loader/dos/dosvm.c

   1 /*
   2  * DOS Virtual Machine
   3  *
   4  * Copyright 1998 Ove Kåven
   5  *
   6  * This code hasn't been completely cleaned up yet.
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <errno.h>
  13 #include <fcntl.h>
  14 #include <signal.h>
  15 #include <unistd.h>
  16 #include <sys/types.h>
  17 #include <sys/stat.h>
  18 #include "windows.h"
  19 #include "winbase.h"
  20 #include "winnt.h"
  21 #include "msdos.h"
  22 #include "miscemu.h"
  23 #include "debug.h"
  24 #include "debugger.h"
  25 #include "module.h"
  26 #include "task.h"
  27 #include "ldt.h"
  28 #include "dosexe.h"
  29
  30 #ifdef MZ_SUPPORTED
  31
  32 #include <sys/mman.h>
  33 #include <sys/vm86.h>
  34
  35 static void DOSVM_Dump( LPDOSTASK lpDosTask, int fn,
  36                         struct vm86plus_struct*VM86 )
  37 {
  38  unsigned iofs;
  39  BYTE*inst;
  40  int x;
  41
  42  switch (VM86_TYPE(fn)) {
  43   case VM86_SIGNAL:
  44    printf("Trapped signal\n"); break;
  45   case VM86_UNKNOWN:
  46    printf("Trapped unhandled GPF\n"); break;
  47   case VM86_INTx:
  48    printf("Trapped INT %02x\n",VM86_ARG(fn)); break;
  49   case VM86_STI:
  50    printf("Trapped STI\n"); break;
  51   case VM86_PICRETURN:
  52    printf("Trapped due to pending PIC request\n"); break;
  53   case VM86_TRAP:
  54    printf("Trapped debug request\n"); break;
  55  }
  56 #define REGS VM86->regs
  57  fprintf(stderr,"AX=%04lX CX=%04lX DX=%04lX BX=%04lX\n",REGS.eax,REGS.ebx,REGS.ecx,REGS.edx);
  58  fprintf(stderr,"SI=%04lX DI=%04lX SP=%04lX BP=%04lX\n",REGS.esi,REGS.edi,REGS.esp,REGS.ebp);
  59  fprintf(stderr,"CS=%04X DS=%04X ES=%04X SS=%04X\n",REGS.cs,REGS.ds,REGS.es,REGS.ss);
  60  fprintf(stderr,"EIP=%04lX EFLAGS=%08lX\n",REGS.eip,REGS.eflags);
  61
  62  iofs=((DWORD)REGS.cs<<4)+REGS.eip;
  63 #undef REGS
  64  inst=(BYTE*)lpDosTask->img+iofs;
  65  printf("Opcodes:");
  66  for (x=0; x<8; x++) printf(" %02x",inst[x]);
  67  printf("\n");
  68
  69  exit(0);
  70 }
  71
  72 static int DOSVM_Int(int vect, PCONTEXT context )
  73 {
  74  /* moved to INT_RealModeInterrupt in msdos/interrupts.c */
  75  INT_RealModeInterrupt(vect,context);
  76  return 0;
  77 }
  78
  79 #define CV CP(eax,Eax); CP(ecx,Ecx); CP(edx,Edx); CP(ebx,Ebx); \
  80            CP(esi,Esi); CP(edi,Edi); CP(esp,Esp); CP(ebp,Ebp); \
  81            CP(cs,SegCs); CP(ds,SegDs); CP(es,SegEs); \
  82            CP(ss,SegSs); CP(fs,SegFs); CP(gs,SegGs); \
  83            CP(eip,Eip); CP(eflags,EFlags)
  84
  85 static int DOSVM_Process( LPDOSTASK lpDosTask, int fn,
  86                           struct vm86plus_struct*VM86 )
  87 {
  88  CONTEXT context;
  89  int ret=0;
  90
  91 #define CP(x,y) context.y = VM86->regs.x
  92  CV;
  93 #undef CP
  94  (void*)V86BASE(&context)=lpDosTask->img;
  95
  96  switch (VM86_TYPE(fn)) {
  97   case VM86_SIGNAL:
  98    printf("Trapped signal\n");
  99    ret=-1; break;
 100   case VM86_UNKNOWN: /* unhandled GPF */
 101    DOSVM_Dump(lpDosTask,fn,VM86);
 102    ctx_debug(SIGSEGV,&context);
 103    break;
 104   case VM86_INTx:
 105    TRACE(int,"DOS EXE calls INT %02x with AX=%04lx\n",VM86_ARG(fn),context.Eax);
