msdos/dosmem.c

   1 /*
   2  * DOS memory emulation
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  * Copyright 1996 Marcus Meissner
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include "config.h"
  23 #include "wine/port.h"
  24
  25 #include <signal.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/types.h>
  29 #ifdef HAVE_SYS_MMAN_H
  30 # include <sys/mman.h>
  31 #endif
  32
  33 #include "winbase.h"
  34 #include "wine/winbase16.h"
  35
  36 #include "global.h"
  37 #include "selectors.h"
  38 #include "miscemu.h"
  39 #include "wine/debug.h"
  40
  41 WINE_DEFAULT_DEBUG_CHANNEL(dosmem);
  42 WINE_DECLARE_DEBUG_CHANNEL(selector);
  43
  44 WORD DOSMEM_0000H;        /* segment at 0:0 */
  45 WORD DOSMEM_BiosDataSeg;  /* BIOS data segment at 0x40:0 */
  46 WORD DOSMEM_BiosSysSeg;   /* BIOS ROM segment at 0xf000:0 */
  47
  48 DWORD DOSMEM_CollateTable;
  49
  50 /* use 2 low bits of 'size' for the housekeeping */
  51
  52 #define DM_BLOCK_DEBUG          0xABE00000
  53 #define DM_BLOCK_TERMINAL       0x00000001
  54 #define DM_BLOCK_FREE           0x00000002
  55 #define DM_BLOCK_MASK           0x001FFFFC
  56
  57 /*
  58 #define __DOSMEM_DEBUG__
  59  */
  60
  61 typedef struct {
  62    unsigned     size;
  63 } dosmem_entry;
  64
  65 typedef struct {
  66   unsigned      blocks;
  67   unsigned      free;
  68 } dosmem_info;
  69
  70 #define NEXT_BLOCK(block) \
  71         (dosmem_entry*)(((char*)(block)) + \
  72          sizeof(dosmem_entry) + ((block)->size & DM_BLOCK_MASK))
  73
  74 #define VM_STUB(x) (0x90CF00CD|(x<<8)) /* INT x; IRET; NOP */
  75 #define VM_STUB_SEGMENT 0xf000         /* BIOS segment */
  76
  77 /* DOS memory base */
  78 static char *DOSMEM_dosmem;
  79 /* DOS system base (for interrupt vector table and BIOS data area)
  80  * ...should in theory (i.e. Windows) be equal to DOSMEM_dosmem (NULL),
  81  * but is normally set to 0xf0000 in Wine to allow trapping of NULL pointers,
  82  * and only relocated to NULL when absolutely necessary */
  83 static char *DOSMEM_sysmem;
  84
  85 /* various real-mode code stubs */
  86 WORD DOSMEM_wrap_seg;
  87 WORD DOSMEM_xms_seg;
  88 WORD DOSMEM_dpmi_seg;
  89 WORD DOSMEM_dpmi_sel;
  90
  91 DWORD DOS_LOLSeg;
  92
  93 /***********************************************************************
  94  *           DOSMEM_SystemBase
  95  *
  96  * Gets the virtual DOS memory base (interrupt table).
  97  */
  98 char *DOSMEM_SystemBase(void)
  99 {
 100     return DOSMEM_sysmem;
 101 }
 102
 103 /***********************************************************************
 104  *           DOSMEM_MemoryBase
 105  *
 106  * Gets the DOS memory base.
 107  */
 108 char *DOSMEM_MemoryBase(void)
 109 {
 110     return DOSMEM_dosmem;
 111 }
 112
 113 /***********************************************************************
 114  *           DOSMEM_MemoryTop
 115  *
 116  * Gets the DOS memory top.
 117  */
 118 static char *DOSMEM_MemoryTop(void)
 119 {
 120     return DOSMEM_dosmem+0x9FFFC; /* 640K */
 121 }
 122
 123 /***********************************************************************
 124  *           DOSMEM_InfoBlock
 125  *
 126  * Gets the DOS memory info block.
 127  */
 128 static dosmem_info *DOSMEM_InfoBlock(void)
 129 {
 130     return (dosmem_info*)(DOSMEM_dosmem+0x10000); /* 64K */
 131 }
 132
 133 /***********************************************************************
 134  *           DOSMEM_RootBlock
 135  *
 136  * Gets the DOS memory root block.
