KernelLand/Kernel/arch/x86/vm8086.c

   1 /*
   2  * Acess2 Kernel (x86)
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * vm8086.c
   6  * - Virtual 8086 Mode Monitor
   7  */
   8 #define DEBUG   0
   9 #include <acess.h>
  10 #include <vm8086.h>
  11 #include <modules.h>
  12 #include <hal_proc.h>
  13 #include <semaphore.h>
  14
  15 // === CONSTANTS ===
  16 #define TRACE_EMU       0
  17
  18 #define VM8086_USER_BASE        0x1000
  19
  20 #define VM8086_MAGIC_CS 0xFFFF
  21 #define VM8086_MAGIC_IP 0x0010
  22 #define VM8086_STACK_SEG        0x9F00
  23 #define VM8086_STACK_OFS        0x0AFE
  24 enum eVM8086_Opcodes
  25 {
  26         VM8086_OP_PUSHF   = 0x9C,
  27         VM8086_OP_POPF    = 0x9D,
  28         VM8086_OP_INT_I   = 0xCD,
  29         VM8086_OP_IRET    = 0xCF,
  30         VM8086_OP_IN_AD   = 0xEC,
  31         VM8086_OP_IN_ADX  = 0xED,
  32         VM8086_OP_OUT_AD  = 0xEE,
  33         VM8086_OP_OUT_ADX = 0xEF
  34 };
  35 #define VM8086_PAGES_PER_INST   4
  36
  37 #define VM8086_BLOCKSIZE        128
  38 #define VM8086_BLOCKCOUNT       ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
  39
  40 // === TYPES ===
  41 struct sVM8086_InternalPages
  42 {
  43         Uint32  Bitmap; // 32 sections = 128 byte blocks
  44         tVAddr  VirtBase;
  45         tPAddr  PhysAddr;
  46 };
  47 struct sVM8086_InternalData
  48 {
  49         struct sVM8086_InternalPages    AllocatedPages[VM8086_PAGES_PER_INST];
  50 };
  51
  52 // === PROTOTYPES ===
  53  int    VM8086_Install(char **Arguments);
  54 void    VM8086_GPF(tRegs *Regs);
  55 //tVM8086       *VM8086_Init(void);
  56
  57 // === GLOBALS ===
  58 MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
  59 tMutex  glVM8086_Process;
  60 tSemaphore      gVM8086_TaskComplete;
  61 tSemaphore      gVM8086_TasksToDo;
  62 tPID    gVM8086_WorkerPID;
  63 tTID    gVM8086_CallingThread;
  64 tVM8086 volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
  65 Uint32  gaVM8086_MemBitmap[VM8086_BLOCKCOUNT/32];
  66  int    gbVM8086_ShadowIF = 0;
  67
  68 // === FUNCTIONS ===
  69 int VM8086_Install(char **Arguments)
  70 {
  71         tPID    pid;
  72
  73         Semaphore_Init(&gVM8086_TasksToDo, 0, 10, "VM8086", "TasksToDo");
  74
  75         // Lock to avoid race conditions
  76         Mutex_Acquire( &glVM8086_Process );
  77
  78         // Create BIOS Call process
  79         pid = Proc_Clone(CLONE_VM);
  80         Log_Debug("VM8086", "pid = %i", pid);
  81         if(pid == -1)
  82         {
  83                 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
  84                 return MODULE_ERR_MISC;
  85         }
  86         if(pid == 0)
  87         {
  88                 Uint    * volatile stacksetup;  // Initialising Stack
  89                 Uint16  * volatile rmstack;     // Real Mode Stack
  90                  int    i;
  91
  92                 Log_Debug("VM8086", "Initialising worker");
  93
  94                 // Set Image Name
  95                 Threads_SetName("VM8086");
  96
  97                 // Map ROM Area
  98                 for(i=0xA0;i<0x100;i++) {
  99                         MM_Map( i * 0x1000, i * 0x1000 );
 100                 }
 101                 MM_Map( 0, 0 ); // IVT / BDA
 102                 if( MM_GetRefCount(0x00000) > 2 ) {
 103                         Log_Notice("VM8086", "Ok, who's touched the IVT? (%i)",
 104                                 MM_GetRefCount(0x00000));
 105                 }
 106                 MM_Map( 0x9F000, 0x9F000 );     // Stack / EBDA
 107                 if( MM_GetRefCount(0x9F000) > 2 ) {
 108                         Log_Notice("VM8086", "And who's been playing with my EBDA? (%i)",
 109                                 MM_GetRefCount(0x9F000));
 110                 }
 111                 // System Stack / Stub
 112                 if( MM_Allocate( 0x100000 ) == 0 ) {
 113                         Log_Error("VM8086", "Unable to allocate memory for stack/stub");
 114                         gVM8086_WorkerPID = 0;
 115                         Threads_Exit(0, 1);
 116                 }
 117
 118                 *(Uint8*)(0x100000) = VM8086_OP_IRET;
 119                 *(Uint8*)(0x100001) = 0x07;     // POP ES
 120                 *(Uint8*)(0x100002) = 0x1F;     // POP DS
 121                 *(Uint8*)(0x100003) = 0xCB;     // RET FAR
 122
 123                 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
 124                 rmstack--;      *rmstack = 0xFFFF;      //CS
 125                 rmstack--;      *rmstack = 0x0010;      //IP
 126
 127                 // Setup Stack
