src/lib/16_mm.c

   1 /* Catacomb Apocalypse Source Code
   2  * Copyright (C) 1993-2014 Flat Rock Software
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 // NEWMM.C
  20
  21 /*
  22 =============================================================================
  23
  24                         ID software memory manager
  25                         --------------------------
  26
  27 Primary coder: John Carmack
  28
  29 RELIES ON
  30 ---------
  31 Quit (char *error) function
  32
  33
  34 WORK TO DO
  35 ----------
  36 MM_SizePtr to change the size of a given pointer
  37
  38 Multiple purge levels utilized
  39
  40 EMS / XMS unmanaged routines
  41
  42 =============================================================================
  43 */
  44 /*
  45
  46 Open Watcom port by sparky4
  47
  48 */
  49 #include "src/lib/16_mm.h"
  50
  51 /*
  52 =============================================================================
  53
  54                                                  GLOBAL VARIABLES
  55
  56 =============================================================================
  57 */
  58
  59 void            (* beforesort) (void);
  60 void            (* aftersort) (void);
  61 void            (* XMSaddr) (void);             // far pointer to XMS driver
  62
  63 /*
  64 =============================================================================
  65
  66                                                  LOCAL VARIABLES
  67
  68 =============================================================================
  69 */
  70
  71 static  char *ParmStringsexmm[] = {"noems","noxms",""};
  72
  73 /*
  74 ======================
  75 =
  76 = MML_CheckForEMS
  77 =
  78 = Routine from p36 of Extending DOS
  79 =
  80 =======================
  81 */
  82
  83 boolean MML_CheckForEMS(void)
  84 {
  85         boolean emmcfems;
  86         static char     emmname[] = "EMMXXXX0"; //fix by andrius4669
  87 //              mov     dx,OFFSET emmname
  88         __asm {
  89                 //LEA   DX, emmname     //fix by andrius4669
  90                 mov     dx,OFFSET emmname       //fix by andrius4669
  91                 mov     ax,0x3d00
  92                 int     0x21            // try to open EMMXXXX0 device
  93                 jc      error
  94
  95                 mov     bx,ax
  96                 mov     ax,0x4400
  97
  98                 int     0x21            // get device info
  99                 jc      error
 100
 101                 and     dx,0x80
 102                 jz      error
 103
 104                 mov     ax,0x4407
 105
 106                 int     0x21            // get status
 107                 jc      error
 108                 or      al,al
 109                 jz      error
 110
 111                 mov     ah,0x3e
 112                 int     0x21            // close handle
 113                 jc      error
 114                 //
 115                 // EMS is good
 116                 //
 117                 mov     emmcfems,1
 118                 jmp End
 119                 error:
 120                 //
 121                 // EMS is bad
 122                 //
 123                 mov     emmcfems,0
 124                 End:
 125         }
 126         return(emmcfems);
 127 }
 128
 129
 130 /*
 131 ======================
 132 =
 133 = MML_SetupEMS
 134 =
 135 =======================
 136 */
 137
 138 unsigned MML_SetupEMS(mminfo_t *mm)
 139 {
 140         char    str[80],str2[10];
 141         unsigned        err;
 142         boolean errorflag=false;
 143         union REGS CPURegs;
 144
 145         unsigned int EMSVer = 0;
 146         byte    EMSstatus;
 147         unsigned        totalEMSpages,freeEMSpages,EMSpageframe,EMSpagesmapped,EMShandle;
 148         totalEMSpages = freeEMSpages = EMSpageframe = EMSpagesmapped = 0;
 149
 150         __asm
 151                 {
 152                 mov     ah,EMS_STATUS
 153                 int     EMS_INT                                         // make sure EMS hardware is present
 154                 or      ah,ah
 155                 //mov   [EMSstatus],ah
 156                 jnz     error
 157
 158                 mov     ah,EMS_VERSION
 159                 int     EMS_INT
 160                 or      ah,ah
 161                 jnz     error
 162                 mov     [EMSVer],ax                             //      set EMSVer
 163                 cmp     al,0x32                                         // only work on ems 3.2 or greater
 164                 jb      error
 165
 166                 mov     ah,EMS_GETFRAME
 167                 int     EMS_INT                                         // find the page frame address
 168                 or      ah,ah
 169                 jnz     error
 170                 mov     [EMSpageframe],bx
 171
 172                 mov     ah,EMS_GETPAGES
 173                 int     EMS_INT                                         // find out how much EMS is there
 174                 or      ah,ah
 175                 jnz     error
 176                 mov     [totalEMSpages],dx
 177                 mov     [freeEMSpages],bx
 178                 or      bx,bx
 179                 jz      noEMS                                           // no EMS at all to allocate
 180                                                                                         //EXPAND DONG!!!!