 137  */
 138 static dosmem_entry *DOSMEM_RootBlock(void)
 139 {
 140     /* first block has to be paragraph-aligned */
 141     return (dosmem_entry*)(((char*)DOSMEM_InfoBlock()) +
 142                            ((((sizeof(dosmem_info) + 0xf) & ~0xf) - sizeof(dosmem_entry))));
 143 }
 144
 145 /***********************************************************************
 146  *           DOSMEM_FillIsrTable
 147  *
 148  * Fill the interrupt table with fake BIOS calls to BIOSSEG (0xf000).
 149  *
 150  * NOTES:
 151  * Linux normally only traps INTs performed from or destined to BIOSSEG
 152  * for us to handle, if the int_revectored table is empty. Filling the
 153  * interrupt table with calls to INT stubs in BIOSSEG allows DOS programs
 154  * to hook interrupts, as well as use their familiar retf tricks to call
 155  * them, AND let Wine handle any unhooked interrupts transparently.
 156  */
 157 static void DOSMEM_FillIsrTable(void)
 158 {
 159     SEGPTR *isr = (SEGPTR*)DOSMEM_sysmem;
 160     int x;
 161
 162     for (x=0; x<256; x++) isr[x]=MAKESEGPTR(VM_STUB_SEGMENT,x*4);
 163 }
 164
 165 static void DOSMEM_MakeIsrStubs(void)
 166 {
 167     DWORD *stub = (DWORD*)(DOSMEM_dosmem + (VM_STUB_SEGMENT << 4));
 168     int x;
 169
 170     for (x=0; x<256; x++) stub[x]=VM_STUB(x);
 171 }
 172
 173 /***********************************************************************
 174  *           DOSMEM_InitDPMI
 175  *
 176  * Allocate the global DPMI RMCB wrapper.
 177  */
 178 static void DOSMEM_InitDPMI(void)
 179 {
 180     LPSTR ptr;
 181
 182     static const char wrap_code[]={
 183      0xCD,0x31, /* int $0x31 */
 184      0xCB       /* lret */
 185     };
 186
 187     static const char enter_xms[]=
 188     {
 189         /* XMS hookable entry point */
 190         0xEB,0x03,           /* jmp entry */
 191         0x90,0x90,0x90,      /* nop;nop;nop */
 192                              /* entry: */
 193         /* real entry point */
 194         /* for simplicity, we'll just use the same hook as DPMI below */
 195         0xCD,0x31,           /* int $0x31 */
 196         0xCB                 /* lret */
 197     };
 198
 199     static const char enter_pm[]=
 200     {
 201         0x50,                /* pushw %ax */
 202         0x52,                /* pushw %dx */
 203         0x55,                /* pushw %bp */
 204         0x89,0xE5,           /* movw %sp,%bp */
 205         /* get return CS */
 206         0x8B,0x56,0x08,      /* movw 8(%bp),%dx */
 207         /* just call int 31 here to get into protected mode... */
 208         /* it'll check whether it was called from dpmi_seg... */
 209         0xCD,0x31,           /* int $0x31 */
 210         /* we are now in the context of a 16-bit relay call */
 211         /* need to fixup our stack;
 212          * 16-bit relay return address will be lost, but we won't worry quite yet */
 213         0x8E,0xD0,           /* movw %ax,%ss */
 214         0x66,0x0F,0xB7,0xE5, /* movzwl %bp,%esp */
 215         /* set return CS */
 216         0x89,0x56,0x08,      /* movw %dx,8(%bp) */
 217         0x5D,                /* popw %bp */
 218         0x5A,                /* popw %dx */
 219         0x58,                /* popw %ax */
 220         0xCB                 /* lret */
 221     };
 222
 223     ptr = DOSMEM_GetBlock( sizeof(wrap_code), &DOSMEM_wrap_seg );
 224     memcpy( ptr, wrap_code, sizeof(wrap_code) );
 225     ptr = DOSMEM_GetBlock( sizeof(enter_xms), &DOSMEM_xms_seg );
 226     memcpy( ptr, enter_xms, sizeof(enter_xms) );
 227     ptr = DOSMEM_GetBlock( sizeof(enter_pm), &DOSMEM_dpmi_seg );
 228     memcpy( ptr, enter_pm, sizeof(enter_pm) );
 229     DOSMEM_dpmi_sel = SELECTOR_AllocBlock( ptr, sizeof(enter_pm), WINE_LDT_FLAGS_CODE );
 230 }
 231
 232 BIOSDATA * DOSMEM_BiosData()
 233 {
 234     return (BIOSDATA *)(DOSMEM_sysmem + 0x400);
 235 }
 236
 237 BYTE * DOSMEM_BiosSys()
 238 {
 239     return DOSMEM_dosmem+0xf0000;
 240 }
 241
 242 /***********************************************************************
 243  *           DOSMEM_FillBiosSegments
 244  *
 245  * Fill the BIOS data segment with dummy values.
