restore some regs
  62         pop     dx
  63         pop     ax
  64
  65 segment_ok:
  66         add     di,type mappable_phys_page_struct
  67         loop    check_segs
  68
  69 ;------------------------
  70 ;       if there were no conflicts, then exit with no error
  71
  72         cmp     segment_error,0
  73         je      rom_scan_no_error       ; exit with no error (carry = 0)
  74
  75 ;------------------------
  76
  77         MOV     DX,OFFSET CRLF          ; skip a blank line
  78         MOV     AH,9                    ; dos prt string
  79         INT     21H                     ;
  80
  81         jmp     rom_scan_code
  82
  83 ;       display no pages message
  84
  85 no_pages_spec:
  86         MOV     DX,OFFSET NO_PAGES_MSG  ; skip a blank line
  87         MOV     AH,9                    ; dos prt string
  88         INT     21H
  89
  90         MOV     DX,OFFSET CRLF          ; skip a blank line
  91         MOV     AH,9                    ; dos prt string
  92         INT     21H                     ;
  93
  94 ;-------------------------------------------------------------------
  95 ;
  96 ;       This routine scans the address range from c000 - FFFF looking
  97 ;       for 16 K gaps.
  98 ;
  99 ;-------------------------------------------------------------------
 100
 101 rom_scan_code:
 102
 103         mov     ax,0c000h               ; start at c000
 104         xor     bx,bx                   ; bx holds count of contiguous pages
 105         mov     cx,15                   ; loop counter
 106         mov     dx,ax                   ; dx holds start of frame
 107
 108 fam2_loop:
 109         call    CHK_FREE_SEGMENT        ; check a 16K block
 110         jc      bad_seg
 111
 112 ;       good 16 segment
 113
 114         call    FoundBlock
 115
 116         add     bx,1                    ; add another page to frame counter
 117         cmp     bx,4                    ; 4 means frame is found
 118         jne     no_frame_yet
 119
 120 ;       a frame has been found
 121
 122         mov     bx,100                  ; make sure we don't look for more frames
 123
 124 no_frame_yet:
 125         add     ax,0400h                ; point to next segment
 126         jmp     continue_loop
 127
 128 ;       bad 16 segment
 129
 130 bad_seg:
 131         add     ax,0400h                ; point to next segment
 132         cmp     bx,100
 133         jae     continue_loop           ; don't reset frame info if one has been found
 134
 135         xor     bx,bx                   ; clear contiguous page counter
 136         mov     dx,ax                   ; make frame pointer point to next page
 137
 138 continue_loop:
 139
 140         loop    fam2_loop
 141         jmp     rom_scan_exit
 142
 143
 144 rom_scan_no_error:
 145         clc
 146         jmp     clean_exit
 147
 148
 149 ;-------------------------------------------------------------------
 150
 151 rom_scan_exit:
 152
 153 ;       display frame if found
 154
 155         cmp     bx,100                  ; >= 100 means frame was found
 156         jb      no_frame_exit
 157
 158         mov     ax,dx                   ; get frame address in ax
 159         call    FoundFrame              ; display frame address
 160
 161
 162 no_frame_exit:
 163         STC                             ; carry = 1 means error
 164
 165 clean_exit:
 166         sti
 167
 168
 169         pop     di
 170         pop     dx
 171         pop     cx
 172         pop     ax
 173
 174         ret
 175
 176 romscan endp
 177
 178
 179
 180 ;-------------------------------------------------------------------
 181 ;
 182 ;       FoundBlock assumes AX = segment address of good 16 K block
 183 ;
 184 ;-------------------------------------------------------------------
 185
 186 FoundBlock      proc    near
 187
 188         push    ax
 189         push    dx
 190         push    es
 191         push    di
 192
 193         push    cs
 194         pop     es
 195
 196         push    cs
 197         pop     ds
 198
 199         MOV     DI,OFFSET hole_address  ; ascii string page frame
 200         CALL    CNVHEXAT
 201
 202         MOV     DX,OFFSET hole_msg      ; start of message
 203         MOV     AH,9                    ; dos prt string
 204         INT     21H                     ;
 205
 206
 207         pop     di
 208         pop     es
 209         pop     dx
 210         pop     ax
 211
 212         ret
 213
 214 FoundBlock      endp
 215
 216 ;-------------------------------------------------------------------
 217 ;
 218 ;       FoundFrame assumes AX = segment address of good 64 K block
 219 ;
 220 ;-------------------------------------------------------------------
 221
 222 FoundFrame      proc    near
 223
 224         push    ax
 225         push    dx
 226         push    es
 227         push    di
 228
 229         push    cs
 230         pop     es
 231
 232         push    cs
 233         pop     ds
 234
 235         MOV     DI,OFFSET frame_address  ; ascii string page frame
 236         CALL    CNVHEXAT
 237