 181                 cmp     [EMSVer],0x40
 182                 jb      low
 183                 cmp     bx,[freeEMSpages]
 184                 jle     getpages
 185                 mov     bx,[freeEMSpages]
 186                 jmp     getpages
 187
 188 low:
 189                 cmp     bx,4
 190                 jle     getpages                                        // there is only 1,2,3,or 4 pages
 191                 mov     bx,4                                            // we can't use more than 4 pages
 192
 193 getpages:
 194                 mov     [EMSpagesmapped],bx
 195                 mov     ah,EMS_ALLOCPAGES                       // allocate up to 64k of EMS
 196                 int     EMS_INT
 197                 or      ah,ah
 198                 jnz     error
 199                 mov     [EMShandle],dx
 200                 jmp End
 201 error:
 202                 mov     errorflag,1
 203                 jmp End
 204 noEMS:
 205 End:
 206         }
 207         if(errorflag==true)
 208         {
 209                 err = CPURegs.h.ah;
 210                 strcpy(str,"MML_SetupEMS: EMS error 0x");
 211                 itoa(err,str2,16);
 212                 strcpy(str,str2);
 213                 printf("%s\n",str);
 214                 return err;
 215         }
 216         mm->totalEMSpages=totalEMSpages;
 217         mm->freeEMSpages=freeEMSpages;
 218         mm->EMSpageframe=EMSpageframe;
 219         mm->EMSpagesmapped=EMSpagesmapped;
 220         mm->EMShandle=EMShandle;
 221         mm->EMSVer=EMSVer;
 222         //mm->EMSstatus=EMSstatus;
 223         return 0;
 224 }
 225
 226
 227 /*
 228 ======================
 229 =
 230 = MML_ShutdownEMS
 231 =
 232 =======================
 233 */
 234
 235 void MML_ShutdownEMS(mminfo_t *mm)
 236 {
 237         boolean errorflag=false;
 238         unsigned EMShandle=mm->EMShandle;
 239
 240         if(!EMShandle)
 241                 return;
 242         __asm
 243         {
 244                 mov     ah,EMS_FREEPAGES
 245                 mov     dx,[EMShandle]
 246                 int     EMS_INT
 247                 or      ah,ah
 248                 jz      ok
 249                 mov     errorflag,1
 250                 ok:
 251         }
 252         if(errorflag==true) printf("MML_ShutdownEMS: Error freeing EMS!");      //++++ add something
 253 }
 254
 255 /*
 256 ====================
 257 =
 258 = MM_MapEMS
 259 =
 260 = Maps the 64k of EMS used by memory manager into the page frame
 261 = for general use.  This only needs to be called if you are keeping
 262 = other things in EMS.
 263 =
 264 ====================
 265 */
 266
 267 unsigned MM_MapEMS(mminfo_t *mm)
 268 {
 269         char    str[80],str2[10];
 270         unsigned        err, EMShandle;
 271         boolean errorflag=false;
 272         int     i;
 273         union REGS CPURegs;
 274         EMShandle=mm->EMShandle;
 275
 276         for (i=0;i<4/*mm->EMSpagesmapped*/;i++)
 277         {
 278                 __asm
 279                 {
 280                         mov     ah,EMS_MAPPAGE
 281                         mov     bx,[i]                  // logical page
 282                         mov     al,bl                   // physical page
 283                         mov     dx,[EMShandle]  // handle
 284                         int     EMS_INT
 285                         or      ah,ah
 286                         jnz     error
 287                         jmp End
 288                         error:
 289                         mov     errorflag,1
 290                         End:
 291                 }
 292                 if(errorflag==true)
 293                 {
 294                         err = CPURegs.h.ah;
 295                         strcpy(str,"MM_MapEMS: EMS error 0x");
 296                         itoa(err,str2,16);
 297                         strcpy(str,str2);
 298                         //printf("%s\n",str);
 299                         printf("FACK! %u\n", err);
 300                         return err;
 301                 }
 302         }
 303         return 0;
 304 }
 305
 306 /*
 307 SUB EMS.MapXPages (PhysicalStart, LogicalStart, NumPages, Handle)\r
 308 \r
 309   'Maps up to 4 logical EMS pages to physical pages in the page frame, where:\r
 310   '\r
 311   'PhysicalStart = Physical page first logical page is mapped to\r
 312   'LogicalStart  = First logical page to map\r
 313   'NumPages      = Number of pages to map (1 to 4)\r
 314   'Handle        = EMS handle logical pages are allocated to\r
 315 \r
 316   'Create a buffer containing the page information\r
 317   FOR x = 0 TO NumPages - 1\r
 318     MapInfo$ = MapInfo$ + MKI$(LogicalStart + x) + MKI$(PhysicalStart + x)\r
 319   NEXT\r
 320 \r
 321   Regs.ax = &H5000                           'Map the pages in the buffer\r
 322   Regs.cx = NumPages                         'to the pageframe\r
 323   Regs.dx = Handle\r
 324   Regs.ds = VARSEG(MapInfo$)\r
 325   Regs.si = SADD(MapInfo$)\r
 326   InterruptX &H67, Regs, Regs\r
 327   EMS.Error = (Regs.ax AND &HFF00&) \ &H100  'Store the status code\r
 328 \r
 329 END SUB
 330 */
 331 void MM_MapXEMS(mminfo_t *mm)
 332 {
 333
 334 }
 335
 336 //==========================================================================
 337
 338 /*
 339 ======================
 340 =
 341 = MML_CheckForXMS
 342 =
 343 = Check for XMM driver
 344 =
 345 =======================
 346 */
 347
 348 boolean MML_CheckForXMS(mminfo_t *mm)
 349 {
 350         boolean errorflag=false;
 351         mm->numUMBs = 0;
 352
 353         __asm
 354         {
 355                 mov     ax,0x4300
 356                 int     0x2f                            // query status of installed diver
 357                 cmp     al,0x80
 358                 je      good
 359                 mov     errorflag,1
 360                 good:
 361         }
 362         if(errorflag==true) return false;
 363         else return true;
 364 }
 365
 366
 367 /*
 368 ======================
 369 =
 370 = MML_SetupXMS
 371 =
 372 = Try to allocate all upper memory block
 373 =
 374 =======================
 375 */
 376
 377 void MML_SetupXMS(mminfo_t *mm, mminfotype *mmi)
 378 {
 379         unsigned        base,size;
 380
 381 getmemory:
 382         __asm
 383         {
 384                 mov     ax,0x4310
 385                 int     0x2f
 386                 mov     [WORD PTR XMSaddr],bx
 387                 mov     [WORD PTR XMSaddr+2],es         // function pointer to XMS driver
 388
 389                 mov     ah,XMS_ALLOCUMB
 390                 mov     dx,0xffff                                       // try for largest block possible
 391                 //mov     ax,dx                                         // Set available Kbytes.
