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     int   i;
 165
 166     static const char wrap_code[]={
 167      0xCD,0x31, /* int $0x31 */
 168      0xCB       /* lret */
 169     };
 170
 171     static const char enter_xms[]=
 172     {
 173         /* XMS hookable entry point */
 174         0xEB,0x03,           /* jmp entry */
 175         0x90,0x90,0x90,      /* nop;nop;nop */
 176                              /* entry: */
 177         /* real entry point */
 178         /* for simplicity, we'll just use the same hook as DPMI below */
 179         0xCD,0x31,           /* int $0x31 */
 180         0xCB                 /* lret */
 181     };
 182
 183     static const char enter_pm[]=
 184     {
 185         0x50,                /* pushw %ax */
 186         0x52,                /* pushw %dx */
 187         0x55,                /* pushw %bp */
 188         0x89,0xE5,           /* movw %sp,%bp */
 189         /* get return CS */
 190         0x8B,0x56,0x08,      /* movw 8(%bp),%dx */
 191         /* just call int 31 here to get into protected mode... */
 192         /* it'll check whether it was called from dpmi_seg... */
 193         0xCD,0x31,           /* int $0x31 */
 194         /* we are now in the context of a 16-bit relay call */
 195         /* need to fixup our stack;
 196          * 16-bit relay return address will be lost, but we won't worry quite yet */
 197         0x8E,0xD0,           /* movw %ax,%ss */
 198         0x66,0x0F,0xB7,0xE5, /* movzwl %bp,%esp */
 199         /* set return CS */
 200         0x89,0x56,0x08,      /* movw %dx,8(%bp) */
 201         0x5D,                /* popw %bp */
 202         0x5A,                /* popw %dx */
 203         0x58,                /* popw %ax */
 204         0xCB                 /* lret */
 205     };
 206
 207     ptr = DOSMEM_GetBlock( sizeof(wrap_code), &DOSMEM_dpmi_segments.wrap_seg );
 208     memcpy( ptr, wrap_code, sizeof(wrap_code) );
 209     ptr = DOSMEM_GetBlock( sizeof(enter_xms), &DOSMEM_dpmi_segments.xms_seg );
 210     memcpy( ptr, enter_xms, sizeof(enter_xms) );
 211     ptr = DOSMEM_GetBlock( sizeof(enter_pm), &DOSMEM_dpmi_segments.dpmi_seg );
 212     memcpy( ptr, enter_pm, sizeof(enter_pm) );
 213     DOSMEM_dpmi_segments.dpmi_sel = SELECTOR_AllocBlock( ptr, sizeof(enter_pm), WINE_LDT_FLAGS_CODE );
 214
 215     ptr = DOSMEM_GetBlock( 4 * 256, &DOSMEM_dpmi_segments.int48_seg );
 216     for(i=0; i<256; i++) {
 217         /*
 218          * Each 32-bit interrupt handler is 4 bytes:
 219          * 0xCD,<i>  = int <i> (nested 16-bit interrupt)
 220          * 0x66,0xCF = iretd   (32-bit interrupt return)
 221          */
 222         ptr[i * 4 + 0] = 0xCD;
 223         ptr[i * 4 + 1] = i;
 224         ptr[i * 4 + 2] = 0x66;
 225         ptr[i * 4 + 3] = 0xCF;
 226     }
 227     DOSMEM_dpmi_segments.int48_sel = SELECTOR_AllocBlock( ptr, 4 * 256, WINE_LDT_FLAGS_CODE );
 228 }
 229
 230 static BIOSDATA * DOSMEM_BiosData(void)
 231 {
 232     return (BIOSDATA *)(DOSMEM_sysmem + 0x400);
 233 }
 234
 235
 236 /***********************************************************************
 237  *           DOSMEM_FillBiosSegments
 238  *
 239  * Fill the BIOS data segment with dummy values.
