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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, 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 <stdarg.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <fcntl.h>
  31 #include <signal.h>
  32 #ifdef HAVE_UNISTD_H
  33 # include <unistd.h>
  34 #endif
  35 #include <sys/types.h>
  36 #ifdef HAVE_SYS_STAT_H
  37 # include <sys/stat.h>
  38 #endif
  39 #ifdef HAVE_SYS_TIME_H
  40 # include <sys/time.h>
  41 #endif
  42 #include "windef.h"
  43 #include "winbase.h"
  44 #include "wine/winbase16.h"
  45 #include "wingdi.h"
  46 #include "winuser.h"
  47 #include "winerror.h"
  48 #include "wine/debug.h"
  49 #include "dosexe.h"
  50 #include "dosvm.h"
  51 #include "vga.h"
  52
  53 WINE_DEFAULT_DEBUG_CHANNEL(module);
  54
  55 static BOOL DOSVM_isdosexe;
  56
  57 /**********************************************************************
  58  *          DOSVM_IsWin16
  59  *
  60  * Return TRUE if we are in Windows process.
  61  */
  62 BOOL DOSVM_IsWin16(void)
  63 {
  64   return DOSVM_isdosexe ? FALSE : TRUE;
  65 }
  66
  67 /**********************************************************************
  68  *          DOSVM_Exit
  69  */
  70 void DOSVM_Exit( WORD retval )
  71 {
  72     DWORD count;
  73
  74     ReleaseThunkLock( &count );
  75     ExitThread( retval );
  76 }
  77
  78
  79 #ifdef MZ_SUPPORTED
  80
  81 #ifdef HAVE_SYS_MMAN_H
  82 # include <sys/mman.h>
  83 #endif
  84
  85 /* define this to try mapping through /proc/pid/mem instead of a temp file,
  86    but Linus doesn't like mmapping /proc/pid/mem, so it doesn't work for me */
  87 #undef MZ_MAPSELF
  88
  89 #define BIOS_DATA_SEGMENT 0x40
  90 #define PSP_SIZE 0x10
  91
  92 #define SEG16(ptr,seg) ((LPVOID)((BYTE*)ptr+((DWORD)(seg)<<4)))
  93 #define SEGPTR16(ptr,segptr) ((LPVOID)((BYTE*)ptr+((DWORD)SELECTOROF(segptr)<<4)+OFFSETOF(segptr)))
  94
  95 /* structures for EXEC */
  96
  97 #include "pshpack1.h"
  98
  99 typedef struct {
 100   WORD env_seg;
 101   DWORD cmdline;
 102   DWORD fcb1;
 103   DWORD fcb2;
 104   WORD init_sp;
 105   WORD init_ss;
 106   WORD init_ip;
 107   WORD init_cs;
 108 } ExecBlock;
 109
 110 typedef struct {
 111   WORD load_seg;
 112   WORD rel_seg;
 113 } OverlayBlock;
 114
 115 #include "poppack.h"
 116
 117 /* global variables */
 118
 119 pid_t dosvm_pid;
 120
 121 static WORD init_cs,init_ip,init_ss,init_sp;
 122 static HANDLE dosvm_thread, loop_thread;
 123 static DWORD dosvm_tid, loop_tid;
 124
 125 static void MZ_Launch( LPCSTR cmdtail, int length );
 126 static BOOL MZ_InitTask(void);
 127
 128 static void MZ_CreatePSP( LPVOID lpPSP, WORD env, WORD par )
 129 {
 130   PDB16*psp=lpPSP;
 131
 132   psp->int20=0x20CD; /* int 20 */
 133   /* some programs use this to calculate how much memory they need */
 134   psp->nextParagraph=0x9FFF; /* FIXME: use a real value */
 135   /* FIXME: dispatcher */
 136   psp->savedint22 = DOSVM_GetRMHandler(0x22);
 137   psp->savedint23 = DOSVM_GetRMHandler(0x23);
 138   psp->savedint24 = DOSVM_GetRMHandler(0x24);
 139   psp->parentPSP=par;
 140   psp->environment=env;
 141   /* FIXME: more PSP stuff */
 142 }
 143
 144 static void MZ_FillPSP( LPVOID lpPSP, LPCSTR cmdtail, int length )
 145 {
 146     PDB16 *psp = lpPSP;
 147
 148     if(length > 127)
 149     {
 150         WARN( "Command tail truncated! (length %d)\n", length );
 151         length = 126;
 152     }
 153
 154     psp->cmdLine[0] = length;
 155
 156     /*
 157      * Length of exactly 127 bytes means that full command line is
 158      * stored in environment variable CMDLINE and PSP contains
 159      * command tail truncated to 126 bytes.