 392                 call    [DWORD PTR XMSaddr]
 393                 or      ax,ax
 394                 jnz     gotone
 395
 396                 cmp     bl,0xb0                                         // error: smaller UMB is available
 397                 jne     done;
 398
 399                 mov     ah,XMS_ALLOCUMB
 400                 call    [DWORD PTR XMSaddr]             // DX holds largest available UMB
 401                 or      ax,ax
 402                 jz      done                                            // another error...
 403
 404 gotone:
 405                 mov     [base],bx
 406                 mov     [size],dx
 407 done:
 408         }
 409         printf("base=%u ", base); printf("size=%u\n", size);
 410         MML_UseSpace(base,size, mm);
 411         mmi->XMSmem += size*16;
 412         mm->UMBbase[mm->numUMBs] = base;
 413         mm->numUMBs++;
 414         if(mm->numUMBs < MAXUMBS)
 415                 goto getmemory;
 416 }
 417
 418
 419 /*
 420 ======================
 421 =
 422 = MML_ShutdownXMS
 423 =
 424 ======================
 425 */
 426
 427 void MML_ShutdownXMS(mminfo_t *mm)
 428 {
 429         int     i;
 430         unsigned        base;
 431
 432         for (i=0;i<mm->numUMBs;i++)
 433         {
 434                 base = mm->UMBbase[i];
 435                 __asm
 436                 {
 437                         mov     ah,XMS_FREEUMB
 438                         mov     dx,[base]
 439                         call    [DWORD PTR XMSaddr]
 440                 }
 441         }
 442 }
 443
 444 //==========================================================================
 445
 446 /*
 447 ======================
 448 =
 449 = MML_UseSpace
 450 =
 451 = Marks a range of paragraphs as usable by the memory manager
 452 = This is used to mark space for the near heap, far heap, ems page frame,
 453 = and upper memory blocks
 454 =
 455 ======================
 456 */
 457
 458 void MML_UseSpace(/*d*/word segstart, dword seglength, mminfo_t *mm)
 459 {
 460         mmblocktype huge *scan,huge *last;
 461         word            segm;
 462         dword   oldend;
 463         dword           extra;
 464
 465         scan = last = mm->mmhead;
 466         mm->mmrover = mm->mmhead;               // reset rover to start of memory
 467
 468 //
 469 // search for the block that contains the range of segments
 470 //
 471         while(scan->start+scan->length < segstart)
 472         {
 473                 last = scan;
 474                 scan = scan->next;
 475         }
 476
 477         //find out how many blocks it spans!
 478         if(seglength>0xffffu)
 479         {
 480 //              segm=seglength/0x4000u;
 481                 segm=seglength/0xffffu;
 482         }
 483         else segm=1;
 484
 485         //++++emsver stuff!
 486         if(segm>1/*extra>0xfffflu*/)
 487         {
 488                 /*__asm
 489                 {
 490                         push    ds
 491                         mov     ax,ds
 492                         inc             ax
 493                         mov     ds,ax
 494                 }*/
 495
 496
 497 //MML_UseSpace(?segstart?, ?length?, mm);
 498
 499                 /*__asm
 500                 {
 501                         pop ds
 502                 }*/
 503                 //printf("MML_UseSpace: Segment spans two blocks!\n");
 504         }
 505
 506 //
 507 // take the given range out of the block
 508 //
 509         oldend = scan->start + scan->length;
 510         extra = oldend - (segstart+seglength);
 511
 512 printf("segm=%u ", segm);
 513 printf("ex=%lu  ", extra);
 514 printf("start+seglen=%lu        ", segstart+seglength);
 515 printf("len=%u  ", scan->length);
 516 printf("segsta=%x       ", segstart);
 517 printf("seglen=%lu\n", seglength);
 518
 519 //segu:
 520 //++++todo: linked list of segment!
