dlls/winedos/int31.c

   1 /*
   2  * DPMI 0.9 emulation
   3  *
   4  * Copyright 1995 Alexandre Julliard
   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
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include "windef.h"
  25 #include "wine/winbase16.h"
  26 #include "miscemu.h"
  27 #include "task.h"
  28 #include "msdos.h"
  29 #include "dosexe.h"
  30
  31 #include "wine/debug.h"
  32
  33 WINE_DEFAULT_DEBUG_CHANNEL(int31);
  34
  35 /* Structure for real-mode callbacks */
  36 typedef struct
  37 {
  38     DWORD edi;
  39     DWORD esi;
  40     DWORD ebp;
  41     DWORD reserved;
  42     DWORD ebx;
  43     DWORD edx;
  44     DWORD ecx;
  45     DWORD eax;
  46     WORD  fl;
  47     WORD  es;
  48     WORD  ds;
  49     WORD  fs;
  50     WORD  gs;
  51     WORD  ip;
  52     WORD  cs;
  53     WORD  sp;
  54     WORD  ss;
  55 } REALMODECALL;
  56
  57 typedef struct tagRMCB {
  58     DWORD address;
  59     DWORD proc_ofs,proc_sel;
  60     DWORD regs_ofs,regs_sel;
  61     struct tagRMCB *next;
  62 } RMCB;
  63
  64 static RMCB *FirstRMCB = NULL;
  65 static WORD dpmi_flag;
  66
  67 /**********************************************************************
  68  *          DOSVM_IsDos32
  69  *
  70  * Return TRUE if we are in 32-bit protected mode DOS process.
  71  */
  72 BOOL DOSVM_IsDos32(void)
  73 {
  74   return (dpmi_flag & 1) ? TRUE : FALSE;
  75 }
  76
  77
  78 /**********************************************************************
  79  *          INT_GetRealModeContext
  80  */
  81 static void INT_GetRealModeContext( REALMODECALL *call, CONTEXT86 *context )
  82 {
  83     context->Eax    = call->eax;
  84     context->Ebx    = call->ebx;
  85     context->Ecx    = call->ecx;
  86     context->Edx    = call->edx;
  87     context->Esi    = call->esi;
  88     context->Edi    = call->edi;
  89     context->Ebp    = call->ebp;
  90     context->EFlags = call->fl | V86_FLAG;
  91     context->Eip    = call->ip;
  92     context->Esp    = call->sp;
  93     context->SegCs  = call->cs;
  94     context->SegDs  = call->ds;
  95     context->SegEs  = call->es;
  96     context->SegFs  = call->fs;
  97     context->SegGs  = call->gs;
  98     context->SegSs  = call->ss;
  99 }
 100
 101
 102 /**********************************************************************
 103  *          INT_SetRealModeContext
 104  */
 105 static void INT_SetRealModeContext( REALMODECALL *call, CONTEXT86 *context )
 106 {
 107     call->eax = context->Eax;
 108     call->ebx = context->Ebx;
 109     call->ecx = context->Ecx;
 110     call->edx = context->Edx;
 111     call->esi = context->Esi;
 112     call->edi = context->Edi;
 113     call->ebp = context->Ebp;
 114     call->fl  = LOWORD(context->EFlags);
 115     call->ip  = LOWORD(context->Eip);
 116     call->sp  = LOWORD(context->Esp);
 117     call->cs  = context->SegCs;
 118     call->ds  = context->SegDs;
 119     call->es  = context->SegEs;
 120     call->fs  = context->SegFs;
 121     call->gs  = context->SegGs;
 122     call->ss  = context->SegSs;
 123 }
 124
 125
 126 #ifdef __i386__
 127
 128 void DPMI_CallRMCB32(RMCB *rmcb, UINT16 ss, DWORD esp, UINT16*es, DWORD*edi)
 129 #if 0 /* original code, which early gccs puke on */
 130 {
 131     int _clobber;
 132     __asm__ __volatile__(
 133         "pushl %%ebp\n"
 134         "pushl %%ebx\n"
 135         "pushl %%es\n"
 136         "pushl %%ds\n"
 137         "pushfl\n"
 138         "mov %7,%%es\n"
 139         "mov %5,%%ds\n"
 140         ".byte 0x36, 0xff, 0x18\n" /* lcall *%ss:(%eax) */
 141         "popl %%ds\n"
 142         "mov %%es,%0\n"
 143         "popl %%es\n"