 160      */
 161     if(length == 127)
 162         length = 126;
 163
 164     if(length > 0)
 165         memmove(psp->cmdLine+1, cmdtail, length);
 166
 167     psp->cmdLine[length+1] = '\r';
 168
 169     /* FIXME: more PSP stuff */
 170 }
 171
 172 static WORD MZ_InitEnvironment( LPCSTR env, LPCSTR name )
 173 {
 174  unsigned sz=0;
 175  unsigned i=0;
 176  WORD seg;
 177  LPSTR envblk;
 178
 179  if (env) {
 180   /* get size of environment block */
 181   while (env[sz++]) sz+=strlen(env+sz)+1;
 182  } else sz++;
 183  /* allocate it */
 184  envblk=DOSMEM_AllocBlock(sz+sizeof(WORD)+strlen(name)+1,&seg);
 185  /* fill it */
 186  if (env) {
 187   memcpy(envblk,env,sz);
 188  } else envblk[0]=0;
 189  /* DOS environment variables are uppercase */
 190  while (envblk[i]){
 191   while (envblk[i] != '='){
 192    if (envblk[i]>='a' && envblk[i] <= 'z'){
 193     envblk[i] -= 32;
 194    }
 195    i++;
 196   }
 197   i += strlen(envblk+i) + 1;
 198  }
 199  /* DOS 3.x: the block contains 1 additional string */
 200  *(WORD*)(envblk+sz)=1;
 201  /* being the program name itself */
 202  strcpy(envblk+sz+sizeof(WORD),name);
 203  return seg;
 204 }
 205
 206 static BOOL MZ_InitMemory(void)
 207 {
 208     /* initialize the memory */
 209     TRACE("Initializing DOS memory structures\n");
 210     DOSMEM_MapDosLayout();
 211     DOSDEV_InstallDOSDevices();
 212     MSCDEX_InstallCDROM();
 213
 214     return TRUE;
 215 }
 216
 217 static BOOL MZ_DoLoadImage( HANDLE hFile, LPCSTR filename, OverlayBlock *oblk, WORD par_env_seg )
 218 {
 219   IMAGE_DOS_HEADER mz_header;
 220   DWORD image_start,image_size,min_size,max_size,avail;
 221   BYTE*psp_start,*load_start;
 222   LPSTR oldenv = 0;
 223   int x, old_com=0, alloc;
 224   SEGPTR reloc;
 225   WORD env_seg, load_seg, rel_seg, oldpsp_seg;
 226   DWORD len;
 227
 228   if (DOSVM_psp) {
 229     /* DOS process already running, inherit from it */
 230     PDB16* par_psp;
 231     alloc=0;
 232     oldpsp_seg = DOSVM_psp;
 233     if( !par_env_seg) {
 234         par_psp = (PDB16*)((DWORD)DOSVM_psp << 4);
 235         oldenv = (LPSTR)((DWORD)par_psp->environment << 4);
 236     }
 237   } else {
 238     /* allocate new DOS process, inheriting from Wine environment */
 239     alloc=1;
 240     oldpsp_seg = 0;
 241     if( !par_env_seg)
 242         oldenv = GetEnvironmentStringsA();
 243   }
 244
 245  SetFilePointer(hFile,0,NULL,FILE_BEGIN);
 246  if (   !ReadFile(hFile,&mz_header,sizeof(mz_header),&len,NULL)
 247      || len != sizeof(mz_header)
 248      || mz_header.e_magic != IMAGE_DOS_SIGNATURE) {
 249   char *p = strrchr( filename, '.' );
 250   if (!p || strcasecmp( p, ".com" ))  /* check for .COM extension */
 251   {
 252       SetLastError(ERROR_BAD_FORMAT);
 253       goto load_error;
 254   }
 255   old_com=1; /* assume .COM file */
 256   image_start=0;
 257   image_size=GetFileSize(hFile,NULL);
 258   min_size=0x10000; max_size=0x100000;
 259   mz_header.e_crlc=0;
 260   mz_header.e_ss=0; mz_header.e_sp=0xFFFE;