 521 //printf("segm=%lu\n", segm);
 522         if(segstart == scan->start)
 523         {
 524                 last->next = scan->next;                        // unlink block
 525                 MM_FreeBlock(scan, mm);
 526                 scan = last;
 527         }
 528         else
 529                 scan->length = segstart-scan->start;    // shorten block
 530
 531 //      segm--;
 532
 533         if(extra > 0)
 534         {
 535                 MM_GetNewBlock(mm);
 536                 mm->mmnew->next = scan->next;
 537                 scan->next = mm->mmnew;
 538                 mm->mmnew->start = segstart+seglength;
 539                 mm->mmnew->length = extra;
 540                 mm->mmnew->attributes = LOCKBIT;
 541         }//else if(segm>0) goto segu;
 542
 543 }
 544
 545 //==========================================================================
 546
 547 /*
 548 ====================
 549 =
 550 = MML_ClearBlock
 551 =
 552 = We are out of blocks, so free a purgable block
 553 =
 554 ====================
 555 */
 556
 557 void MML_ClearBlock(mminfo_t *mm)
 558 {
 559         mmblocktype huge *scan,huge *last;
 560
 561         scan = mm->mmhead->next;
 562
 563         while(scan)
 564         {
 565                 if(!(scan->attributes&LOCKBIT) && (scan->attributes&PURGEBITS))
 566                 {
 567                         MM_FreePtr(scan->useptr, mm);
 568                         return;
 569                 }
 570                 scan = scan->next;
 571         }
 572
 573         printf("MM_ClearBlock: No purgable blocks!\n");
 574 }
 575
 576
 577 //==========================================================================
 578
 579 /*
 580 ===================
 581 =
 582 = MM_Startup
 583 =
 584 = Grabs all space from turbo with malloc/farmalloc
 585 = Allocates bufferseg misc buffer
 586 =
 587 ===================
 588 */
 589
 590 void MM_Startup(mminfo_t *mm, mminfotype *mmi)
 591 {
 592         int i;
 593         dword length;
 594         void huge       *start;
 595         unsigned        segstart,seglength,endfree;
 596
 597         if(mm->mmstarted)
 598                 MM_Shutdown(mm);
 599
 600         mm->mmstarted = true;
 601         mm->bombonerror = true;
 602 //
 603 // set up the linked list (everything in the free list;
 604 //
 605         mm->mmhead = NULL;
 606         mm->mmfree = &(mm->mmblocks[0]);
 607         for(i=0;i<MAXBLOCKS-1;i++)
 608         {
 609                 mm->mmblocks[i].next = &(mm->mmblocks[i+1]);
 610         }
 611         mm->mmblocks[i].next = NULL;
 612
 613 //
 614 // locked block of all memory until we punch out free space
 615 //
 616         MM_GetNewBlock(mm);
 617         mm->mmhead = mm->mmnew;                         // this will allways be the first node
 618         mm->mmnew->start = 0;
 619         mm->mmnew->length = 0xffff;
 620         mm->mmnew->attributes = LOCKBIT;
 621         mm->mmnew->next = NULL;
 622         mm->mmrover = mm->mmhead;
 623
 624 //      farlen=_bios_memsize()*1024;
 625
 626 //
 627 // get all available near conventional memory segments
 628 //
 629 //----  length=coreleft();
 630         _nheapgrow();
 631         length=_memavl();
 632         start = (void huge *)(mm->nearheap = malloc(length));
 633         length -= 16-(FP_OFF(start)&15);
 634         length -= SAVENEARHEAP;
 635         seglength = length / 16;                        // now in paragraphs
 636         segstart = FP_SEG(start)+(FP_OFF(start)+15)/16;
 637         MML_UseSpace(segstart,seglength, mm);
 638         mmi->nearheap = length;
 639         //printf("near heap ok!\n");
 640
 641 //
 642 // get all available far conventional memory segments
 643 //
 644 //----  length=farcoreleft();
 645         _fheapgrow();
 646         length=_memavl();
 647         start = mm->farheap = halloc(length, sizeof(byte));
 648         //start = mm->farheap = _fmalloc(length);
 649         length -= 16-(FP_OFF(start)&15);
 650         length -= SAVEFARHEAP;
 651         seglength = length / 16;                        // now in paragraphs
 652         segstart = FP_SEG(start)+(FP_OFF(start)+15)/16;
 653         MML_UseSpace(segstart,seglength, mm);
 654         mmi->farheap = length;
 655         mmi->mainmem = mmi->nearheap + mmi->farheap;
 656         //printf("far heap ok!\n");
 657
 658
 659 //
 660 // detect EMS and allocate up to 64K at page frame
 661 //
 662         printf("EMS!\n\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");       //bug!
 663         mmi->EMSmem = 0;
 664         for(i = 1;i < __argc;i++)
 665         {
 666                 if(US_CheckParm(__argv[i],ParmStringsexmm) == 0)
 667                         goto emsskip;                           // param NOEMS
 668         }
 669         printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 670         if(MML_CheckForEMS())
 671         {
 672 printf("EMS1\n");
 673                 MML_SetupEMS(mm);                                       // allocate space
 674 printf("EMS2\n");
 675                 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 676                 //TODO: EMS4! AND EMS 3.2 MASSIVE DATA HANDLMENT!
