board/MAI/bios_emulator/scitech/src/pm/dos/_pm.asm

   1 ;****************************************************************************
   2 ;*
   3 ;*                  SciTech OS Portability Manager Library
   4 ;*
   5 ;*  ========================================================================
   6 ;*
   7 ;*    The contents of this file are subject to the SciTech MGL Public
   8 ;*    License Version 1.0 (the "License"); you may not use this file
   9 ;*    except in compliance with the License. You may obtain a copy of
  10 ;*    the License at http://www.scitechsoft.com/mgl-license.txt
  11 ;*
  12 ;*    Software distributed under the License is distributed on an
  13 ;*    "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  14 ;*    implied. See the License for the specific language governing
  15 ;*    rights and limitations under the License.
  16 ;*
  17 ;*    The Original Code is Copyright (C) 1991-1998 SciTech Software, Inc.
  18 ;*
  19 ;*    The Initial Developer of the Original Code is SciTech Software, Inc.
  20 ;*    All Rights Reserved.
  21 ;*
  22 ;*  ========================================================================
  23 ;*
  24 ;* Language:    80386 Assembler, TASM 4.0 or NASM
  25 ;* Environment: IBM PC Real mode and 16/32 bit protected mode
  26 ;*
  27 ;* Description: Low level assembly support for the PM library specific to
  28 ;*              MSDOS.
  29 ;*
  30 ;****************************************************************************
  31
  32         IDEAL
  33
  34 include "scitech.mac"               ; Memory model macros
  35
  36 header      _pmdos                  ; Set up memory model
  37
  38 begdataseg  _pmdos
  39
  40 ifndef  flatmodel
  41
  42 struc   rmregs_s
  43 ax          dw  ?
  44 ax_high     dw  ?
  45 bx          dw  ?
  46 bx_high     dw  ?
  47 cx          dw  ?
  48 cx_high     dw  ?
  49 dx          dw  ?
  50 dx_high     dw  ?
  51 si          dw  ?
  52 si_high     dw  ?
  53 di          dw  ?
  54 di_high     dw  ?
  55 cflag       dw  ?
  56 cflag_high  dw  ?
  57 ends    rmregs_s
  58 RMREGS  = (rmregs_s PTR es:bx)
  59
  60 struc   rmsregs_s
  61 es      dw  ?
  62 cs      dw  ?
  63 ss      dw  ?
  64 ds      dw  ?
  65 ends    rmsregs_s
  66 RMSREGS = (rmsregs_s PTR es:bx)
  67
  68 endif   ; !flatmodel
  69
  70 ifdef flatmodel
  71     cextern _PM_savedDS,USHORT
  72     cextern _PM_VXD_off,UINT
  73     cextern _PM_VXD_sel,UINT
  74 ifdef   DOS4GW
  75     cextern _PM_haveCauseWay,UINT
  76 endif
  77 endif
  78 intel_id        db  "GenuineIntel"  ; Intel vendor ID
  79
  80 PMHELP_GETPDB       EQU 0026h
  81 PMHELP_FLUSHTLB     EQU 0027h
  82
  83 enddataseg  _pmdos
  84
  85 P586
  86
  87 begcodeseg  _pmdos                  ; Start of code segment
  88
  89 ifndef  flatmodel
  90
  91 ;----------------------------------------------------------------------------
  92 ; void PM_callRealMode(unsigned s,unsigned o, RMREGS *regs,
  93 ;   RMSREGS *sregs)
  94 ;----------------------------------------------------------------------------
  95 ; Calls a real mode procedure, loading the appropriate registers values
  96 ; from the passed in structures. Only the DS and ES register are loaded
  97 ; from the SREGS structure.
