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 struct DPMI_segments DOSMEM_dpmi_segments;
  87
  88 /***********************************************************************
  89  *           DOSMEM_GetDPMISegments
  90  */
  91 const struct DPMI_segments *DOSMEM_GetDPMISegments(void)
  92 {
  93     return &DOSMEM_dpmi_segments;
  94 }
  95
  96 /***********************************************************************
  97  *           DOSMEM_MemoryTop
  98  *
  99  * Gets the DOS memory top.
 100  */
 101 static char *DOSMEM_MemoryTop(void)
 102 {
 103     return DOSMEM_dosmem+0x9FFFC; /* 640K */
 104 }
 105
 106 /***********************************************************************
 107  *           DOSMEM_InfoBlock
 108  *
 109  * Gets the DOS memory info block.
 110  */
 111 static dosmem_info *DOSMEM_InfoBlock(void)
 112 {
 113     return (dosmem_info*)(DOSMEM_dosmem+0x10000); /* 64K */
 114 }
 115
 116 /***********************************************************************
 117  *           DOSMEM_RootBlock
 118  *
 119  * Gets the DOS memory root block.
 120  */
 121 static dosmem_entry *DOSMEM_RootBlock(void)
 122 {
 123     /* first block has to be paragraph-aligned */
 124     return (dosmem_entry*)(((char*)DOSMEM_InfoBlock()) +
 125                            ((((sizeof(dosmem_info) + 0xf) & ~0xf) - sizeof(dosmem_entry))));
 126 }
 127
 128 /***********************************************************************
 129  *           DOSMEM_FillIsrTable
 130  *
 131  * Fill the interrupt table with fake BIOS calls to BIOSSEG (0xf000).
 132  *
 133  * NOTES:
 134  * Linux normally only traps INTs performed from or destined to BIOSSEG
 135  * for us to handle, if the int_revectored table is empty. Filling the
 136  * interrupt table with calls to INT stubs in BIOSSEG allows DOS programs
 137  * to hook interrupts, as well as use their familiar retf tricks to call
 138  * them, AND let Wine handle any unhooked interrupts transparently.
 139  */
 140 static void DOSMEM_FillIsrTable(void)
 141 {
 142     SEGPTR *isr = (SEGPTR*)DOSMEM_sysmem;
 143     int x;
 144
 145     for (x=0; x<256; x++) isr[x]=MAKESEGPTR(VM_STUB_SEGMENT,x*4);
 146 }
 147
 148 static void DOSMEM_MakeIsrStubs(void)
 149 {
 150     DWORD *stub = (DWORD*)(DOSMEM_dosmem + (VM_STUB_SEGMENT << 4));
 151     int x;
 152
 153     for (x=0; x<256; x++) stub[x]=VM_STUB(x);
 154 }
 155
 156 /***********************************************************************
 157  *           DOSMEM_InitDPMI
 158  *
 159  * Allocate the global DPMI RMCB wrapper.