 261   mz_header.e_cs=0; mz_header.e_ip=0x100;
 262  } else {
 263   /* calculate load size */
 264   image_start=mz_header.e_cparhdr<<4;
 265   image_size=mz_header.e_cp<<9; /* pages are 512 bytes */
 266   /* From Ralf Brown Interrupt List: If the word at offset 02h is 4, it should
 267    * be treated as 00h, since pre-1.10 versions of the MS linker set it that
 268    * way. */
 269   if ((mz_header.e_cblp!=0)&&(mz_header.e_cblp!=4)) image_size-=512-mz_header.e_cblp;
 270   image_size-=image_start;
 271   min_size=image_size+((DWORD)mz_header.e_minalloc<<4)+(PSP_SIZE<<4);
 272   max_size=image_size+((DWORD)mz_header.e_maxalloc<<4)+(PSP_SIZE<<4);
 273  }
 274
 275   if (alloc) MZ_InitMemory();
 276
 277   if (oblk) {
 278     /* load overlay into preallocated memory */
 279     load_seg=oblk->load_seg;
 280     rel_seg=oblk->rel_seg;
 281     load_start=(LPBYTE)((DWORD)load_seg<<4);
 282   } else {
 283     /* allocate environment block */
 284     if( par_env_seg)
 285         env_seg = par_env_seg;
 286     else
 287         env_seg=MZ_InitEnvironment(oldenv, filename);
 288     if (alloc)
 289         FreeEnvironmentStringsA( oldenv);
 290
 291     /* allocate memory for the executable */
 292     TRACE("Allocating DOS memory (min=%d, max=%d)\n",min_size,max_size);
 293     avail=DOSMEM_Available();
 294     if (avail<min_size) {
 295       ERR("insufficient DOS memory\n");
 296       SetLastError(ERROR_NOT_ENOUGH_MEMORY);
 297       goto load_error;
 298     }
 299     if (avail>max_size) avail=max_size;
 300     psp_start=DOSMEM_AllocBlock(avail,&DOSVM_psp);
 301     if (!psp_start) {
 302       ERR("error allocating DOS memory\n");
 303       SetLastError(ERROR_NOT_ENOUGH_MEMORY);
 304       goto load_error;
 305     }
 306     load_seg=DOSVM_psp+(old_com?0:PSP_SIZE);
 307     rel_seg=load_seg;
 308     load_start=psp_start+(PSP_SIZE<<4);
 309     MZ_CreatePSP(psp_start, env_seg, oldpsp_seg);
 310   }
 311
 312  /* load executable image */
 313  TRACE("loading DOS %s image, %08x bytes\n",old_com?"COM":"EXE",image_size);
 314  SetFilePointer(hFile,image_start,NULL,FILE_BEGIN);
 315  if (!ReadFile(hFile,load_start,image_size,&len,NULL) || len != image_size) {
 316   /* check if this is due to the workaround for the pre-1.10 MS linker and we
 317      really had only 4 bytes on the last page */
 318   if (mz_header.e_cblp != 4 || image_size - len != 512 - 4) {
 319     SetLastError(ERROR_BAD_FORMAT);
 320     goto load_error;
 321   }
 322  }
 323
 324  if (mz_header.e_crlc) {
 325   /* load relocation table */
 326   TRACE("loading DOS EXE relocation table, %d entries\n",mz_header.e_crlc);
 327   /* FIXME: is this too slow without read buffering? */
 328   SetFilePointer(hFile,mz_header.e_lfarlc,NULL,FILE_BEGIN);
 329   for (x=0; x<mz_header.e_crlc; x++) {
 330    if (!ReadFile(hFile,&reloc,sizeof(reloc),&len,NULL) || len != sizeof(reloc)) {
 331     SetLastError(ERROR_BAD_FORMAT);
 332     goto load_error;
 333    }
 334    *(WORD*)SEGPTR16(load_start,reloc)+=rel_seg;
 335   }
 336  }
 337
 338   if (!oblk) {