 246  */
 247 static void DOSMEM_FillBiosSegments(void)
 248 {
 249     BYTE *pBiosSys = DOSMEM_BiosSys();
 250     BYTE *pBiosROMTable = pBiosSys+0xe6f5;
 251     BIOSDATA *pBiosData = DOSMEM_BiosData();
 252
 253     /* bogus 0xe0xx addresses !! Adapt int 0x10/0x1b if change needed */
 254     VIDEOFUNCTIONALITY *pVidFunc = (VIDEOFUNCTIONALITY *)(pBiosSys+0xe000);
 255     VIDEOSTATE *pVidState = (VIDEOSTATE *)(pBiosSys+0xe010);
 256     int i;
 257
 258       /* Clear all unused values */
 259     memset( pBiosData, 0, sizeof(*pBiosData) );
 260     memset( pVidFunc,  0, sizeof(*pVidFunc ) );
 261     memset( pVidState, 0, sizeof(*pVidState) );
 262
 263     /* FIXME: should check the number of configured drives and ports */
 264
 265     pBiosData->Com1Addr             = 0x3f8;
 266     pBiosData->Com2Addr             = 0x2f8;
 267     pBiosData->Lpt1Addr             = 0x378;
 268     pBiosData->Lpt2Addr             = 0x278;
 269     pBiosData->InstalledHardware    = 0x5463;
 270     pBiosData->MemSize              = 640;
 271     pBiosData->NextKbdCharPtr       = 0x1e;
 272     pBiosData->FirstKbdCharPtr      = 0x1e;
 273     pBiosData->VideoMode            = 3;
 274     pBiosData->VideoColumns         = 80;
 275     pBiosData->VideoPageSize        = 80 * 25 * 2;
 276     pBiosData->VideoPageStartAddr   = 0xb800;
 277     pBiosData->VideoCtrlAddr        = 0x3d4;
 278     pBiosData->Ticks                = INT1A_GetTicksSinceMidnight();
 279     pBiosData->NbHardDisks          = 2;
 280     pBiosData->KbdBufferStart       = 0x1e;
 281     pBiosData->KbdBufferEnd         = 0x3e;
 282     pBiosData->RowsOnScreenMinus1   = 23;
 283     pBiosData->BytesPerChar         = 0x10;
 284     pBiosData->ModeOptions          = 0x64;
 285     pBiosData->FeatureBitsSwitches  = 0xf9;
 286     pBiosData->VGASettings          = 0x51;
 287     pBiosData->DisplayCombination   = 0x08;
 288     pBiosData->DiskDataRate         = 0;
 289
 290     /* fill ROM configuration table (values from Award) */
 291     *(pBiosROMTable+0x0)        = 0x08; /* number of bytes following LO */
 292     *(pBiosROMTable+0x1)        = 0x00; /* number of bytes following HI */
 293     *(pBiosROMTable+0x2)        = 0xfc; /* model */
 294     *(pBiosROMTable+0x3)        = 0x01; /* submodel */
 295     *(pBiosROMTable+0x4)        = 0x00; /* BIOS revision */
 296     *(pBiosROMTable+0x5)        = 0x74; /* feature byte 1 */
 297     *(pBiosROMTable+0x6)        = 0x00; /* feature byte 2 */
 298     *(pBiosROMTable+0x7)        = 0x00; /* feature byte 3 */
 299     *(pBiosROMTable+0x8)        = 0x00; /* feature byte 4 */
 300     *(pBiosROMTable+0x9)        = 0x00; /* feature byte 5 */
 301
 302
 303     for (i = 0; i < 7; i++)
 304         pVidFunc->ModeSupport[i] = 0xff;
 305
 306     pVidFunc->ScanlineSupport     = 7;
 307     pVidFunc->NumberCharBlocks    = 0;
 308     pVidFunc->ActiveCharBlocks    = 0;
 309     pVidFunc->MiscFlags           = 0x8ff;
 310     pVidFunc->SavePointerFlags    = 0x3f;
 311