 238         MOV     DX,OFFSET frame_msg      ; start of message
 239         MOV     AH,9                    ; dos prt string
 240         INT     21H                     ;
 241
 242
 243         pop     di
 244         pop     es
 245         pop     dx
 246         pop     ax
 247
 248         ret
 249
 250 FoundFrame      endp
 251
 252
 253
 254
 255
 256
 257 ;-------------------------------------------------------------------
 258 ;-------------------------------------------------------------------
 259 ;-------------------------------------------------------------------
 260 ;-------------------------------------------------------------------
 261 ;-------------------------------------------------------------------
 262 ;-------------------------------------------------------------------
 263 ;-------------------------------------------------------------------
 264 ;-------------------------------------------------------------------
 265 ;-------------------------------------------------------------------
 266 ;-------------------------------------------------------------------
 267 ;-------------------------------------------------------------------
 268 ;-------------------------------------------------------------------
 269 ;------------------------------------------------------------------------
 270 ;                                                           03/04/88 jwg:
 271 ;  PROCEDURE NAME:  CHK_FREE_SEGMENT                                    :
 272 ;                                                                       :
 273 ;  THIS PROCEDURE CHECKS EACH OF THE 2K BOUNDARIES IN THE 16K SEGMENT   :
 274 ;  TO DETERMINE IF A ROM SEGMENT IS EMPTY.  IT VERIFIES THAT NO ROM     :
 275 ;  FROM A PRECEEDING ADDRESS EXTENDS INTO THIS 16K SEGMENT.  ALSO THE   :
 276 ;  16K BLOCK IS CHECKED FOR THE PRESENCE OF ANY RESPONDING CARD.        :
 277 ;                                                                       :
 278 ;  ENTRY: AX - CONTAINS 16K SEGMENT ADDRESS                             :
 279 ;  EXIT: CARRY FLAG = 0 - SEGMENT FREE                                  :
 280 ;        CARRY FLAG = 1 - SEGMENT IN USE                                :
 281 ;                                                                       :
 282 ;------------------------------------------------------------------------
 283
 284 ROM_SCAN        EQU     0AA55H
 285 CARD_SEL_PORT   EQU     091h            ; CARD SELECTED LATCH PORT
 286
 287
 288 CHK_FREE_SEGMENT    PROC  NEAR
 289
 290         PUSH    AX                      ; Save work registers
 291         PUSH    BX
 292         PUSH    CX
 293         PUSH    DX
 294         PUSH    DI
 295         PUSH    ES                      ; Save data segment register
 296         MOV     BX,AX                   ; Save segment start address
 297         MOV     CX,AX                   ; Save in work register
 298         ADD     CX,0400h                ; Determine End segment address of FIFE
 299 ;       MOV     DX,0C000h-00100h        ; Get address of start of ROM area
 300         mov     dx,ax                   ; gga
 301         sub     dx,0100h                ; gga
 302 CHK_FREE_NEXT:
 303         ADD     DX,00100h               ; Add offset to get next 2K segment
 304         CMP     DX,CX                   ; Check for past end of 16K ROM area
 305         JAE     CHK_FREE_OK             ; IF (NC) then Exit, segment was free
 306
 307                                         ;       CHECK FOR ROM BLOCK SIGNATURE
 308         MOV     ES,DX                   ; Change to new ROM segment
 309         CMP     ES:WORD PTR [0],ROM_SCAN; Check if a ROM module is present
 310         JE      CHK_FREE_SIZE           ; Go check length if ROM SCAN signature
 311
 312         CMP     BX,DX                   ; Check if into the target segment yet
 313         JA      CHK_FREE_NEXT           ; Loop and check next 2K block in not
 314
 315                                         ;       CHECK FOR CARD RESPONDING IN 2K
 316         NOP                             ; Following sequence can not be traced..
 317 ;;;;;   CALL    CARD_SEL_NOW            ; Reset CARD SELECTED FEED BACK latch  .
 318         XOR     DI,DI                   ; Clear source pointer                 .
 319         MOV     AX,0FFFFh               ; Get expected floating bus pattern    .
 320         PUSH    CX                      ; Save CX                              .
 321         MOV     CX,00400h               ; Get count of 1 K words (2K bytes)    .
 322         REPE    SCASW                   ; Check for all bits on in block ES:DI .
 323         POP     CX                      ; Recover end segment address          .
 324         JNE     CHK_FREE_ERROR          ; Exit if anything there               .
 325
 326 ;;;;;;  cmp     rom_scan_type,family1   ; gga only do the card select check on PS2's
 327 ;;;;;;  je      skip_ps2_check
 328
 329 ;;;;;;  CALL    CARD_SEL_NOW            ; Check for a CARD SELECTED by scan    .
 330 ;;;;;;  JC      CHK_FREE_ERROR          ; Exit (CY) if a card responded ........