 677                 MML_UseSpace(mm->EMSpageframe,(MAPPAGES)*0x4000lu, mm);
 678 printf("EMS3\n");
 679                 MM_MapEMS(mm);                                  // map in used pages
 680 printf("EMS4\n");
 681                 mmi->EMSmem = (MAPPAGES)*0x4000lu;
 682         }
 683
 684 //
 685 // detect XMS and get upper memory blocks
 686 //
 687 emsskip:
 688         mmi->XMSmem = 0;
 689         for(i = 1;i < __argc;i++)
 690         {
 691                 if(US_CheckParm(__argv[i],ParmStringsexmm) == 0)
 692                         goto xmsskip;                           // param NOXMS
 693         }
 694         printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
 695         if(MML_CheckForXMS(mm))
 696         {
 697                 printf("XMS!\n");
 698                 //MML_SetupXMS(mm, mmi);                                        // allocate as many UMBs as possible
 699         }
 700
 701 //
 702 // allocate the misc buffer
 703 //
 704 xmsskip:
 705         mm->mmrover = mm->mmhead;               // start looking for space after low block
 706
 707         MM_GetPtr(&(mm->bufferseg),BUFFERSIZE, mm, mmi);
 708 }
 709
 710 //==========================================================================
 711
 712 /*
 713 ====================
 714 =
 715 = MM_Shutdown
 716 =
 717 = Frees all conventional, EMS, and XMS allocated
 718 =
 719 ====================
 720 */
 721
 722 void MM_Shutdown(mminfo_t *mm)
 723 {
 724         if(!(mm->mmstarted))
 725                 return;
 726
 727         _ffree(mm->farheap);
 728         printf("far freed\n");
 729         free(mm->nearheap);
 730         printf("near freed\n");
 731         //hfree(mm->hugeheap);
 732         //printf("huge freed\n");
 733         if(MML_CheckForEMS()){ MML_ShutdownEMS(mm); printf("EMS freed\n"); }
 734         if(MML_CheckForXMS(mm)){ MML_ShutdownXMS(mm); printf("XMS freed\n"); }
 735 }
 736
 737 //==========================================================================
 738
 739 /*
 740 ====================
 741 =
 742 = MM_GetPtr
 743 =
 744 = Allocates an unlocked, unpurgable block
 745 =
 746 ====================
 747 */
 748
 749 void MM_GetPtr(memptr *baseptr,dword size, mminfo_t *mm, mminfotype *mmi)
 750 {
 751         mmblocktype huge *scan,huge *lastscan,huge *endscan,huge *purge,huge *next;
 752         int                     search;
 753         unsigned        needed,startseg;
 754
 755         needed = (size+15)/16;          // convert size from bytes to paragraphs
 756
 757         MM_GetNewBlock(mm);                             // fill in start and next after a spot is found
 758         mm->mmnew->length = needed;
 759         mm->mmnew->useptr = baseptr;
 760         mm->mmnew->attributes = BASEATTRIBUTES;
 761
 762         for(search = 0; search<3; search++)
 763         {
 764         //
 765         // first search:        try to allocate right after the rover, then on up
 766         // second search:       search from the head pointer up to the rover
 767         // third search:        compress memory, then scan from start
 768                 if(search == 1 && mm->mmrover == mm->mmhead)
 769                         search++;
 770
 771                 switch(search)
 772                 {
 773                 case 0:
 774                         lastscan = mm->mmrover;
 775                         scan = mm->mmrover->next;
 776                         endscan = NULL;
 777                         break;
 778                 case 1:
 779                         lastscan = mm->mmhead;
 780                         scan = mm->mmhead->next;
 781                         endscan = mm->mmrover;
 782                         break;
 783                 case 2:
 784                         MM_SortMem(mm);
 785                         lastscan = mm->mmhead;
 786                         scan = mm->mmhead->next;
 787                         endscan = NULL;
 788                         break;
 789                 }
 790
 791                 startseg = lastscan->start + lastscan->length;
 792
 793                 while(scan != endscan)
 794                 {
 795                         if(scan->start - startseg >= needed)
 796                         {
 797                         //
 798                         // got enough space between the end of lastscan and
 799                         // the start of scan, so throw out anything in the middle
 800                         // and allocate the new block
 801                         //
 802                                 purge = lastscan->next;
 803                                 lastscan->next = mm->mmnew;
 804                                 mm->mmnew->start = *(unsigned *)baseptr = startseg;
 805                                 mm->mmnew->next = scan;
 806                                 while(purge != scan)
 807                                 {       // free the purgable block
 808                                         next = purge->next;
 809                                         MM_FreeBlock(purge, mm);
 810                                         purge = next;           // purge another if not at scan
 811                                 }
 812                                 mm->mmrover = mm->mmnew;
 813                                 return; // good allocation!
 814                         }
 815
 816                         //
 817                         // if this block is purge level zero or locked, skip past it
 818                         //
 819                         if((scan->attributes & LOCKBIT)
 820                                 || !(scan->attributes & PURGEBITS) )
 821                         {
 822                                 lastscan = scan;
 823                                 startseg = lastscan->start + lastscan->length;
 824                         }
 825
 826
 827                         scan=scan->next;                // look at next line
 828                 }
 829         }
 830
 831         if (mm->bombonerror)
 832                 printf(OUT_OF_MEM_MSG,(size-mmi->nearheap));
