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