 144         "popl %%ebx\n"
 145         "popl %%ebp\n"
 146     : "=d" (*es), "=D" (*edi), "=S" (_clobber), "=a" (_clobber), "=c" (_clobber)
 147     : "0" (ss), "2" (esp),
 148       "4" (rmcb->regs_sel), "1" (rmcb->regs_ofs),
 149       "3" (&rmcb->proc_ofs) );
 150 }
 151 #else /* code generated by a gcc new enough */
 152 ;
 153 __ASM_GLOBAL_FUNC(DPMI_CallRMCB32,
 154     "pushl %ebp\n\t"
 155     "movl %esp,%ebp\n\t"
 156     "pushl %edi\n\t"
 157     "pushl %esi\n\t"
 158     "movl 0x8(%ebp),%eax\n\t"
 159     "movl 0x10(%ebp),%esi\n\t"
 160     "movl 0xc(%ebp),%edx\n\t"
 161     "movl 0x10(%eax),%ecx\n\t"
 162     "movl 0xc(%eax),%edi\n\t"
 163     "addl $0x4,%eax\n\t"
 164     "pushl %ebp\n\t"
 165     "pushl %ebx\n\t"
 166     "pushl %es\n\t"
 167     "pushl %ds\n\t"
 168     "pushfl\n\t"
 169     "mov %cx,%es\n\t"
 170     "mov %dx,%ds\n\t"
 171     ".byte 0x36, 0xff, 0x18\n\t" /* lcall *%ss:(%eax) */
 172     "popl %ds\n\t"
 173     "mov %es,%dx\n\t"
 174     "popl %es\n\t"
 175     "popl %ebx\n\t"
 176     "popl %ebp\n\t"
 177     "movl 0x14(%ebp),%eax\n\t"
 178     "movw %dx,(%eax)\n\t"
 179     "movl 0x18(%ebp),%edx\n\t"
 180     "movl %edi,(%edx)\n\t"
 181     "popl %esi\n\t"
 182     "popl %edi\n\t"
 183     "leave\n\t"
 184     "ret")
 185 #endif
 186
 187 #endif /* __i386__ */
 188
 189 /**********************************************************************
 190  *          DPMI_CallRMCBProc
 191  *
 192  * This routine does the hard work of calling a callback procedure.
 193  */
 194 static void DPMI_CallRMCBProc( CONTEXT86 *context, RMCB *rmcb, WORD flag )
 195 {
 196     if (IS_SELECTOR_SYSTEM( rmcb->proc_sel )) {
 197         /* Wine-internal RMCB, call directly */
 198         ((RMCBPROC)rmcb->proc_ofs)(context);
 199     } else {
 200 #ifdef __i386__
 201         UINT16 ss,es;
 202         DWORD esp,edi;
 203
 204         INT_SetRealModeContext(MapSL(MAKESEGPTR( rmcb->regs_sel, rmcb->regs_ofs )), context);
 205         ss = SELECTOR_AllocBlock( (void *)(context->SegSs<<4), 0x10000, WINE_LDT_FLAGS_DATA );
 206         esp = context->Esp;
 207
 208         FIXME("untested!\n");
 209
 210         /* The called proc ends with an IRET, and takes these parameters:
 211          * DS:ESI = pointer to real-mode SS:SP
 212          * ES:EDI = pointer to real-mode call structure
 213          * It returns:
 214          * ES:EDI = pointer to real-mode call structure (may be a copy)
 215          * It is the proc's responsibility to change the return CS:IP in the
 216          * real-mode call structure. */
 217         if (flag & 1) {
 218             /* 32-bit DPMI client */
 219             DPMI_CallRMCB32(rmcb, ss, esp, &es, &edi);
 220         } else {
 221             /* 16-bit DPMI client */
 222             CONTEXT86 ctx = *context;
 223             ctx.SegCs = rmcb->proc_sel;
 224             ctx.Eip   = rmcb->proc_ofs;
 225             ctx.SegDs = ss;
 226             ctx.Esi   = esp;
 227             ctx.SegEs = rmcb->regs_sel;
 228             ctx.Edi   = rmcb->regs_ofs;
 229             /* FIXME: I'm pretty sure this isn't right - should push flags first */
 230             wine_call_to_16_regs_short(&ctx, 0);
 231             es = ctx.SegEs;
 232             edi = ctx.Edi;
 233         }
 234         FreeSelector16(ss);
 235         INT_GetRealModeContext( MapSL( MAKESEGPTR( es, edi )), context);
 236 #else
 237         ERR("RMCBs only implemented for i386\n");
 238 #endif
 239     }
 240 }
 241
 242
 243 /**********************************************************************
 244  *          DPMI_CallRMProc
 245  *
 246  * This routine does the hard work of calling a real mode procedure.
