Kernel/arch/x86/vm8086.c

   1 /*
   2  * Acess2 VM8086 Driver
   3  * - By John Hodge (thePowersGang)
   4  */
   5 #define DEBUG   0
   6 #include <acess.h>
   7 #include <vm8086.h>
   8 #include <modules.h>
   9 #include <hal_proc.h>
  10
  11 // === CONSTANTS ===
  12 #define VM8086_MAGIC_CS 0xFFFF
  13 #define VM8086_MAGIC_IP 0x0010
  14 #define VM8086_STACK_SEG        0x9F00
  15 #define VM8086_STACK_OFS        0x0AFE
  16 enum eVM8086_Opcodes
  17 {
  18         VM8086_OP_PUSHF   = 0x9C,
  19         VM8086_OP_POPF    = 0x9D,
  20         VM8086_OP_INT_I   = 0xCD,
  21         VM8086_OP_IRET    = 0xCF,
  22         VM8086_OP_IN_AD   = 0xEC,
  23         VM8086_OP_IN_ADX  = 0xED,
  24         VM8086_OP_OUT_AD  = 0xEE,
  25         VM8086_OP_OUT_ADX = 0xEF
  26 };
  27 #define VM8086_PAGES_PER_INST   4
  28
  29 #define VM8086_BLOCKSIZE        128
  30 #define VM8086_BLOCKCOUNT       ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
  31
  32 // === TYPES ===
  33 struct sVM8086_InternalData
  34 {
  35         struct {
  36                 Uint32  Bitmap; // 32 sections = 128 byte blocks
  37                 tVAddr  VirtBase;
  38                 tPAddr  PhysAddr;
  39         }       AllocatedPages[VM8086_PAGES_PER_INST];
  40 };
  41
  42 // === PROTOTYPES ===
  43  int    VM8086_Install(char **Arguments);
  44 void    VM8086_GPF(tRegs *Regs);
  45 //tVM8086       *VM8086_Init(void);
  46
  47 // === GLOBALS ===
  48 MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
  49 tMutex  glVM8086_Process;
  50 tPID    gVM8086_WorkerPID;
  51 tTID    gVM8086_CallingThread;
  52 tVM8086 volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
  53 Uint32  gaVM8086_MemBitmap[VM8086_BLOCKCOUNT/32];
  54
  55 // === FUNCTIONS ===
  56 int VM8086_Install(char **Arguments)
  57 {
  58         tPID    pid;
  59
  60         // Lock to avoid race conditions
  61         Mutex_Acquire( &glVM8086_Process );
  62
  63         // Create BIOS Call process
  64         pid = Proc_Clone(CLONE_VM);
  65         if(pid == -1)
  66         {
  67                 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
  68                 return MODULE_ERR_MISC;
  69         }
  70         if(pid == 0)
  71         {
  72                 Uint    * volatile stacksetup;  // Initialising Stack
  73                 Uint16  * volatile rmstack;     // Real Mode Stack
  74                  int    i;
  75
  76                 // Set Image Name
  77                 Threads_SetName("VM8086");
  78
  79                 Log_Debug("VM8086", "Mapping memory");
  80
  81                 // Map ROM Area
  82                 for(i=0xA0;i<0x100;i++) {
  83                         MM_Map( i * 0x1000, i * 0x1000 );
  84                 }
  85                 Log_Debug("VM8086", "ROM area mapped");
  86                 MM_Map( 0, 0 ); // IVT / BDA
  87                 // Map (but allow allocation) of 0x1000 - 0x9F000
  88                 // - So much hack, it isn't funny
  89                 for(i=1;i<0x9F;i++) {
  90                         MM_Map( i * 0x1000, i * 0x1000 );
  91                         MM_DerefPhys( i * 0x1000 );     // Above
  92                         while(MM_GetRefCount(i*0x1000))
  93                                 MM_DerefPhys( i * 0x1000 );     // Phys setup
  94                 }
  95                 MM_Map( 0x9F000, 0x9F000 );     // Stack / EBDA
  96                 // System Stack / Stub
  97                 if( MM_Allocate( 0x100000 ) == 0 ) {
  98                         Log_Error("VM8086", "Unable to allocate memory for stack/stub");
  99                         gVM8086_WorkerPID = 0;
 100                         Threads_Exit(0, 1);
 101                 }
 102                 Log_Debug("VM8086", "Mapped low memory");
 103
 104                 *(Uint8*)(0x100000) = VM8086_OP_IRET;
 105                 *(Uint8*)(0x100001) = 0x07;     // POP ES
 106                 *(Uint8*)(0x100002) = 0x1F;     // POP DS
 107                 *(Uint8*)(0x100003) = 0xCB;     // RET FAR
 108
 109                 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
 110                 rmstack--;      *rmstack = 0xFFFF;      //CS
 111                 rmstack--;      *rmstack = 0x0010;      //IP
 112
 113                 // Setup Stack
 114                 stacksetup = (Uint*)0x101000;
 115                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // GS
 116                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // FS
 117                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // DS
 118                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // ES
