dlls/winedos/module.c

   1 /*
   2  * DOS (MZ) loader
   3  *
   4  * Copyright 1998 Ove Kåven
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  * Note: This code hasn't been completely cleaned up yet.
  21  */
  22
  23 #include "config.h"
  24 #include "wine/port.h"
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <fcntl.h>
  30 #include <signal.h>
  31 #ifdef HAVE_UNISTD_H
  32 # include <unistd.h>
  33 #endif
  34 #include <sys/types.h>
  35 #include <sys/stat.h>
  36 #ifdef HAVE_SYS_TIME_H
  37 # include <sys/time.h>
  38 #endif
  39 #include "windef.h"
  40 #include "wine/winbase16.h"
  41 #include "wingdi.h"
  42 #include "winuser.h"
  43 #include "winerror.h"
  44 #include "task.h"
  45 #include "file.h"
  46 #include "miscemu.h"
  47 #include "wine/debug.h"
  48 #include "dosexe.h"
  49 #include "dosvm.h"
  50 #include "vga.h"
  51
  52 WINE_DEFAULT_DEBUG_CHANNEL(module);
  53
  54 static BOOL DOSVM_isdosexe;
  55
  56 /**********************************************************************
  57  *          DOSVM_IsWin16
  58  *
  59  * Return TRUE if we are in Windows process.
  60  */
  61 BOOL DOSVM_IsWin16(void)
  62 {
  63   return DOSVM_isdosexe ? FALSE : TRUE;
  64 }
  65
  66 #ifdef MZ_SUPPORTED
  67
  68 #ifdef HAVE_SYS_MMAN_H
  69 # include <sys/mman.h>
  70 #endif
  71
  72 /* define this to try mapping through /proc/pid/mem instead of a temp file,
  73    but Linus doesn't like mmapping /proc/pid/mem, so it doesn't work for me */
  74 #undef MZ_MAPSELF
  75
  76 #define BIOS_DATA_SEGMENT 0x40
  77 #define PSP_SIZE 0x10
  78
  79 #define SEG16(ptr,seg) ((LPVOID)((BYTE*)ptr+((DWORD)(seg)<<4)))
  80 #define SEGPTR16(ptr,segptr) ((LPVOID)((BYTE*)ptr+((DWORD)SELECTOROF(segptr)<<4)+OFFSETOF(segptr)))
  81
  82 /* structures for EXEC */
  83
  84 typedef struct {
  85   WORD env_seg;
  86   DWORD cmdline WINE_PACKED;
  87   DWORD fcb1 WINE_PACKED;
  88   DWORD fcb2 WINE_PACKED;
  89   WORD init_sp;
  90   WORD init_ss;
  91   WORD init_ip;
  92   WORD init_cs;
  93 } ExecBlock;
  94
  95 typedef struct {
  96   WORD load_seg;
  97   WORD rel_seg;
  98 } OverlayBlock;
  99
 100 /* global variables */
 101
 102 pid_t dosvm_pid;
 103
 104 static WORD init_cs,init_ip,init_ss,init_sp;
 105 static HANDLE dosvm_thread, loop_thread;
 106 static DWORD dosvm_tid, loop_tid;
 107
 108 static void MZ_Launch( LPCSTR cmdtail, int length );
 109 static BOOL MZ_InitTask(void);
 110
 111 static void MZ_CreatePSP( LPVOID lpPSP, WORD env, WORD par )
 112 {
 113   PDB16*psp=lpPSP;
 114
 115   psp->int20=0x20CD; /* int 20 */
 116   /* some programs use this to calculate how much memory they need */
 117   psp->nextParagraph=0x9FFF; /* FIXME: use a real value */
 118   /* FIXME: dispatcher */
 119   psp->savedint22 = DOSVM_GetRMHandler(0x22);
 120   psp->savedint23 = DOSVM_GetRMHandler(0x23);
 121   psp->savedint24 = DOSVM_GetRMHandler(0x24);
 122   psp->parentPSP=par;
 123   psp->environment=env;
 124   /* FIXME: more PSP stuff */
 125 }
 126
 127 static void MZ_FillPSP( LPVOID lpPSP, LPCSTR cmdtail, int length )
 128 {
 129     PDB16 *psp = lpPSP;
 130
 131     if(length > 127)
 132     {
 133         WARN( "Command tail truncated! (length %d)\n", length );
 134         length = 126;
 135     }
 136
 137     psp->cmdLine[0] = length;
 138
 139     /*
 140      * Length of exactly 127 bytes means that full command line is
 141      * stored in environment variable CMDLINE and PSP contains
 142      * command tail truncated to 126 bytes.