 833         else
 834                 mm->mmerror = true;
 835 }
 836
 837 //==========================================================================
 838
 839 /*
 840 ====================
 841 =
 842 = MM_FreePtr
 843 =
 844 = Allocates an unlocked, unpurgable block
 845 =
 846 ====================
 847 */
 848
 849 void MM_FreePtr(memptr *baseptr, mminfo_t *mm)
 850 {
 851         mmblocktype huge *scan,huge *last;
 852
 853         last = mm->mmhead;
 854         scan = last->next;
 855
 856         if(baseptr == mm->mmrover->useptr)      // removed the last allocated block
 857                 mm->mmrover = mm->mmhead;
 858
 859         while(scan->useptr != baseptr && scan)
 860         {
 861                 last = scan;
 862                 scan = scan->next;
 863         }
 864
 865         if(!scan)
 866         {
 867                 printf("MM_FreePtr: Block not found!");
 868                 return;
 869         }
 870
 871         last->next = scan->next;
 872
 873         MM_FreeBlock(scan, mm);
 874 }
 875 //==========================================================================
 876
 877 /*
 878 =====================
 879 =
 880 = MM_SetPurge
 881 =
 882 = Sets the purge level for a block (locked blocks cannot be made purgable)
 883 =
 884 =====================
 885 */
 886
 887 void MM_SetPurge(memptr *baseptr, int purge, mminfo_t *mm)
 888 {
 889         mmblocktype huge *start;
 890
 891         start = mm->mmrover;
 892
 893         do
 894         {
 895                 if(mm->mmrover->useptr == baseptr)
 896                         break;
 897
 898                 mm->mmrover = mm->mmrover->next;
 899
 900                 if(!mm->mmrover)
 901                         mm->mmrover = mm->mmhead;
 902                 else if(mm->mmrover == start)
 903                 {
 904                         printf("MM_SetPurge: Block not found!");
 905                         return;
 906                 }
 907
 908         } while(1);
 909
 910         mm->mmrover->attributes &= ~PURGEBITS;
 911         mm->mmrover->attributes |= purge;
 912 }
 913
 914 //==========================================================================
 915
 916 /*
 917 =====================
 918 =
 919 = MM_SetLock
 920 =
 921 = Locks / unlocks the block
 922 =
 923 =====================
 924 */
 925
 926 void MM_SetLock(memptr *baseptr, boolean locked, mminfo_t *mm)
 927 {
 928         mmblocktype huge *start;
 929
 930         start = mm->mmrover;
 931
 932         do
 933         {
 934                 if(mm->mmrover->useptr == baseptr)
 935                         break;
 936
 937                 mm->mmrover = mm->mmrover->next;
 938
 939                 if(!mm->mmrover)
 940                         mm->mmrover = mm->mmhead;
 941                 else if(mm->mmrover == start)
 942                 {
 943                         printf("MM_SetLock: Block not found!");
 944                         return;
 945                 }
 946
 947         } while(1);
 948
 949         mm->mmrover->attributes &= ~LOCKBIT;
 950         mm->mmrover->attributes |= locked*LOCKBIT;
 951 }
 952
 953 //==========================================================================
 954
 955 /*
 956 =====================
 957 =
 958 = MM_SortMem
 959 =
 960 = Throws out all purgable stuff and compresses movable blocks
 961 =
 962 =====================
 963 */
 964
 965 void MM_SortMem(mminfo_t *mm)
 966 {
 967         mmblocktype huge *scan,huge *last,huge *next;
 968         unsigned        start,length,source,dest,oldborder;
 969         int                     playing;
 970
 971         //
 972         // lock down a currently playing sound
 973         //
 974 /*++++  playing = SD_SoundPlaying ();
 975         if(playing)
 976         {
 977                 switch (SoundMode)
 978                 {
 979                 case sdm_PC:
 980                         playing += STARTPCSOUNDS;
 981                         break;
 982                 case sdm_AdLib:
 983                         playing += STARTADLIBSOUNDS;
 984                         break;
 985                 }
 986                 MM_SetLock(&(memptr)audiosegs[playing],true);
 987         }
 988
 989
 990         SD_StopSound();*/
 991 //      oldborder = bordercolor;
 992 //      VW_ColorBorder (15);
 993
 994         if(beforesort)
 995                 beforesort();
 996
 997         scan = mm->mmhead;
 998
 999         last = NULL;            // shut up compiler warning
1000
1001         while(scan)
1002         {
1003                 if(scan->attributes & LOCKBIT)
1004                 {
1005                 //
1006                 // block is locked, so try to pile later blocks right after it
1007                 //
1008                         start = scan->start + scan->length;
1009                 }
1010                 else
1011                 {
1012                         if(scan->attributes & PURGEBITS)
1013                         {
1014                         //
1015                         // throw out the purgable block
1016                         //
1017                                 next = scan->next;
1018                                 MM_FreeBlock(scan, mm);
1019                                 last->next = next;
1020                                 scan = next;
1021                                 continue;
1022                         }
1023                         else
1024                         {
1025                         //
1026                         // push the non purgable block on top of the last moved block
1027                         //
1028                                 if(scan->start != start)
1029                                 {
1030                                         length = scan->length;
1031                                         source = scan->start;
1032                                         dest = start;
1033                                         while(length > 0xf00)
1034                                         {