 119                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // SS
 120                 stacksetup--;   *stacksetup = VM8086_STACK_OFS-2;       // SP
 121                 stacksetup--;   *stacksetup = 0x20202;  // FLAGS
 122                 stacksetup--;   *stacksetup = 0xFFFF;   // CS
 123                 stacksetup--;   *stacksetup = 0x10;     // IP
 124                 stacksetup--;   *stacksetup = 0xAAAA;   // AX
 125                 stacksetup--;   *stacksetup = 0xCCCC;   // CX
 126                 stacksetup--;   *stacksetup = 0xDDDD;   // DX
 127                 stacksetup--;   *stacksetup = 0xBBBB;   // BX
 128                 stacksetup--;   *stacksetup = 0x5454;   // SP
 129                 stacksetup--;   *stacksetup = 0xB4B4;   // BP
 130                 stacksetup--;   *stacksetup = 0x5151;   // SI
 131                 stacksetup--;   *stacksetup = 0xD1D1;   // DI
 132                 stacksetup--;   *stacksetup = 0x20|3;   // DS - Kernel
 133                 stacksetup--;   *stacksetup = 0x20|3;   // ES - Kernel
 134                 stacksetup--;   *stacksetup = 0x20|3;   // FS
 135                 stacksetup--;   *stacksetup = 0x20|3;   // GS
 136                 __asm__ __volatile__ (
 137                 "mov %%eax,%%esp;\n\t"  // Set stack pointer
 138                 "pop %%gs;\n\t"
 139                 "pop %%fs;\n\t"
 140                 "pop %%es;\n\t"
 141                 "pop %%ds;\n\t"
 142                 "popa;\n\t"
 143                 "iret;\n\t" : : "a" (stacksetup));
 144                 for(;;);        // Shouldn't be reached
 145         }
 146
 147         gVM8086_WorkerPID = pid;
 148         Log_Log("VM8086", "gVM8086_WorkerPID = %i", pid);
 149         while( gpVM8086_State != NULL )
 150                 Threads_Yield();        // Yield to allow the child to initialise
 151
 152         // Worker killed itself
 153         if( gVM8086_WorkerPID != pid ) {
 154                 return MODULE_ERR_MISC;
 155         }
 156
 157         return MODULE_ERR_OK;
 158 }
 159
 160 void VM8086_GPF(tRegs *Regs)
 161 {
 162         Uint8   opcode;
 163
 164         //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
 165
 166         if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
 167         && Threads_GetPID() == gVM8086_WorkerPID)
 168         {
 169                 if( gpVM8086_State == (void*)-1 ) {
 170                         Log_Log("VM8086", "Worker thread ready and waiting");
 171                         gpVM8086_State = NULL;
 172                         Mutex_Release( &glVM8086_Process );     // Release lock obtained in VM8086_Install
 173                 }
 174                 //Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
 175                 //      gpVM8086_State, gVM8086_CallingThread);
 176                 if( gpVM8086_State ) {
 177                         gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
 178                         gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
 179                         gpVM8086_State->BP = Regs->ebp;
 180                         gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
 181                         gpVM8086_State->DS = Regs->ds;  gpVM8086_State->ES = Regs->es;
 182                         gpVM8086_State = NULL;
 183                         // Wake the caller
 184                         Threads_WakeTID(gVM8086_CallingThread);
 185                 }
 186
 187                 //Log_Log("VM8086", "Waiting for something to do");
 188                 __asm__ __volatile__ ("sti");
 189                 // Wait for a new task
 190                 while(!gpVM8086_State) {
 191                         Threads_Sleep();
 192                         //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
 193                 }
 194
 195                 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
 196                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
 197                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
 198                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
 199                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
 200                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
 201                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
 202
 203                 // Set Registers
 204                 Regs->eip = 0x11;       Regs->cs = 0xFFFF;
 205                 Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
 206                 Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
 207                 Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