  98 ;----------------------------------------------------------------------------
  99 cprocstart  PM_callRealMode
 100
 101         ARG     s:WORD, o:WORD, regs:DWORD, sregs:DWORD
 102
 103         LOCAL   addr:DWORD, bxVal:WORD, esVal:WORD, flags:WORD = LocalSize
 104
 105         enter_c
 106         push    ds
 107         push    es
 108
 109         mov     ax,[o]              ; Build the address to call in 'addr'
 110         mov     [WORD addr],ax
 111         mov     ax,[s]
 112         mov     [WORD addr+2],ax
 113
 114         les     bx,[sregs]
 115         mov     ax,[RMSREGS.ds]
 116         mov     ds,ax               ; DS := passed in value
 117         mov     ax,[RMSREGS.es]
 118         mov     [esVal],ax
 119         les     bx,[regs]
 120         mov     ax,[RMREGS.bx]
 121         mov     [bxVal],ax
 122         mov     ax,[RMREGS.ax]      ; AX := passed in value
 123         mov     cx,[RMREGS.cx]      ; CX := passed in value
 124         mov     dx,[RMREGS.dx]      ; DX := passed in value
 125         mov     si,[RMREGS.si]      ; SI := passed in value
 126         mov     di,[RMREGS.di]      ; DI := passed in value
 127         push    bp
 128         push    [esVal]
 129         pop     es                  ; ES := passed in value
 130         mov     bx,[bxVal]          ; BX := passed in value
 131
 132         call    [addr]              ; Call the specified routine
 133
 134         pushf                       ; Save flags for later
 135         pop     [flags]
 136
 137         pop     bp
 138         push    es
 139         pop     [esVal]
 140         push    bx
 141         pop     [bxVal]
 142         les     bx,[sregs]
 143         push    ds
 144         pop     [RMSREGS.ds]        ; Save value of DS
 145         push    [esVal]
 146         pop     [RMSREGS.es]        ; Save value of ES
 147         les     bx,[regs]
 148         mov     [RMREGS.ax],ax      ; Save value of AX
 149         mov     [RMREGS.cx],cx      ; Save value of CX
 150         mov     [RMREGS.dx],dx      ; Save value of DX
 151         mov     [RMREGS.si],si      ; Save value of SI
 152         mov     [RMREGS.di],di      ; Save value of DI
 153         mov     ax,[flags]          ; Return flags
 154         and     ax,1h               ; Isolate carry flag
 155         mov     [RMREGS.cflag],ax   ; Save carry flag status
 156         mov     ax,[bxVal]
 157         mov     [RMREGS.bx],ax      ; Save value of BX
 158
 159         pop     es
 160         pop     ds
 161         leave_c
 162         ret
 163
 164 cprocend
 165
 166 endif
 167
 168 ;----------------------------------------------------------------------------
 169 ; void PM_segread(PMSREGS *sregs)
 170 ;----------------------------------------------------------------------------
 171 ; Read the current value of all segment registers
 172 ;----------------------------------------------------------------------------
 173 cprocstartdll16 PM_segread
 174
 175         ARG     sregs:DPTR
 176
 177         enter_c
 178
 179         mov     ax,es
 180         _les    _si,[sregs]
 181         mov     [_ES _si],ax
 182         mov     [_ES _si+2],cs
 183         mov     [_ES _si+4],ss
 184         mov     [_ES _si+6],ds
 185         mov     [_ES _si+8],fs
 186         mov     [_ES _si+10],gs
 187
 188         leave_c
 189         ret
 190
 191 cprocend
 192
 193 ; Create a table of the 256 different interrupt calls that we can jump
 194 ; into
 195
 196 ifdef   USE_NASM
 197
 198 %assign intno 0
 199
 200 intTable:
 201 %rep    256
 202         db      0CDh
 203         db      intno
 204 %assign intno   intno + 1
 205         ret
 206         nop
 207 %endrep
 208
 209 else
 210
 211 intno = 0
 212
 213 intTable:
 214         REPT    256
 215         db      0CDh
 216         db      intno
 217 intno = intno + 1
 218         ret
 219         nop
 220         ENDM
 221
 222 endif
 223
 224 ;----------------------------------------------------------------------------
 225 ; _PM_genInt    - Generate the appropriate interrupt
 226 ;----------------------------------------------------------------------------
 227 cprocnear   _PM_genInt
 228
 229         push    _ax                     ; Save _ax
 230         push    _bx                     ; Save _bx
 231 ifdef flatmodel
 232         mov     ebx,[UINT esp+12]       ; EBX := interrupt number
 233 else
 234         mov     bx,sp                   ; Make sure ESP is zeroed
 235         mov     bx,[UINT ss:bx+6]       ; BX := interrupt number
 236 endif
 237         mov     _ax,offset intTable     ; Point to interrupt generation table
 238         shl     _bx,2                   ; _BX := index into table
 239         add     _ax,_bx                 ; _AX := pointer to interrupt code
 240 ifdef flatmodel
 241         xchg    eax,[esp+4]             ; Restore eax, and set for int
 242 else
 243         mov     bx,sp
 244         xchg    ax,[ss:bx+2]            ; Restore ax, and set for int
 245 endif
 246         pop     _bx                     ; restore _bx
 247         ret
 248
 249 cprocend
 250
 251 ;----------------------------------------------------------------------------
 252 ; int PM_int386x(int intno, PMREGS *in, PMREGS *out,PMSREGS *sregs)
 253 ;----------------------------------------------------------------------------
 254 ; Issues a software interrupt in protected mode. This routine has been
 255 ; written to allow user programs to load CS and DS with different values
 256 ; other than the default.