 339     init_cs = load_seg+mz_header.e_cs;
 340     init_ip = mz_header.e_ip;
 341     init_ss = load_seg+mz_header.e_ss;
 342     init_sp = mz_header.e_sp;
 343     if (old_com){
 344       /* .COM files exit with ret. Make sure they jump to psp start (=int 20) */
 345       WORD* stack = PTR_REAL_TO_LIN(init_ss, init_sp);
 346       *stack = 0;
 347     }
 348
 349     TRACE("entry point: %04x:%04x\n",init_cs,init_ip);
 350   }
 351
 352   if (alloc && !MZ_InitTask()) {
 353     SetLastError(ERROR_GEN_FAILURE);
 354     return FALSE;
 355   }
 356
 357   return TRUE;
 358
 359 load_error:
 360   DOSVM_psp = oldpsp_seg;
 361
 362   return FALSE;
 363 }
 364
 365 /***********************************************************************
 366  *              wine_load_dos_exe (WINEDOS.@)
 367  *
 368  * Called from WineVDM when a new real-mode DOS process is started.
 369  * Loads DOS program into memory and executes the program.
 370  */
 371 void WINAPI wine_load_dos_exe( LPCSTR filename, LPCSTR cmdline )
 372 {
 373     char dos_cmdtail[126];
 374     int  dos_length = 0;
 375
 376     HANDLE hFile = CreateFileA( filename, GENERIC_READ, FILE_SHARE_READ,
 377                                 NULL, OPEN_EXISTING, 0, 0 );
 378     if (hFile == INVALID_HANDLE_VALUE) return;
 379     DOSVM_isdosexe = TRUE;
 380
 381     if(cmdline && *cmdline)
 382     {
 383         dos_length = strlen(cmdline);
 384         memmove( dos_cmdtail + 1, cmdline,
 385                  (dos_length < 125) ? dos_length : 125 );
 386
 387         /* Non-empty command tail always starts with at least one space. */
 388         dos_cmdtail[0] = ' ';
 389         dos_length++;
 390
 391         /*
 392          * If command tail is longer than 126 characters,
 393          * set tail length to 127 and fill CMDLINE environment variable
 394          * with full command line (this includes filename).
 395          */
 396         if (dos_length > 126)
 397         {
 398             char *cmd = HeapAlloc( GetProcessHeap(), 0,
 399                                    dos_length + strlen(filename) + 4 );
 400             char *ptr = cmd;
 401
 402             if (!cmd)
 403                 return;
 404
 405             /*
 406              * Append filename. If path includes spaces, quote the path.
 407              */
 408             if (strchr(filename, ' '))
 409             {
 410                 *ptr++ = '\"';
 411                 strcpy( ptr, filename );
 412                 ptr += strlen(filename);
 413                 *ptr++ = '\"';
 414             }
 415             else
 416             {
 417                 strcpy( ptr, filename );
 418                 ptr += strlen(filename);
 419             }
 420
 421             /*
 422              * Append command tail.
 423              */
 424             if (cmdline[0] != ' ')
 425                 *ptr++ = ' ';
 426             strcpy( ptr, cmdline );
 427
 428             /*
 429              * Set environment variable. This will be passed to
 430              * new DOS process.