 240  */
 241 static void DOSMEM_FillBiosSegments(void)
 242 {
 243     BYTE *pBiosSys = DOSMEM_dosmem + 0xf0000;
 244     BYTE *pBiosROMTable = pBiosSys+0xe6f5;
 245     BIOS_EXTRA *extra = (BIOS_EXTRA *)(DOSMEM_dosmem + (int)BIOS_EXTRA_PTR);
 246     BIOSDATA *pBiosData = DOSMEM_BiosData();
 247
 248     /* Supported VESA mode, see int10.c */
 249     WORD ConstVesaModeList[]={0x00,0x01,0x02,0x03,0x07,0x0D,0x0E,0x10,0x12,0x13,
 250                               0x100,0x101,0x102,0x103,0x104,0x105,0x106,0x107,0x10D,0x10E,
 251                               0x10F,0x110,0x111,0x112,0x113,0x114,0x115,0x116,0x117,0x118,
 252                               0x119,0x11A,0x11B,0xFFFF};
 253     char * ConstVesaString = "WINE SVGA BOARD";
 254     int i;
 255
 256     VIDEOFUNCTIONALITY *pVidFunc = &extra->vid_func;
 257     VIDEOSTATE *pVidState = &extra->vid_state;
 258     VESAINFO *pVesaInfo = &extra->vesa_info;
 259     char * VesaString = extra->vesa_string;
 260     WORD * VesaModeList = extra->vesa_modes;
 261
 262       /* Clear all unused values */
 263     memset( pBiosData, 0, sizeof(*pBiosData) );
 264     memset( pVidFunc,  0, sizeof(*pVidFunc ) );
 265     memset( pVidState, 0, sizeof(*pVidState) );
 266     memset( pVesaInfo, 0, sizeof(*pVesaInfo) );
 267
 268     /* FIXME: should check the number of configured drives and ports */
 269     pBiosData->Com1Addr             = 0x3f8;
 270     pBiosData->Com2Addr             = 0x2f8;
 271     pBiosData->Lpt1Addr             = 0x378;
 272     pBiosData->Lpt2Addr             = 0x278;
 273     pBiosData->InstalledHardware    = 0x5463;
 274     pBiosData->MemSize              = 640;
 275     pBiosData->NextKbdCharPtr       = 0x1e;
 276     pBiosData->FirstKbdCharPtr      = 0x1e;
 277     pBiosData->VideoMode            = 3;
 278     pBiosData->VideoColumns         = 80;
 279     pBiosData->VideoPageSize        = 80 * 25 * 2;
 280     pBiosData->VideoPageStartAddr   = 0xb800;
 281     pBiosData->VideoCtrlAddr        = 0x3d4;
 282     pBiosData->Ticks                = INT1A_GetTicksSinceMidnight();
 283     pBiosData->NbHardDisks          = 2;
 284     pBiosData->KbdBufferStart       = 0x1e;
 285     pBiosData->KbdBufferEnd         = 0x3e;
 286     pBiosData->RowsOnScreenMinus1   = 24;
 287     pBiosData->BytesPerChar         = 0x10;
 288     pBiosData->ModeOptions          = 0x64;
 289     pBiosData->FeatureBitsSwitches  = 0xf9;
 290     pBiosData->VGASettings          = 0x51;
 291     pBiosData->DisplayCombination   = 0x08;
 292     pBiosData->DiskDataRate         = 0;
 293
 294     /* fill ROM configuration table (values from Award) */
 295     *(pBiosROMTable+0x0)        = 0x08; /* number of bytes following LO */
 296     *(pBiosROMTable+0x1)        = 0x00; /* number of bytes following HI */
 297     *(pBiosROMTable+0x2)        = 0xfc; /* model */
 298     *(pBiosROMTable+0x3)        = 0x01; /* submodel */
 299     *(pBiosROMTable+0x4)        = 0x00; /* BIOS revision */
 300     *(pBiosROMTable+0x5)        = 0x74; /* feature byte 1 */
 301     *(pBiosROMTable+0x6)        = 0x00; /* feature byte 2 */
 302     *(pBiosROMTable+0x7)        = 0x00; /* feature byte 3 */
 303     *(pBiosROMTable+0x8)        = 0x00; /* feature byte 4 */
 304     *(pBiosROMTable+0x9)        = 0x00; /* feature byte 5 */
 305
 306
 307     for (i = 0; i < 7; i++)
 308         pVidFunc->ModeSupport[i] = 0xff;
 309
 310     pVidFunc->ScanlineSupport     = 7;
 311     pVidFunc->NumberCharBlocks    = 0;
 312     pVidFunc->ActiveCharBlocks    = 0;
 313     pVidFunc->MiscFlags           = 0x8ff;
 314     pVidFunc->SavePointerFlags    = 0x3f;
 315
 316                                     /* FIXME: always real mode ? */