1035                                                 movedata(source,0,dest,0,0xf00*16);
1036                                                 length -= 0xf00;
1037                                                 source += 0xf00;
1038                                                 dest += 0xf00;
1039                                         }
1040                                         movedata(source,0,dest,0,length*16);
1041
1042                                         scan->start = start;
1043                                         *(unsigned *)scan->useptr = start;
1044                                 }
1045                                 start = scan->start + scan->length;
1046                         }
1047                 }
1048
1049                 last = scan;
1050                 scan = scan->next;              // go to next block
1051         }
1052
1053         mm->mmrover = mm->mmhead;
1054
1055         if(aftersort)
1056                 aftersort();
1057
1058 //      VW_ColorBorder (oldborder);
1059
1060 /*++++  if(playing)
1061                 MM_SetLock(&(memptr)audiosegs[playing],false);*/
1062 }
1063
1064
1065 //==========================================================================
1066
1067 //****#if 0
1068 /*
1069 =====================
1070 =
1071 = MM_ShowMemory
1072 =
1073 =====================
1074 */
1075
1076 void MM_ShowMemory(page_t *page, mminfo_t *mm)
1077 {
1078         mmblocktype huge *scan;
1079         word color,temp;
1080         long    end,owner;
1081         word chx,chy;
1082         byte    scratch[160],str[16];
1083
1084 //****  VW_SetDefaultColors();
1085 //****  VW_SetLineWidth(40);
1086 //++++mh        temp = bufferofs;
1087 //++++mh        bufferofs = 0;
1088 //****  VW_SetScreen (0,0);
1089
1090         scan = mm->mmhead;
1091
1092         end = -1;
1093
1094 CA_OpenDebug ();
1095
1096         chx=0;
1097         chy=0;
1098
1099         while(scan)
1100         {
1101                 if(scan->attributes & PURGEBITS)
1102                         color = 5;              // dark purple = purgable
1103                 else
1104                         color = 9;              // medium blue = non purgable
1105                 if(scan->attributes & LOCKBIT)
1106                         color = 12;             // red = locked
1107                 if(scan->start<=end)
1108                 {
1109                         //printf(");
1110                         write(debughandle,"\nMM_ShowMemory: Memory block order currupted!\n",strlen("\nMM_ShowMemory: Memory block order currupted!\n"));
1111                         //modexprint(&page, chx, chy, 1, 0, 24, "\nMM_ShowMemory: Memory block order currupted!\n");
1112                         return;
1113                 }
1114                 end = scan->start+scan->length-1;
1115                 chy = scan->start/320;
1116                 chx = scan->start%320;
1117                                 //modexhlin(page, scan->start, (unsigned)end, chy, color);
1118                                 //for(chx=scan->start;chx+4>=(word)end;chx+=4)
1119                                 //{
1120                                         modexClearRegion(page, chx, chy, 4, 4, color);
1121                                 //}
1122
1123 //++++          VW_Hlin(scan->start,(unsigned)end,0,color);
1124
1125 //++++          VW_Plot(scan->start,0,15);
1126                                 modexClearRegion(page, chx, chy, 4, 4, 15);
1127                 if(scan->next->start > end+1)
1128 //++++                  VW_Hlin(end+1,scan->next->start,0,0);   // black = free
1129                         //for(chx=scan->next->start;chx+4>=(word)end+1;chx+=4)
1130                         //{
1131                                 chx+=scan->next->start;
1132                                 modexClearRegion(page, chx, chy, 4, 4, 2);
1133                         //}
1134                                         //modexhlin(page, end+1,scan->next->start, chy, 0);
1135
1136 /*
1137                 end = scan->length-1;
1138                 y = scan->start/320;
1139                 x = scan->start%320;
1140                 VW_Hlin(x,x+end,y,color);
1141                 VW_Plot(x,y,15);
1142                 if (scan->next && scan->next->start > end+1)
1143                         VW_Hlin(x+end+1,x+(scan->next->start-scan->start),y,0); // black = free
1144
1145 */
1146
1147 //****#if 0
1148 printf("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");     //bug!
1149 strcpy(scratch,"Seg:");
1150 ultoa (scan->start,str,16);
1151 strcat (scratch,str);
1152 strcat (scratch,"\tSize:");
1153 ltoa ((dword)scan->length*16,str,10);
1154 strcat (scratch,str);
1155 strcat (scratch,"\tOwner:0x");
1156 owner = (unsigned)scan->useptr;
1157 ultoa (owner,str,16);
1158 strcat (scratch,str);
1159 strcat (scratch,"\n");
1160 write(debughandle,scratch,strlen(scratch));
1161 //modexprint(page, chx, chy, 1, 0, 24, &scratch);
1162 chy+=4;
1163 //fprintf(stdout, "%s", scratch);
1164 //****#endif
1165
1166                 scan = scan->next;
1167         }
1168
1169 CA_CloseDebug ();
1170
1171 //++++mh        IN_Ack();
1172 //****  VW_SetLineWidth(64);
1173 //++++mh        bufferofs = temp;
1174 }
1175 //****#endif
1176
1177 //==========================================================================\r
1178 \r
1179 /*\r
1180 =====================\r
1181 =\r
1182 = MM_DumpData\r
1183 =\r
1184 =====================\r
1185 */\r
1186 \r
1187 void MM_DumpData(mminfo_t *mm)\r
1188 {\r
1189         mmblocktype far *scan,far *best;\r
1190         long    lowest,oldlowest;\r
1191         word    owner;\r
1192         byte    lock,purge;\r
1193         FILE    *dumpfile;\r
1194 \r
1195 \r
1196         free (mm->nearheap);\r
1197         dumpfile = fopen ("mmdump.txt","w");\r
1198         if (!dumpfile){\r
1199                 printf("MM_DumpData: Couldn't open MMDUMP.TXT!");
1200                 return;
1201         }\r
1202 \r
1203         lowest = -1;\r
1204         do\r
1205         {\r
1206                 oldlowest = lowest;\r