 208                 Regs->ebp = gpVM8086_State->BP;
 209                 Regs->ds = 0x23;        Regs->es = 0x23;
 210                 Regs->fs = 0x23;        Regs->gs = 0x23;
 211                 return ;
 212         }
 213
 214         opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
 215         Regs->eip ++;
 216         switch(opcode)
 217         {
 218         case VM8086_OP_PUSHF:   //PUSHF
 219                 Regs->esp -= 2;
 220                 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
 221                 #if TRACE_EMU
 222                 Log_Debug("VM8086", "Emulated PUSHF");
 223                 #endif
 224                 break;
 225         case VM8086_OP_POPF:    //POPF
 226                 Regs->eflags &= 0xFFFF0002;
 227                 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0xFFFD;        // Changing IF is not allowed
 228                 Regs->esp += 2;
 229                 #if TRACE_EMU
 230                 Log_Debug("VM8086", "Emulated POPF");
 231                 #endif
 232                 break;
 233
 234         case VM8086_OP_INT_I:   //INT imm8
 235                 {
 236                  int    id;
 237                 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
 238                 Regs->eip ++;
 239
 240                 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
 241                 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
 242
 243                 Regs->cs = *(Uint16*)(4*id + 2);
 244                 Regs->eip = *(Uint16*)(4*id);
 245                 #if TRACE_EMU
 246                 Log_Debug("VM8086", "Emulated INT 0x%x", id);
 247                 #endif
 248                 }
 249                 break;
 250
 251         case VM8086_OP_IRET:    //IRET
 252                 Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 253                 Regs->cs  = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 254                 #if TRACE_EMU
 255                 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
 256                 #endif
 257                 break;
 258
 259
 260         case VM8086_OP_IN_AD:   //IN AL, DX
 261                 Regs->eax &= 0xFFFFFF00;
 262                 Regs->eax |= inb(Regs->edx&0xFFFF);
 263                 #if TRACE_EMU
 264                 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 265                 #endif
 266                 break;
 267         case VM8086_OP_IN_ADX:  //IN AX, DX
 268                 Regs->eax &= 0xFFFF0000;
 269                 Regs->eax |= inw(Regs->edx&0xFFFF);
 270                 #if TRACE_EMU
 271                 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 272                 #endif
 273                 break;
 274
 275         case VM8086_OP_OUT_AD:  //OUT DX, AL
 276                 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
 277                 #if TRACE_EMU
 278                 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
 279                 #endif
 280                 break;
 281         case VM8086_OP_OUT_ADX: //OUT DX, AX
 282                 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 283                 #if TRACE_EMU
 284                 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 285                 #endif
 286                 break;
 287
 288         // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
 289         case 0xFA:      //CLI
 290                 break;
 291         case 0xFB:      //STI
 292                 break;
 293
 294         case 0x66:
 295                 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
 296                 switch( opcode )
 297                 {
 298                 case VM8086_OP_IN_ADX:  //IN AX, DX
 299                         Regs->eax = ind(Regs->edx&0xFFFF);
 300                         #if TRACE_EMU
 301                         Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 302                         #endif
 303                         break;
 304                 case VM8086_OP_OUT_ADX: //OUT DX, AX
 305                         outd(Regs->edx&0xFFFF, Regs->eax);
 306                         #if TRACE_EMU
 307                         Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
 308                         #endif
 309                         break;
 310                 default:
 311                         Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
 312                                 Regs->cs, Regs->eip,
 313                                 opcode
 314                                 );
 315                         // Force an end to the call
 316                         Regs->cs = VM8086_MAGIC_CS;