 317     pVidState->StaticFuncTable    = BIOS_EXTRA_SEGPTR + offsetof(BIOS_EXTRA,vid_func);
 318     pVidState->VideoMode          = pBiosData->VideoMode; /* needs updates! */
 319     pVidState->NumberColumns      = pBiosData->VideoColumns; /* needs updates! */
 320     pVidState->RegenBufLen        = 0;
 321     pVidState->RegenBufAddr       = 0;
 322
 323     for (i = 0; i < 8; i++)
 324         pVidState->CursorPos[i] = 0;
 325
 326     pVidState->CursorType         = 0x0a0b;  /* start/end line */
 327     pVidState->ActivePage         = 0;
 328     pVidState->CRTCPort           = 0x3da;
 329     pVidState->Port3x8            = 0;
 330     pVidState->Port3x9            = 0;
 331     pVidState->NumberRows         = 23;     /* number of rows - 1 */
 332     pVidState->BytesPerChar       = 0x10;
 333     pVidState->DCCActive          = pBiosData->DisplayCombination;
 334     pVidState->DCCAlternate       = 0;
 335     pVidState->NumberColors       = 16;
 336     pVidState->NumberPages        = 1;
 337     pVidState->NumberScanlines    = 3; /* (0,1,2,3) = (200,350,400,480) */
 338     pVidState->CharBlockPrimary   = 0;
 339     pVidState->CharBlockSecondary = 0;
 340     pVidState->MiscFlags =
 341                            (pBiosData->VGASettings & 0x0f)
 342                          | ((pBiosData->ModeOptions & 1) << 4); /* cursor emulation */
 343     pVidState->NonVGASupport      = 0;
 344     pVidState->VideoMem           = (pBiosData->ModeOptions & 0x60 >> 5);
 345     pVidState->SavePointerState   = 0;
 346     pVidState->DisplayStatus      = 4;
 347
 348     /* SVGA structures */
 349     pVesaInfo->Signature          = *(DWORD*)"VESA";
 350     pVesaInfo->Major              = 2;
 351     pVesaInfo->Minor              = 0;
 352                                     /* FIXME: always real mode ? */
 353     pVesaInfo->StaticVendorString = BIOS_EXTRA_SEGPTR + offsetof(BIOS_EXTRA,vesa_string);
 354     pVesaInfo->CapabilitiesFlags  = 0xfffffffd; /* FIXME: not really supported */
 355                                     /* FIXME: always real mode ? */
 356     pVesaInfo->StaticModeList     = BIOS_EXTRA_SEGPTR + offsetof(BIOS_EXTRA,vesa_modes);
 357
 358     strcpy(VesaString,ConstVesaString);
 359     memcpy(VesaModeList,ConstVesaModeList,sizeof(ConstVesaModeList));
 360
 361     /* BIOS date string */
 362     strcpy((char *)pBiosSys+0xfff5, "13/01/99");
 363
 364     /* BIOS ID */
 365     *(pBiosSys+0xfffe) = 0xfc;
 366 }
 367
 368 /***********************************************************************
 369  *           DOSMEM_InitCollateTable
 370  *
 371  * Initialises the collate table (character sorting, language dependent)
 372  */
 373 static void DOSMEM_InitCollateTable()
 374 {
 375         DWORD           x;
 376         unsigned char   *tbl;
 377         int             i;
 378
 379         x = GlobalDOSAlloc16(258);
 380         DOSMEM_CollateTable = MAKELONG(0,(x>>16));
 381         tbl = DOSMEM_MapRealToLinear(DOSMEM_CollateTable);
 382         *(WORD*)tbl     = 0x100;
 383         tbl += 2;
 384         for ( i = 0; i < 0x100; i++) *tbl++ = i;
 385 }
 386
 387 /***********************************************************************
 388  *           DOSMEM_InitErrorTable
 389  *
 390  * Initialises the error tables (DOS 5+)
 391  */
 392 static void DOSMEM_InitErrorTable()
 393 {
 394 #if 0  /* no longer used */
 395         DWORD           x;
 396         char            *call;
 397
 398         /* We will use a snippet of real mode code that calls */
 399         /* a WINE-only interrupt to handle moving the requested */
 400         /* message into the buffer... */
 401
 402         /* FIXME - There is still something wrong... */
 403
 404         /* FIXME - Find hex values for opcodes...