 143      */
 144     if(length == 127)
 145         length = 126;
 146
 147     if(length > 0)
 148         memmove(psp->cmdLine+1, cmdtail, length);
 149
 150     psp->cmdLine[length+1] = '\r';
 151
 152     /* FIXME: more PSP stuff */
 153 }
 154
 155 static WORD MZ_InitEnvironment( LPCSTR env, LPCSTR name )
 156 {
 157  unsigned sz=0;
 158  WORD seg;
 159  LPSTR envblk;
 160
 161  if (env) {
 162   /* get size of environment block */
 163   while (env[sz++]) sz+=strlen(env+sz)+1;
 164  } else sz++;
 165  /* allocate it */
 166  envblk=DOSMEM_GetBlock(sz+sizeof(WORD)+strlen(name)+1,&seg);
 167  /* fill it */
 168  if (env) {
 169   memcpy(envblk,env,sz);
 170  } else envblk[0]=0;
 171  /* DOS 3.x: the block contains 1 additional string */
 172  *(WORD*)(envblk+sz)=1;
 173  /* being the program name itself */
 174  strcpy(envblk+sz+sizeof(WORD),name);
 175  return seg;
 176 }
 177
 178 static BOOL MZ_InitMemory(void)
 179 {
 180     /* initialize the memory */
 181     TRACE("Initializing DOS memory structures\n");
 182     DOSMEM_Init(TRUE);
 183     DOSDEV_InstallDOSDevices();
 184
 185     return TRUE;
 186 }
 187
 188 static BOOL MZ_DoLoadImage( HANDLE hFile, LPCSTR filename, OverlayBlock *oblk )
 189 {
 190   IMAGE_DOS_HEADER mz_header;
 191   DWORD image_start,image_size,min_size,max_size,avail;
 192   BYTE*psp_start,*load_start,*oldenv;
 193   int x, old_com=0, alloc;
 194   SEGPTR reloc;
 195   WORD env_seg, load_seg, rel_seg, oldpsp_seg;
 196   DWORD len;
 197
 198   if (DOSVM_psp) {
 199     /* DOS process already running, inherit from it */
 200     PDB16* par_psp = (PDB16*)((DWORD)DOSVM_psp << 4);
 201     alloc=0;
 202     oldenv = (LPBYTE)((DWORD)par_psp->environment << 4);
 203     oldpsp_seg = DOSVM_psp;
 204   } else {
 205     /* allocate new DOS process, inheriting from Wine environment */
 206     alloc=1;
 207     oldenv = GetEnvironmentStringsA();
 208     oldpsp_seg = 0;
 209   }
 210
 211  SetFilePointer(hFile,0,NULL,FILE_BEGIN);
 212  if (   !ReadFile(hFile,&mz_header,sizeof(mz_header),&len,NULL)
 213      || len != sizeof(mz_header)
 214      || mz_header.e_magic != IMAGE_DOS_SIGNATURE) {
 215   char *p = strrchr( filename, '.' );
 216   if (!p || strcasecmp( p, ".com" ))  /* check for .COM extension */
 217   {
 218       SetLastError(ERROR_BAD_FORMAT);
 219       goto load_error;
 220   }
 221   old_com=1; /* assume .COM file */
 222   image_start=0;
 223   image_size=GetFileSize(hFile,NULL);
 224   min_size=0x10000; max_size=0x100000;
 225   mz_header.e_crlc=0;
 226   mz_header.e_ss=0; mz_header.e_sp=0xFFFE;
 227   mz_header.e_cs=0; mz_header.e_ip=0x100;
 228  } else {
 229   /* calculate load size */
 230   image_start=mz_header.e_cparhdr<<4;
 231   image_size=mz_header.e_cp<<9; /* pages are 512 bytes */
 232   if ((mz_header.e_cblp!=0)&&(mz_header.e_cblp!=4)) image_size-=512-mz_header.e_cblp;
 233   image_size-=image_start;