 247  */
 248 int DPMI_CallRMProc( CONTEXT86 *context, LPWORD stack, int args, int iret )
 249 {
 250     LPWORD stack16;
 251     LPVOID addr = NULL; /* avoid gcc warning */
 252     RMCB *CurrRMCB;
 253     int alloc = 0, already = 0;
 254     BYTE *code;
 255
 256     TRACE("EAX=%08lx EBX=%08lx ECX=%08lx EDX=%08lx\n",
 257                  context->Eax, context->Ebx, context->Ecx, context->Edx );
 258     TRACE("ESI=%08lx EDI=%08lx ES=%04lx DS=%04lx CS:IP=%04lx:%04x, %d WORD arguments, %s\n",
 259                  context->Esi, context->Edi, context->SegEs, context->SegDs,
 260                  context->SegCs, LOWORD(context->Eip), args, iret?"IRET":"FAR" );
 261
 262 callrmproc_again:
 263
 264 /* there might be some code that just jumps to RMCBs or the like,
 265    in which case following the jumps here might get us to a shortcut */
 266     code = CTX_SEG_OFF_TO_LIN(context, context->SegCs, context->Eip);
 267     switch (*code) {
 268     case 0xe9: /* JMP NEAR */
 269       context->Eip += 3 + *(WORD *)(code+1);
 270       /* yeah, I know these gotos don't look good... */
 271       goto callrmproc_again;
 272     case 0xea: /* JMP FAR */
 273       context->Eip = *(WORD *)(code+1);
 274       context->SegCs = *(WORD *)(code+3);
 275       /* ...but since the label is there anyway... */
 276       goto callrmproc_again;
 277     case 0xeb: /* JMP SHORT */
 278       context->Eip += 2 + *(signed char *)(code+1);
 279       /* ...because of other gotos below, so... */
 280       goto callrmproc_again;
 281     }
 282
 283 /* shortcut for chaining to internal interrupt handlers */
 284     if ((context->SegCs == 0xF000) && iret)
 285     {
 286         DOSVM_RealModeInterrupt( LOWORD(context->Eip)/4, context);
 287         return 0;
 288     }
 289
 290 /* shortcut for RMCBs */
 291     CurrRMCB = FirstRMCB;
 292
 293     while (CurrRMCB && (HIWORD(CurrRMCB->address) != context->SegCs))
 294         CurrRMCB = CurrRMCB->next;
 295
 296     if (!CurrRMCB && !MZ_Current())
 297     {
 298         FIXME("DPMI real-mode call using DOS VM task system, not fully tested!\n");
 299         TRACE("creating VM86 task\n");
 300         MZ_AllocDPMITask();
 301     }
 302     if (!already) {
 303         if (!context->SegSs) {
 304             alloc = 1; /* allocate default stack */
 305             stack16 = addr = DOSMEM_GetBlock( 64, (UINT16 *)&(context->SegSs) );
 306             context->Esp = 64-2;
 307             stack16 += 32-1;
 308             if (!addr) {
 309                 ERR("could not allocate default stack\n");
 310                 return 1;
 311             }
 312         } else {
 313             stack16 = CTX_SEG_OFF_TO_LIN(context, context->SegSs, context->Esp);
 314         }
 315         context->Esp -= (args + (iret?1:0)) * sizeof(WORD);
 316         stack16 -= args;
 317         if (args) memcpy(stack16, stack, args*sizeof(WORD) );
 318         /* push flags if iret */
 319         if (iret) {
 320             stack16--; args++;
 321             *stack16 = LOWORD(context->EFlags);
 322         }