 128                 stacksetup = (Uint*)0x101000;
 129                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // GS
 130                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // FS
 131                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // DS
 132                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // ES
 133                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // SS
 134                 stacksetup--;   *stacksetup = VM8086_STACK_OFS-2;       // SP
 135                 stacksetup--;   *stacksetup = 0x20202;  // FLAGS
 136                 stacksetup--;   *stacksetup = 0xFFFF;   // CS
 137                 stacksetup--;   *stacksetup = 0x10;     // IP
 138                 stacksetup--;   *stacksetup = 0xAAAA;   // AX
 139                 stacksetup--;   *stacksetup = 0xCCCC;   // CX
 140                 stacksetup--;   *stacksetup = 0xDDDD;   // DX
 141                 stacksetup--;   *stacksetup = 0xBBBB;   // BX
 142                 stacksetup--;   *stacksetup = 0x5454;   // SP
 143                 stacksetup--;   *stacksetup = 0xB4B4;   // BP
 144                 stacksetup--;   *stacksetup = 0x5151;   // SI
 145                 stacksetup--;   *stacksetup = 0xD1D1;   // DI
 146                 stacksetup--;   *stacksetup = 0x20|3;   // DS - Kernel
 147                 stacksetup--;   *stacksetup = 0x20|3;   // ES - Kernel
 148                 stacksetup--;   *stacksetup = 0x20|3;   // FS
 149                 stacksetup--;   *stacksetup = 0x20|3;   // GS
 150                 __asm__ __volatile__ (
 151                 "mov %%eax,%%esp;\n\t"  // Set stack pointer
 152                 "pop %%gs;\n\t"
 153                 "pop %%fs;\n\t"
 154                 "pop %%es;\n\t"
 155                 "pop %%ds;\n\t"
 156                 "popa;\n\t"
 157                 "iret;\n\t" : : "a" (stacksetup));
 158                 for(;;);        // Shouldn't be reached
 159         }
 160
 161         gVM8086_WorkerPID = pid;
 162
 163         // It's released when the GPF fires
 164         Mutex_Acquire( &glVM8086_Process );
 165         Mutex_Release( &glVM8086_Process );
 166
 167         // Worker killed itself
 168         if( gVM8086_WorkerPID != pid ) {
 169                 return MODULE_ERR_MISC;
 170         }
 171
 172         return MODULE_ERR_OK;
 173 }
 174
 175 void VM8086_GPF(tRegs *Regs)
 176 {
 177         Uint8   opcode;
 178         Uint16  newcs, newip;
 179
 180 //      Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
 181
 182         LOG("VM8086 GPF at %04x:%04x", Regs->cs, Regs->eip);
 183
 184         if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
 185         && Threads_GetPID() == gVM8086_WorkerPID)
 186         {
 187                  int    i;
 188                 if( gpVM8086_State == (void*)-1 ) {
 189                         Log_Log("VM8086", "Worker thread ready and waiting");
 190                         gpVM8086_State = NULL;
 191                         Mutex_Release( &glVM8086_Process );     // Release lock obtained in VM8086_Install
 192                 }
 193 //              Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
 194 //                      gpVM8086_State, gVM8086_CallingThread);
 195                 if( gpVM8086_State ) {
 196                         gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
 197                         gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
 198                         gpVM8086_State->BP = Regs->ebp;
 199                         gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
 200                         gpVM8086_State->DS = Regs->ds;  gpVM8086_State->ES = Regs->es;
 201
 202                         LOG("gpVM8086_State = %p", gpVM8086_State);
 203                         LOG("gpVM8086_State->Internal = %p", gpVM8086_State->Internal);
 204                         for( i = 0; i < VM8086_PAGES_PER_INST; i ++ ) {
 205                                 if( !gpVM8086_State->Internal->AllocatedPages[i].VirtBase )
 206                                         continue ;
 207                                 MM_Deallocate( VM8086_USER_BASE + i*PAGE_SIZE );
 208                         }
 209
 210                         gpVM8086_State = NULL;
 211
 212                         // Wake the caller
 213                         Semaphore_Signal(&gVM8086_TaskComplete, 1);
 214                 }
 215
 216                 //Log_Log("VM8086", "Waiting for something to do");
 217                 __asm__ __volatile__ ("sti");
 218                 Semaphore_Wait(&gVM8086_TasksToDo, 1);
 219
