msdos/dosmem.c

   1 /*
   2  * DOS memory emulation
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  * Copyright 1996 Marcus Meissner
   6  */
   7
   8 #include <signal.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include "winbase.h"
  12 #include "wine/winbase16.h"
  13 #include "global.h"
  14 #include "ldt.h"
  15 #include "miscemu.h"
  16 #include "vga.h"
  17 #include "module.h"
  18 #include "task.h"
  19 #include "debug.h"
  20
  21 HANDLE16 DOSMEM_BiosDataSeg;  /* BIOS data segment at 0x40:0 */
  22 HANDLE16 DOSMEM_BiosSysSeg;   /* BIOS ROM segment at 0xf000:0 */
  23
  24 #pragma pack(1)
  25
  26 typedef struct
  27 {
  28     WORD  Com1Addr;                  /* 00: COM1 I/O address */
  29     WORD  Com2Addr;                  /* 02: COM2 I/O address */
  30     WORD  Com3Addr;                  /* 04: COM3 I/O address */
  31     WORD  Com4Addr;                  /* 06: COM4 I/O address */
  32     WORD  Lpt1Addr;                  /* 08: LPT1 I/O address */
  33     WORD  Lpt2Addr;                  /* 0a: LPT2 I/O address */
  34     WORD  Lpt3Addr;                  /* 0c: LPT3 I/O address */
  35     WORD  Lpt4Addr;                  /* 0e: LPT4 I/O address */
  36     WORD  InstalledHardware;         /* 10: Installed hardware flags */
  37     BYTE  POSTstatus;                /* 12: Power-On Self Test status */
  38     WORD  MemSize WINE_PACKED;       /* 13: Base memory size in Kb */
  39     WORD  unused1 WINE_PACKED;       /* 15: Manufacturing test scratch pad */
  40     BYTE  KbdFlags1;                 /* 17: Keyboard flags 1 */
  41     BYTE  KbdFlags2;                 /* 18: Keyboard flags 2 */
  42     BYTE  unused2;                   /* 19: Keyboard driver workspace */
  43     WORD  NextKbdCharPtr;            /* 1a: Next character in kbd buffer */
  44     WORD  FirstKbdCharPtr;           /* 1c: First character in kbd buffer */
  45     WORD  KbdBuffer[16];             /* 1e: Keyboard buffer */
  46     BYTE  DisketteStatus1;           /* 3e: Diskette recalibrate status */
  47     BYTE  DisketteStatus2;           /* 3f: Diskette motor status */
  48     BYTE  DisketteStatus3;           /* 40: Diskette motor timeout */
  49     BYTE  DisketteStatus4;           /* 41: Diskette last operation status */
  50     BYTE  DiskStatus[7];             /* 42: Disk status/command bytes */
  51     BYTE  VideoMode;                 /* 49: Video mode */
  52     WORD  VideoColumns;              /* 4a: Number of columns */
  53     WORD  VideoPageSize;             /* 4c: Video page size in bytes */
  54     WORD  VideoPageStartAddr;        /* 4e: Video page start address */
  55     BYTE  VideoCursorPos[16];        /* 50: Cursor position for 8 pages */
  56     WORD  VideoCursorType;           /* 60: Video cursor type */
  57     BYTE  VideoCurPage;              /* 62: Video current page */
  58     WORD  VideoCtrlAddr WINE_PACKED; /* 63: Video controller address */
  59     BYTE  VideoReg1;                 /* 65: Video mode select register */
  60     BYTE  VideoReg2;                 /* 66: Video CGA palette register */
  61     DWORD ResetEntry WINE_PACKED;    /* 67: Warm reset entry point */
  62     BYTE  LastIRQ;                   /* 6b: Last unexpected interrupt */
  63     DWORD Ticks;                     /* 6c: Ticks since midnight */
  64     BYTE  TicksOverflow;             /* 70: Timer overflow if past midnight */
  65     BYTE  CtrlBreakFlag;             /* 71: Ctrl-Break flag */
  66     WORD  ResetFlag;                 /* 72: POST Reset flag */