 160  */
 161 static void DOSMEM_InitDPMI(void)
 162 {
 163     LPSTR ptr;
 164
 165     static const char wrap_code[]={
 166      0xCD,0x31, /* int $0x31 */
 167      0xCB       /* lret */
 168     };
 169
 170     static const char enter_xms[]=
 171     {
 172         /* XMS hookable entry point */
 173         0xEB,0x03,           /* jmp entry */
 174         0x90,0x90,0x90,      /* nop;nop;nop */
 175                              /* entry: */
 176         /* real entry point */
 177         /* for simplicity, we'll just use the same hook as DPMI below */
 178         0xCD,0x31,           /* int $0x31 */
 179         0xCB                 /* lret */
 180     };
 181
 182     static const char enter_pm[]=
 183     {
 184         0x50,                /* pushw %ax */
 185         0x52,                /* pushw %dx */
 186         0x55,                /* pushw %bp */
 187         0x89,0xE5,           /* movw %sp,%bp */
 188         /* get return CS */
 189         0x8B,0x56,0x08,      /* movw 8(%bp),%dx */
 190         /* just call int 31 here to get into protected mode... */
 191         /* it'll check whether it was called from dpmi_seg... */
 192         0xCD,0x31,           /* int $0x31 */
 193         /* we are now in the context of a 16-bit relay call */
 194         /* need to fixup our stack;
 195          * 16-bit relay return address will be lost, but we won't worry quite yet */
 196         0x8E,0xD0,           /* movw %ax,%ss */
 197         0x66,0x0F,0xB7,0xE5, /* movzwl %bp,%esp */
 198         /* set return CS */
 199         0x89,0x56,0x08,      /* movw %dx,8(%bp) */
 200         0x5D,                /* popw %bp */
 201         0x5A,                /* popw %dx */
 202         0x58,                /* popw %ax */
 203         0xCB                 /* lret */
 204     };
 205
 206     ptr = DOSMEM_GetBlock( sizeof(wrap_code), &DOSMEM_dpmi_segments.wrap_seg );
 207     memcpy( ptr, wrap_code, sizeof(wrap_code) );
 208     ptr = DOSMEM_GetBlock( sizeof(enter_xms), &DOSMEM_dpmi_segments.xms_seg );
 209     memcpy( ptr, enter_xms, sizeof(enter_xms) );
 210     ptr = DOSMEM_GetBlock( sizeof(enter_pm), &DOSMEM_dpmi_segments.dpmi_seg );
 211     memcpy( ptr, enter_pm, sizeof(enter_pm) );
 212     DOSMEM_dpmi_segments.dpmi_sel = SELECTOR_AllocBlock( ptr, sizeof(enter_pm), WINE_LDT_FLAGS_CODE );
 213 }
 214
 215 static BIOSDATA * DOSMEM_BiosData(void)
 216 {
 217     return (BIOSDATA *)(DOSMEM_sysmem + 0x400);
 218 }
 219
 220
 221 /***********************************************************************
 222  *           DOSMEM_FillBiosSegments
 223  *
 224  * Fill the BIOS data segment with dummy values.
 225  */
 226 static void DOSMEM_FillBiosSegments(void)
 227 {
 228     BYTE *pBiosSys = DOSMEM_dosmem + 0xf0000;
 229     BYTE *pBiosROMTable = pBiosSys+0xe6f5;
 230     BIOS_EXTRA *extra = (BIOS_EXTRA *)(DOSMEM_dosmem + (int)BIOS_EXTRA_PTR);
 231     BIOSDATA *pBiosData = DOSMEM_BiosData();
 232
 233     /* Supported VESA mode, see int10.c */
 234     WORD ConstVesaModeList[]={0x00,0x01,0x02,0x03,0x07,0x0D,0x0E,0x10,0x12,0x13,
 235                               0x100,0x101,0x102,0x103,0x104,0x105,0x106,0x107,0x10D,0x10E,
 236                               0x10F,0x110,0x111,0x112,0x113,0x114,0x115,0x116,0x117,0x118,
 237                               0x119,0x11A,0x11B,0xFFFF};
 238     char * ConstVesaString = "WINE SVGA BOARD";
 239     int i;
 240
 241     VIDEOFUNCTIONALITY *pVidFunc = &extra->vid_func;
 242     VIDEOSTATE *pVidState = &extra->vid_state;
 243     VESAINFO *pVesaInfo = &extra->vesa_info;
 244     char * VesaString = extra->vesa_string;
 245     WORD * VesaModeList = extra->vesa_modes;
 246
 247       /* Clear all unused values */
 248     memset( pBiosData, 0, sizeof(*pBiosData) );
 249     memset( pVidFunc,  0, sizeof(*pVidFunc ) );
 250     memset( pVidState, 0, sizeof(*pVidState) );