 431              */
 432             if (!SetEnvironmentVariableA( "CMDLINE", cmd ))
 433             {
 434                 HeapFree(GetProcessHeap(), 0, cmd );
 435                 return;
 436             }
 437
 438             HeapFree(GetProcessHeap(), 0, cmd );
 439             dos_length = 127;
 440         }
 441     }
 442
 443     if (MZ_DoLoadImage( hFile, filename, NULL, 0 ))
 444         MZ_Launch( dos_cmdtail, dos_length );
 445 }
 446
 447 /***********************************************************************
 448  *              MZ_Exec
 449  *
 450  * this may only be called from existing DOS processes
 451  */
 452 BOOL WINAPI MZ_Exec( CONTEXT86 *context, LPCSTR filename, BYTE func, LPVOID paramblk )
 453 {
 454   DWORD binType;
 455   STARTUPINFOA st;
 456   PROCESS_INFORMATION pe;
 457   HANDLE hFile;
 458
 459   BOOL ret = FALSE;
 460
 461   if(!GetBinaryTypeA(filename, &binType))   /* determine what kind of binary this is */
 462   {
 463     return FALSE; /* binary is not an executable */
 464   }
 465
 466   /* handle non-dos executables */
 467   if(binType != SCS_DOS_BINARY)
 468   {
 469     if(func == 0) /* load and execute */
 470     {
 471       LPSTR fullCmdLine;
 472       WORD fullCmdLength;
 473       LPBYTE psp_start = (LPBYTE)((DWORD)DOSVM_psp << 4);
 474       PDB16 *psp = (PDB16 *)psp_start;
 475       ExecBlock *blk = paramblk;
 476       LPBYTE cmdline = PTR_REAL_TO_LIN(SELECTOROF(blk->cmdline),OFFSETOF(blk->cmdline));
 477       LPBYTE envblock = PTR_REAL_TO_LIN(psp->environment, 0);
 478       int    cmdLength = cmdline[0];
 479
 480       /*
 481        * If cmdLength is 127, command tail is truncated and environment
 482        * variable CMDLINE should contain full command line
 483        * (this includes filename).
 484        */
 485       if (cmdLength == 127)
 486       {
 487           FIXME( "CMDLINE argument passing is unimplemented.\n" );
 488           cmdLength = 126; /* FIXME */
 489       }
 490
 491       fullCmdLength = (strlen(filename) + 1) + cmdLength + 1; /* filename + space + cmdline + terminating null character */
 492
 493       fullCmdLine = HeapAlloc(GetProcessHeap(), 0, fullCmdLength);
 494       if(!fullCmdLine) return FALSE; /* return false on memory alloc failure */
 495
 496       /* build the full command line from the executable file and the command line being passed in */
 497       snprintf(fullCmdLine, fullCmdLength, "%s ", filename); /* start off with the executable filename and a space */
 498       memcpy(fullCmdLine + strlen(fullCmdLine), cmdline + 1, cmdLength); /* append cmdline onto the end */
 499       fullCmdLine[fullCmdLength - 1] = 0; /* null terminate string */
 500
 501       ZeroMemory (&st, sizeof(STARTUPINFOA));
 502       st.cb = sizeof(STARTUPINFOA);
 503       ret = CreateProcessA (NULL, fullCmdLine, NULL, NULL, TRUE, 0, envblock, NULL, &st, &pe);
 504
 505       /* wait for the app to finish and clean up PROCESS_INFORMATION handles */
 506       if(ret)
 507       {
 508         WaitForSingleObject(pe.hProcess, INFINITE);  /* wait here until the child process is complete */
 509         CloseHandle(pe.hProcess);
 510         CloseHandle(pe.hThread);
 511       }
 512
 513       HeapFree(GetProcessHeap(), 0, fullCmdLine);  /* free the memory we allocated */
 514     }
 515     else
 516     {