  67     BYTE  DiskOpStatus;              /* 74: Last hard-disk operation status */
  68     BYTE  NbHardDisks;               /* 75: Number of hard disks */
  69     BYTE  DiskCtrlByte;              /* 76: Disk control byte */
  70     BYTE  DiskIOPort;                /* 77: Disk I/O port offset */
  71     BYTE  LptTimeout[4];             /* 78: Timeouts for parallel ports */
  72     BYTE  ComTimeout[4];             /* 7c: Timeouts for serial ports */
  73     WORD  KbdBufferStart;            /* 80: Keyboard buffer start */
  74     WORD  KbdBufferEnd;              /* 82: Keyboard buffer end */
  75     BYTE  RowsOnScreenMinus1;        /* 84: EGA only */
  76     WORD  BytesPerChar;              /* 85: EGA only */
  77     BYTE  ModeOptions;               /* 87: EGA only */
  78     BYTE  FeatureBitsSwitches;       /* 88: EGA only */
  79     BYTE  unknown;                   /* 89: ??? */
  80     BYTE  DisplayCombination;        /* 8A: VGA display combinations */
  81     BYTE  DiskDataRate;              /* 8B: Last disk data rate selected */
  82 } BIOSDATA;
  83
  84 #pragma pack(4)
  85
  86 static BIOSDATA *pBiosData = NULL;
  87 static char     *DOSMEM_dosmem;
  88
  89        DWORD     DOSMEM_CollateTable;
  90
  91        DWORD     DOSMEM_ErrorCall;
  92        DWORD     DOSMEM_ErrorBuffer;
  93
  94 /* use 2 low bits of 'size' for the housekeeping */
  95
  96 #define DM_BLOCK_DEBUG          0xABE00000
  97 #define DM_BLOCK_TERMINAL       0x00000001
  98 #define DM_BLOCK_FREE           0x00000002
  99 #define DM_BLOCK_MASK           0x001FFFFC
 100
 101 /*
 102 #define __DOSMEM_DEBUG__
 103  */
 104
 105 typedef struct {
 106    unsigned     size;
 107 } dosmem_entry;
 108
 109 typedef struct {
 110   unsigned      blocks;
 111   unsigned      free;
 112 } dosmem_info;
 113
 114 #define NEXT_BLOCK(block) \
 115         (dosmem_entry*)(((char*)(block)) + \
 116          sizeof(dosmem_entry) + ((block)->size & DM_BLOCK_MASK))
 117
 118 #define VM_STUB(x) (0x90CF00CD|(x<<8)) /* INT x; IRET; NOP */
 119 #define VM_STUB_SEGMENT 0xf000         /* BIOS segment */
 120
 121 /***********************************************************************
 122  *           DOSMEM_MemoryBase
 123  *
 124  * Gets the DOS memory base.
 125  */
 126 char *DOSMEM_MemoryBase(HMODULE16 hModule)
 127 {
 128     TDB *pTask = hModule ? NULL : (TDB *)GlobalLock16( GetCurrentTask() );
 129     NE_MODULE *pModule = (hModule || pTask) ? NE_GetPtr( hModule ? hModule : pTask->hModule ) : NULL;
 130
 131     GlobalUnlock16( GetCurrentTask() );
 132     if (pModule && pModule->dos_image)
 133         return pModule->dos_image;
 134     else
 135         return DOSMEM_dosmem;
 136 }
 137
 138 /***********************************************************************
 139  *           DOSMEM_MemoryTop
 140  *
 141  * Gets the DOS memory top.
 142  */
 143 static char *DOSMEM_MemoryTop(HMODULE16 hModule)
 144 {
 145     return DOSMEM_MemoryBase(hModule)+0x9FFFC; /* 640K */
 146 }
 147
 148 /***********************************************************************
 149  *           DOSMEM_InfoBlock
 150  *
 151  * Gets the DOS memory info block.
 152  */
 153 static dosmem_info *DOSMEM_InfoBlock(HMODULE16 hModule)
 154 {
 155     return (dosmem_info*)(DOSMEM_MemoryBase(hModule)+0x10000); /* 64K */
 156 }
 157
 158 /***********************************************************************
 159  *           DOSMEM_RootBlock
 160  *
 161  * Gets the DOS memory root block.