 331
 332 ;;;;;;skip_ps2_check:
 333         JMP     CHK_FREE_NEXT           ; ELSE check next 2K address
 334
 335 CHK_FREE_SIZE:                          ;       CHECK LENGTH INTO 16K SEGMENT
 336         push    cx                      ; gga
 337         MOV     AL,ES:BYTE PTR [2]      ; Get ROM module length in 512 bytes
 338         MOV     AH,0                    ; Clear high byte
 339         mov     cl,5                    ; gga
 340         SHL     AX,cl                   ; gga convert to segment length (16 byte)
 341         pop     cx                      ; gga
 342         ADD     AX,DX                   ; Determine ending segment size
 343         CMP     BX,AX                   ; Does ROM extend into this 16K segment
 344         JNB     CHK_FREE_NEXT           ; IF not then continue search
 345
 346 CHK_FREE_ERROR:
 347         STC                             ; ELSE (CY), Exit with segment not free
 348 CHK_FREE_OK:
 349         POP     ES                      ; restore segment register
 350         POP     DI
 351         POP     DX
 352         POP     CX                      ; restore all registers
 353         POP     BX
 354         POP     AX
 355         RET                             ; EXIT (NC) if segment free to test
 356
 357 CHK_FREE_SEGMENT    ENDP
 358
 359
 360 ;------------------------------------------------------------------------
 361 ;                                                           03/04/88 jwg:
 362 ;  PROCEDURE NAME:  CARD_SEL_FBK                                        :
 363 ;                                                                       :
 364 ;  THIS PROCEDURE CHECKS THE CARD SELECTED FEEDBACK LINE AND LATCH      :
 365 ;  TO VERIFY THAT THIS LINE WAS ACTIVATED.  METHOD IS TO CLEAR THE      :
 366 ;  LATCH AND READ A LOCATION USING THE PASSED SEGMENT ADDRESS.  IF      :
 367 ;  ANY CARD RESPONDS THE LATCH WILL BE SET ON.                          :
 368 ;                                                                       :
 369 ;    NOTE:  These routines can not be traced with a debug-er            :
 370 ;           as VIDEO updates also set the card selected latch.          :
 371 ;                                                                       :
 372 ; ENTRY: AX - ADDRESS OF SELECTED SEGMENT                               :
 373 ;                                                                       :
 374 ;  EXIT: CARRY FLAG = 0 - CARD SELECTED LATCH WAS NOT SET (OFF)         :
 375 ;        CARRY FLAG = 1 - CARD SELECTED LATCH WAS SET BY TEST           :
 376 ;                                                                       :
 377 ;------------------------------------------------------------------------
 378
 379 ;;;;;CARD_SEL_FBK    PROC    NEAR            ;       TEST CARD SELECTED FEED BACK
 380
 381 ;;;;;        CLI                             ; Block interrupts during operation
 382 ;;;;;        CALL    CARD_SEL_NOW            ; Read current port value to clear
 383 ;;;;;        PUSH    DS                      ; Save segment register
 384 ;;;;;        MOV     DS,AX                   ; Set segment
 385 ;;;;;        CMP     DS:BYTE PTR [0],AL      ; Read first byte with dummy compare
 386 ;;;;;        POP     DS                      ; Restore segment selector
 387 ;;;;;        CALL    CARD_SEL_NOW            ; Read current port value and clear
 388 ;;;;;        STI                             ; Enable interrupts
 389 ;;;;;        RET                             ; RETurn (CY)= 1 if latch  set by read
 390
 391 ;;;;;CARD_SEL_FBK    ENDP
 392
 393 ;------------------------------------------------------------------------
 394 ;                                                           03/04/88 jwg:
 395 ;  PROCEDURE NAME:  CARD_SEL_NOW  (CURRENT VALUE)                       :
 396 ;                                                                       :
 397 ;  THIS PROCEDURE READS AND RESETS THE CURRENT CARD SELECTED FEEDBACK   :
 398 ;  LATCH AND RETURNS THE STATUS.                                        :
 399 ;                                                                       :
 400 ;    NOTE:  This routine can not be traced with a debug-er              :
 401 ;           as VIDEO updates also set the card selected latch.          :
 402 ;                                                                       :
 403 ; ENTRY: NONE                                                           :
 404 ;                                                                       :
 405 ;  EXIT: CARRY FLAG = 0 - CARD SELECTED LATCH WAS NOT SET (OFF)         :
 406 ;        CARRY FLAG = 1 - CARD SELECTED LATCH WAS SET ON WHEN READ      :
 407 ;                                                                       :
 408 ;------------------------------------------------------------------------
 409
 410 ;;;;;CARD_SEL_NOW    PROC    NEAR            ;       READ CARD SELECTED FEED BACK
 411
 412 ;;;;;        PUSH    AX                      ; Save segment address
 413 ;;;;;        IN      AL,CARD_SEL_PORT        ; Read current port value and clear
 414 ;;;;;        RCR     AL,1                    ; Move bit 0 into CY flag
 415 ;;;;;        POP     AX                      ; Recover segment address
 416 ;;;;;        RET                             ; RETurn (CY)= 0 if latch set
 417
 418 ;;;;;CARD_SEL_NOW    ENDP
 419
 420 \1a