 251     memset( pVesaInfo, 0, sizeof(*pVesaInfo) );
 252
 253     /* FIXME: should check the number of configured drives and ports */
 254     pBiosData->Com1Addr             = 0x3f8;
 255     pBiosData->Com2Addr             = 0x2f8;
 256     pBiosData->Lpt1Addr             = 0x378;
 257     pBiosData->Lpt2Addr             = 0x278;
 258     pBiosData->InstalledHardware    = 0x5463;
 259     pBiosData->MemSize              = 640;
 260     pBiosData->NextKbdCharPtr       = 0x1e;
 261     pBiosData->FirstKbdCharPtr      = 0x1e;
 262     pBiosData->VideoMode            = 3;
 263     pBiosData->VideoColumns         = 80;
 264     pBiosData->VideoPageSize        = 80 * 25 * 2;
 265     pBiosData->VideoPageStartAddr   = 0xb800;
 266     pBiosData->VideoCtrlAddr        = 0x3d4;
 267     pBiosData->Ticks                = INT1A_GetTicksSinceMidnight();
 268     pBiosData->NbHardDisks          = 2;
 269     pBiosData->KbdBufferStart       = 0x1e;
 270     pBiosData->KbdBufferEnd         = 0x3e;
 271     pBiosData->RowsOnScreenMinus1   = 24;
 272     pBiosData->BytesPerChar         = 0x10;
 273     pBiosData->ModeOptions          = 0x64;
 274     pBiosData->FeatureBitsSwitches  = 0xf9;
 275     pBiosData->VGASettings          = 0x51;
 276     pBiosData->DisplayCombination   = 0x08;
 277     pBiosData->DiskDataRate         = 0;
 278
 279     /* fill ROM configuration table (values from Award) */
 280     *(pBiosROMTable+0x0)        = 0x08; /* number of bytes following LO */
 281     *(pBiosROMTable+0x1)        = 0x00; /* number of bytes following HI */
 282     *(pBiosROMTable+0x2)        = 0xfc; /* model */
 283     *(pBiosROMTable+0x3)        = 0x01; /* submodel */
 284     *(pBiosROMTable+0x4)        = 0x00; /* BIOS revision */
 285     *(pBiosROMTable+0x5)        = 0x74; /* feature byte 1 */
 286     *(pBiosROMTable+0x6)        = 0x00; /* feature byte 2 */
 287     *(pBiosROMTable+0x7)        = 0x00; /* feature byte 3 */
 288     *(pBiosROMTable+0x8)        = 0x00; /* feature byte 4 */
 289     *(pBiosROMTable+0x9)        = 0x00; /* feature byte 5 */
 290
 291
 292     for (i = 0; i < 7; i++)
 293         pVidFunc->ModeSupport[i] = 0xff;
 294
 295     pVidFunc->ScanlineSupport     = 7;
 296     pVidFunc->NumberCharBlocks    = 0;
 297     pVidFunc->ActiveCharBlocks    = 0;
 298     pVidFunc->MiscFlags           = 0x8ff;
 299     pVidFunc->SavePointerFlags    = 0x3f;
 300
 301                                     /* FIXME: always real mode ? */
 302     pVidState->StaticFuncTable    = BIOS_EXTRA_SEGPTR + offsetof(BIOS_EXTRA,vid_func);
 303     pVidState->VideoMode          = pBiosData->VideoMode; /* needs updates! */
 304     pVidState->NumberColumns      = pBiosData->VideoColumns; /* needs updates! */
 305     pVidState->RegenBufLen        = 0;
 306     pVidState->RegenBufAddr       = 0;
 307
 308     for (i = 0; i < 8; i++)
 309         pVidState->CursorPos[i] = 0;
 310
 311     pVidState->CursorType         = 0x0a0b;  /* start/end line */
 312     pVidState->ActivePage         = 0;
 313     pVidState->CRTCPort           = 0x3da;
 314     pVidState->Port3x8            = 0;
 315     pVidState->Port3x9            = 0;
 316     pVidState->NumberRows         = 23;     /* number of rows - 1 */
 317     pVidState->BytesPerChar       = 0x10;
 318     pVidState->DCCActive          = pBiosData->DisplayCombination;
 319     pVidState->DCCAlternate       = 0;
 320     pVidState->NumberColors       = 16;
 321     pVidState->NumberPages        = 1;
 322     pVidState->NumberScanlines    = 3; /* (0,1,2,3) = (200,350,400,480) */
 323     pVidState->CharBlockPrimary   = 0;
 324     pVidState->CharBlockSecondary = 0;
 325     pVidState->MiscFlags =
 326                            (pBiosData->VGASettings & 0x0f)
 327                          | ((pBiosData->ModeOptions & 1) << 4); /* cursor emulation */
 328     pVidState->NonVGASupport      = 0;