 323         /* push return address (return to interrupt wrapper) */
 324         *(--stack16) = DOSVM_dpmi_segments->wrap_seg;
 325         *(--stack16) = 0;
 326         /* adjust stack */
 327         context->Esp -= 2*sizeof(WORD);
 328         already = 1;
 329     }
 330
 331     if (CurrRMCB) {
 332         /* RMCB call, invoke protected-mode handler directly */
 333         DPMI_CallRMCBProc(context, CurrRMCB, dpmi_flag);
 334         /* check if we returned to where we thought we would */
 335         if ((context->SegCs != DOSVM_dpmi_segments->wrap_seg) ||
 336             (LOWORD(context->Eip) != 0)) {
 337             /* we need to continue at different address in real-mode space,
 338                so we need to set it all up for real mode again */
 339             goto callrmproc_again;
 340         }
 341     } else {
 342         TRACE("entering real mode...\n");
 343         DOSVM_Enter( context );
 344         TRACE("returned from real-mode call\n");
 345     }
 346     if (alloc) DOSMEM_FreeBlock( addr );
 347     return 0;
 348 }
 349
 350
 351 /**********************************************************************
 352  *          CallRMInt   (WINEDOS.@)
 353  */
 354 void WINAPI DOSVM_CallRMInt( CONTEXT86 *context )
 355 {
 356     CONTEXT86 realmode_ctx;
 357     FARPROC16 rm_int = DOSVM_GetRMHandler( BL_reg(context) );
 358     REALMODECALL *call = MapSL( MAKESEGPTR( context->SegEs, DI_reg(context) ));
 359     INT_GetRealModeContext( call, &realmode_ctx );
 360
 361     /* we need to check if a real-mode program has hooked the interrupt */
 362     if (HIWORD(rm_int)!=0xF000) {
 363         /* yup, which means we need to switch to real mode... */
 364         realmode_ctx.SegCs = HIWORD(rm_int);
 365         realmode_ctx.Eip   = LOWORD(rm_int);
 366         if (DPMI_CallRMProc( &realmode_ctx, NULL, 0, TRUE))
 367           SET_CFLAG(context);
 368     } else {
 369         RESET_CFLAG(context);
 370         /* use the IP we have instead of BL_reg, in case some apps
 371            decide to move interrupts around for whatever reason... */
 372         DOSVM_RealModeInterrupt( LOWORD(rm_int)/4, &realmode_ctx );
 373     }
 374     INT_SetRealModeContext( call, &realmode_ctx );
 375 }
 376
 377
 378 /**********************************************************************
 379  *          CallRMProc   (WINEDOS.@)
 380  */
 381 void WINAPI DOSVM_CallRMProc( CONTEXT86 *context, int iret )
 382 {
 383     REALMODECALL *p = MapSL( MAKESEGPTR( context->SegEs, DI_reg(context) ));
 384     CONTEXT86 context16;
 385
 386     TRACE("RealModeCall: EAX=%08lx EBX=%08lx ECX=%08lx EDX=%08lx\n",
 387           p->eax, p->ebx, p->ecx, p->edx);
 388     TRACE("              ESI=%08lx EDI=%08lx ES=%04x DS=%04x CS:IP=%04x:%04x, %d WORD arguments, %s\n",
 389           p->esi, p->edi, p->es, p->ds, p->cs, p->ip, CX_reg(context), iret?"IRET":"FAR" );
 390
 391     if (!(p->cs) && !(p->ip)) { /* remove this check
 392                                    if Int21/6501 case map function
 393                                    has been implemented */