 234   min_size=image_size+((DWORD)mz_header.e_minalloc<<4)+(PSP_SIZE<<4);
 235   max_size=image_size+((DWORD)mz_header.e_maxalloc<<4)+(PSP_SIZE<<4);
 236  }
 237
 238   if (alloc) MZ_InitMemory();
 239
 240   if (oblk) {
 241     /* load overlay into preallocated memory */
 242     load_seg=oblk->load_seg;
 243     rel_seg=oblk->rel_seg;
 244     load_start=(LPBYTE)((DWORD)load_seg<<4);
 245   } else {
 246     /* allocate environment block */
 247     env_seg=MZ_InitEnvironment(oldenv, filename);
 248
 249     /* allocate memory for the executable */
 250     TRACE("Allocating DOS memory (min=%ld, max=%ld)\n",min_size,max_size);
 251     avail=DOSMEM_Available();
 252     if (avail<min_size) {
 253       ERR("insufficient DOS memory\n");
 254       SetLastError(ERROR_NOT_ENOUGH_MEMORY);
 255       goto load_error;
 256     }
 257     if (avail>max_size) avail=max_size;
 258     psp_start=DOSMEM_GetBlock(avail,&DOSVM_psp);
 259     if (!psp_start) {
 260       ERR("error allocating DOS memory\n");
 261       SetLastError(ERROR_NOT_ENOUGH_MEMORY);
 262       goto load_error;
 263     }
 264     load_seg=DOSVM_psp+(old_com?0:PSP_SIZE);
 265     rel_seg=load_seg;
 266     load_start=psp_start+(PSP_SIZE<<4);
 267     MZ_CreatePSP(psp_start, env_seg, oldpsp_seg);
 268   }
 269
 270  /* load executable image */
 271  TRACE("loading DOS %s image, %08lx bytes\n",old_com?"COM":"EXE",image_size);
 272  SetFilePointer(hFile,image_start,NULL,FILE_BEGIN);
 273  if (!ReadFile(hFile,load_start,image_size,&len,NULL) || len != image_size) {
 274   SetLastError(ERROR_BAD_FORMAT);
 275   goto load_error;
 276  }
 277
 278  if (mz_header.e_crlc) {
 279   /* load relocation table */
 280   TRACE("loading DOS EXE relocation table, %d entries\n",mz_header.e_crlc);
 281   /* FIXME: is this too slow without read buffering? */
 282   SetFilePointer(hFile,mz_header.e_lfarlc,NULL,FILE_BEGIN);
 283   for (x=0; x<mz_header.e_crlc; x++) {
 284    if (!ReadFile(hFile,&reloc,sizeof(reloc),&len,NULL) || len != sizeof(reloc)) {
 285     SetLastError(ERROR_BAD_FORMAT);
 286     goto load_error;
 287    }
 288    *(WORD*)SEGPTR16(load_start,reloc)+=rel_seg;
 289   }
 290  }
 291
 292   if (!oblk) {
 293     init_cs = load_seg+mz_header.e_cs;
 294     init_ip = mz_header.e_ip;
 295     init_ss = load_seg+mz_header.e_ss;
 296     init_sp = mz_header.e_sp;
 297
 298     TRACE("entry point: %04x:%04x\n",init_cs,init_ip);
 299   }
 300
 301   if (alloc && !MZ_InitTask()) {
 302     SetLastError(ERROR_GEN_FAILURE);
 303     return FALSE;
 304   }
 305
 306   return TRUE;
 307
 308 load_error:
 309   DOSVM_psp = oldpsp_seg;
 310
 311   return FALSE;
 312 }
 313
 314 /***********************************************************************
 315  *              wine_load_dos_exe (WINEDOS.@)
 316  *
 317  * Called from WineVDM when a new real-mode DOS process is started.
 318  * Loads DOS program into memory and executes the program.