 517       FIXME("EXEC type of %d not implemented for non-dos executables\n", func);
 518       ret = FALSE;
 519     }
 520
 521     return ret;
 522   } /* if(binType != SCS_DOS_BINARY) */
 523
 524
 525   /* handle dos executables */
 526
 527   hFile = CreateFileA( filename, GENERIC_READ, FILE_SHARE_READ,
 528                              NULL, OPEN_EXISTING, 0, 0);
 529   if (hFile == INVALID_HANDLE_VALUE) return FALSE;
 530
 531   switch (func) {
 532   case 0: /* load and execute */
 533   case 1: /* load but don't execute */
 534     {
 535       /* save current process's return SS:SP now */
 536       LPBYTE psp_start = (LPBYTE)((DWORD)DOSVM_psp << 4);
 537       PDB16 *psp = (PDB16 *)psp_start;
 538       psp->saveStack = (DWORD)MAKESEGPTR(context->SegSs, LOWORD(context->Esp));
 539     }
 540     ret = MZ_DoLoadImage( hFile, filename, NULL, ((ExecBlock *)paramblk)->env_seg );
 541     if (ret) {
 542       /* MZ_LoadImage created a new PSP and loaded new values into it,
 543        * let's work on the new values now */
 544       LPBYTE psp_start = (LPBYTE)((DWORD)DOSVM_psp << 4);
 545       ExecBlock *blk = paramblk;
 546       LPBYTE cmdline = PTR_REAL_TO_LIN(SELECTOROF(blk->cmdline),OFFSETOF(blk->cmdline));
 547
 548       /* First character contains the length of the command line. */
 549       MZ_FillPSP(psp_start, (LPSTR)cmdline + 1, cmdline[0]);
 550
 551       /* the lame MS-DOS engineers decided that the return address should be in int22 */
 552       DOSVM_SetRMHandler(0x22, (FARPROC16)MAKESEGPTR(context->SegCs, LOWORD(context->Eip)));
 553       if (func) {
 554         /* don't execute, just return startup state */
 555         /*
 556          * From Ralph Brown:
 557          *  For function 01h, the AX value to be passed to the child program
 558          *  is put on top of the child's stack
 559          */
 560         LPBYTE stack;
 561         init_sp -= 2;
 562         stack = CTX_SEG_OFF_TO_LIN(context, init_ss, init_sp);
 563         /* FIXME: push AX correctly */
 564         stack[0] = 0x00;    /* push AL */
 565         stack[1] = 0x00;    /* push AH */
 566
 567         blk->init_cs = init_cs;
 568         blk->init_ip = init_ip;
 569         blk->init_ss = init_ss;
 570         blk->init_sp = init_sp;
 571       } else {
 572         /* execute by making us return to new process */
 573         context->SegCs = init_cs;
 574         context->Eip   = init_ip;
 575         context->SegSs = init_ss;
 576         context->Esp   = init_sp;
 577         context->SegDs = DOSVM_psp;
 578         context->SegEs = DOSVM_psp;
 579         context->Eax   = 0;
 580       }
 581     }
 582     break;
 583   case 3: /* load overlay */
 584     {
 585       OverlayBlock *blk = paramblk;
 586       ret = MZ_DoLoadImage( hFile, filename, blk, 0);
 587     }
 588     break;
 589   default:
 590     FIXME("EXEC load type %d not implemented\n", func);
 591     SetLastError(ERROR_INVALID_FUNCTION);
 592     break;
 593   }
 594   CloseHandle(hFile);
 595   return ret;
 596 }
 597
 598 /***********************************************************************
 599  *              MZ_AllocDPMITask
 600  */
 601 void WINAPI MZ_AllocDPMITask( void )
 602 {
 603   MZ_InitMemory();
 604   MZ_InitTask();
 605 }
 606
 607 /***********************************************************************
