dlls/winedos/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 <stdarg.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30 #ifdef HAVE_SYS_MMAN_H
  31 # include <sys/mman.h>
  32 #endif
  33
  34 #include "windef.h"
  35 #include "winbase.h"
  36 #include "winreg.h"
  37 #include "excpt.h"
  38 #include "winternl.h"
  39 #include "wine/winbase16.h"
  40
  41 #include "dosexe.h"
  42 #include "wine/debug.h"
  43
  44 WINE_DEFAULT_DEBUG_CHANNEL(dosmem);
  45
  46 /* DOS memory highest address (including HMA) */
  47 #define DOSMEM_SIZE             0x110000
  48 #define DOSMEM_64KB             0x10000
  49
  50 /* see dlls/kernel/dosmem.c for the details */
  51 static char *DOSMEM_dosmem;
  52 static char *DOSMEM_sysmem;
  53
  54 /* use 2 low bits of 'size' for the housekeeping */
  55 #define DM_BLOCK_DEBUG          0xABE00000
  56 #define DM_BLOCK_TERMINAL       0x00000001
  57 #define DM_BLOCK_FREE           0x00000002
  58 #define DM_BLOCK_MASK           0x001FFFFC
  59
  60 /*
  61 #define __DOSMEM_DEBUG__
  62  */
  63
  64 typedef struct {
  65    unsigned     size;
  66 } dosmem_entry;
  67
  68 typedef struct {
  69   unsigned      blocks;
  70   unsigned      free;
  71 } dosmem_info;
  72
  73 static inline dosmem_entry* next_block(dosmem_entry* block)
  74 {
  75     return (dosmem_entry*)((char*)block +
  76                            sizeof(dosmem_entry) + (block->size & DM_BLOCK_MASK));
  77 }
  78
  79 #define VM_STUB(x) (0x90CF00CD|(x<<8)) /* INT x; IRET; NOP */
  80 #define VM_STUB_SEGMENT 0xf000         /* BIOS segment */
  81
  82 /* FIXME: this should be moved to the LOL, and the whole allocation strategy
  83  * should use real MCB
  84  */
  85 static dosmem_info* DOSMEM_info_block;
  86
  87 /***********************************************************************
  88  *           DOSMEM_MemoryTop
  89  *
  90  * Gets the DOS memory top.
  91  */
  92 static char *DOSMEM_MemoryTop(void)
  93 {
  94     return DOSMEM_dosmem+0x9FFFC; /* 640K */
  95 }
  96
  97 /***********************************************************************
  98  *           DOSMEM_RootBlock
  99  *
 100  * Gets the DOS memory root block.
 101  */
 102 static dosmem_entry *DOSMEM_RootBlock(void)
 103 {
 104     /* first block has to be paragraph-aligned */
 105     return (dosmem_entry*)(((char*)DOSMEM_info_block) +
 106                            ((((sizeof(dosmem_info) + 0xf) & ~0xf) - sizeof(dosmem_entry))));
 107 }
 108
 109 /***********************************************************************
 110  *           DOSMEM_FillIsrTable
 111  *
 112  * Fill the interrupt table with fake BIOS calls to BIOSSEG (0xf000).
 113  *
 114  * NOTES:
 115  * Linux normally only traps INTs performed from or destined to BIOSSEG
 116  * for us to handle, if the int_revectored table is empty. Filling the
 117  * interrupt table with calls to INT stubs in BIOSSEG allows DOS programs
 118  * to hook interrupts, as well as use their familiar retf tricks to call
 119  * them, AND let Wine handle any unhooked interrupts transparently.
 120  */
 121 static void DOSMEM_FillIsrTable(void)
 122 {
 123     SEGPTR *isr = (SEGPTR*)DOSMEM_sysmem;
 124     int x;
 125
 126     for (x=0; x<256; x++) isr[x]=MAKESEGPTR(VM_STUB_SEGMENT,x*4);
 127 }
 128
 129 static void DOSMEM_MakeIsrStubs(void)
 130 {
 131     DWORD *stub = (DWORD*)(DOSMEM_dosmem + (VM_STUB_SEGMENT << 4));
 132     int x;
 133
 134     for (x=0; x<256; x++) stub[x]=VM_STUB(x);
 135 }
 136
 137 BIOSDATA* DOSVM_BiosData(void)
 138 {
 139     return (BIOSDATA *)(DOSMEM_sysmem + 0x400);
 140 }
 141
 142 /**********************************************************************
 143  *          DOSMEM_GetTicksSinceMidnight
 144  *
 145  * Return number of clock ticks since midnight.