 312     pVidState->StaticFuncTable    = 0xf000e000;  /* FIXME: always real mode ? */
 313     pVidState->VideoMode          = pBiosData->VideoMode; /* needs updates! */
 314     pVidState->NumberColumns      = pBiosData->VideoColumns; /* needs updates! */
 315     pVidState->RegenBufLen        = 0;
 316     pVidState->RegenBufAddr       = 0;
 317
 318     for (i = 0; i < 8; i++)
 319         pVidState->CursorPos[i] = 0;
 320
 321     pVidState->CursorType         = 0x0a0b;  /* start/end line */
 322     pVidState->ActivePage         = 0;
 323     pVidState->CRTCPort           = 0x3da;
 324     pVidState->Port3x8            = 0;
 325     pVidState->Port3x9            = 0;
 326     pVidState->NumberRows         = 23;     /* number of rows - 1 */
 327     pVidState->BytesPerChar       = 0x10;
 328     pVidState->DCCActive          = pBiosData->DisplayCombination;
 329     pVidState->DCCAlternate       = 0;
 330     pVidState->NumberColors       = 16;
 331     pVidState->NumberPages        = 1;
 332     pVidState->NumberScanlines    = 3; /* (0,1,2,3) = (200,350,400,480) */
 333     pVidState->CharBlockPrimary   = 0;
 334     pVidState->CharBlockSecondary = 0;
 335     pVidState->MiscFlags =
 336                            (pBiosData->VGASettings & 0x0f)
 337                          | ((pBiosData->ModeOptions & 1) << 4); /* cursor emulation */
 338     pVidState->NonVGASupport      = 0;
 339     pVidState->VideoMem           = (pBiosData->ModeOptions & 0x60 >> 5);
 340     pVidState->SavePointerState   = 0;
 341     pVidState->DisplayStatus      = 4;
 342
 343     /* BIOS date string */
 344     strcpy((char *)pBiosSys+0xfff5, "13/01/99");
 345
 346     /* BIOS ID */
 347     *(pBiosSys+0xfffe) = 0xfc;
 348 }
 349
 350 /***********************************************************************
 351  *           DOSMEM_InitCollateTable
 352  *
 353  * Initialises the collate table (character sorting, language dependent)
 354  */
 355 static void DOSMEM_InitCollateTable()
 356 {
 357         DWORD           x;
 358         unsigned char   *tbl;
 359         int             i;
 360
 361         x = GlobalDOSAlloc16(258);
 362         DOSMEM_CollateTable = MAKELONG(0,(x>>16));
 363         tbl = DOSMEM_MapRealToLinear(DOSMEM_CollateTable);
 364         *(WORD*)tbl     = 0x100;
 365         tbl += 2;
 366         for ( i = 0; i < 0x100; i++) *tbl++ = i;
 367 }
 368
 369 /***********************************************************************
 370  *           DOSMEM_InitErrorTable
 371  *
 372  * Initialises the error tables (DOS 5+)
 373  */
 374 static void DOSMEM_InitErrorTable()
 375 {
 376 #if 0  /* no longer used */
 377         DWORD           x;
 378         char            *call;
 379
 380         /* We will use a snippet of real mode code that calls */
 381         /* a WINE-only interrupt to handle moving the requested */
 382         /* message into the buffer... */
 383
 384         /* FIXME - There is still something wrong... */
 385
 386         /* FIXME - Find hex values for opcodes...