 608  *              MZ_RunInThread
 609  */
 610 void WINAPI MZ_RunInThread( PAPCFUNC proc, ULONG_PTR arg )
 611 {
 612   if (loop_thread) {
 613     DOS_SPC spc;
 614     HANDLE event;
 615
 616     spc.proc = proc;
 617     spc.arg = arg;
 618     event = CreateEventW(NULL, TRUE, FALSE, NULL);
 619     PostThreadMessageA(loop_tid, WM_USER, (WPARAM)event, (LPARAM)&spc);
 620     WaitForSingleObject(event, INFINITE);
 621     CloseHandle(event);
 622   } else
 623     proc(arg);
 624 }
 625
 626 static DWORD WINAPI MZ_DOSVM( LPVOID lpExtra )
 627 {
 628   CONTEXT context;
 629   INT ret;
 630
 631   dosvm_pid = getpid();
 632
 633   memset( &context, 0, sizeof(context) );
 634   context.SegCs  = init_cs;
 635   context.Eip    = init_ip;
 636   context.SegSs  = init_ss;
 637   context.Esp    = init_sp;
 638   context.SegDs  = DOSVM_psp;
 639   context.SegEs  = DOSVM_psp;
 640   context.EFlags = V86_FLAG | VIF_MASK;
 641   DOSVM_SetTimer(0x10000);
 642   ret = DOSVM_Enter( &context );
 643   if (ret == -1)
 644   {
 645       /* fetch the app name from the environment */
 646       PDB16 *psp = PTR_REAL_TO_LIN( DOSVM_psp, 0 );
 647       char *env = PTR_REAL_TO_LIN( psp->environment, 0 );
 648       while (*env) env += strlen(env) + 1;
 649       env += 1 + sizeof(WORD);
 650
 651       if (GetLastError() == ERROR_NOT_SUPPORTED)
 652           MESSAGE( "wine: Cannot start DOS application %s\n"
 653                    "      because vm86 mode is not supported on this platform.\n",
 654                    debugstr_a(env) );
 655       else
 656           FIXME( "vm86 mode failed error %u\n", GetLastError() );
 657   }
 658   dosvm_pid = 0;
 659   return ret != 0;
 660 }
 661
 662 static BOOL MZ_InitTask(void)
 663 {
 664   if (!DuplicateHandle(GetCurrentProcess(), GetCurrentThread(),
 665                        GetCurrentProcess(), &loop_thread,
 666                        0, FALSE, DUPLICATE_SAME_ACCESS))
 667     return FALSE;
 668   dosvm_thread = CreateThread(NULL, 0, MZ_DOSVM, NULL, CREATE_SUSPENDED, &dosvm_tid);
 669   if (!dosvm_thread) {
 670     CloseHandle(loop_thread);
 671     loop_thread = 0;
 672     return FALSE;
 673   }
 674   loop_tid = GetCurrentThreadId();
 675   return TRUE;
 676 }
 677
 678 static void MZ_Launch( LPCSTR cmdtail, int length )
 679 {
 680   TDB *pTask = GlobalLock16( GetCurrentTask() );
 681   BYTE *psp_start = PTR_REAL_TO_LIN( DOSVM_psp, 0 );
 682   DWORD rv;
 683   SYSLEVEL *lock;
 684   MSG msg;
 685
 686   MZ_FillPSP(psp_start, cmdtail, length);
 687   pTask->flags |= TDBF_WINOLDAP;
 688
 689   /* DTA is set to PSP:0080h when a program is started. */
 690   pTask->dta = MAKESEGPTR( DOSVM_psp, 0x80 );
 691
 692   GetpWin16Lock( &lock );
 693   _LeaveSysLevel( lock );
 694
 695   /* force the message queue to be created */
 696   PeekMessageW(&msg, NULL, WM_USER, WM_USER, PM_NOREMOVE);
 697
 698   ResumeThread(dosvm_thread);
 699   rv = DOSVM_Loop(dosvm_thread);
 700
 701   CloseHandle(dosvm_thread);
 702   dosvm_thread = 0; dosvm_tid = 0;
 703   CloseHandle(loop_thread);
 704   loop_thread = 0; loop_tid = 0;
 705
 706   VGA_Clean();
 707   ExitProcess(rv);
 708 }
 709
 710 /***********************************************************************
 711  *              MZ_Exit
 712  */
 713 void WINAPI MZ_Exit( CONTEXT86 *context, BOOL cs_psp, WORD retval )