 405
 406            (On call, AX contains message number
 407                      DI contains 'offset' (??)
 408             Resturn, ES:DI points to counted string )
 409
 410            PUSH BX
 411            MOV BX, AX
 412            MOV AX, (arbitrary subfunction number)
 413            INT (WINE-only interrupt)
 414            POP BX
 415            RET
 416
 417         */
 418
 419         const int       code = 4;
 420         const int       buffer = 80;
 421         const int       SIZE_TO_ALLOCATE = code + buffer;
 422
 423         /* FIXME - Complete rewrite of the table system to save */
 424         /* precious DOS space. Now, we return the 0001:???? as */
 425         /* DOS 4+ (??, it seems to be the case in MS 7.10) treats that */
 426         /* as a special case and programs will use the alternate */
 427         /* interface (a farcall returned with INT 24 (AX = 0x122e, DL = */
 428         /* 0x08) which lets us have a smaller memory footprint anyway. */
 429
 430         x = GlobalDOSAlloc16(SIZE_TO_ALLOCATE);
 431
 432         DOSMEM_ErrorCall = MAKELONG(0,(x>>16));
 433         DOSMEM_ErrorBuffer = DOSMEM_ErrorCall + code;
 434
 435         call = DOSMEM_MapRealToLinear(DOSMEM_ErrorCall);
 436
 437         memset(call, 0, SIZE_TO_ALLOCATE);
 438 #endif
 439         /* FIXME - Copy assembly into buffer here */
 440 }
 441
 442 /***********************************************************************
 443  *           DOSMEM_InitMemory
 444  *
 445  * Initialises the DOS memory structures.
 446  */
 447 static void DOSMEM_InitMemory(void)
 448 {
 449    /* Low 64Kb are reserved for DOS/BIOS so the useable area starts at
 450     * 1000:0000 and ends at 9FFF:FFEF. */
 451
 452     dosmem_info*        info_block = DOSMEM_InfoBlock();
 453     dosmem_entry*       root_block = DOSMEM_RootBlock();
 454     dosmem_entry*       dm;
 455
 456     root_block->size = DOSMEM_MemoryTop() - (((char*)root_block) + sizeof(dosmem_entry));
 457
 458     info_block->blocks = 0;
 459     info_block->free = root_block->size;
 460
 461     dm = NEXT_BLOCK(root_block);
 462     dm->size = DM_BLOCK_TERMINAL;
 463     root_block->size |= DM_BLOCK_FREE
 464 #ifdef __DOSMEM_DEBUG__
 465                      | DM_BLOCK_DEBUG
 466 #endif
 467                      ;
 468 }
 469
 470 /**********************************************************************
 471  *              setup_dos_mem
 472  *
 473  * Setup the first megabyte for DOS memory access
 474  */
 475 static void setup_dos_mem( int dos_init )
 476 {
 477     int sys_offset = 0;
 478     int page_size = getpagesize();
 479     void *addr = wine_anon_mmap( (void *)page_size, 0x110000-page_size,
 480                                  PROT_READ | PROT_WRITE | PROT_EXEC, 0 );
 481     if (addr == (void *)page_size)  /* we got what we wanted */
 482     {
 483         /* now map from address 0 */
 484         addr = wine_anon_mmap( NULL, 0x110000, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_FIXED );
 485         if (addr)
 486         {
 487             ERR("MAP_FIXED failed at address 0 for DOS address space\n" );
 488             ExitProcess(1);
 489         }
 490
 491         /* inform the memory manager that there is a mapping here */
 492         VirtualAlloc( addr, 0x110000, MEM_RESERVE | MEM_SYSTEM, PAGE_EXECUTE_READWRITE );
 493
 494         /* protect the first 64K to catch NULL pointers */
 495         if (!dos_init)
 496         {
 497             VirtualProtect( addr, 0x10000, PAGE_NOACCESS, NULL );
 498             /* move the BIOS and ISR area from 0x00000 to 0xf0000 */
 499             sys_offset += 0xf0000;
 500         }
 501     }
 502     else
 503     {
 504         ERR("Cannot use first megabyte for DOS address space, please report\n" );
 505         if (dos_init) ExitProcess(1);
 506         /* allocate the DOS area somewhere else */
 507         addr = VirtualAlloc( NULL, 0x110000, MEM_COMMIT, PAGE_EXECUTE_READWRITE );
 508         if (!addr)
 509         {
 510             ERR( "Cannot allocate DOS memory\n" );
 511             ExitProcess(1);
 512         }
 513     }
 514     DOSMEM_dosmem = addr;
 515     DOSMEM_sysmem = (char*)addr + sys_offset;
 516 }
 517
 518
 519 /***********************************************************************
 520  *           DOSMEM_Init
 521  *
 522  * Create the dos memory segments, and store them into the KERNEL
 523  * exported values.