 329     pVidState->VideoMem           = (pBiosData->ModeOptions & 0x60 >> 5);
 330     pVidState->SavePointerState   = 0;
 331     pVidState->DisplayStatus      = 4;
 332
 333     /* SVGA structures */
 334     pVesaInfo->Signature          = *(DWORD*)"VESA";
 335     pVesaInfo->Major              = 2;
 336     pVesaInfo->Minor              = 0;
 337                                     /* FIXME: always real mode ? */
 338     pVesaInfo->StaticVendorString = BIOS_EXTRA_SEGPTR + offsetof(BIOS_EXTRA,vesa_string);
 339     pVesaInfo->CapabilitiesFlags  = 0xfffffffd; /* FIXME: not really supported */
 340                                     /* FIXME: always real mode ? */
 341     pVesaInfo->StaticModeList     = BIOS_EXTRA_SEGPTR + offsetof(BIOS_EXTRA,vesa_modes);
 342
 343     strcpy(VesaString,ConstVesaString);
 344     memcpy(VesaModeList,ConstVesaModeList,sizeof(ConstVesaModeList));
 345
 346     /* BIOS date string */
 347     strcpy((char *)pBiosSys+0xfff5, "13/01/99");
 348
 349     /* BIOS ID */
 350     *(pBiosSys+0xfffe) = 0xfc;
 351 }
 352
 353 /***********************************************************************
 354  *           DOSMEM_InitCollateTable
 355  *
 356  * Initialises the collate table (character sorting, language dependent)
 357  */
 358 static void DOSMEM_InitCollateTable()
 359 {
 360         DWORD           x;
 361         unsigned char   *tbl;
 362         int             i;
 363
 364         x = GlobalDOSAlloc16(258);
 365         DOSMEM_CollateTable = MAKELONG(0,(x>>16));
 366         tbl = DOSMEM_MapRealToLinear(DOSMEM_CollateTable);
 367         *(WORD*)tbl     = 0x100;
 368         tbl += 2;
 369         for ( i = 0; i < 0x100; i++) *tbl++ = i;
 370 }
 371
 372 /***********************************************************************
 373  *           DOSMEM_InitErrorTable
 374  *
 375  * Initialises the error tables (DOS 5+)
 376  */
 377 static void DOSMEM_InitErrorTable()
 378 {
 379 #if 0  /* no longer used */
 380         DWORD           x;
 381         char            *call;
 382
 383         /* We will use a snippet of real mode code that calls */
 384         /* a WINE-only interrupt to handle moving the requested */
 385         /* message into the buffer... */
 386
 387         /* FIXME - There is still something wrong... */
 388
 389         /* FIXME - Find hex values for opcodes...
 390
 391            (On call, AX contains message number
 392                      DI contains 'offset' (??)
 393             Resturn, ES:DI points to counted string )
 394
 395            PUSH BX
 396            MOV BX, AX
 397            MOV AX, (arbitrary subfunction number)
 398            INT (WINE-only interrupt)
 399            POP BX
 400            RET
 401
 402         */
 403
 404         const int       code = 4;
 405         const int       buffer = 80;
 406         const int       SIZE_TO_ALLOCATE = code + buffer;
 407
 408         /* FIXME - Complete rewrite of the table system to save */
 409         /* precious DOS space. Now, we return the 0001:???? as */
 410         /* DOS 4+ (??, it seems to be the case in MS 7.10) treats that */
 411         /* as a special case and programs will use the alternate */
 412         /* interface (a farcall returned with INT 24 (AX = 0x122e, DL = */
 413         /* 0x08) which lets us have a smaller memory footprint anyway. */
 414
 415         x = GlobalDOSAlloc16(SIZE_TO_ALLOCATE);
 416
 417         DOSMEM_ErrorCall = MAKELONG(0,(x>>16));
 418         DOSMEM_ErrorBuffer = DOSMEM_ErrorCall + code;
 419
 420         call = DOSMEM_MapRealToLinear(DOSMEM_ErrorCall);
 421
 422         memset(call, 0, SIZE_TO_ALLOCATE);
 423 #endif
 424         /* FIXME - Copy assembly into buffer here */
 425 }
 426
 427 /***********************************************************************
 428  *           DOSMEM_InitMemory
 429  *
 430  * Initialises the DOS memory structures.