 162  */
 163 static dosmem_entry *DOSMEM_RootBlock(HMODULE16 hModule)
 164 {
 165     /* first block has to be paragraph-aligned */
 166     return (dosmem_entry*)(((char*)DOSMEM_InfoBlock(hModule)) +
 167                            ((((sizeof(dosmem_info) + 0xf) & ~0xf) - sizeof(dosmem_entry))));
 168 }
 169
 170 /***********************************************************************
 171  *           DOSMEM_FillIsrTable
 172  *
 173  * Fill the interrupt table with fake BIOS calls to BIOSSEG (0xf000).
 174  *
 175  * NOTES:
 176  * Linux normally only traps INTs performed from or destined to BIOSSEG
 177  * for us to handle, if the int_revectored table is empty. Filling the
 178  * interrupt table with calls to INT stubs in BIOSSEG allows DOS programs
 179  * to hook interrupts, as well as use their familiar retf tricks to call
 180  * them, AND let Wine handle any unhooked interrupts transparently.
 181  */
 182 static void DOSMEM_FillIsrTable(HMODULE16 hModule)
 183 {
 184     SEGPTR *isr = (SEGPTR*)DOSMEM_MemoryBase(hModule);
 185     DWORD *stub = (DWORD*)((char*)isr + (VM_STUB_SEGMENT << 4));
 186     int x;
 187
 188     for (x=0; x<256; x++) isr[x]=PTR_SEG_OFF_TO_SEGPTR(VM_STUB_SEGMENT,x*4);
 189     for (x=0; x<256; x++) stub[x]=VM_STUB(x);
 190 }
 191
 192 /***********************************************************************
 193  *           DOSMEM_InitDPMI
 194  *
 195  * Allocate the global DPMI RMCB wrapper.
 196  */
 197 static void DOSMEM_InitDPMI(void)
 198 {
 199     extern UINT16 DPMI_wrap_seg;
 200     static char wrap_code[]={
 201      0xCD,0x31, /* int $0x31 */
 202      0xCB       /* lret */
 203     };
 204     LPSTR wrapper = (LPSTR)DOSMEM_GetBlock(0, sizeof(wrap_code), &DPMI_wrap_seg);
 205
 206     memcpy(wrapper, wrap_code, sizeof(wrap_code));
 207 }
 208
 209 /***********************************************************************
 210  *           DOSMEM_FillBiosSegments
 211  *
 212  * Fill the BIOS data segment with dummy values.
 213  */
 214 static void DOSMEM_FillBiosSegments(void)
 215 {
 216     BYTE *pBiosSys = (BYTE *)GlobalLock16( DOSMEM_BiosSysSeg );
 217     BYTE *pBiosROMTable = pBiosSys+0xe6f5;
 218
 219     pBiosData = (BIOSDATA *)GlobalLock16( DOSMEM_BiosDataSeg );
 220
 221       /* Clear all unused values */
 222     memset( pBiosData, 0, sizeof(*pBiosData) );
 223
 224     /* FIXME: should check the number of configured drives and ports */
 225
 226     pBiosData->Com1Addr             = 0x3f8;
 227     pBiosData->Com2Addr             = 0x2f8;
 228     pBiosData->Lpt1Addr             = 0x378;
 229     pBiosData->Lpt2Addr             = 0x278;
 230     pBiosData->InstalledHardware    = 0x5463;
 231     pBiosData->MemSize              = 640;
 232     pBiosData->NextKbdCharPtr       = 0x1e;
 233     pBiosData->FirstKbdCharPtr      = 0x1e;
 234     pBiosData->VideoMode            = 3;
 235     pBiosData->VideoColumns         = 80;
 236     pBiosData->VideoPageSize        = 80 * 25 * 2;
 237     pBiosData->VideoPageStartAddr   = 0xb800;
 238     pBiosData->VideoCtrlAddr        = 0x3d4;
 239     pBiosData->Ticks                = INT1A_GetTicksSinceMidnight();
 240     pBiosData->NbHardDisks          = 2;
 241     pBiosData->KbdBufferStart       = 0x1e;
 242     pBiosData->KbdBufferEnd         = 0x3e;
 243     pBiosData->RowsOnScreenMinus1   = 23;
 244     pBiosData->BytesPerChar         = 0x10;
 245     pBiosData->ModeOptions          = 0x64;
 246     pBiosData->FeatureBitsSwitches  = 0xf9;
 247     pBiosData->unknown              = 0x51;
 248     pBiosData->DisplayCombination   = 0x08;
 249     pBiosData->DiskDataRate         = 0;