 319  */
 320 void WINAPI wine_load_dos_exe( LPCSTR filename, LPCSTR cmdline )
 321 {
 322     char dos_cmdtail[126];
 323     int  dos_length = 0;
 324
 325     HANDLE hFile = CreateFileA( filename, GENERIC_READ, FILE_SHARE_READ,
 326                                 NULL, OPEN_EXISTING, 0, 0 );
 327     if (hFile == INVALID_HANDLE_VALUE) return;
 328     DOSVM_isdosexe = TRUE;
 329
 330     if(cmdline && *cmdline)
 331     {
 332         dos_length = strlen(cmdline);
 333         memmove( dos_cmdtail + 1, cmdline,
 334                  (dos_length < 125) ? dos_length : 125 );
 335
 336         /* Non-empty command tail always starts with at least one space. */
 337         dos_cmdtail[0] = ' ';
 338         dos_length++;
 339
 340         /*
 341          * If command tail is longer than 126 characters,
 342          * set tail length to 127 and fill CMDLINE environment variable
 343          * with full command line (this includes filename).
 344          */
 345         if (dos_length > 126)
 346         {
 347             char *cmd = HeapAlloc( GetProcessHeap(), 0,
 348                                    dos_length + strlen(filename) + 4 );
 349             char *ptr = cmd;
 350
 351             if (!cmd)
 352                 return;
 353
 354             /*
 355              * Append filename. If path includes spaces, quote the path.
 356              */
 357             if (strchr(filename, ' '))
 358             {
 359                 *ptr++ = '\"';
 360                 strcpy( ptr, filename );
 361                 ptr += strlen(filename);
 362                 *ptr++ = '\"';
 363             }
 364             else
 365             {
 366                 strcpy( ptr, filename );
 367                 ptr += strlen(filename);
 368             }
 369
 370             /*
 371              * Append command tail.
 372              */
 373             if (cmdline[0] != ' ')
 374                 *ptr++ = ' ';
 375             strcpy( ptr, cmdline );
 376
 377             /*
 378              * Set environment variable. This will be passed to
 379              * new DOS process.
 380              */
 381             if (!SetEnvironmentVariableA( "CMDLINE", cmd ))
 382             {
 383                 HeapFree(GetProcessHeap(), 0, cmd );
 384                 return;
 385             }
 386
 387             HeapFree(GetProcessHeap(), 0, cmd );
 388             dos_length = 127;
 389         }
 390     }
 391
 392     if (MZ_DoLoadImage( hFile, filename, NULL ))
 393         MZ_Launch( dos_cmdtail, dos_length );
 394 }
 395
 396 /***********************************************************************
 397  *              MZ_Exec
 398  *
 399  * this may only be called from existing DOS processes
 400  */
 401 BOOL WINAPI MZ_Exec( CONTEXT86 *context, LPCSTR filename, BYTE func, LPVOID paramblk )
 402 {
 403   DWORD binType;
 404   STARTUPINFOA st;
 405   PROCESS_INFORMATION pe;
 406   HANDLE hFile;
 407
 408   BOOL ret = FALSE;
 409
 410   if(!GetBinaryTypeA(filename, &binType))   /* determine what kind of binary this is */
 411   {
 412     return FALSE; /* binary is not an executable */
 413   }
 414
 415   /* handle non-dos executables */
 416   if(binType != SCS_DOS_BINARY)
 417   {
 418     if(func == 0) /* load and execute */
 419     {
 420       LPBYTE fullCmdLine;
 421       WORD fullCmdLength;
 422       LPBYTE psp_start = (LPBYTE)((DWORD)DOSVM_psp << 4);
 423       PDB16 *psp = (PDB16 *)psp_start;
 424       ExecBlock *blk = (ExecBlock *)paramblk;
 425       LPBYTE cmdline = PTR_REAL_TO_LIN(SELECTOROF(blk->cmdline),OFFSETOF(blk->cmdline));
 426       LPBYTE envblock = PTR_REAL_TO_LIN(psp->environment, 0);
 427       int    cmdLength = cmdline[0];
 428
 429       /*
 430        * If cmdLength is 127, command tail is truncated and environment
 431        * variable CMDLINE should contain full command line
 432        * (this includes filename).