 714 {
 715   if (DOSVM_psp) {
 716     WORD psp_seg = cs_psp ? context->SegCs : DOSVM_psp;
 717     LPBYTE psp_start = (LPBYTE)((DWORD)psp_seg << 4);
 718     PDB16 *psp = (PDB16 *)psp_start;
 719     WORD parpsp = psp->parentPSP; /* check for parent DOS process */
 720     if (parpsp) {
 721       /* retrieve parent's return address */
 722       FARPROC16 retaddr = DOSVM_GetRMHandler(0x22);
 723       /* restore interrupts */
 724       DOSVM_SetRMHandler(0x22, psp->savedint22);
 725       DOSVM_SetRMHandler(0x23, psp->savedint23);
 726       DOSVM_SetRMHandler(0x24, psp->savedint24);
 727       /* FIXME: deallocate file handles etc */
 728       /* free process's associated memory
 729        * FIXME: walk memory and deallocate all blocks owned by process */
 730       DOSMEM_FreeBlock( PTR_REAL_TO_LIN(psp->environment,0) );
 731       DOSMEM_FreeBlock( PTR_REAL_TO_LIN(DOSVM_psp,0) );
 732       /* switch to parent's PSP */
 733       DOSVM_psp = parpsp;
 734       psp_start = (LPBYTE)((DWORD)parpsp << 4);
 735       psp = (PDB16 *)psp_start;
 736       /* now return to parent */
 737       DOSVM_retval = retval;
 738       context->SegCs = SELECTOROF(retaddr);
 739       context->Eip   = OFFSETOF(retaddr);
 740       context->SegSs = SELECTOROF(psp->saveStack);
 741       context->Esp   = OFFSETOF(psp->saveStack);
 742       return;
 743     } else
 744       TRACE("killing DOS task\n");
 745   }
 746   DOSVM_Exit( retval );
 747 }
 748
 749
 750 /***********************************************************************
 751  *              MZ_Current
 752  */
 753 BOOL WINAPI MZ_Current( void )
 754 {
 755   return (dosvm_pid != 0); /* FIXME: do a better check */
 756 }
 757
 758 #else /* !MZ_SUPPORTED */
 759
 760 /***********************************************************************
 761  *              wine_load_dos_exe (WINEDOS.@)
 762  */
 763 void WINAPI wine_load_dos_exe( LPCSTR filename, LPCSTR cmdline )
 764 {
 765     FIXME("DOS executables not supported on this platform\n");
 766     SetLastError(ERROR_BAD_FORMAT);
 767 }
 768
 769 /***********************************************************************
 770  *              MZ_Exec
 771  */
 772 BOOL WINAPI MZ_Exec( CONTEXT86 *context, LPCSTR filename, BYTE func, LPVOID paramblk )
 773 {
 774   /* can't happen */
 775   SetLastError(ERROR_BAD_FORMAT);
 776   return FALSE;
 777 }
 778
 779 /***********************************************************************
 780  *              MZ_AllocDPMITask
 781  */
 782 void WINAPI MZ_AllocDPMITask( void )
 783 {
 784     FIXME("Actual real-mode calls not supported on this platform!\n");
 785 }
 786
 787 /***********************************************************************
 788  *              MZ_RunInThread
 789  */
 790 void WINAPI MZ_RunInThread( PAPCFUNC proc, ULONG_PTR arg )
 791 {
 792     proc(arg);
 793 }
 794
 795 /***********************************************************************
 796  *              MZ_Exit
 797  */
 798 void WINAPI MZ_Exit( CONTEXT86 *context, BOOL cs_psp, WORD retval )
 799 {
 800   DOSVM_Exit( retval );
 801 }
 802
 803 /***********************************************************************
 804  *              MZ_Current
 805  */
 806 BOOL WINAPI MZ_Current( void )
 807 {
 808     return FALSE;
 809 }
 810
 811 #endif /* !MZ_SUPPORTED */