 250
 251     /* fill ROM configuration table (values from Award) */
 252     *(WORD *)(pBiosROMTable)= 0x08; /* number of bytes following */
 253     *(pBiosROMTable+0x2)        = 0xfc; /* model */
 254     *(pBiosROMTable+0x3)        = 0x01; /* submodel */
 255     *(pBiosROMTable+0x4)        = 0x00; /* BIOS revision */
 256     *(pBiosROMTable+0x5)        = 0x74; /* feature byte 1 */
 257     *(pBiosROMTable+0x6)        = 0x00; /* feature byte 2 */
 258     *(pBiosROMTable+0x7)        = 0x00; /* feature byte 3 */
 259     *(pBiosROMTable+0x8)        = 0x00; /* feature byte 4 */
 260     *(pBiosROMTable+0x9)        = 0x00; /* feature byte 5 */
 261
 262     /* BIOS date string */
 263     strcpy((char *)pBiosSys+0xfff5, "13/01/99");
 264
 265     /* BIOS ID */
 266     *(pBiosSys+0xfffe) = 0xfc;
 267 }
 268
 269 /***********************************************************************
 270  *           DOSMEM_InitCollateTable
 271  *
 272  * Initialises the collate table (character sorting, language dependent)
 273  */
 274 static void DOSMEM_InitCollateTable()
 275 {
 276         DWORD           x;
 277         unsigned char   *tbl;
 278         int             i;
 279
 280         x = GlobalDOSAlloc16(258);
 281         DOSMEM_CollateTable = MAKELONG(0,(x>>16));
 282         tbl = DOSMEM_MapRealToLinear(DOSMEM_CollateTable);
 283         *(WORD*)tbl     = 0x100;
 284         tbl += 2;
 285         for ( i = 0; i < 0x100; i++) *tbl++ = i;
 286 }
 287
 288 /***********************************************************************
 289  *           DOSMEM_InitErrorTable
 290  *
 291  * Initialises the error tables (DOS 5+)
 292  */
 293 static void DOSMEM_InitErrorTable()
 294 {
 295         DWORD           x;
 296         char            *call;
 297
 298         /* We will use a snippet of real mode code that calls */
 299         /* a WINE-only interrupt to handle moving the requested */
 300         /* message into the buffer... */
 301
 302         /* FIXME - There is still something wrong... */
 303
 304         /* FIXME - Find hex values for opcodes...
 305
 306            (On call, AX contains message number
 307                      DI contains 'offset' (??)
 308             Resturn, ES:DI points to counted string )
 309
 310            PUSH BX
 311            MOV BX, AX
 312            MOV AX, (arbitrary subfunction number)
 313            INT (WINE-only interrupt)
 314            POP BX
 315            RET
 316
 317         */
 318
 319         const int       code = 4;
 320         const int       buffer = 80;
 321         const int       SIZE_TO_ALLOCATE = code + buffer;
 322
 323         /* FIXME - Complete rewrite of the table system to save */
 324         /* precious DOS space. Now, we return the 0001:???? as */
 325         /* DOS 4+ (??, it seems to be the case in MS 7.10) treats that */
 326         /* as a special case and programs will use the alternate */
 327         /* interface (a farcall returned with INT 24 (AX = 0x122e, DL = */
 328         /* 0x08) which lets us have a smaller memory footprint anyway. */
 329
 330         x = GlobalDOSAlloc16(SIZE_TO_ALLOCATE);
 331
 332         DOSMEM_ErrorCall = MAKELONG(0,(x>>16));
 333         DOSMEM_ErrorBuffer = DOSMEM_ErrorCall + code;
 334
 335         call = DOSMEM_MapRealToLinear(DOSMEM_ErrorCall);
 336
 337         memset(call, 0, SIZE_TO_ALLOCATE);
 338
 339         /* Fixme - Copy assembly into buffer here */
 340 }
 341
 342 /***********************************************************************
 343  *           DOSMEM_InitMemory
 344  *
 345  * Initialises the DOS memory structures.