 524  */
 525 BOOL DOSMEM_Init(BOOL dos_init)
 526 {
 527     static int already_done, already_mapped;
 528
 529     if (!already_done)
 530     {
 531         setup_dos_mem( dos_init );
 532
 533         DOSMEM_0000H = GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_sysmem,
 534                                            0x10000, 0, WINE_LDT_FLAGS_DATA );
 535         DOSMEM_BiosDataSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_sysmem + 0x400,
 536                                                 0x100, 0, WINE_LDT_FLAGS_DATA );
 537         DOSMEM_BiosSysSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0xf0000,
 538                                                0x10000, 0, WINE_LDT_FLAGS_DATA );
 539         DOSMEM_FillBiosSegments();
 540         DOSMEM_FillIsrTable();
 541         DOSMEM_InitMemory();
 542         DOSMEM_InitCollateTable();
 543         DOSMEM_InitErrorTable();
 544         DOSMEM_InitDPMI();
 545         already_done = 1;
 546     }
 547     else if (dos_init && !already_mapped)
 548     {
 549         if (DOSMEM_dosmem)
 550         {
 551             ERR( "Needs access to the first megabyte for DOS mode\n" );
 552             ExitProcess(1);
 553         }
 554         MESSAGE( "Warning: unprotecting the first 64KB of memory to allow real-mode calls.\n"
 555                  "         NULL pointer accesses will no longer be caught.\n" );
 556         VirtualProtect( NULL, 0x10000, PAGE_EXECUTE_READWRITE, NULL );
 557         /* copy the BIOS and ISR area down */
 558         memcpy( DOSMEM_dosmem, DOSMEM_sysmem, 0x400 + 0x100 );
 559         DOSMEM_sysmem = DOSMEM_dosmem;
 560         SetSelectorBase( DOSMEM_0000H, 0 );
 561         SetSelectorBase( DOSMEM_BiosDataSeg, 0x400 );
 562         /* we may now need the actual interrupt stubs, and since we've just moved the
 563          * interrupt vector table away, we can fill the area with stubs instead... */
 564         DOSMEM_MakeIsrStubs();
 565         already_mapped = 1;
 566     }
 567     return TRUE;
 568 }
 569
 570
 571 /***********************************************************************
 572  *           DOSMEM_Tick
 573  *
 574  * Increment the BIOS tick counter. Called by timer signal handler.
 575  */
 576 void DOSMEM_Tick( WORD timer )
 577 {
 578     BIOSDATA *pBiosData = DOSMEM_BiosData();
 579     if (pBiosData) pBiosData->Ticks++;
 580 }
 581
 582 /***********************************************************************
 583  *           DOSMEM_GetBlock
 584  *
 585  * Carve a chunk of the DOS memory block (without selector).
 586  */
 587 LPVOID DOSMEM_GetBlock(UINT size, UINT16* pseg)
 588 {
 589    UINT          blocksize;
 590    char         *block = NULL;
 591    dosmem_info  *info_block = DOSMEM_InfoBlock();
 592    dosmem_entry *dm;
 593 #ifdef __DOSMEM_DEBUG_
 594    dosmem_entry *prev = NULL;
 595 #endif
 596
 597    if( size > info_block->free ) return NULL;
 598    dm = DOSMEM_RootBlock();
 599
 600    while (dm && dm->size != DM_BLOCK_TERMINAL)
 601    {
 602 #ifdef __DOSMEM_DEBUG__
 603        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 604        {
 605             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 606             return NULL;
 607        }
 608        prev = dm;
 609 #endif
 610        if( dm->size & DM_BLOCK_FREE )
 611        {
 612            dosmem_entry  *next = NEXT_BLOCK(dm);
 613
 614            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 615            {
 616                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 617                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 618                next = NEXT_BLOCK(dm);
 619            }
 620
 621            blocksize = dm->size & DM_BLOCK_MASK;
 622            if( blocksize >= size )
 623            {
 624                block = ((char*)dm) + sizeof(dosmem_entry);
 625                if( blocksize - size > 0x20 )
 626                {
 627                    /* split dm so that the next one stays
 628                     * paragraph-aligned (and dm loses free bit) */
 629
 630                    dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 631                                               sizeof(dosmem_entry));
 632                    next = (dosmem_entry*)(((char*)dm) +
 633                            sizeof(dosmem_entry) + dm->size);
 634                    next->size = (blocksize - (dm->size +