 257 ;----------------------------------------------------------------------------
 258 cprocstartdll16 PM_int386x
 259
 260         ARG     intno:UINT, inptr:DPTR, outptr:DPTR, sregs:DPTR
 261
 262         LOCAL   flags:UINT, sv_ds:UINT, sv_esi:ULONG = LocalSize
 263
 264         enter_c
 265         push    ds
 266         push    es                  ; Save segment registers
 267         push    fs
 268         push    gs
 269
 270         _lds    _si,[sregs]         ; DS:_SI -> Load segment registers
 271         mov     es,[_si]
 272         mov     bx,[_si+6]
 273         mov     [sv_ds],_bx         ; Save value of user DS on stack
 274         mov     fs,[_si+8]
 275         mov     gs,[_si+10]
 276
 277         _lds    _si,[inptr]         ; Load CPU registers
 278         mov     eax,[_si]
 279         mov     ebx,[_si+4]
 280         mov     ecx,[_si+8]
 281         mov     edx,[_si+12]
 282         mov     edi,[_si+20]
 283         mov     esi,[_si+16]
 284
 285         push    ds                  ; Save value of DS
 286         push    _bp                 ; Some interrupts trash this!
 287         clc                         ; Generate the interrupt
 288         push    [UINT intno]
 289         mov     ds,[WORD sv_ds]     ; Set value of user's DS selector
 290         call    _PM_genInt
 291         pop     _bp                 ; Pop intno from stack (flags unchanged)
 292         pop     _bp                 ; Restore value of stack frame pointer
 293         pop     ds                  ; Restore value of DS
 294
 295         pushf                       ; Save flags for later
 296         pop     [UINT flags]
 297         push    esi                 ; Save ESI for later
 298         pop     [DWORD sv_esi]
 299         push    ds                  ; Save DS for later
 300         pop     [UINT sv_ds]
 301
 302         _lds    _si,[outptr]        ; Save CPU registers
 303         mov     [_si],eax
 304         mov     [_si+4],ebx
 305         mov     [_si+8],ecx
 306         mov     [_si+12],edx
 307         push    [DWORD sv_esi]
 308         pop     [DWORD _si+16]
 309         mov     [_si+20],edi
 310
 311         mov     _bx,[flags]         ; Return flags
 312         and     ebx,1h              ; Isolate carry flag
 313         mov     [_si+24],ebx        ; Save carry flag status
 314
 315         _lds    _si,[sregs]         ; Save segment registers
 316         mov     [_si],es
 317         mov     _bx,[sv_ds]
 318         mov     [_si+6],bx          ; Get returned DS from stack
 319         mov     [_si+8],fs
 320         mov     [_si+10],gs
 321
 322         pop     gs                  ; Restore segment registers
 323         pop     fs
 324         pop     es
 325         pop     ds
 326         leave_c
 327         ret
 328
 329 cprocend
 330
 331 ifndef flatmodel
 332 _PM_savedDS     dw  _DATA           ; Saved value of DS
 333 endif
 334
 335 ;----------------------------------------------------------------------------
 336 ; void PM_saveDS(void)
 337 ;----------------------------------------------------------------------------
 338 ; Save the value of DS into a section of the code segment, so that we can
 339 ; quickly load this value at a later date in the PM_loadDS() routine from
 340 ; inside interrupt handlers etc. The method to do this is different
 341 ; depending on the DOS extender being used.
 342 ;----------------------------------------------------------------------------
 343 cprocstartdll16 PM_saveDS
 344
 345 ifdef flatmodel
 346         mov     [_PM_savedDS],ds    ; Store away in data segment
 347 endif
 348         ret
 349
 350 cprocend
 351
 352 ;----------------------------------------------------------------------------
 353 ; void PM_loadDS(void)
 354 ;----------------------------------------------------------------------------
 355 ; Routine to load the DS register with the default value for the current
 356 ; DOS extender. Only the DS register is loaded, not the ES register, so
 357 ; if you wish to call C code, you will need to also load the ES register
 358 ; in 32 bit protected mode.