 146  */
 147 static DWORD DOSMEM_GetTicksSinceMidnight(void)
 148 {
 149     SYSTEMTIME time;
 150
 151     /* This should give us the (approximately) correct
 152      * 18.206 clock ticks per second since midnight.
 153      */
 154
 155     GetLocalTime( &time );
 156
 157     return (((time.wHour * 3600 + time.wMinute * 60 +
 158               time.wSecond) * 18206) / 1000) +
 159              (time.wMilliseconds * 1000 / 54927);
 160 }
 161
 162 /***********************************************************************
 163  *           DOSMEM_FillBiosSegments
 164  *
 165  * Fill the BIOS data segment with dummy values.
 166  */
 167 static void DOSMEM_FillBiosSegments(void)
 168 {
 169     char *pBiosSys = DOSMEM_dosmem + 0xf0000;
 170     BYTE *pBiosROMTable = pBiosSys+0xe6f5;
 171     BIOSDATA *pBiosData = DOSVM_BiosData();
 172
 173       /* Clear all unused values */
 174     memset( pBiosData, 0, sizeof(*pBiosData) );
 175
 176     /* FIXME: should check the number of configured drives and ports */
 177     pBiosData->Com1Addr             = 0x3f8;
 178     pBiosData->Com2Addr             = 0x2f8;
 179     pBiosData->Lpt1Addr             = 0x378;
 180     pBiosData->Lpt2Addr             = 0x278;
 181     pBiosData->InstalledHardware    = 0x5463;
 182     pBiosData->MemSize              = 640;
 183     pBiosData->NextKbdCharPtr       = 0x1e;
 184     pBiosData->FirstKbdCharPtr      = 0x1e;
 185     pBiosData->VideoMode            = 3;
 186     pBiosData->VideoColumns         = 80;
 187     pBiosData->VideoPageSize        = 80 * 25 * 2;
 188     pBiosData->VideoPageStartAddr   = 0xb800;
 189     pBiosData->VideoCtrlAddr        = 0x3d4;
 190     pBiosData->Ticks                = DOSMEM_GetTicksSinceMidnight();
 191     pBiosData->NbHardDisks          = 2;
 192     pBiosData->KbdBufferStart       = 0x1e;
 193     pBiosData->KbdBufferEnd         = 0x3e;
 194     pBiosData->RowsOnScreenMinus1   = 24;
 195     pBiosData->BytesPerChar         = 0x10;
 196     pBiosData->ModeOptions          = 0x64;
 197     pBiosData->FeatureBitsSwitches  = 0xf9;
 198     pBiosData->VGASettings          = 0x51;
 199     pBiosData->DisplayCombination   = 0x08;
 200     pBiosData->DiskDataRate         = 0;
 201
 202     /* fill ROM configuration table (values from Award) */
 203     *(pBiosROMTable+0x0)        = 0x08; /* number of bytes following LO */
 204     *(pBiosROMTable+0x1)        = 0x00; /* number of bytes following HI */
 205     *(pBiosROMTable+0x2)        = 0xfc; /* model */
 206     *(pBiosROMTable+0x3)        = 0x01; /* submodel */
 207     *(pBiosROMTable+0x4)        = 0x00; /* BIOS revision */
 208     *(pBiosROMTable+0x5)        = 0x74; /* feature byte 1 */
 209     *(pBiosROMTable+0x6)        = 0x00; /* feature byte 2 */
 210     *(pBiosROMTable+0x7)        = 0x00; /* feature byte 3 */
 211     *(pBiosROMTable+0x8)        = 0x00; /* feature byte 4 */
 212     *(pBiosROMTable+0x9)        = 0x00; /* feature byte 5 */
 213
 214     /* BIOS date string */
 215     strcpy(pBiosSys+0xfff5, "13/01/99");
 216
 217     /* BIOS ID */
 218     *(pBiosSys+0xfffe) = 0xfc;
 219
 220     /* Reboot vector (f000:fff0 or ffff:0000) */
 221     *(DWORD*)(pBiosSys + 0xfff0) = VM_STUB(0x19);
 222 }
 223
 224 /***********************************************************************
 225  *           BiosTick
 226  *
 227  * Increment the BIOS tick counter. Called by timer signal handler.