 346  */
 347 static void DOSMEM_InitMemory(HMODULE16 hModule)
 348 {
 349    /* Low 64Kb are reserved for DOS/BIOS so the useable area starts at
 350     * 1000:0000 and ends at 9FFF:FFEF. */
 351
 352     dosmem_info*        info_block = DOSMEM_InfoBlock(hModule);
 353     dosmem_entry*       root_block = DOSMEM_RootBlock(hModule);
 354     dosmem_entry*       dm;
 355
 356     root_block->size = DOSMEM_MemoryTop(hModule) - (((char*)root_block) + sizeof(dosmem_entry));
 357
 358     info_block->blocks = 0;
 359     info_block->free = root_block->size;
 360
 361     dm = NEXT_BLOCK(root_block);
 362     dm->size = DM_BLOCK_TERMINAL;
 363     root_block->size |= DM_BLOCK_FREE
 364 #ifdef __DOSMEM_DEBUG__
 365                      | DM_BLOCK_DEBUG;
 366 #endif
 367                      ;
 368 }
 369
 370 /***********************************************************************
 371  *           DOSMEM_Init
 372  *
 373  * Create the dos memory segments, and store them into the KERNEL
 374  * exported values.
 375  */
 376 BOOL DOSMEM_Init(HMODULE16 hModule)
 377 {
 378     if (!hModule)
 379     {
 380         /* Allocate 1 MB dosmemory
 381          * - it is mostly wasted but we can use some of it to
 382          *   store internal translation tables, etc...
 383          */
 384         DOSMEM_dosmem = VirtualAlloc( NULL, 0x100000, MEM_COMMIT,
 385                                       PAGE_EXECUTE_READWRITE );
 386         if (!DOSMEM_dosmem)
 387         {
 388             WARN(dosmem, "Could not allocate DOS memory.\n" );
 389             return FALSE;
 390         }
 391         DOSMEM_BiosDataSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0x400,
 392                                      0x100, 0, FALSE, FALSE, FALSE, NULL );
 393         DOSMEM_BiosSysSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0xf0000,
 394                                      0x10000, 0, FALSE, FALSE, FALSE, NULL );
 395         DOSMEM_FillIsrTable(0);
 396         DOSMEM_FillBiosSegments();
 397         DOSMEM_InitMemory(0);
 398         DOSMEM_InitCollateTable();
 399         DOSMEM_InitErrorTable();
 400         DOSMEM_InitDPMI();
 401     }
 402     else
 403     {
 404 #if 0
 405         DOSMEM_FillIsrTable(hModule);
 406         DOSMEM_InitMemory(hModule);
 407 #else
 408         /* bootstrap the new V86 task with a copy of the "system" memory */
 409         memcpy(DOSMEM_MemoryBase(hModule), DOSMEM_dosmem, 0x100000);
 410 #endif
 411     }
 412     return TRUE;
 413 }
 414
 415
 416 /***********************************************************************
 417  *           DOSMEM_Tick
 418  *
 419  * Increment the BIOS tick counter. Called by timer signal handler.
 420  */
 421 void DOSMEM_Tick( WORD timer )
 422 {
 423     if (pBiosData) pBiosData->Ticks++;
 424 }
 425
 426 /***********************************************************************
 427  *           DOSMEM_GetBlock
 428  *
 429  * Carve a chunk of the DOS memory block (without selector).