 220                 for( i = 0; i < VM8086_PAGES_PER_INST; i ++ )
 221                 {
 222                         if( !gpVM8086_State->Internal->AllocatedPages[i].VirtBase )
 223                                 continue ;
 224                         MM_Map( VM8086_USER_BASE + i*PAGE_SIZE, gpVM8086_State->Internal->AllocatedPages[i].PhysAddr );
 225                 }
 226
 227
 228                 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
 229                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
 230                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
 231                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
 232                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
 233                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
 234                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
 235
 236                 // Set Registers
 237                 Regs->eip = 0x11;       Regs->cs = 0xFFFF;
 238                 Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
 239                 Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
 240                 Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
 241                 Regs->ebp = gpVM8086_State->BP;
 242                 Regs->ds = 0x23;        Regs->es = 0x23;
 243                 Regs->fs = 0x23;        Regs->gs = 0x23;
 244                 return ;
 245         }
 246
 247         opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
 248         Regs->eip ++;
 249         switch(opcode)
 250         {
 251         case VM8086_OP_PUSHF:   //PUSHF
 252                 Regs->esp -= 2;
 253                 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
 254                 if( gbVM8086_ShadowIF )
 255                         *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) |= 0x200;
 256                 else
 257                         *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) &= ~0x200;
 258                 #if TRACE_EMU
 259                 Log_Debug("VM8086", "%04x:%04x Emulated PUSHF (value 0x%x)",
 260                         Regs->cs, Regs->eip-1, Regs->eflags & 0xFFFF);
 261                 #endif
 262                 break;
 263         case VM8086_OP_POPF:    //POPF
 264                 // Changing IF is not allowed
 265                 Regs->eflags &= 0xFFFF0202;
 266                 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );
 267                 gbVM8086_ShadowIF = !!(*(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0x200);
 268                 Regs->esp += 2;
 269                 #if TRACE_EMU
 270                 Log_Debug("VM8086", "%04x:%04x Emulated POPF (new value 0x%x)",
 271                         Regs->cs, Regs->eip-1, Regs->eflags & 0xFFFF);
 272                 #endif
 273                 break;
 274
 275         case VM8086_OP_INT_I:   //INT imm8
 276                 {
 277                  int    id;
 278                 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
 279                 Regs->eip ++;
 280
 281                 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags;
 282                 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
 283                 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
 284
 285                 newcs = *(Uint16*)(4*id + 2);
 286                 newip = *(Uint16*)(4*id);
 287                 #if TRACE_EMU
 288                 Log_Debug("VM8086", "%04x:%04x Emulated INT 0x%x (%04x:%04x) - AX=%04x,BX=%04x",
 289                         Regs->cs, Regs->eip-2, id, newcs, newip, Regs->eax, Regs->ebx);
 290                 #endif
 291                 Regs->cs = newcs;
 292                 Regs->eip = newip;
 293                 }
 294                 break;
 295
 296         case VM8086_OP_IRET:    //IRET
 297                 newip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
 298                 newcs = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
 299                 #if TRACE_EMU
 300                 Log_Debug("VM8086", "%04x:%04x IRET to %04x:%04x",
 301                         Regs->cs, Regs->eip-1, newcs, newip);
 302                 #endif
 303                 Regs->cs = newcs;
 304                 Regs->eip = newip;
 305                 break;
 306
 307
 308         case VM8086_OP_IN_AD:   //IN AL, DX
 309                 Regs->eax &= 0xFFFFFF00;
 310                 Regs->eax |= inb(Regs->edx&0xFFFF);
 311                 #if TRACE_EMU
 312                 Log_Debug("VM8086", "%04x:%04x Emulated IN AL, DX (Port 0x%x [Val 0x%02x])",