 433        */
 434       if (cmdLength == 127)
 435       {
 436           FIXME( "CMDLINE argument passing is unimplemented.\n" );
 437           cmdLength = 126; /* FIXME */
 438       }
 439
 440       fullCmdLength = (strlen(filename) + 1) + cmdLength + 1; /* filename + space + cmdline + terminating null character */
 441
 442       fullCmdLine = HeapAlloc(GetProcessHeap(), 0, fullCmdLength);
 443       if(!fullCmdLine) return FALSE; /* return false on memory alloc failure */
 444
 445       /* build the full command line from the executable file and the command line being passed in */
 446       snprintf(fullCmdLine, fullCmdLength, "%s ", filename); /* start off with the executable filename and a space */
 447       memcpy(fullCmdLine + strlen(fullCmdLine), cmdline + 1, cmdLength); /* append cmdline onto the end */
 448       fullCmdLine[fullCmdLength - 1] = 0; /* null terminate string */
 449
 450       ZeroMemory (&st, sizeof(STARTUPINFOA));
 451       st.cb = sizeof(STARTUPINFOA);
 452       ret = CreateProcessA (NULL, fullCmdLine, NULL, NULL, TRUE, 0, envblock, NULL, &st, &pe);
 453
 454       /* wait for the app to finish and clean up PROCESS_INFORMATION handles */
 455       if(ret)
 456       {
 457         WaitForSingleObject(pe.hProcess, INFINITE);  /* wait here until the child process is complete */
 458         CloseHandle(pe.hProcess);
 459         CloseHandle(pe.hThread);
 460       }
 461
 462       HeapFree(GetProcessHeap(), 0, fullCmdLine);  /* free the memory we allocated */
 463     }
 464     else
 465     {
 466       FIXME("EXEC type of %d not implemented for non-dos executables\n", func);
 467       ret = FALSE;
 468     }
 469
 470     return ret;
 471   } /* if(binType != SCS_DOS_BINARY) */
 472
 473
 474   /* handle dos executables */
 475
 476   hFile = CreateFileA( filename, GENERIC_READ, FILE_SHARE_READ,
 477                              NULL, OPEN_EXISTING, 0, 0);
 478   if (hFile == INVALID_HANDLE_VALUE) return FALSE;
 479
 480   switch (func) {
 481   case 0: /* load and execute */
 482   case 1: /* load but don't execute */
 483     {
 484       /* save current process's return SS:SP now */
 485       LPBYTE psp_start = (LPBYTE)((DWORD)DOSVM_psp << 4);
 486       PDB16 *psp = (PDB16 *)psp_start;
 487       psp->saveStack = (DWORD)MAKESEGPTR(context->SegSs, LOWORD(context->Esp));
 488     }
 489     ret = MZ_DoLoadImage( hFile, filename, NULL );
 490     if (ret) {
 491       /* MZ_LoadImage created a new PSP and loaded new values into it,
 492        * let's work on the new values now */
 493       LPBYTE psp_start = (LPBYTE)((DWORD)DOSVM_psp << 4);
 494       ExecBlock *blk = (ExecBlock *)paramblk;
 495       LPBYTE cmdline = PTR_REAL_TO_LIN(SELECTOROF(blk->cmdline),OFFSETOF(blk->cmdline));
 496
 497       /* First character contains the length of the command line. */
 498       MZ_FillPSP(psp_start, cmdline + 1, cmdline[0]);
 499
 500       /* the lame MS-DOS engineers decided that the return address should be in int22 */
 501       DOSVM_SetRMHandler(0x22, (FARPROC16)MAKESEGPTR(context->SegCs, LOWORD(context->Eip)));
 502       if (func) {
 503         /* don't execute, just return startup state */
 504         blk->init_cs = init_cs;
 505         blk->init_ip = init_ip;
 506         blk->init_ss = init_ss;
 507         blk->init_sp = init_sp;
 508       } else {
 509         /* execute by making us return to new process */
 510         context->SegCs = init_cs;