 359 ;----------------------------------------------------------------------------
 360 cprocstartdll16 PM_loadDS
 361
 362         mov     ds,[cs:_PM_savedDS] ; We can access the proper DS through CS
 363         ret
 364
 365 cprocend
 366
 367 ifdef flatmodel
 368
 369 ;----------------------------------------------------------------------------
 370 ; ibool DPMI_allocateCallback(void (*pmcode)(), void *rmregs, long *RMCB)
 371 ;----------------------------------------------------------------------------
 372 cprocstart  _DPMI_allocateCallback
 373
 374         ARG     pmcode:CPTR, rmregs:DPTR, RMCB:DPTR
 375
 376         enter_c
 377         push    ds
 378         push    es
 379
 380         push    cs
 381         pop     ds
 382         mov     esi,[pmcode]    ; DS:ESI -> protected mode code to call
 383         mov     edi,[rmregs]    ; ES:EDI -> real mode register buffer
 384         mov     ax,303h         ; AX := allocate realmode callback function
 385         int     31h
 386         mov     eax,0           ; Return failure!
 387         jc      @@Fail
 388
 389         mov     eax,[RMCB]
 390         shl     ecx,16
 391         mov     cx,dx
 392         mov     [es:eax],ecx    ; Return real mode address
 393         mov     eax,1           ; Return success!
 394
 395 @@Fail: pop     es
 396         pop     ds
 397         leave_c
 398         ret
 399
 400 cprocend
 401
 402 ;----------------------------------------------------------------------------
 403 ; void DPMI_freeCallback(long RMCB)
 404 ;----------------------------------------------------------------------------
 405 cprocstart  _DPMI_freeCallback
 406
 407         ARG     RMCB:ULONG
 408
 409         enter_c
 410
 411         mov     cx,[WORD RMCB+2]
 412         mov     dx,[WORD RMCB]  ; CX:DX := real mode callback
 413         mov     ax,304h
 414         int     31h
 415
 416         leave_c
 417         ret
 418
 419 cprocend
 420
 421 endif
 422
 423 ; Macro to delay briefly to ensure that enough time has elapsed between
 424 ; successive I/O accesses so that the device being accessed can respond
 425 ; to both accesses even on a very fast PC.
 426
 427 ifdef   USE_NASM
 428 %macro  DELAY 0
 429         jmp     short $+2
 430         jmp     short $+2
 431         jmp     short $+2
 432 %endmacro
 433 %macro  IODELAYN 1
 434 %rep    %1
 435         DELAY
 436 %endrep
 437 %endmacro
 438 else
 439 macro   DELAY
 440         jmp     short $+2
 441         jmp     short $+2
 442         jmp     short $+2
 443 endm
 444 macro   IODELAYN    N
 445     rept    N
 446         DELAY
 447     endm
 448 endm
 449 endif
 450
 451 ;----------------------------------------------------------------------------
 452 ; uchar _PM_readCMOS(int index)
 453 ;----------------------------------------------------------------------------
 454 ; Read the value of a specific CMOS register. We do this with both
 455 ; normal interrupts and NMI disabled.
 456 ;----------------------------------------------------------------------------
 457 cprocstart  _PM_readCMOS
 458
 459         ARG     index:UINT
 460
 461         push    _bp
 462         mov     _bp,_sp
 463         pushfd
 464         mov     al,[BYTE index]
 465         or      al,80h              ; Add disable NMI flag
 466         cli
 467         out     70h,al
 468         IODELAYN 5
 469         in      al,71h
 470         mov     ah,al
 471         xor     al,al
 472         IODELAYN 5
 473         out     70h,al              ; Re-enable NMI
 474         sti
 475         mov     al,ah               ; Return value in AL
 476         popfd
 477         pop     _bp
 478         ret
 479
 480 cprocend
 481
 482 ;----------------------------------------------------------------------------
 483 ; void _PM_writeCMOS(int index,uchar value)
 484 ;----------------------------------------------------------------------------
 485 ; Read the value of a specific CMOS register. We do this with both
 486 ; normal interrupts and NMI disabled.