 387
 388            (On call, AX contains message number
 389                      DI contains 'offset' (??)
 390             Resturn, ES:DI points to counted string )
 391
 392            PUSH BX
 393            MOV BX, AX
 394            MOV AX, (arbitrary subfunction number)
 395            INT (WINE-only interrupt)
 396            POP BX
 397            RET
 398
 399         */
 400
 401         const int       code = 4;
 402         const int       buffer = 80;
 403         const int       SIZE_TO_ALLOCATE = code + buffer;
 404
 405         /* FIXME - Complete rewrite of the table system to save */
 406         /* precious DOS space. Now, we return the 0001:???? as */
 407         /* DOS 4+ (??, it seems to be the case in MS 7.10) treats that */
 408         /* as a special case and programs will use the alternate */
 409         /* interface (a farcall returned with INT 24 (AX = 0x122e, DL = */
 410         /* 0x08) which lets us have a smaller memory footprint anyway. */
 411
 412         x = GlobalDOSAlloc16(SIZE_TO_ALLOCATE);
 413
 414         DOSMEM_ErrorCall = MAKELONG(0,(x>>16));
 415         DOSMEM_ErrorBuffer = DOSMEM_ErrorCall + code;
 416
 417         call = DOSMEM_MapRealToLinear(DOSMEM_ErrorCall);
 418
 419         memset(call, 0, SIZE_TO_ALLOCATE);
 420 #endif
 421         /* FIXME - Copy assembly into buffer here */
 422 }
 423
 424 /***********************************************************************
 425  *           DOSMEM_InitMemory
 426  *
 427  * Initialises the DOS memory structures.
 428  */
 429 static void DOSMEM_InitMemory(void)
 430 {
 431    /* Low 64Kb are reserved for DOS/BIOS so the useable area starts at
 432     * 1000:0000 and ends at 9FFF:FFEF. */
 433
 434     dosmem_info*        info_block = DOSMEM_InfoBlock();
 435     dosmem_entry*       root_block = DOSMEM_RootBlock();
 436     dosmem_entry*       dm;
 437
 438     root_block->size = DOSMEM_MemoryTop() - (((char*)root_block) + sizeof(dosmem_entry));
 439
 440     info_block->blocks = 0;
 441     info_block->free = root_block->size;
 442
 443     dm = NEXT_BLOCK(root_block);
 444     dm->size = DM_BLOCK_TERMINAL;
 445     root_block->size |= DM_BLOCK_FREE
 446 #ifdef __DOSMEM_DEBUG__
 447                      | DM_BLOCK_DEBUG
 448 #endif
 449                      ;
 450 }
 451
 452 /**********************************************************************
 453  *              setup_dos_mem
 454  *
 455  * Setup the first megabyte for DOS memory access
 456  */
 457 static void setup_dos_mem( int dos_init )
 458 {
 459     int sys_offset = 0;
 460     int page_size = getpagesize();
 461     void *addr = wine_anon_mmap( (void *)page_size, 0x110000-page_size,
 462                                  PROT_READ | PROT_WRITE | PROT_EXEC, 0 );
 463     if (addr == (void *)page_size)  /* we got what we wanted */
 464     {
 465         /* now map from address 0 */
 466         addr = wine_anon_mmap( NULL, 0x110000, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_FIXED );
 467         if (addr)
 468         {
 469             ERR("MAP_FIXED failed at address 0 for DOS address space\n" );
 470             ExitProcess(1);
 471         }
 472
 473         /* inform the memory manager that there is a mapping here */
 474         VirtualAlloc( addr, 0x110000, MEM_RESERVE | MEM_SYSTEM, PAGE_EXECUTE_READWRITE );
 475
 476         /* protect the first 64K to catch NULL pointers */
 477         if (!dos_init)
 478         {
 479             VirtualProtect( addr, 0x10000, PAGE_NOACCESS, NULL );
 480             /* move the BIOS and ISR area from 0x00000 to 0xf0000 */
 481             sys_offset += 0xf0000;
 482         }
 483     }
 484     else
 485     {
 486         ERR("Cannot use first megabyte for DOS address space, please report\n" );
 487         if (dos_init) ExitProcess(1);
 488         /* allocate the DOS area somewhere else */
 489         addr = VirtualAlloc( NULL, 0x110000, MEM_COMMIT, PAGE_EXECUTE_READWRITE );
 490         if (!addr)
 491         {
 492             ERR( "Cannot allocate DOS memory\n" );
 493             ExitProcess(1);
 494         }
 495     }
 496     DOSMEM_dosmem = addr;
 497     DOSMEM_sysmem = (char*)addr + sys_offset;
 498 }
 499
 500
 501 /***********************************************************************
 502  *           DOSMEM_Init
 503  *
 504  * Create the dos memory segments, and store them into the KERNEL
 505  * exported values.