 635                            sizeof(dosmem_entry))) | DM_BLOCK_FREE
 636 #ifdef __DOSMEM_DEBUG__
 637                                                   | DM_BLOCK_DEBUG
 638 #endif
 639                                                   ;
 640                } else dm->size &= DM_BLOCK_MASK;
 641
 642                info_block->blocks++;
 643                info_block->free -= dm->size;
 644                if( pseg ) *pseg = (block - DOSMEM_dosmem) >> 4;
 645 #ifdef __DOSMEM_DEBUG__
 646                dm->size |= DM_BLOCK_DEBUG;
 647 #endif
 648                break;
 649            }
 650            dm = next;
 651        }
 652        else dm = NEXT_BLOCK(dm);
 653    }
 654    return (LPVOID)block;
 655 }
 656
 657 /***********************************************************************
 658  *           DOSMEM_FreeBlock
 659  */
 660 BOOL DOSMEM_FreeBlock(void* ptr)
 661 {
 662    dosmem_info  *info_block = DOSMEM_InfoBlock();
 663
 664    if( ptr >= (void*)(((char*)DOSMEM_RootBlock()) + sizeof(dosmem_entry)) &&
 665        ptr < (void*)DOSMEM_MemoryTop() && !((((char*)ptr)
 666                   - DOSMEM_dosmem) & 0xf) )
 667    {
 668        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 669
 670        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 671 #ifdef __DOSMEM_DEBUG__
 672          && ((dm->size & DM_BLOCK_DEBUG) == DM_BLOCK_DEBUG )
 673 #endif
 674          )
 675        {
 676              info_block->blocks--;
 677              info_block->free += dm->size;
 678
 679              dm->size |= DM_BLOCK_FREE;
 680              return TRUE;
 681        }
 682    }
 683    return FALSE;
 684 }
 685
 686 /***********************************************************************
 687  *           DOSMEM_ResizeBlock
 688  */
 689 LPVOID DOSMEM_ResizeBlock(void* ptr, UINT size, UINT16* pseg)
 690 {
 691    char         *block = NULL;
 692    dosmem_info  *info_block = DOSMEM_InfoBlock();
 693
 694    if( ptr >= (void*)(((char*)DOSMEM_RootBlock()) + sizeof(dosmem_entry)) &&
 695        ptr < (void*)DOSMEM_MemoryTop() && !((((char*)ptr)
 696                   - DOSMEM_dosmem) & 0xf) )
 697    {
 698        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 699
 700        if( pseg ) *pseg = ((char*)ptr - DOSMEM_dosmem) >> 4;
 701
 702        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 703          )
 704        {
 705              dosmem_entry  *next = NEXT_BLOCK(dm);
 706              UINT blocksize, orgsize = dm->size & DM_BLOCK_MASK;
 707
 708              while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 709              {
 710                  dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 711                  next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 712                  next = NEXT_BLOCK(dm);
 713              }
 714
 715              blocksize = dm->size & DM_BLOCK_MASK;
 716              if (blocksize >= size)
 717              {
 718                  block = ((char*)dm) + sizeof(dosmem_entry);
 719                  if( blocksize - size > 0x20 )
 720                  {
 721                      /* split dm so that the next one stays
 722                       * paragraph-aligned (and next gains free bit) */
 723
 724                      dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 725                                                 sizeof(dosmem_entry));
 726                      next = (dosmem_entry*)(((char*)dm) +
 727                              sizeof(dosmem_entry) + dm->size);
 728                      next->size = (blocksize - (dm->size +
 729                              sizeof(dosmem_entry))) | DM_BLOCK_FREE
 730                                                     ;
 731                  } else dm->size &= DM_BLOCK_MASK;
 732
 733                  info_block->free += orgsize - dm->size;
 734              } else {
 735                  /* the collapse didn't help, try getting a new block */
 736                  block = DOSMEM_GetBlock(size, pseg);
 737                  if (block) {
 738                      /* we got one, copy the old data there (we do need to, right?) */
 739                      memcpy(block, ((char*)dm) + sizeof(dosmem_entry),
 740                                    (size<orgsize) ? size : orgsize);
 741                      /* free old block */
 742                      info_block->blocks--;
 743                      info_block->free += dm->size;