 511         context->Eip   = init_ip;
 512         context->SegSs = init_ss;
 513         context->Esp   = init_sp;
 514         context->SegDs = DOSVM_psp;
 515         context->SegEs = DOSVM_psp;
 516         context->Eax   = 0;
 517       }
 518     }
 519     break;
 520   case 3: /* load overlay */
 521     {
 522       OverlayBlock *blk = (OverlayBlock *)paramblk;
 523       ret = MZ_DoLoadImage( hFile, filename, blk );
 524     }
 525     break;
 526   default:
 527     FIXME("EXEC load type %d not implemented\n", func);
 528     SetLastError(ERROR_INVALID_FUNCTION);
 529     break;
 530   }
 531   CloseHandle(hFile);
 532   return ret;
 533 }
 534
 535 /***********************************************************************
 536  *              MZ_AllocDPMITask
 537  */
 538 void WINAPI MZ_AllocDPMITask( void )
 539 {
 540   MZ_InitMemory();
 541   MZ_InitTask();
 542 }
 543
 544 /***********************************************************************
 545  *              MZ_RunInThread
 546  */
 547 void WINAPI MZ_RunInThread( PAPCFUNC proc, ULONG_PTR arg )
 548 {
 549   if (loop_thread) {
 550     DOS_SPC spc;
 551     HANDLE event;
 552
 553     spc.proc = proc;
 554     spc.arg = arg;
 555     event = CreateEventA(NULL, TRUE, FALSE, NULL);
 556     PostThreadMessageA(loop_tid, WM_USER, (WPARAM)event, (LPARAM)&spc);
 557     WaitForSingleObject(event, INFINITE);
 558     CloseHandle(event);
 559   } else
 560     proc(arg);
 561 }
 562
 563 static DWORD WINAPI MZ_DOSVM( LPVOID lpExtra )
 564 {
 565   CONTEXT context;
 566   DWORD ret;
 567
 568   dosvm_pid = getpid();
 569
 570   memset( &context, 0, sizeof(context) );
 571   context.SegCs  = init_cs;
 572   context.Eip    = init_ip;
 573   context.SegSs  = init_ss;
 574   context.Esp    = init_sp;
 575   context.SegDs  = DOSVM_psp;
 576   context.SegEs  = DOSVM_psp;
 577   context.EFlags = V86_FLAG | VIF_MASK;
 578   DOSVM_SetTimer(0x10000);
 579   ret = DOSVM_Enter( &context );
 580
 581   dosvm_pid = 0;
 582   return ret;
 583 }
 584
 585 static BOOL MZ_InitTask(void)
 586 {
 587   if (!DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
 588                        GetCurrentProcess(), &loop_thread,
 589                        0, FALSE, DUPLICATE_SAME_ACCESS))
 590     return FALSE;
 591   dosvm_thread = CreateThread(NULL, 0, MZ_DOSVM, NULL, CREATE_SUSPENDED, &dosvm_tid);
 592   if (!dosvm_thread) {
 593     CloseHandle(loop_thread);
 594     loop_thread = 0;
 595     return FALSE;
 596   }
 597   loop_tid = GetCurrentThreadId();
 598   return TRUE;
 599 }
 600
 601 static void MZ_Launch( LPCSTR cmdtail, int length )
 602 {
 603   TDB *pTask = GlobalLock16( GetCurrentTask() );
 604   BYTE *psp_start = PTR_REAL_TO_LIN( DOSVM_psp, 0 );
 605   DWORD rv;
 606   SYSLEVEL *lock;
 607
 608   MZ_FillPSP(psp_start, cmdtail, length);
 609   pTask->flags |= TDBF_WINOLDAP;
 610
 611   /* DTA is set to PSP:0080h when a program is started. */
 612   pTask->dta = MAKESEGPTR( DOSVM_psp, 0x80 );
 613
 614   GetpWin16Lock( &lock );
 615   _LeaveSysLevel( lock );
 616
 617   ResumeThread(dosvm_thread);
 618   rv = DOSVM_Loop(dosvm_thread);
 619
 620   CloseHandle(dosvm_thread);
 621   dosvm_thread = 0; dosvm_tid = 0;
 622   CloseHandle(loop_thread);
 623   loop_thread = 0; loop_tid = 0;
 624
 625   VGA_Clean();
 626   ExitThread(rv);
 627 }
 628
 629 /***********************************************************************