 430  */
 431 LPVOID DOSMEM_GetBlock(HMODULE16 hModule, UINT size, UINT16* pseg)
 432 {
 433    UINT          blocksize;
 434    char         *block = NULL;
 435    dosmem_info  *info_block = DOSMEM_InfoBlock(hModule);
 436    dosmem_entry *dm;
 437 #ifdef __DOSMEM_DEBUG_
 438    dosmem_entry *prev = NULL;
 439 #endif
 440
 441    if( size > info_block->free ) return NULL;
 442    dm = DOSMEM_RootBlock(hModule);
 443
 444    while (dm && dm->size != DM_BLOCK_TERMINAL)
 445    {
 446 #ifdef __DOSMEM_DEBUG__
 447        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 448        {
 449             WARN(dosmem,"MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 450             return NULL;
 451        }
 452        prev = dm;
 453 #endif
 454        if( dm->size & DM_BLOCK_FREE )
 455        {
 456            dosmem_entry  *next = NEXT_BLOCK(dm);
 457
 458            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 459            {
 460                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 461                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 462                next = NEXT_BLOCK(dm);
 463            }
 464
 465            blocksize = dm->size & DM_BLOCK_MASK;
 466            if( blocksize >= size )
 467            {
 468                block = ((char*)dm) + sizeof(dosmem_entry);
 469                if( blocksize - size > 0x20 )
 470                {
 471                    /* split dm so that the next one stays
 472                     * paragraph-aligned (and dm loses free bit) */
 473
 474                    dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 475                                               sizeof(dosmem_entry));
 476                    next = (dosmem_entry*)(((char*)dm) +
 477                            sizeof(dosmem_entry) + dm->size);
 478                    next->size = (blocksize - (dm->size +
 479                            sizeof(dosmem_entry))) | DM_BLOCK_FREE
 480 #ifdef __DOSMEM_DEBUG__
 481                                                   | DM_BLOCK_DEBUG
 482 #endif
 483                                                   ;
 484                } else dm->size &= DM_BLOCK_MASK;
 485
 486                info_block->blocks++;
 487                info_block->free -= dm->size;
 488                if( pseg ) *pseg = (block - DOSMEM_MemoryBase(hModule)) >> 4;
 489 #ifdef __DOSMEM_DEBUG__
 490                dm->size |= DM_BLOCK_DEBUG;
 491 #endif
 492                break;
 493            }
 494            dm = next;
 495        }
 496        else dm = NEXT_BLOCK(dm);
 497    }
 498    return (LPVOID)block;
 499 }
 500
 501 /***********************************************************************
 502  *           DOSMEM_FreeBlock
 503  */
 504 BOOL DOSMEM_FreeBlock(HMODULE16 hModule, void* ptr)
 505 {
 506    dosmem_info  *info_block = DOSMEM_InfoBlock(hModule);
 507
 508    if( ptr >= (void*)(((char*)DOSMEM_RootBlock(hModule)) + sizeof(dosmem_entry)) &&
 509        ptr < (void*)DOSMEM_MemoryTop(hModule) && !((((char*)ptr)
 510                   - DOSMEM_MemoryBase(hModule)) & 0xf) )
 511    {
 512        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 513
 514        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 515 #ifdef __DOSMEM_DEBUG__
 516          && ((dm->size & DM_BLOCK_DEBUG) == DM_BLOCK_DEBUG )
 517 #endif
 518          )
 519        {
 520              info_block->blocks--;
 521              info_block->free += dm->size;
 522
 523              dm->size |= DM_BLOCK_FREE;
 524              return TRUE;
 525        }
 526    }
 527    return FALSE;
 528 }
 529
 530 /***********************************************************************
 531  *           DOSMEM_ResizeBlock
 532  */
 533 LPVOID DOSMEM_ResizeBlock(HMODULE16 hModule, void* ptr, UINT size, UINT16* pseg)
 534 {
 535    char         *block = NULL;
 536    dosmem_info  *info_block = DOSMEM_InfoBlock(hModule);
 537
 538    if( ptr >= (void*)(((char*)DOSMEM_RootBlock(hModule)) + sizeof(dosmem_entry)) &&
 539        ptr < (void*)DOSMEM_MemoryTop(hModule) && !((((char*)ptr)
 540                   - DOSMEM_MemoryBase(hModule)) & 0xf) )
 541    {
 542        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 543
 544        if( pseg ) *pseg = ((char*)ptr - DOSMEM_MemoryBase(hModule)) >> 4;
 545
 546        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 547          )
 548        {
 549              dosmem_entry  *next = NEXT_BLOCK(dm);
 550              UINT blocksize, orgsize = dm->size & DM_BLOCK_MASK;
 551
 552              while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 553              {
 554                  dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 555                  next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 556                  next = NEXT_BLOCK(dm);