 506  */
 507 BOOL DOSMEM_Init(BOOL dos_init)
 508 {
 509     static int already_done, already_mapped;
 510
 511     if (!already_done)
 512     {
 513         setup_dos_mem( dos_init );
 514
 515         DOSMEM_0000H = GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_sysmem,
 516                                            0x10000, 0, WINE_LDT_FLAGS_DATA );
 517         DOSMEM_BiosDataSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_sysmem + 0x400,
 518                                                 0x100, 0, WINE_LDT_FLAGS_DATA );
 519         DOSMEM_BiosSysSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0xf0000,
 520                                                0x10000, 0, WINE_LDT_FLAGS_DATA );
 521         DOSMEM_FillBiosSegments();
 522         DOSMEM_FillIsrTable();
 523         DOSMEM_InitMemory();
 524         DOSMEM_InitCollateTable();
 525         DOSMEM_InitErrorTable();
 526         DOSMEM_InitDPMI();
 527         already_done = 1;
 528     }
 529     else if (dos_init && !already_mapped)
 530     {
 531         if (DOSMEM_dosmem)
 532         {
 533             ERR( "Needs access to the first megabyte for DOS mode\n" );
 534             ExitProcess(1);
 535         }
 536         MESSAGE( "Warning: unprotecting the first 64KB of memory to allow real-mode calls.\n"
 537                  "         NULL pointer accesses will no longer be caught.\n" );
 538         VirtualProtect( NULL, 0x10000, PAGE_EXECUTE_READWRITE, NULL );
 539         /* copy the BIOS and ISR area down */
 540         memcpy( DOSMEM_dosmem, DOSMEM_sysmem, 0x400 + 0x100 );
 541         DOSMEM_sysmem = DOSMEM_dosmem;
 542         SetSelectorBase( DOSMEM_0000H, 0 );
 543         SetSelectorBase( DOSMEM_BiosDataSeg, 0x400 );
 544         /* we may now need the actual interrupt stubs, and since we've just moved the
 545          * interrupt vector table away, we can fill the area with stubs instead... */
 546         DOSMEM_MakeIsrStubs();
 547         already_mapped = 1;
 548     }
 549     return TRUE;
 550 }
 551
 552
 553 /***********************************************************************
 554  *           DOSMEM_Tick
 555  *
 556  * Increment the BIOS tick counter. Called by timer signal handler.
 557  */
 558 void DOSMEM_Tick( WORD timer )
 559 {
 560     BIOSDATA *pBiosData = DOSMEM_BiosData();
 561     if (pBiosData) pBiosData->Ticks++;
 562 }
 563
 564 /***********************************************************************
 565  *           DOSMEM_GetBlock
 566  *
 567  * Carve a chunk of the DOS memory block (without selector).
 568  */
 569 LPVOID DOSMEM_GetBlock(UINT size, UINT16* pseg)
 570 {
 571    UINT          blocksize;
 572    char         *block = NULL;
 573    dosmem_info  *info_block = DOSMEM_InfoBlock();
 574    dosmem_entry *dm;
 575 #ifdef __DOSMEM_DEBUG_
 576    dosmem_entry *prev = NULL;
 577 #endif
 578
 579    if( size > info_block->free ) return NULL;
 580    dm = DOSMEM_RootBlock();
 581
 582    while (dm && dm->size != DM_BLOCK_TERMINAL)
 583    {
 584 #ifdef __DOSMEM_DEBUG__
 585        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 586        {
 587             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 588             return NULL;
 589        }
 590        prev = dm;
 591 #endif
 592        if( dm->size & DM_BLOCK_FREE )
 593        {
 594            dosmem_entry  *next = NEXT_BLOCK(dm);
 595
 596            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 597            {
 598                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 599                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 600                next = NEXT_BLOCK(dm);
 601            }
 602
 603            blocksize = dm->size & DM_BLOCK_MASK;
 604            if( blocksize >= size )
 605            {
 606                block = ((char*)dm) + sizeof(dosmem_entry);
 607                if( blocksize - size > 0x20 )
 608                {
 609                    /* split dm so that the next one stays
 610                     * paragraph-aligned (and dm loses free bit) */
 611
 612                    dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 613                                               sizeof(dosmem_entry));
 614                    next = (dosmem_entry*)(((char*)dm) +
 615                            sizeof(dosmem_entry) + dm->size);
 616                    next->size = (blocksize - (dm->size +