 394         SET_CFLAG(context);
 395         return;
 396      }
 397     INT_GetRealModeContext(p, &context16);
 398     DPMI_CallRMProc( &context16, ((LPWORD)MapSL(MAKESEGPTR(context->SegSs, LOWORD(context->Esp))))+3,
 399                      CX_reg(context), iret );
 400     INT_SetRealModeContext(p, &context16);
 401 }
 402
 403
 404 /* (see dosmem.c, function DOSMEM_InitDPMI) */
 405 static void StartPM( CONTEXT86 *context )
 406 {
 407     UINT16 cs, ss, ds, es;
 408     CONTEXT86 pm_ctx;
 409     DWORD psp_ofs = (DWORD)(DOSVM_psp<<4);
 410     PDB16 *psp = (PDB16 *)psp_ofs;
 411     HANDLE16 env_seg = psp->environment;
 412     unsigned char selflags = WINE_LDT_FLAGS_DATA;
 413
 414     RESET_CFLAG(context);
 415     dpmi_flag = AX_reg(context);
 416 /* our mode switch wrapper have placed the desired CS into DX */
 417     cs = SELECTOR_AllocBlock( (void *)(DX_reg(context)<<4), 0x10000, WINE_LDT_FLAGS_CODE );
 418 /* due to a flaw in some CPUs (at least mine), it is best to mark stack segments as 32-bit if they
 419    can be used in 32-bit code. Otherwise, these CPUs may not set the high word of esp during a
 420    ring transition (from kernel code) to the 16-bit stack, and this causes trouble if executing
 421    32-bit code using this stack. */
 422     if (dpmi_flag & 1) selflags |= WINE_LDT_FLAGS_32BIT;
 423     ss = SELECTOR_AllocBlock( (void *)(context->SegSs<<4), 0x10000, selflags );
 424 /* do the same for the data segments, just in case */
 425     if (context->SegDs == context->SegSs) ds = ss;
 426     else ds = SELECTOR_AllocBlock( (void *)(context->SegDs<<4), 0x10000, selflags );
 427     es = SELECTOR_AllocBlock( psp, 0x100, selflags );
 428 /* convert environment pointer, as the spec says, but we're a bit lazy about the size here... */
 429     psp->environment = SELECTOR_AllocBlock( (void *)(env_seg<<4), 0x10000, WINE_LDT_FLAGS_DATA );
 430
 431     pm_ctx = *context;
 432     pm_ctx.SegCs = DOSVM_dpmi_segments->dpmi_sel;
 433 /* our mode switch wrapper expects the new CS in DX, and the new SS in AX */
 434     pm_ctx.Eax   = ss;
 435     pm_ctx.Edx   = cs;
 436     pm_ctx.SegDs = ds;
 437     pm_ctx.SegEs = es;
 438     pm_ctx.SegFs = 0;
 439     pm_ctx.SegGs = 0;
 440
 441     TRACE("DOS program is now entering protected mode\n");
 442     wine_call_to_16_regs_short(&pm_ctx, 0);
 443
 444     /* in the current state of affairs, we won't ever actually return here... */
 445     /* we should have int21/ah=4c do it someday, though... */
 446
 447     FreeSelector16(psp->environment);
 448     psp->environment = env_seg;
 449     FreeSelector16(es);
 450     if (ds != ss) FreeSelector16(ds);
 451     FreeSelector16(ss);
 452     FreeSelector16(cs);
 453 }
 454
 455 static RMCB *DPMI_AllocRMCB( void )
 456 {
 457     RMCB *NewRMCB = HeapAlloc(GetProcessHeap(), 0, sizeof(RMCB));
 458     UINT16 uParagraph;
 459
 460     if (NewRMCB)
 461     {
 462         LPVOID RMCBmem = DOSMEM_GetBlock(4, &uParagraph);
 463         LPBYTE p = RMCBmem;
 464
 465         *p++ = 0xcd; /* RMCB: */