 557              }
 558
 559              blocksize = dm->size & DM_BLOCK_MASK;
 560              if (blocksize >= size)
 561              {
 562                  block = ((char*)dm) + sizeof(dosmem_entry);
 563                  if( blocksize - size > 0x20 )
 564                  {
 565                      /* split dm so that the next one stays
 566                       * paragraph-aligned (and next gains free bit) */
 567
 568                      dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 569                                                 sizeof(dosmem_entry));
 570                      next = (dosmem_entry*)(((char*)dm) +
 571                              sizeof(dosmem_entry) + dm->size);
 572                      next->size = (blocksize - (dm->size +
 573                              sizeof(dosmem_entry))) | DM_BLOCK_FREE
 574                                                     ;
 575                  } else dm->size &= DM_BLOCK_MASK;
 576
 577                  info_block->free += orgsize - dm->size;
 578              } else {
 579                  block = DOSMEM_GetBlock(hModule, size, pseg);
 580                  if (block) {
 581                      info_block->blocks--;
 582                      info_block->free += dm->size;
 583
 584                      dm->size |= DM_BLOCK_FREE;
 585                  }
 586              }
 587        }
 588    }
 589    return (LPVOID)block;
 590 }
 591
 592
 593 /***********************************************************************
 594  *           DOSMEM_Available
 595  */
 596 UINT DOSMEM_Available(HMODULE16 hModule)
 597 {
 598    UINT          blocksize, available = 0;
 599    dosmem_entry *dm;
 600
 601    dm = DOSMEM_RootBlock(hModule);
 602
 603    while (dm && dm->size != DM_BLOCK_TERMINAL)
 604    {
 605 #ifdef __DOSMEM_DEBUG__
 606        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 607        {
 608             WARN(dosmem,"MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 609             return NULL;
 610        }
 611        prev = dm;
 612 #endif
 613        if( dm->size & DM_BLOCK_FREE )
 614        {
 615            dosmem_entry  *next = NEXT_BLOCK(dm);
 616
 617            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 618            {
 619                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 620                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 621                next = NEXT_BLOCK(dm);
 622            }
 623
 624            blocksize = dm->size & DM_BLOCK_MASK;
 625            if ( blocksize > available ) available = blocksize;
 626            dm = next;
 627        }
 628        else dm = NEXT_BLOCK(dm);
 629    }
 630    return available;
 631 }
 632
 633
 634 /***********************************************************************
 635  *           DOSMEM_MapLinearToDos
 636  *
 637  * Linear address to the DOS address space.
 638  */
 639 UINT DOSMEM_MapLinearToDos(LPVOID ptr)
 640 {
 641     if (((char*)ptr >= DOSMEM_MemoryBase(0)) &&
 642         ((char*)ptr < DOSMEM_MemoryBase(0) + 0x100000))
 643           return (UINT)ptr - (UINT)DOSMEM_MemoryBase(0);
 644     return (UINT)ptr;
 645 }
 646
 647
 648 /***********************************************************************
 649  *           DOSMEM_MapDosToLinear
 650  *
 651  * DOS linear address to the linear address space.
 652  */
 653 LPVOID DOSMEM_MapDosToLinear(UINT ptr)
 654 {
 655     if (ptr < 0x100000) return (LPVOID)(ptr + (UINT)DOSMEM_MemoryBase(0));
 656     return (LPVOID)ptr;
 657 }
 658
 659
 660 /***********************************************************************
 661  *           DOSMEM_MapRealToLinear
 662  *
 663  * Real mode DOS address into a linear pointer
 664  */
 665 LPVOID DOSMEM_MapRealToLinear(DWORD x)
 666 {
 667    LPVOID       lin;
 668
 669    lin=DOSMEM_MemoryBase(0)+(x&0xffff)+(((x&0xffff0000)>>16)*16);
 670    TRACE(selector,"(0x%08lx) returns 0x%p.\n",
 671                     x,lin );
 672    return lin;
 673 }
 674
 675 /***********************************************************************
 676  *           DOSMEM_AllocSelector
 677  *
 678  * Allocates a protected mode selector for a realmode segment.
 679  */
 680 WORD DOSMEM_AllocSelector(WORD realsel)
 681 {
 682         HMODULE16 hModule = GetModuleHandle16("KERNEL");
 683         WORD    sel;
 684
 685         sel=GLOBAL_CreateBlock(
 686                 GMEM_FIXED,DOSMEM_dosmem+realsel*16,0x10000,
 687                 hModule,FALSE,FALSE,FALSE,NULL
 688         );
 689         TRACE(selector,"(0x%04x) returns 0x%04x.\n",
 690                 realsel,sel
 691         );
 692         return sel;
 693 }
 694