 617                            sizeof(dosmem_entry))) | DM_BLOCK_FREE
 618 #ifdef __DOSMEM_DEBUG__
 619                                                   | DM_BLOCK_DEBUG
 620 #endif
 621                                                   ;
 622                } else dm->size &= DM_BLOCK_MASK;
 623
 624                info_block->blocks++;
 625                info_block->free -= dm->size;
 626                if( pseg ) *pseg = (block - DOSMEM_dosmem) >> 4;
 627 #ifdef __DOSMEM_DEBUG__
 628                dm->size |= DM_BLOCK_DEBUG;
 629 #endif
 630                break;
 631            }
 632            dm = next;
 633        }
 634        else dm = NEXT_BLOCK(dm);
 635    }
 636    return (LPVOID)block;
 637 }
 638
 639 /***********************************************************************
 640  *           DOSMEM_FreeBlock
 641  */
 642 BOOL DOSMEM_FreeBlock(void* ptr)
 643 {
 644    dosmem_info  *info_block = DOSMEM_InfoBlock();
 645
 646    if( ptr >= (void*)(((char*)DOSMEM_RootBlock()) + sizeof(dosmem_entry)) &&
 647        ptr < (void*)DOSMEM_MemoryTop() && !((((char*)ptr)
 648                   - DOSMEM_dosmem) & 0xf) )
 649    {
 650        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 651
 652        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 653 #ifdef __DOSMEM_DEBUG__
 654          && ((dm->size & DM_BLOCK_DEBUG) == DM_BLOCK_DEBUG )
 655 #endif
 656          )
 657        {
 658              info_block->blocks--;
 659              info_block->free += dm->size;
 660
 661              dm->size |= DM_BLOCK_FREE;
 662              return TRUE;
 663        }
 664    }
 665    return FALSE;
 666 }
 667
 668 /***********************************************************************
 669  *           DOSMEM_ResizeBlock
 670  */
 671 LPVOID DOSMEM_ResizeBlock(void* ptr, UINT size, UINT16* pseg)
 672 {
 673    char         *block = NULL;
 674    dosmem_info  *info_block = DOSMEM_InfoBlock();
 675
 676    if( ptr >= (void*)(((char*)DOSMEM_RootBlock()) + sizeof(dosmem_entry)) &&
 677        ptr < (void*)DOSMEM_MemoryTop() && !((((char*)ptr)
 678                   - DOSMEM_dosmem) & 0xf) )
 679    {
 680        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 681
 682        if( pseg ) *pseg = ((char*)ptr - DOSMEM_dosmem) >> 4;
 683
 684        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 685          )
 686        {
 687              dosmem_entry  *next = NEXT_BLOCK(dm);
 688              UINT blocksize, orgsize = dm->size & DM_BLOCK_MASK;
 689
 690              while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 691              {
 692                  dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 693                  next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 694                  next = NEXT_BLOCK(dm);
 695              }
 696
 697              blocksize = dm->size & DM_BLOCK_MASK;
 698              if (blocksize >= size)
 699              {
 700                  block = ((char*)dm) + sizeof(dosmem_entry);
 701                  if( blocksize - size > 0x20 )
 702                  {
 703                      /* split dm so that the next one stays
 704                       * paragraph-aligned (and next gains free bit) */
 705
 706                      dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 707                                                 sizeof(dosmem_entry));
 708                      next = (dosmem_entry*)(((char*)dm) +
 709                              sizeof(dosmem_entry) + dm->size);
 710                      next->size = (blocksize - (dm->size +
 711                              sizeof(dosmem_entry))) | DM_BLOCK_FREE
 712                                                     ;
 713                  } else dm->size &= DM_BLOCK_MASK;
 714
 715                  info_block->free += orgsize - dm->size;
 716              } else {
 717                  /* the collapse didn't help, try getting a new block */
 718                  block = DOSMEM_GetBlock(size, pseg);
 719                  if (block) {
 720                      /* we got one, copy the old data there (we do need to, right?) */
 721                      memcpy(block, ((char*)dm) + sizeof(dosmem_entry),
 722                                    (size<orgsize) ? size : orgsize);
 723                      /* free old block */
 724                      info_block->blocks--;
 725                      info_block->free += dm->size;