 228  */
 229 void BiosTick( WORD timer )
 230 {
 231     BIOSDATA *pBiosData = DOSVM_BiosData();
 232     if (pBiosData) pBiosData->Ticks++;
 233 }
 234
 235 /***********************************************************************
 236  *           DOSMEM_AllocBlock
 237  *
 238  * Carve a chunk of the DOS memory block (without selector).
 239  */
 240 LPVOID DOSMEM_AllocBlock(UINT size, UINT16* pseg)
 241 {
 242    UINT          blocksize;
 243    char         *block = NULL;
 244    dosmem_info  *info_block = DOSMEM_info_block;
 245    dosmem_entry *dm;
 246 #ifdef __DOSMEM_DEBUG_
 247    dosmem_entry *prev = NULL;
 248 #endif
 249
 250    if( size > info_block->free ) return NULL;
 251    dm = DOSMEM_RootBlock();
 252
 253    while (dm && dm->size != DM_BLOCK_TERMINAL)
 254    {
 255 #ifdef __DOSMEM_DEBUG__
 256        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 257        {
 258             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 259             return NULL;
 260        }
 261        prev = dm;
 262 #endif
 263        if( dm->size & DM_BLOCK_FREE )
 264        {
 265            dosmem_entry  *next = next_block(dm);
 266
 267            while ( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 268            {
 269                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 270                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 271                next = next_block(dm);
 272            }
 273
 274            blocksize = dm->size & DM_BLOCK_MASK;
 275            if( blocksize >= size )
 276            {
 277                block = ((char*)dm) + sizeof(dosmem_entry);
 278                if( blocksize - size > 0x20 )
 279                {
 280                    /* split dm so that the next one stays
 281                     * paragraph-aligned (and dm loses free bit) */
 282
 283                    dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 284                                               sizeof(dosmem_entry));
 285                    next = (dosmem_entry*)(((char*)dm) +
 286                            sizeof(dosmem_entry) + dm->size);
 287                    next->size = (blocksize - (dm->size +
 288                            sizeof(dosmem_entry))) | DM_BLOCK_FREE
 289 #ifdef __DOSMEM_DEBUG__
 290                                                   | DM_BLOCK_DEBUG
 291 #endif
 292                                                   ;
 293                } else dm->size &= DM_BLOCK_MASK;
 294
 295                info_block->blocks++;
 296                info_block->free -= dm->size;
 297                if( pseg ) *pseg = (block - DOSMEM_dosmem) >> 4;
 298 #ifdef __DOSMEM_DEBUG__
 299                dm->size |= DM_BLOCK_DEBUG;
 300 #endif
 301                break;
 302            }
 303            dm = next;
 304        }
 305        else dm = next_block(dm);
 306    }
 307    return (LPVOID)block;
 308 }
 309
 310 /***********************************************************************
 311  *           DOSMEM_FreeBlock
 312  */
 313 BOOL DOSMEM_FreeBlock(void* ptr)
 314 {
 315    dosmem_info  *info_block = DOSMEM_info_block;
 316
 317    if( ptr >= (void*)(((char*)DOSMEM_RootBlock()) + sizeof(dosmem_entry)) &&
 318        ptr < (void*)DOSMEM_MemoryTop() && !((((char*)ptr)
 319                   - DOSMEM_dosmem) & 0xf) )
 320    {
 321        dosmem_entry  *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 322
 323        if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
 324 #ifdef __DOSMEM_DEBUG__
 325          && ((dm->size & DM_BLOCK_DEBUG) == DM_BLOCK_DEBUG )
 326 #endif
 327          )
 328        {
 329              info_block->blocks--;
 330              info_block->free += dm->size;
 331
 332              dm->size |= DM_BLOCK_FREE;
 333              return TRUE;
 334        }
 335    }
 336    return FALSE;
 337 }
 338
 339 /***********************************************************************
 340  *           DOSMEM_ResizeBlock
 341  *
 342  * Resize DOS memory block in place. Returns block size or -1 on error.