 487 ;----------------------------------------------------------------------------
 488 cprocstart  _PM_writeCMOS
 489
 490         ARG     index:UINT, value:UCHAR
 491
 492         push    _bp
 493         mov     _bp,_sp
 494         pushfd
 495         mov     al,[BYTE index]
 496         or      al,80h              ; Add disable NMI flag
 497         cli
 498         out     70h,al
 499         IODELAYN 5
 500         mov     al,[value]
 501         out     71h,al
 502         xor     al,al
 503         IODELAYN 5
 504         out     70h,al              ; Re-enable NMI
 505         sti
 506         popfd
 507         pop     _bp
 508         ret
 509
 510 cprocend
 511
 512 ifdef   flatmodel
 513
 514 ;----------------------------------------------------------------------------
 515 ; int _PM_pagingEnabled(void)
 516 ;----------------------------------------------------------------------------
 517 ; Returns 1 if paging is enabled, 0 if not or -1 if not at ring 0
 518 ;----------------------------------------------------------------------------
 519 cprocstart  _PM_pagingEnabled
 520
 521         mov     eax,-1
 522 ifdef   DOS4GW
 523         mov     cx,cs
 524         and     ecx,3
 525         jz      @@Ring0
 526         cmp     [UINT _PM_haveCauseWay],0
 527         jnz     @@Ring0
 528         jmp     @@Exit
 529
 530 @@Ring0:
 531         mov     eax,cr0                 ; Load CR0
 532         shr     eax,31                  ; Isolate paging enabled bit
 533 endif
 534 @@Exit: ret
 535
 536 cprocend
 537
 538 ;----------------------------------------------------------------------------
 539 ; _PM_getPDB - Return the Page Table Directory Base address
 540 ;----------------------------------------------------------------------------
 541 cprocstart  _PM_getPDB
 542
 543 ifdef   DOS4GW
 544         mov     ax,cs
 545         and     eax,3
 546         jz      @@Ring0
 547         cmp     [UINT _PM_haveCauseWay],0
 548         jnz     @@Ring0
 549 endif
 550
 551 ; Call VxD if running at ring 3 in a DOS box
 552
 553         cmp     [WORD _PM_VXD_sel],0
 554         jz      @@Fail
 555         mov     eax,PMHELP_GETPDB
 556 ifdef   USE_NASM
 557         call    far dword [_PM_VXD_off]
 558 else
 559         call    [FCPTR _PM_VXD_off]
 560 endif
 561         ret
 562
 563 @@Ring0:
 564 ifdef   DOS4GW
 565         mov     eax,cr3
 566         and     eax,0FFFFF000h
 567         ret
 568 endif
 569 @@Fail: xor     eax,eax
 570         ret
 571
 572 cprocend
 573
 574 ;----------------------------------------------------------------------------
 575 ; PM_flushTLB - Flush the Translation Lookaside buffer
 576 ;----------------------------------------------------------------------------
 577 cprocstart  PM_flushTLB
 578
 579         mov     ax,cs
 580         and     eax,3
 581         jz      @@Ring0
 582 ifdef   DOS4GW
 583         cmp     [UINT _PM_haveCauseWay],0
 584         jnz     @@Ring0
 585 endif
 586
 587 ; Call VxD if running at ring 3 in a DOS box
 588
 589         cmp     [WORD _PM_VXD_sel],0
 590         jz      @@Fail
 591         mov     eax,PMHELP_FLUSHTLB
 592 ifdef   USE_NASM
 593         call    far dword [_PM_VXD_off]
 594 else
 595         call    [FCPTR _PM_VXD_off]
 596 endif
 597         ret
 598
 599 @@Ring0:
 600 ifdef   DOS4GW
 601         wbinvd                  ; Flush the CPU cache
 602         mov     eax,cr3
 603         mov     cr3,eax         ; Flush the TLB
 604 endif
 605 @@Fail: ret
 606
 607 cprocend
 608
 609 endif
 610
 611 ;----------------------------------------------------------------------------
 612 ; void _PM_VxDCall(VXD_regs far *r,uint off,uint sel);
 613 ;----------------------------------------------------------------------------
 614 cprocstart  _PM_VxDCall
 615
 616         ARG     r:DPTR, off:UINT, sel:UINT
 617
 618         enter_c
 619
 620 ; Load all registers from the registers structure
 621
 622         mov     ebx,[r]
 623         mov     eax,[ebx+0]
 624         mov     ecx,[ebx+8]
 625         mov     edx,[ebx+12]
 626         mov     esi,[ebx+16]
 627         mov     edi,[ebx+20]
 628         mov     ebx,[ebx+4]         ; Trashes BX structure pointer!
 629
 630 ; Call the VxD entry point (on stack)
 631
 632 ifdef   USE_NASM
 633         call far dword [off]
 634 else
 635         call    [FCPTR off]
 636 endif
 637
 638 ; Save all registers back in the structure
 639
 640         push    ebx                 ; Push EBX onto stack for later
 641         mov     ebx,[r]
 642         mov     [ebx+0],eax
 643         mov     [ebx+8],ecx
 644         mov     [ebx+12],edx
 645         mov     [ebx+16],esi
 646         mov     [ebx+20],edi
 647         pop     [DWORD ebx+4]       ; Save value of EBX from stack
 648
 649         leave_c
 650         ret
 651
 652 cprocend
 653
 654 endcodeseg  _pmdos
 655
 656         END                     ; End of module