 726
 727                      dm->size |= DM_BLOCK_FREE;
 728                  } else {
 729                      /* and Bill Gates said 640K should be enough for everyone... */
 730
 731                      /* need to split original and collapsed blocks apart again,
 732                       * and free the collapsed blocks again, before exiting */
 733                      if( blocksize - orgsize > 0x20 )
 734                      {
 735                          /* split dm so that the next one stays
 736                           * paragraph-aligned (and next gains free bit) */
 737
 738                          dm->size = (((orgsize + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 739                                                        sizeof(dosmem_entry));
 740                          next = (dosmem_entry*)(((char*)dm) +
 741                                  sizeof(dosmem_entry) + dm->size);
 742                          next->size = (blocksize - (dm->size +
 743                                  sizeof(dosmem_entry))) | DM_BLOCK_FREE
 744                                                         ;
 745                      } else dm->size &= DM_BLOCK_MASK;
 746                  }
 747              }
 748        }
 749    }
 750    return (LPVOID)block;
 751 }
 752
 753
 754 /***********************************************************************
 755  *           DOSMEM_Available
 756  */
 757 UINT DOSMEM_Available(void)
 758 {
 759    UINT          blocksize, available = 0;
 760    dosmem_entry *dm;
 761
 762    dm = DOSMEM_RootBlock();
 763
 764    while (dm && dm->size != DM_BLOCK_TERMINAL)
 765    {
 766 #ifdef __DOSMEM_DEBUG__
 767        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 768        {
 769             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 770             return NULL;
 771        }
 772        prev = dm;
 773 #endif
 774        if( dm->size & DM_BLOCK_FREE )
 775        {
 776            dosmem_entry  *next = NEXT_BLOCK(dm);
 777
 778            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 779            {
 780                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 781                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 782                next = NEXT_BLOCK(dm);
 783            }
 784
 785            blocksize = dm->size & DM_BLOCK_MASK;
 786            if ( blocksize > available ) available = blocksize;
 787            dm = next;
 788        }
 789        else dm = NEXT_BLOCK(dm);
 790    }
 791    return available;
 792 }
 793
 794
 795 /***********************************************************************
 796  *           DOSMEM_MapLinearToDos
 797  *
 798  * Linear address to the DOS address space.
 799  */
 800 UINT DOSMEM_MapLinearToDos(LPVOID ptr)
 801 {
 802     if (((char*)ptr >= DOSMEM_dosmem) &&
 803         ((char*)ptr < DOSMEM_dosmem + 0x100000))
 804           return (UINT)ptr - (UINT)DOSMEM_dosmem;
 805     return (UINT)ptr;
 806 }
 807
 808
 809 /***********************************************************************
 810  *           DOSMEM_MapDosToLinear
 811  *
 812  * DOS linear address to the linear address space.
 813  */
 814 LPVOID DOSMEM_MapDosToLinear(UINT ptr)
 815 {
 816     if (ptr < 0x100000) return (LPVOID)(ptr + (UINT)DOSMEM_dosmem);
 817     return (LPVOID)ptr;
 818 }
 819
 820
 821 /***********************************************************************
 822  *           DOSMEM_MapRealToLinear
 823  *
 824  * Real mode DOS address into a linear pointer
 825  */
 826 LPVOID DOSMEM_MapRealToLinear(DWORD x)
 827 {
 828    LPVOID       lin;
 829
 830    lin=DOSMEM_dosmem+(x&0xffff)+(((x&0xffff0000)>>16)*16);
 831    TRACE_(selector)("(0x%08lx) returns %p.\n", x, lin );
 832    return lin;
 833 }
 834
 835 /***********************************************************************
 836  *           DOSMEM_AllocSelector
 837  *
 838  * Allocates a protected mode selector for a realmode segment.
 839  */
 840 WORD DOSMEM_AllocSelector(WORD realsel)
 841 {
 842         HMODULE16 hModule = GetModuleHandle16("KERNEL");
 843         WORD    sel;
 844
 845         sel=GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_dosmem+realsel*16, 0x10000,
 846                                 hModule, WINE_LDT_FLAGS_DATA );
 847         TRACE_(selector)("(0x%04x) returns 0x%04x.\n", realsel,sel);
 848         return sel;
 849 }
 850