 343  *
 344  * If exact is TRUE, returned value is either old or requested block
 345  * size. If exact is FALSE, block is expanded even if there is not
 346  * enough space for full requested block size.
 347  */
 348 UINT DOSMEM_ResizeBlock(void *ptr, UINT size, BOOL exact)
 349 {
 350    char         *block = NULL;
 351    dosmem_info  *info_block = DOSMEM_info_block;
 352    dosmem_entry *dm;
 353    dosmem_entry *next;
 354    UINT blocksize;
 355    UINT orgsize;
 356
 357    if( (ptr < (void*)(sizeof(dosmem_entry) + (char*)DOSMEM_RootBlock())) ||
 358        (ptr >= (void*)DOSMEM_MemoryTop()) ||
 359        (((((char*)ptr) - DOSMEM_dosmem) & 0xf) != 0) )
 360      return (UINT)-1;
 361
 362    dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
 363    if( dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL) )
 364        return (UINT)-1;
 365
 366    next = next_block(dm);
 367    orgsize = dm->size & DM_BLOCK_MASK;
 368
 369    /* collapse free blocks */
 370    while ( next->size & DM_BLOCK_FREE )
 371    {
 372        dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 373        next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 374        next = next_block(dm);
 375    }
 376
 377    blocksize = dm->size & DM_BLOCK_MASK;
 378
 379    /*
 380     * If collapse didn't help we either expand block to maximum
 381     * available size (exact == FALSE) or give collapsed blocks
 382     * back to free storage (exact == TRUE).
 383     */
 384    if (blocksize < size)
 385        size = exact ? orgsize : blocksize;
 386
 387    block = ((char*)dm) + sizeof(dosmem_entry);
 388    if( blocksize - size > 0x20 )
 389    {
 390        /*
 391         * split dm so that the next one stays
 392         * paragraph-aligned (and next gains free bit)
 393         */
 394
 395        dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
 396                    sizeof(dosmem_entry));
 397        next = (dosmem_entry*)(((char*)dm) +
 398                               sizeof(dosmem_entry) + dm->size);
 399        next->size = (blocksize - (dm->size +
 400                                   sizeof(dosmem_entry))) | DM_BLOCK_FREE;
 401    }
 402    else
 403    {
 404        dm->size &= DM_BLOCK_MASK;
 405    }
 406
 407    /*
 408     * Adjust available memory if block size changes.
 409     */
 410    info_block->free += orgsize - dm->size;
 411
 412    return size;
 413 }
 414
 415 /***********************************************************************
 416  *           DOSMEM_Available
 417  */
 418 UINT DOSMEM_Available(void)
 419 {
 420    UINT          blocksize, available = 0;
 421    dosmem_entry *dm;
 422
 423    dm = DOSMEM_RootBlock();
 424
 425    while (dm && dm->size != DM_BLOCK_TERMINAL)
 426    {
 427 #ifdef __DOSMEM_DEBUG__
 428        if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
 429        {
 430             WARN("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
 431             return NULL;
 432        }
 433        prev = dm;
 434 #endif
 435        if( dm->size & DM_BLOCK_FREE )
 436        {
 437            dosmem_entry  *next = next_block(dm);
 438
 439            while ( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
 440            {
 441                dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
 442                next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
 443                next = next_block(dm);
 444            }
 445
 446            blocksize = dm->size & DM_BLOCK_MASK;
 447            if ( blocksize > available ) available = blocksize;
 448            dm = next;
 449        }
 450        else dm = next_block(dm);
 451    }
 452    return available;
 453 }
 454
 455 /***********************************************************************
 456  *           DOSMEM_InitMemory
 457  *
 458  * Initialises the DOS memory structures.