 317                         Regs->eip = VM8086_MAGIC_IP;
 318                         break;
 319                 }
 320                 break;
 321
 322         default:
 323                 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
 324                         opcode, Regs->cs, Regs->eip);
 325                 // Force an end to the call
 326                 Regs->cs = VM8086_MAGIC_CS;
 327                 Regs->eip = VM8086_MAGIC_IP;
 328                 break;
 329         }
 330 }
 331
 332 /**
 333  * \brief Create an instance of the VM8086 Emulator
 334  */
 335 tVM8086 *VM8086_Init(void)
 336 {
 337         tVM8086 *ret;
 338         ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
 339         ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
 340         return ret;
 341 }
 342
 343 void VM8086_Free(tVM8086 *State)
 344 {
 345          int    i;
 346         for( i = VM8086_PAGES_PER_INST; i --; )
 347                 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
 348         free(State);
 349 }
 350
 351 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
 352 {
 353          int    i, j, base = 0;
 354          int    nBlocks, rem;
 355
 356         Size = (Size + 127) & ~127;
 357         nBlocks = Size / 128;
 358
 359         if(Size > 4096) return NULL;
 360
 361         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 362         {
 363                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  continue;
 364
 365
 366                 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 367
 368                 rem = nBlocks;
 369                 base = 0;
 370                 // Scan the bitmap for a free block
 371                 for( j = 0; j < 32; j++ ) {
 372                         if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
 373                                 base = j+1;
 374                                 rem = nBlocks;
 375                         }
 376
 377                         rem --;
 378                         if(rem == 0)    // Goodie, there's a gap
 379                         {
 380                                 for( j = 0; j < nBlocks; j++ )
 381                                         State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
 382                                 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
 383                                 *Offset = 0;
 384                                 LOG("Allocated at #%i,%04x", i, base*128);
 385                                 LOG(" - %x:%x", *Segment, *Offset);
 386                                 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
 387                         }
 388                 }
 389         }
 390
 391         // No pages with free space?, allocate a new one
 392         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 393         {
 394                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  break;
 395         }
 396         // Darn, we can't allocate any more
 397         if( i == VM8086_PAGES_PER_INST ) {
 398                 Log_Warning("VM8086", "Out of pages in %p", State);
 399                 return NULL;
 400         }
 401
 402         State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
 403                 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
 404         State->Internal->AllocatedPages[i].Bitmap = 0;
 405
 406         for( j = 0; j < nBlocks; j++ )
 407                 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
 408         LOG("AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 409         *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
 410         *Offset = 0;
 411         LOG(" - %x:%x", *Segment, *Offset);
 412         return (void*) State->Internal->AllocatedPages[i].VirtBase;
 413 }
 414
 415 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
 416 {
 417         return (void*)( KERNEL_BASE + Segment*16 + Offset );
 418 }
 419
 420 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
 421 {
 422         State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
 423         State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
 424
 425 //      Log_Debug("VM8086", "Software interrupt %i to %04x:%04x", Interrupt, State->CS, State->IP);
 426
 427         Mutex_Acquire( &glVM8086_Process );
 428
 429         gpVM8086_State = State;
 430         gVM8086_CallingThread = Threads_GetTID();
 431         Threads_WakeTID( gVM8086_WorkerPID );
 432         Threads_Sleep();
 433         while( gpVM8086_State != NULL ) Threads_Sleep();
 434
 435         Mutex_Release( &glVM8086_Process );
 436 }