 431  */
 432 static void DOSMEM_InitMemory(void)
 433 {
 434    /* Low 64Kb are reserved for DOS/BIOS so the useable area starts at
 435     * 1000:0000 and ends at 9FFF:FFEF. */
 436
 437     dosmem_info*        info_block = DOSMEM_InfoBlock();
 438     dosmem_entry*       root_block = DOSMEM_RootBlock();
 439     dosmem_entry*       dm;
 440
 441     root_block->size = DOSMEM_MemoryTop() - (((char*)root_block) + sizeof(dosmem_entry));
 442
 443     info_block->blocks = 0;
 444     info_block->free = root_block->size;
 445
 446     dm = NEXT_BLOCK(root_block);
 447     dm->size = DM_BLOCK_TERMINAL;
 448     root_block->size |= DM_BLOCK_FREE
 449 #ifdef __DOSMEM_DEBUG__
 450                      | DM_BLOCK_DEBUG
 451 #endif
 452                      ;
 453 }
 454
 455 /**********************************************************************
 456  *              setup_dos_mem
 457  *
 458  * Setup the first megabyte for DOS memory access
 459  */
 460 static void setup_dos_mem( int dos_init )
 461 {
 462     int sys_offset = 0;
 463     int page_size = getpagesize();
 464     void *addr = wine_anon_mmap( (void *)page_size, 0x110000-page_size,
 465                                  PROT_READ | PROT_WRITE | PROT_EXEC, 0 );
 466     if (addr == (void *)page_size)  /* we got what we wanted */
 467     {
 468         /* now map from address 0 */
 469         addr = wine_anon_mmap( NULL, 0x110000, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_FIXED );
 470         if (addr)
 471         {
 472             ERR("MAP_FIXED failed at address 0 for DOS address space\n" );
 473             ExitProcess(1);
 474         }
 475
 476         /* inform the memory manager that there is a mapping here */
 477         VirtualAlloc( addr, 0x110000, MEM_RESERVE | MEM_SYSTEM, PAGE_EXECUTE_READWRITE );
 478
 479         /* protect the first 64K to catch NULL pointers */
 480         if (!dos_init)
 481         {
 482             VirtualProtect( addr, 0x10000, PAGE_NOACCESS, NULL );
 483             /* move the BIOS and ISR area from 0x00000 to 0xf0000 */
 484             sys_offset += 0xf0000;
 485         }
 486     }
 487     else
 488     {
 489         ERR("Cannot use first megabyte for DOS address space, please report\n" );
 490         if (dos_init) ExitProcess(1);
 491         /* allocate the DOS area somewhere else */
 492         addr = VirtualAlloc( NULL, 0x110000, MEM_COMMIT, PAGE_EXECUTE_READWRITE );
 493         if (!addr)
 494         {
 495             ERR( "Cannot allocate DOS memory\n" );
 496             ExitProcess(1);
 497         }
 498     }
 499     DOSMEM_dosmem = addr;
 500     DOSMEM_sysmem = (char*)addr + sys_offset;
 501 }
 502
 503
 504 /***********************************************************************
 505  *           DOSMEM_Init
 506  *
 507  * Create the dos memory segments, and store them into the KERNEL
 508  * exported values.