 106    ret=DOSVM_Int(VM86_ARG(fn),&context); break;
 107   case VM86_STI:
 108    break;
 109   case VM86_PICRETURN:
 110    printf("Trapped due to pending PIC request\n"); break;
 111   case VM86_TRAP:
 112    ctx_debug(SIGTRAP,&context);
 113    break;
 114   default:
 115    DOSVM_Dump(lpDosTask,fn,VM86);
 116  }
 117
 118 #define CP(x,y) VM86->regs.x = context.y
 119  CV;
 120 #undef CP
 121  return ret;
 122 }
 123
 124 int DOSVM_Enter( PCONTEXT context )
 125 {
 126  TDB *pTask = (TDB *)GlobalLock16( GetCurrentTask() );
 127  NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 128  LPDOSTASK lpDosTask;
 129  struct vm86plus_struct VM86;
 130  int stat;
 131
 132  GlobalUnlock16( GetCurrentTask() );
 133  if (!pModule) {
 134   ERR(module,"No task is currently active!\n");
 135   return -1;
 136  }
 137  if (!pModule->lpDosTask) {
 138   /* no VM86 (dosmod) task is currently running, start one */
 139   if ((lpDosTask = calloc(1, sizeof(DOSTASK))) == NULL)
 140     return 0;
 141   lpDosTask->hModule=pModule->self;
 142   stat=MZ_InitMemory(lpDosTask,pModule);
 143   if (stat>=32) stat=MZ_InitTask(lpDosTask);
 144   if (stat<32) {
 145    free(lpDosTask);
 146    return -1;
 147   }
 148   pModule->lpDosTask = lpDosTask;
 149   pModule->dos_image = lpDosTask->img;
 150   /* Note: we're leaving it running after this, in case we need it again,
 151      as this minimizes the overhead of starting it up every time...
 152      it will be killed automatically when the current task terminates */
 153  } else lpDosTask=pModule->lpDosTask;
 154
 155  if (context) {
 156 #define CP(x,y) VM86.regs.x = context->y
 157   CV;
 158 #undef CP
 159  } else {
 160 /* initial setup */
 161   memset(&VM86,0,sizeof(VM86));
 162   VM86.regs.cs=lpDosTask->init_cs;
 163   VM86.regs.eip=lpDosTask->init_ip;
 164   VM86.regs.ss=lpDosTask->init_ss;
 165   VM86.regs.esp=lpDosTask->init_sp;
 166   VM86.regs.ds=lpDosTask->psp_seg;
 167   VM86.regs.es=lpDosTask->psp_seg;
 168   /* hmm, what else do we need? */
 169  }
 170
 171  /* main exchange loop */
 172  stat = VM86_ENTER;
 173  do {
 174   /* transmit VM86 structure to dosmod task */
 175   if (write(lpDosTask->write_pipe,&stat,sizeof(stat))!=sizeof(stat))
 176    return -1;
 177   if (write(lpDosTask->write_pipe,&VM86,sizeof(VM86))!=sizeof(VM86))
 178    return -1;
 179   /* wait for response */
 180   do {
 181    if (read(lpDosTask->read_pipe,&stat,sizeof(stat))!=sizeof(stat)) {
 182     if ((errno==EINTR)||(errno==EAGAIN)) continue;
 183     return -1;
 184    }
 185   } while (0);
 186   do {
 187    if (read(lpDosTask->read_pipe,&VM86,sizeof(VM86))!=sizeof(VM86)) {
 188     if ((errno==EINTR)||(errno==EAGAIN)) continue;
 189     return -1;
 190    }
 191   } while (0);
 192   /* got response */
 193  } while (DOSVM_Process(lpDosTask,stat,&VM86)>=0);
 194
 195  if (context) {
 196 #define CP(x,y) context->y = VM86.regs.x
 197   CV;
 198 #undef CP
 199  }
 200  return 0;
 201 }
 202
 203 #else /* !MZ_SUPPORTED */
 204
 205 int DOSVM_Enter( PCONTEXT context )
 206 {
 207  ERR(module,"DOS realmode not supported on this architecture!\n");
 208  return -1;
 209 }
 210
 211 #endif