 630  *              MZ_Exit
 631  */
 632 void WINAPI MZ_Exit( CONTEXT86 *context, BOOL cs_psp, WORD retval )
 633 {
 634   if (DOSVM_psp) {
 635     WORD psp_seg = cs_psp ? context->SegCs : DOSVM_psp;
 636     LPBYTE psp_start = (LPBYTE)((DWORD)psp_seg << 4);
 637     PDB16 *psp = (PDB16 *)psp_start;
 638     WORD parpsp = psp->parentPSP; /* check for parent DOS process */
 639     if (parpsp) {
 640       /* retrieve parent's return address */
 641       FARPROC16 retaddr = DOSVM_GetRMHandler(0x22);
 642       /* restore interrupts */
 643       DOSVM_SetRMHandler(0x22, psp->savedint22);
 644       DOSVM_SetRMHandler(0x23, psp->savedint23);
 645       DOSVM_SetRMHandler(0x24, psp->savedint24);
 646       /* FIXME: deallocate file handles etc */
 647       /* free process's associated memory
 648        * FIXME: walk memory and deallocate all blocks owned by process */
 649       DOSMEM_FreeBlock( PTR_REAL_TO_LIN(psp->environment,0) );
 650       DOSMEM_FreeBlock( PTR_REAL_TO_LIN(DOSVM_psp,0) );
 651       /* switch to parent's PSP */
 652       DOSVM_psp = parpsp;
 653       psp_start = (LPBYTE)((DWORD)parpsp << 4);
 654       psp = (PDB16 *)psp_start;
 655       /* now return to parent */
 656       DOSVM_retval = retval;
 657       context->SegCs = SELECTOROF(retaddr);
 658       context->Eip   = OFFSETOF(retaddr);
 659       context->SegSs = SELECTOROF(psp->saveStack);
 660       context->Esp   = OFFSETOF(psp->saveStack);
 661       return;
 662     } else
 663       TRACE("killing DOS task\n");
 664   }
 665   ExitThread( retval );
 666 }
 667
 668
 669 /***********************************************************************
 670  *              MZ_Current
 671  */
 672 BOOL WINAPI MZ_Current( void )
 673 {
 674   return (dosvm_pid != 0); /* FIXME: do a better check */
 675 }
 676
 677 #else /* !MZ_SUPPORTED */
 678
 679 /***********************************************************************
 680  *              wine_load_dos_exe (WINEDOS.@)
 681  */
 682 void WINAPI wine_load_dos_exe( LPCSTR filename, LPCSTR cmdline )
 683 {
 684   WARN("DOS executables not supported on this platform\n");
 685   SetLastError(ERROR_BAD_FORMAT);
 686 }
 687
 688 /***********************************************************************
 689  *              MZ_Exec
 690  */
 691 BOOL WINAPI MZ_Exec( CONTEXT86 *context, LPCSTR filename, BYTE func, LPVOID paramblk )
 692 {
 693   /* can't happen */
 694   SetLastError(ERROR_BAD_FORMAT);
 695   return FALSE;
 696 }
 697
 698 /***********************************************************************
 699  *              MZ_AllocDPMITask
 700  */
 701 void WINAPI MZ_AllocDPMITask( void )
 702 {
 703     ERR("Actual real-mode calls not supported on this platform!\n");
 704 }
 705
 706 /***********************************************************************
 707  *              MZ_RunInThread
 708  */
 709 void WINAPI MZ_RunInThread( PAPCFUNC proc, ULONG_PTR arg )
 710 {
 711     proc(arg);
 712 }
 713
 714 /***********************************************************************
 715  *              MZ_Exit
 716  */
 717 void WINAPI MZ_Exit( CONTEXT86 *context, BOOL cs_psp, WORD retval )
 718 {
 719   ExitThread( retval );
 720 }
 721
 722 /***********************************************************************
 723  *              MZ_Current
 724  */
 725 BOOL WINAPI MZ_Current( void )
 726 {
 727     return FALSE;
 728 }
 729
 730 #endif /* !MZ_SUPPORTED */