 466         *p++ = 0x31; /* int $0x31 */
 467 /* it is the called procedure's task to change the return CS:EIP
 468    the DPMI 0.9 spec states that if it doesn't, it will be called again */
 469         *p++ = 0xeb;
 470         *p++ = 0xfc; /* jmp RMCB */
 471         NewRMCB->address = MAKELONG(0, uParagraph);
 472         NewRMCB->next = FirstRMCB;
 473         FirstRMCB = NewRMCB;
 474     }
 475     return NewRMCB;
 476 }
 477
 478
 479 FARPROC16 WINAPI DPMI_AllocInternalRMCB( RMCBPROC proc )
 480 {
 481     RMCB *NewRMCB = DPMI_AllocRMCB();
 482
 483     if (NewRMCB) {
 484         NewRMCB->proc_ofs = (DWORD)proc;
 485         NewRMCB->proc_sel = 0;
 486         NewRMCB->regs_ofs = 0;
 487         NewRMCB->regs_sel = 0;
 488         return (FARPROC16)(NewRMCB->address);
 489     }
 490     return NULL;
 491 }
 492
 493
 494 static int DPMI_FreeRMCB( DWORD address )
 495 {
 496     RMCB *CurrRMCB = FirstRMCB;
 497     RMCB *PrevRMCB = NULL;
 498
 499     while (CurrRMCB && (CurrRMCB->address != address))
 500     {
 501         PrevRMCB = CurrRMCB;
 502         CurrRMCB = CurrRMCB->next;
 503     }
 504     if (CurrRMCB)
 505     {
 506         if (PrevRMCB)
 507         PrevRMCB->next = CurrRMCB->next;
 508             else
 509         FirstRMCB = CurrRMCB->next;
 510         DOSMEM_FreeBlock(PTR_REAL_TO_LIN(SELECTOROF(CurrRMCB->address),OFFSETOF(CurrRMCB->address)));
 511         HeapFree(GetProcessHeap(), 0, CurrRMCB);
 512         return 0;
 513     }
 514     return 1;
 515 }
 516
 517
 518 void WINAPI DPMI_FreeInternalRMCB( FARPROC16 proc )
 519 {
 520     DPMI_FreeRMCB( (DWORD)proc );
 521 }
 522
 523
 524 /**********************************************************************
 525  *          RawModeSwitch   (WINEDOS.@)
 526  *
 527  * DPMI Raw Mode Switch handler
 528  */
 529 void WINAPI DOSVM_RawModeSwitch( CONTEXT86 *context )
 530 {
 531   CONTEXT86 rm_ctx;
 532   int ret;
 533
 534   /* initialize real-mode context as per spec */
 535   memset(&rm_ctx, 0, sizeof(rm_ctx));
 536   rm_ctx.SegDs  = AX_reg(context);
 537   rm_ctx.SegEs  = CX_reg(context);
 538   rm_ctx.SegSs  = DX_reg(context);
 539   rm_ctx.Esp    = context->Ebx;
 540   rm_ctx.SegCs  = SI_reg(context);
 541   rm_ctx.Eip    = context->Edi;
 542   rm_ctx.Ebp    = context->Ebp;
 543   rm_ctx.SegFs  = 0;
 544   rm_ctx.SegGs  = 0;
 545   rm_ctx.EFlags = context->EFlags; /* at least we need the IF flag */
 546
 547   /* enter real mode again */
 548   TRACE("re-entering real mode at %04lx:%04lx\n",rm_ctx.SegCs,rm_ctx.Eip);
 549   ret = DOSVM_Enter( &rm_ctx );
 550   /* when the real-mode stuff call its mode switch address,
 551      DOSVM_Enter will return and we will continue here */
 552
 553   if (ret<0) {
 554     ERR("Sync lost!\n");
 555     /* if the sync was lost, there's no way to recover */
 556     ExitProcess(1);
 557   }
 558
 559   /* alter protected-mode context as per spec */
 560   context->SegDs   = LOWORD(rm_ctx.Eax);
 561   context->SegEs   = LOWORD(rm_ctx.Ecx);
 562   context->SegSs   = LOWORD(rm_ctx.Edx);
 563   context->Esp     = rm_ctx.Ebx;