 313                         Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFF);
 314                 #endif
 315                 break;
 316         case VM8086_OP_IN_ADX:  //IN AX, DX
 317                 Regs->eax &= 0xFFFF0000;
 318                 Regs->eax |= inw(Regs->edx&0xFFFF);
 319                 #if TRACE_EMU
 320                 Log_Debug("VM8086", "%04x:%04x Emulated IN AX, DX (Port 0x%x [Val 0x%04x])",
 321                         Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 322                 #endif
 323                 break;
 324
 325         case VM8086_OP_OUT_AD:  //OUT DX, AL
 326                 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
 327                 #if TRACE_EMU
 328                 Log_Debug("VM8086", "%04x:%04x Emulated OUT DX, AL (*0x%04x = 0x%02x)",
 329                         Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFF);
 330                 #endif
 331                 break;
 332         case VM8086_OP_OUT_ADX: //OUT DX, AX
 333                 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 334                 #if TRACE_EMU
 335                 Log_Debug("VM8086", "%04x:%04x Emulated OUT DX, AX (*0x%04x = 0x%04x)",
 336                         Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 337                 #endif
 338                 break;
 339
 340         // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
 341         case 0xFA:      //CLI
 342                 #if TRACE_EMU
 343                 Log_Debug("VM8086", "%04x:%04x Ignored CLI",
 344                         Regs->cs, Regs->eip);
 345                 #endif
 346                 gbVM8086_ShadowIF = 0;
 347                 break;
 348         case 0xFB:      //STI
 349                 #if TRACE_EMU
 350                 Log_Debug("VM8086", "%04x:%04x Ignored STI",
 351                         Regs->cs, Regs->eip);
 352                 #endif
 353                 gbVM8086_ShadowIF = 1;
 354                 break;
 355
 356         case 0x66:
 357                 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
 358                 Regs->eip ++;
 359                 switch( opcode )
 360                 {
 361                 case VM8086_OP_IN_ADX:  //IN AX, DX
 362                         Regs->eax = ind(Regs->edx&0xFFFF);
 363                         #if TRACE_EMU
 364                         Log_Debug("VM8086", "%04x:%04x Emulated IN EAX, DX (Port 0x%x [Val 0x%08x])",
 365                                 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax);
 366                         #endif
 367                         break;
 368                 case VM8086_OP_OUT_ADX: //OUT DX, AX
 369                         outd(Regs->edx&0xFFFF, Regs->eax);
 370                         #if TRACE_EMU
 371                         Log_Debug("VM8086", "%04x:%04x Emulated OUT DX, EAX (*0x%04x = 0x%08x)",
 372                                 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax);
 373                         #endif
 374                         break;
 375                 default:
 376                         Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
 377                                 Regs->cs, Regs->eip-2,
 378                                 opcode
 379                                 );
 380                         // Force an end to the call
 381                         Regs->cs = VM8086_MAGIC_CS;
 382                         Regs->eip = VM8086_MAGIC_IP;
 383                         break;
 384                 }
 385                 break;
 386
 387         case 0x0F:
 388                 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
 389                 Log_Error("VM8086", "Error - Unknown opcode 0F %02x caused a GPF at %04x:%04x",
 390                         opcode, Regs->cs, Regs->eip);
 391                 // Force an end to the call
 392                 Regs->cs = VM8086_MAGIC_CS;
 393                 Regs->eip = VM8086_MAGIC_IP;
 394                 break;
 395
 396         default:
 397                 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
 398                         opcode, Regs->cs, Regs->eip-1);
 399                 // Force an end to the call
 400                 Regs->cs = VM8086_MAGIC_CS;
 401                 Regs->eip = VM8086_MAGIC_IP;
 402                 break;
 403         }
 404 }
 405
 406 /**
 407  * \brief Create an instance of the VM8086 Emulator
 408  */
 409 tVM8086 *VM8086_Init(void)
 410 {
 411         tVM8086 *ret;
 412         ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
 413         ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