 509  */
 510 BOOL DOSMEM_Init(BOOL dos_init)
 511 {
 512     static int already_done, already_mapped;
 513
 514     if (!already_done)
 515     {
 516         setup_dos_mem( dos_init );
 517
 518         DOSMEM_0000H = GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_sysmem,
 519                                            0x10000, 0, WINE_LDT_FLAGS_DATA );
 520         DOSMEM_BiosDataSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_sysmem + 0x400,
 521                                                 0x100, 0, WINE_LDT_FLAGS_DATA );
 522         DOSMEM_BiosSysSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0xf0000,
 523                                                0x10000, 0, WINE_LDT_FLAGS_DATA );
 524         DOSMEM_FillBiosSegments();
 525         DOSMEM_FillIsrTable();
 526         DOSMEM_InitMemory();
 527         DOSMEM_InitCollateTable();
 528         DOSMEM_InitErrorTable();
 529         DOSMEM_InitDPMI();
 530         already_done = 1;
 531     }
 532     else if (dos_init && !already_mapped)
 533     {
 534         if (DOSMEM_dosmem)
 535         {
 536             ERR( "Needs access to the first megabyte for DOS mode\n" );
 537             ExitProcess(1);
 538         }
 539         MESSAGE( "Warning: unprotecting the first 64KB of memory to allow real-mode calls.\n"
 540                  "         NULL pointer accesses will no longer be caught.\n" );
 541         VirtualProtect( NULL, 0x10000, PAGE_EXECUTE_READWRITE, NULL );
 542         /* copy the BIOS and ISR area down */
 543         memcpy( DOSMEM_dosmem, DOSMEM_sysmem, 0x400 + 0x100 );
 544         DOSMEM_sysmem = DOSMEM_dosmem;
 545         SetSelectorBase( DOSMEM_0000H, 0 );
 546         SetSelectorBase( DOSMEM_BiosDataSeg, 0x400 );
 547         /* we may now need the actual interrupt stubs, and since we've just moved the
 548          * interrupt vector table away, we can fill the area with stubs instead... */
 549         DOSMEM_MakeIsrStubs();
 550         already_mapped = 1;
 551     }
 552     return TRUE;
 553 }
 554
 555
 556 /***********************************************************************
 557  *           DOSMEM_Tick
 558  *
 559  * Increment the BIOS tick counter. Called by timer signal handler.
 560  */
 561 void DOSMEM_Tick( WORD timer )
 562 {
 563     BIOSDATA *pBiosData = DOSMEM_BiosData();
 564     if (pBiosData) pBiosData->Ticks++;
 565 }
 566
 567 /***********************************************************************
 568  *           DOSMEM_GetBlock
 569  *
 570  * Carve a chunk of the DOS memory block (without selector).
 571  */
 572 LPVOID DOSMEM_GetBlock(UINT size, UINT16* pseg)
 573 {
 574    UINT          blocksize;
 575    char         *block = NULL;
 576    dosmem_info  *info_block = DOSMEM_InfoBlock();
 577    dosmem_entry *dm;
 578 #ifdef __DOSMEM_DEBUG_
 579    dosmem_entry *prev = NULL;
 580 #endif
 581
 582    if( size > info_block->free ) return NULL;
 583    dm = DOSMEM_RootBlock();
 584
 585    while (dm && dm->size != DM_BLOCK_TERMINAL)
 586    {
 587 #ifdef __DOSMEM_DEBUG__
 588        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 589        {
 590             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 591             return NULL;
 592        }
 593        prev = dm;
 594 #endif
 595        if( dm->size & DM_BLOCK_FREE )
 596        {
 597            dosmem_entry  *next = NEXT_BLOCK(dm);
 598
 599            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 600            {
 601                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 602                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 603                next = NEXT_BLOCK(dm);
 604            }
 605
 606            blocksize = dm->size & DM_BLOCK_MASK;
 607            if( blocksize >= size )
 608            {
 609                block = ((char*)dm) + sizeof(dosmem_entry);
 610                if( blocksize - size > 0x20 )
 611                {
 612                    /* split dm so that the next one stays
 613                     * paragraph-aligned (and dm loses free bit) */
 614
 615                    dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 616                                               sizeof(dosmem_entry));
 617                    next = (dosmem_entry*)(((char*)dm) +
 618                            sizeof(dosmem_entry) + dm->size);
 619                    next->size = (blocksize - (dm->size +