 564   context->SegCs   = LOWORD(rm_ctx.Esi);
 565   context->Eip     = rm_ctx.Edi;
 566   context->Ebp     = rm_ctx.Ebp;
 567   context->SegFs   = 0;
 568   context->SegGs   = 0;
 569
 570   /* Return to new address and hope that we didn't mess up */
 571   TRACE("re-entering protected mode at %04lx:%08lx\n",
 572       context->SegCs, context->Eip);
 573 }
 574
 575
 576 /**********************************************************************
 577  *          AllocRMCB   (WINEDOS.@)
 578  */
 579 void WINAPI DOSVM_AllocRMCB( CONTEXT86 *context )
 580 {
 581     RMCB *NewRMCB = DPMI_AllocRMCB();
 582
 583     TRACE("Function to call: %04x:%04x\n", (WORD)context->SegDs, SI_reg(context) );
 584
 585     if (NewRMCB)
 586     {
 587         /* FIXME: if 32-bit DPMI client, use ESI and EDI */
 588         NewRMCB->proc_ofs = LOWORD(context->Esi);
 589         NewRMCB->proc_sel = context->SegDs;
 590         NewRMCB->regs_ofs = LOWORD(context->Edi);
 591         NewRMCB->regs_sel = context->SegEs;
 592         SET_LOWORD( context->Ecx, HIWORD(NewRMCB->address) );
 593         SET_LOWORD( context->Edx, LOWORD(NewRMCB->address) );
 594     }
 595     else
 596     {
 597         SET_LOWORD( context->Eax, 0x8015 ); /* callback unavailable */
 598         SET_CFLAG(context);
 599     }
 600 }
 601
 602
 603 /**********************************************************************
 604  *          FreeRMCB   (WINEDOS.@)
 605  */
 606 void WINAPI DOSVM_FreeRMCB( CONTEXT86 *context )
 607 {
 608     FIXME("callback address: %04x:%04x\n",
 609           CX_reg(context), DX_reg(context));
 610
 611     if (DPMI_FreeRMCB(MAKELONG(DX_reg(context), CX_reg(context)))) {
 612         SET_LOWORD( context->Eax, 0x8024 ); /* invalid callback address */
 613         SET_CFLAG(context);
 614     }
 615 }
 616
 617
 618 /**********************************************************************
 619  *          DOSVM_Int31Handler
 620  *
 621  * Handler for real-mode int 31h (DPMI).
 622  */
 623 void WINAPI DOSVM_Int31Handler( CONTEXT86 *context )
 624 {
 625     /* check if it's our wrapper */
 626     TRACE("called from real mode\n");
 627     if (context->SegCs==DOSVM_dpmi_segments->dpmi_seg) {
 628         /* This is the protected mode switch */
 629         StartPM(context);
 630         return;
 631     }
 632     else if (context->SegCs==DOSVM_dpmi_segments->xms_seg)
 633     {
 634         /* This is the XMS driver entry point */
 635         XMS_Handler(context);
 636         return;
 637     }
 638     else
 639     {
 640         /* Check for RMCB */
 641         RMCB *CurrRMCB = FirstRMCB;
 642
 643         while (CurrRMCB && (HIWORD(CurrRMCB->address) != context->SegCs))
 644             CurrRMCB = CurrRMCB->next;
 645
 646         if (CurrRMCB) {
 647             /* RMCB call, propagate to protected-mode handler */
 648             DPMI_CallRMCBProc(context, CurrRMCB, dpmi_flag);
 649             return;
 650         }
 651     }
 652
 653     /* chain to protected mode handler */
 654     INT_Int31Handler( context );
 655 }