1207                 lowest = 0xffff;\r
1208 \r
1209                 scan = mm->mmhead;\r
1210                 while (scan)\r
1211                 {\r
1212                         owner = (word)scan->useptr;\r
1213 \r
1214                         if (owner && owner<lowest && owner > oldlowest)\r
1215                         {\r
1216                                 best = scan;\r
1217                                 lowest = owner;\r
1218                         }\r
1219 \r
1220                         scan = scan->next;\r
1221                 }\r
1222 \r
1223                 if (lowest != 0xffff)\r
1224                 {\r
1225                         if (best->attributes & PURGEBITS)\r
1226                                 purge = 'P';\r
1227                         else\r
1228                                 purge = '-';\r
1229                         if (best->attributes & LOCKBIT)\r
1230                                 lock = 'L';\r
1231                         else\r
1232                                 lock = '-';\r
1233                         fprintf (dumpfile,"0x%p (%c%c) = %u\n"\r
1234                         ,(word)lowest,lock,purge,best->length);\r
1235                 }\r
1236 \r
1237         } while (lowest != 0xffff);\r
1238 \r
1239         fclose (dumpfile);\r
1240         printf("MMDUMP.TXT created.");\r
1241 }
1242
1243 //==========================================================================
1244
1245
1246 /*
1247 ======================
1248 =
1249 = MM_UnusedMemory
1250 =
1251 = Returns the total free space without purging
1252 =
1253 ======================
1254 */
1255
1256 dword MM_UnusedMemory(mminfo_t *mm)
1257 {
1258         dword free;
1259         mmblocktype huge *scan;
1260
1261         free = 0;
1262         scan = mm->mmhead;
1263
1264         while(scan->next)
1265         {
1266                 free += scan->next->start - (scan->start + scan->length);
1267                 scan = scan->next;
1268         }
1269
1270         return free*16l;
1271 //      return free;
1272 }
1273
1274 //==========================================================================
1275
1276
1277 /*
1278 ======================
1279 =
1280 = MM_TotalFree
1281 =
1282 = Returns the total free space with purging
1283 =
1284 ======================
1285 */
1286
1287 dword MM_TotalFree(mminfo_t *mm)
1288 {
1289         dword free;
1290         mmblocktype huge *scan;
1291
1292         free = 0;
1293         scan = mm->mmhead;
1294
1295         while(scan->next)
1296         {
1297                 if((scan->attributes&PURGEBITS) && !(scan->attributes&LOCKBIT))
1298                         free += scan->length;
1299                 free += scan->next->start - (scan->start + scan->length);
1300                 scan = scan->next;
1301         }
1302
1303         return free*16l;
1304 //      return free;
1305 }
1306
1307 //==========================================================================
1308
1309 /*
1310 =====================
1311 =
1312 = MM_Report
1313 =
1314 =====================
1315 */
1316
1317 void MM_Report(page_t *page, mminfo_t *mm, mminfotype *mmi)
1318 {
1319         printf("\n");
1320         if(MML_CheckForEMS())
1321         {
1322                 printf("Expanded memory manager present. EMM v%x.%x available\n", mm->EMSVer>>4,mm->EMSVer&0x0F);
1323                 printf("totalEMSpages=%u\n", mm->totalEMSpages);
1324                 printf("Page frame @0x%04x\n", mm->freeEMSpages);
1325                 printf("EMSpageframe=%x\n", mm->EMSpageframe);
1326         }
1327         if(MML_CheckForXMS(mm)) printf("XMSaddr=%Fp\n", *XMSaddr);
1328         printf("near=%lu\n", mmi->nearheap);
1329         printf("far=%lu\n", mmi->farheap);
1330         printf("EMSmem=%lu\n", mmi->EMSmem);
1331         printf("XMSmem=%lu\n", mmi->XMSmem);
1332         printf("mainmem=%lu\n", mmi->mainmem);
1333         printf("UnusedMemory=%lu\n", MM_UnusedMemory(mm));
1334         printf("TotalFree=%lu\n", MM_TotalFree(mm));
1335 //      printf("\n");
1336 //      printf("UnusedMemory=%lu kb\n", MM_UnusedMemory()/10248);
1337 //      printf("TotalFree=%lu kb\n", MM_TotalFree()/10248);
1338 }
1339
1340 //==========================================================================
1341
1342 /*
1343 =====================
1344 =
1345 = MM_EMSVer
1346 =
1347 =====================
1348
1349
1350 int MM_EMSVer(void)
1351 {
1352         int EMSver;
1353         __asm
1354         {
1355                 mov             ah,EMS_VERSION
1356                 int             EMS_INT
1357                 mov             EMSver,ax
1358         }
1359         return(EMSver);
1360 }*/
1361
1362 //==========================================================================
1363
1364 /*
1365 =====================
1366 =
1367 = MM_BombOnError
1368 =
1369 =====================
1370 */
1371
1372 void MM_BombOnError(boolean bomb, mminfo_t *mm)
1373 {
1374         mm->bombonerror = bomb;
1375 }
1376
1377 void MM_GetNewBlock(mminfo_t *mm)
1378 {
1379         if(!mm->mmfree)
1380                 MML_ClearBlock(mm);
1381         mm->mmnew=mm->mmfree;
1382         mm->mmfree=mm->mmfree->next;
1383         /*if(!(mm->mmnew=mm->mmfree))
1384         {
1385                 printf("MM_GETNEWBLOCK: No free blocks!");
1386                 return;
1387         }
1388         mm->mmfree=mm->mmfree->next;*/
1389 }
1390
1391 void MM_FreeBlock(mmblocktype *x, mminfo_t *mm)
1392 {
1393         x->useptr=NULL;
1394         x->next=mm->mmfree;
1395         mm->mmfree=x;
1396 }
1397
1398 void MM_seguin(void)
1399 {
1400         __asm
1401         {
1402                 push    ds
1403                 mov     ax,ds
1404                 inc             ax
1405                 mov     ds,ax
1406         }
1407 }
1408
1409 void MM_segude(void)
1410 {
1411         __asm
1412         {
1413                 pop ds
1414         }
1415 }
1416
1417 /*
1418 pull data from far and put it into ds var
1419 mov ax,es:si
1420 mov x,ax
1421 */
1422 /*
1423 ss stack segment
1424 sp top of stack
1425 bp bottem of stack
1426 */