 620                            sizeof(dosmem_entry))) | DM_BLOCK_FREE
 621 #ifdef __DOSMEM_DEBUG__
 622                                                   | DM_BLOCK_DEBUG
 623 #endif
 624                                                   ;
 625                } else dm->size &= DM_BLOCK_MASK;
 626
 627                info_block->blocks++;
 628                info_block->free -= dm->size;
 629                if( pseg ) *pseg = (block - DOSMEM_dosmem) >> 4;
 630 #ifdef __DOSMEM_DEBUG__
 631                dm->size |= DM_BLOCK_DEBUG;
 632 #endif
 633                break;
 634            }
 635            dm = next;
 636        }
 637        else dm = NEXT_BLOCK(dm);
 638    }
 639    return (LPVOID)block;
 640 }
 641
 642 /***********************************************************************
 643  *           DOSMEM_FreeBlock
 644  */
 645 BOOL DOSMEM_FreeBlock(void* ptr)
 646 {
 647    dosmem_info  *info_block = DOSMEM_InfoBlock();
 648
 649    if( ptr >= (void*)(((char*)DOSMEM_RootBlock()) + sizeof(dosmem_entry)) &&
 650        ptr < (void*)DOSMEM_MemoryTop() && !((((char*)ptr)
 651                   - DOSMEM_dosmem) & 0xf) )
 652    {
 653        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 654
 655        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 656 #ifdef __DOSMEM_DEBUG__
 657          && ((dm->size & DM_BLOCK_DEBUG) == DM_BLOCK_DEBUG )
 658 #endif
 659          )
 660        {
 661              info_block->blocks--;
 662              info_block->free += dm->size;
 663
 664              dm->size |= DM_BLOCK_FREE;
 665              return TRUE;
 666        }
 667    }
 668    return FALSE;
 669 }
 670
 671 /***********************************************************************
 672  *           DOSMEM_ResizeBlock
 673  */
 674 LPVOID DOSMEM_ResizeBlock(void* ptr, UINT size, UINT16* pseg)
 675 {
 676    char         *block = NULL;
 677    dosmem_info  *info_block = DOSMEM_InfoBlock();
 678
 679    if( ptr >= (void*)(((char*)DOSMEM_RootBlock()) + sizeof(dosmem_entry)) &&
 680        ptr < (void*)DOSMEM_MemoryTop() && !((((char*)ptr)
 681                   - DOSMEM_dosmem) & 0xf) )
 682    {
 683        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 684
 685        if( pseg ) *pseg = ((char*)ptr - DOSMEM_dosmem) >> 4;
 686
 687        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 688          )
 689        {
 690              dosmem_entry  *next = NEXT_BLOCK(dm);
 691              UINT blocksize, orgsize = dm->size & DM_BLOCK_MASK;
 692
 693              while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 694              {
 695                  dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 696                  next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 697                  next = NEXT_BLOCK(dm);
 698              }
 699
 700              blocksize = dm->size & DM_BLOCK_MASK;
 701              if (blocksize >= size)
 702              {
 703                  block = ((char*)dm) + sizeof(dosmem_entry);
 704                  if( blocksize - size > 0x20 )
 705                  {
 706                      /* split dm so that the next one stays
 707                       * paragraph-aligned (and next gains free bit) */
 708
 709                      dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 710                                                 sizeof(dosmem_entry));
 711                      next = (dosmem_entry*)(((char*)dm) +
 712                              sizeof(dosmem_entry) + dm->size);
 713                      next->size = (blocksize - (dm->size +
 714                              sizeof(dosmem_entry))) | DM_BLOCK_FREE
 715                                                     ;
 716                  } else dm->size &= DM_BLOCK_MASK;
 717
 718                  info_block->free += orgsize - dm->size;
 719              } else {
 720                  /* the collapse didn't help, try getting a new block */
 721                  block = DOSMEM_GetBlock(size, pseg);
 722                  if (block) {
 723                      /* we got one, copy the old data there (we do need to, right?) */
 724                      memcpy(block, ((char*)dm) + sizeof(dosmem_entry),
 725                                    (size<orgsize) ? size : orgsize);
 726                      /* free old block */
 727                      info_block->blocks--;
 728                      info_block->free += dm->size;