 744
 745                      dm->size |= DM_BLOCK_FREE;
 746                  } else {
 747                      /* and Bill Gates said 640K should be enough for everyone... */
 748
 749                      /* need to split original and collapsed blocks apart again,
 750                       * and free the collapsed blocks again, before exiting */
 751                      if( blocksize - orgsize > 0x20 )
 752                      {
 753                          /* split dm so that the next one stays
 754                           * paragraph-aligned (and next gains free bit) */
 755
 756                          dm->size = (((orgsize + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 757                                                        sizeof(dosmem_entry));
 758                          next = (dosmem_entry*)(((char*)dm) +
 759                                  sizeof(dosmem_entry) + dm->size);
 760                          next->size = (blocksize - (dm->size +
 761                                  sizeof(dosmem_entry))) | DM_BLOCK_FREE
 762                                                         ;
 763                      } else dm->size &= DM_BLOCK_MASK;
 764                  }
 765              }
 766        }
 767    }
 768    return (LPVOID)block;
 769 }
 770
 771
 772 /***********************************************************************
 773  *           DOSMEM_Available
 774  */
 775 UINT DOSMEM_Available(void)
 776 {
 777    UINT          blocksize, available = 0;
 778    dosmem_entry *dm;
 779
 780    dm = DOSMEM_RootBlock();
 781
 782    while (dm && dm->size != DM_BLOCK_TERMINAL)
 783    {
 784 #ifdef __DOSMEM_DEBUG__
 785        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 786        {
 787             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 788             return NULL;
 789        }
 790        prev = dm;
 791 #endif
 792        if( dm->size & DM_BLOCK_FREE )
 793        {
 794            dosmem_entry  *next = NEXT_BLOCK(dm);
 795
 796            while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 797            {
 798                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 799                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 800                next = NEXT_BLOCK(dm);
 801            }
 802
 803            blocksize = dm->size & DM_BLOCK_MASK;
 804            if ( blocksize > available ) available = blocksize;
 805            dm = next;
 806        }
 807        else dm = NEXT_BLOCK(dm);
 808    }
 809    return available;
 810 }
 811
 812
 813 /***********************************************************************
 814  *           DOSMEM_MapLinearToDos
 815  *
 816  * Linear address to the DOS address space.
 817  */
 818 UINT DOSMEM_MapLinearToDos(LPVOID ptr)
 819 {
 820     if (((char*)ptr >= DOSMEM_dosmem) &&
 821         ((char*)ptr < DOSMEM_dosmem + 0x100000))
 822           return (UINT)ptr - (UINT)DOSMEM_dosmem;
 823     return (UINT)ptr;
 824 }
 825
 826
 827 /***********************************************************************
 828  *           DOSMEM_MapDosToLinear
 829  *
 830  * DOS linear address to the linear address space.
 831  */
 832 LPVOID DOSMEM_MapDosToLinear(UINT ptr)
 833 {
 834     if (ptr < 0x100000) return (LPVOID)(ptr + (UINT)DOSMEM_dosmem);
 835     return (LPVOID)ptr;
 836 }
 837
 838
 839 /***********************************************************************
 840  *           DOSMEM_MapRealToLinear
 841  *
 842  * Real mode DOS address into a linear pointer
 843  */
 844 LPVOID DOSMEM_MapRealToLinear(DWORD x)
 845 {
 846    LPVOID       lin;
 847
 848    lin=DOSMEM_dosmem+(x&0xffff)+(((x&0xffff0000)>>16)*16);
 849    TRACE_(selector)("(0x%08lx) returns %p.\n", x, lin );
 850    return lin;
 851 }
 852
 853 /***********************************************************************
 854  *           DOSMEM_AllocSelector
 855  *
 856  * Allocates a protected mode selector for a realmode segment.
 857  */
 858 WORD DOSMEM_AllocSelector(WORD realsel)
 859 {
 860         HMODULE16 hModule = GetModuleHandle16("KERNEL");
 861         WORD    sel;
 862
 863         sel=GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_dosmem+realsel*16, 0x10000,
 864                                 hModule, WINE_LDT_FLAGS_DATA );
 865         TRACE_(selector)("(0x%04x) returns 0x%04x.\n", realsel,sel);
 866         return sel;
 867 }