 414         return ret;
 415 }
 416
 417 void VM8086_Free(tVM8086 *State)
 418 {
 419          int    i;
 420         // TODO: Make sure the state isn't in use currently
 421         for( i = VM8086_PAGES_PER_INST; i --; )
 422                 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
 423         free(State);
 424 }
 425
 426 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
 427 {
 428         struct sVM8086_InternalPages    *pages = State->Internal->AllocatedPages;
 429          int    i, j, base = 0;
 430          int    nBlocks, rem;
 431
 432         Size = (Size + 127) & ~127;
 433         nBlocks = Size / 128;
 434
 435         if(Size > 4096) return NULL;
 436
 437         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 438         {
 439                 if( pages[i].VirtBase == 0 )    continue;
 440
 441                 //Log_Debug("VM8086", "pages[%i].Bitmap = 0b%b", i, pages[i].Bitmap);
 442
 443                 rem = nBlocks;
 444                 base = 0;
 445                 // Scan the bitmap for a free block
 446                 for( j = 0; j < 32; j++ ) {
 447                         if( pages[i].Bitmap & (1 << j) ) {
 448                                 base = j+1;
 449                                 rem = nBlocks;
 450                         }
 451
 452                         rem --;
 453                         if(rem == 0)    // Goodie, there's a gap
 454                         {
 455                                 for( j = 0; j < nBlocks; j++ )
 456                                         pages[i].Bitmap |= 1 << (base + j);
 457                                 *Segment = (VM8086_USER_BASE + i * 0x1000) / 16 + base * 8;
 458                                 *Offset = 0;
 459                                 LOG("Allocated at #%i,%04x", i, base*8*16);
 460                                 LOG(" - %x:%x", *Segment, *Offset);
 461                                 return (void*)( pages[i].VirtBase + base * 8 * 16 );
 462                         }
 463                 }
 464         }
 465
 466         // No pages with free space?, allocate a new one
 467         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 468         {
 469                 if( pages[i].VirtBase == 0 )    break;
 470         }
 471         // Darn, we can't allocate any more
 472         if( i == VM8086_PAGES_PER_INST ) {
 473                 Log_Warning("VM8086", "Out of pages in %p", State);
 474                 return NULL;
 475         }
 476
 477         pages[i].VirtBase = MM_AllocDMA(1, -1, &pages[i].PhysAddr);
 478         if( pages[i].VirtBase == 0 ) {
 479                 Log_Warning("VM8086", "Unable to allocate data page");
 480                 return NULL;
 481         }
 482         pages[i].Bitmap = 0;
 483         LOG("AllocatedPages[%i].VirtBase = %p", i, pages[i].VirtBase);
 484         LOG("AllocatedPages[%i].PhysAddr = %P", i, pages[i].PhysAddr);
 485
 486         for( j = 0; j < nBlocks; j++ )
 487                 pages[i].Bitmap |= 1 << j;
 488         LOG("AllocatedPages[%i].Bitmap = 0b%b", i, pages[i].Bitmap);
 489         *Segment = (VM8086_USER_BASE + i * 0x1000) / 16;
 490         *Offset = 0;
 491         LOG(" - %04x:%04x", *Segment, *Offset);
 492         return (void*) pages[i].VirtBase;
 493 }
 494
 495 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
 496 {
 497         Uint32  addr = Segment * 16 + Offset;
 498
 499         if( VM8086_USER_BASE <= addr && addr < VM8086_USER_BASE + VM8086_PAGES_PER_INST*0x1000 )
 500         {
 501                 int pg = (addr - VM8086_USER_BASE) / 0x1000;
 502                 if( State->Internal->AllocatedPages[pg].VirtBase == 0)
 503                         return NULL;
 504                 else
 505                         return (Uint8*)State->Internal->AllocatedPages[pg].VirtBase + (addr & 0xFFF);
 506         }
 507         else
 508         {
 509                 return (void*)( KERNEL_BASE + addr );
 510         }
 511 }
 512
 513 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
 514 {
 515         State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
 516         State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
 517
 518 //      Log_Debug("VM8086", "Software interrupt %i to %04x:%04x", Interrupt, State->CS, State->IP);
 519
 520         Mutex_Acquire( &glVM8086_Process );
 521
 522         gpVM8086_State = State;
 523         gVM8086_CallingThread = Threads_GetTID();
 524         Semaphore_Signal(&gVM8086_TasksToDo, 1);
 525
 526         Semaphore_Wait(&gVM8086_TaskComplete, 1);
 527
 528         Mutex_Release( &glVM8086_Process );
 529 }