 729
 730                      dm->size |= DM_BLOCK_FREE;
 731                  } else {
 732                      /* and Bill Gates said 640K should be enough for everyone... */
 733
 734                      /* need to split original and collapsed blocks apart again,
 735                       * and free the collapsed blocks again, before exiting */
 736                      if( blocksize - orgsize > 0x20 )
 737                      {
 738                          /* split dm so that the next one stays
 739                           * paragraph-aligned (and next gains free bit) */
 740
 741                          dm->size = (((orgsize + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 742                                                        sizeof(dosmem_entry));
 743                          next = (dosmem_entry*)(((char*)dm) +
 744                                  sizeof(dosmem_entry) + dm->size);
 745                          next->size = (blocksize - (dm->size +
 746                                  sizeof(dosmem_entry))) | DM_BLOCK_FREE
 747                                                         ;
 748                      } else dm->size &= DM_BLOCK_MASK;
 749                  }
 750              }
 751        }
 752    }
 753    return (LPVOID)block;
 754 }
 755
 756
 757 /***********************************************************************
 758  *           DOSMEM_Available
 759  */
 760 UINT DOSMEM_Available(void)
 761 {
 762    UINT          blocksize, available = 0;
 763    dosmem_entry *dm;
 764
 765    dm = DOSMEM_RootBlock();
 766
 767    while (dm && dm->size != DM_BLOCK_TERMINAL)
 768    {
 769 #ifdef __DOSMEM_DEBUG__
 770        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 771        {
 772             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 773             return NULL;
 774        }
 775        prev = dm;
 776 #endif
 777        if( dm->size & DM_BLOCK_FREE )
 778        {
 779            dosmem_entry  *next = NEXT_BLOCK(dm);
 780
 781            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 782            {
 783                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 784                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 785                next = NEXT_BLOCK(dm);
 786            }
 787
 788            blocksize = dm->size & DM_BLOCK_MASK;
 789            if ( blocksize > available ) available = blocksize;
 790            dm = next;
 791        }
 792        else dm = NEXT_BLOCK(dm);
 793    }
 794    return available;
 795 }
 796
 797
 798 /***********************************************************************
 799  *           DOSMEM_MapLinearToDos
 800  *
 801  * Linear address to the DOS address space.
 802  */
 803 UINT DOSMEM_MapLinearToDos(LPVOID ptr)
 804 {
 805     if (((char*)ptr >= DOSMEM_dosmem) &&
 806         ((char*)ptr < DOSMEM_dosmem + 0x100000))
 807           return (UINT)ptr - (UINT)DOSMEM_dosmem;
 808     return (UINT)ptr;
 809 }
 810
 811
 812 /***********************************************************************
 813  *           DOSMEM_MapDosToLinear
 814  *
 815  * DOS linear address to the linear address space.
 816  */
 817 LPVOID DOSMEM_MapDosToLinear(UINT ptr)
 818 {
 819     if (ptr < 0x100000) return (LPVOID)(ptr + (UINT)DOSMEM_dosmem);
 820     return (LPVOID)ptr;
 821 }
 822
 823
 824 /***********************************************************************
 825  *           DOSMEM_MapRealToLinear
 826  *
 827  * Real mode DOS address into a linear pointer
 828  */
 829 LPVOID DOSMEM_MapRealToLinear(DWORD x)
 830 {
 831    LPVOID       lin;
 832
 833    lin=DOSMEM_dosmem+(x&0xffff)+(((x&0xffff0000)>>16)*16);
 834    TRACE_(selector)("(0x%08lx) returns %p.\n", x, lin );
 835    return lin;
 836 }
 837
 838 /***********************************************************************
 839  *           DOSMEM_AllocSelector
 840  *
 841  * Allocates a protected mode selector for a realmode segment.
 842  */
 843 WORD DOSMEM_AllocSelector(WORD realsel)
 844 {
 845         HMODULE16 hModule = GetModuleHandle16("KERNEL");
 846         WORD    sel;
 847
 848         sel=GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_dosmem+realsel*16, 0x10000,
 849                                 hModule, WINE_LDT_FLAGS_DATA );
 850         TRACE_(selector)("(0x%04x) returns 0x%04x.\n", realsel,sel);
 851         return sel;
 852 }