 459  */
 460 static void DOSMEM_InitMemory(char* addr)
 461 {
 462     dosmem_entry*       root_block;
 463     dosmem_entry*       dm;
 464
 465     DOSMEM_FillBiosSegments();
 466     DOSMEM_FillIsrTable();
 467
 468     DOSMEM_info_block = (dosmem_info*)addr;
 469     root_block = DOSMEM_RootBlock();
 470     root_block->size = DOSMEM_MemoryTop() - (((char*)root_block) + sizeof(dosmem_entry));
 471
 472     DOSMEM_info_block->blocks = 0;
 473     DOSMEM_info_block->free = root_block->size;
 474
 475     dm = next_block(root_block);
 476     dm->size = DM_BLOCK_TERMINAL;
 477     root_block->size |= DM_BLOCK_FREE
 478 #ifdef __DOSMEM_DEBUG__
 479         | DM_BLOCK_DEBUG
 480 #endif
 481         ;
 482
 483     TRACE("DOS conventional memory initialized, %d bytes free.\n",
 484           DOSMEM_Available());
 485 }
 486
 487 /******************************************************************
 488  *             DOSMEM_InitDosMemory
 489  *
 490  * When WineDOS is loaded, initializes the current DOS memory layout.
 491  */
 492 BOOL DOSMEM_InitDosMemory(void)
 493 {
 494     HMODULE16           hModule;
 495     unsigned short      sel;
 496     LDT_ENTRY           entry;
 497     DWORD               reserve;
 498
 499     if (!(hModule = GetModuleHandle16("KERNEL"))) return FALSE;
 500     /* KERNEL.194: __F000H */
 501     sel = LOWORD(GetProcAddress16(hModule, (LPCSTR)(ULONG_PTR)194));
 502     wine_ldt_get_entry(sel, &entry);
 503     DOSMEM_dosmem = (char*)wine_ldt_get_base(&entry) - 0xF0000;
 504     /* KERNEL.183: __0000H */
 505     sel = LOWORD(GetProcAddress16(hModule, (LPCSTR)(DWORD_PTR)183));
 506     wine_ldt_get_entry(sel, &entry);
 507     DOSMEM_sysmem = wine_ldt_get_base(&entry);
 508
 509     /*
 510      * Reserve either:
 511      * - lowest 64k for NULL pointer catching (Win16)
 512      * - lowest 1k for interrupt handlers and
 513      *   another 0.5k for BIOS, DOS and intra-application
 514      *   areas (DOS)
 515      */
 516     if (DOSMEM_dosmem != DOSMEM_sysmem)
 517         reserve = 0x10000; /* 64k */
 518     else
 519         reserve = 0x600; /* 1.5k */
 520
 521     /*
 522      * Round to paragraph boundary in order to make
 523      * sure the alignment is correct.
 524      */
 525     reserve = ((reserve + 15) >> 4) << 4;
 526
 527     /*
 528      * Set DOS memory base and initialize conventional memory.
 529      */
 530     DOSMEM_InitMemory(DOSMEM_dosmem + reserve);
 531     return TRUE;
 532 }
 533
 534 /******************************************************************
 535  *              DOSMEM_MapDosLayout
 536  *
 537  * Initialize the first MB of memory to look like a real DOS setup
 538  */
 539 BOOL DOSMEM_MapDosLayout(void)
 540 {
 541     static int already_mapped;
 542
 543     if (!already_mapped)
 544     {
 545         HMODULE16       hModule;
 546         unsigned short  sel;
 547         LDT_ENTRY       entry;
 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 memory to allow real-mode calls.\n"
 555                  "         NULL pointer accesses will no longer be caught.\n" );
 556         VirtualProtect( NULL, DOSMEM_SIZE, 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         hModule = GetModuleHandle16("KERNEL");
 561         /* selector to 0000H */
 562         sel = LOWORD(GetProcAddress16(hModule, (LPCSTR)(DWORD_PTR)183));
 563         wine_ldt_get_entry(sel, &entry);
 564         wine_ldt_set_base(&entry, NULL);
 565         wine_ldt_set_entry(sel, &entry);
 566         /* selector to BiosData */
 567         sel = LOWORD(GetProcAddress16(hModule, (LPCSTR)(DWORD_PTR)193));
 568         wine_ldt_get_entry(sel, &entry);
 569         wine_ldt_set_base(&entry, (const void*)0x400);
 570         wine_ldt_set_entry(sel, &entry);
 571         /* we may now need the actual interrupt stubs, and since we've just moved the
 572          * interrupt vector table away, we can fill the area with stubs instead... */
 573         DOSMEM_MakeIsrStubs();
 574         already_mapped = 1;
 575     }
 576     return TRUE;
 577 }