KernelLand/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 #include <semaphore.h>
  11
  12 // === CONSTANTS ===
  13 #define VM8086_MAGIC_CS 0xFFFF
  14 #define VM8086_MAGIC_IP 0x0010
  15 #define VM8086_STACK_SEG        0x9F00
  16 #define VM8086_STACK_OFS        0x0AFE
  17 enum eVM8086_Opcodes
  18 {
  19         VM8086_OP_PUSHF   = 0x9C,
  20         VM8086_OP_POPF    = 0x9D,
  21         VM8086_OP_INT_I   = 0xCD,
  22         VM8086_OP_IRET    = 0xCF,
  23         VM8086_OP_IN_AD   = 0xEC,
  24         VM8086_OP_IN_ADX  = 0xED,
  25         VM8086_OP_OUT_AD  = 0xEE,
  26         VM8086_OP_OUT_ADX = 0xEF
  27 };
  28 #define VM8086_PAGES_PER_INST   4
  29
  30 #define VM8086_BLOCKSIZE        128
  31 #define VM8086_BLOCKCOUNT       ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
  32
  33 // === TYPES ===
  34 struct sVM8086_InternalData
  35 {
  36         struct {
  37                 Uint32  Bitmap; // 32 sections = 128 byte blocks
  38                 tVAddr  VirtBase;
  39                 tPAddr  PhysAddr;
  40         }       AllocatedPages[VM8086_PAGES_PER_INST];
  41 };
  42
  43 // === PROTOTYPES ===
  44  int    VM8086_Install(char **Arguments);
  45 void    VM8086_GPF(tRegs *Regs);
  46 //tVM8086       *VM8086_Init(void);
  47
  48 // === GLOBALS ===
  49 MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
  50 tMutex  glVM8086_Process;
  51 tSemaphore      gVM8086_TaskComplete;
  52 tSemaphore      gVM8086_TasksToDo;
  53 tPID    gVM8086_WorkerPID;
  54 tTID    gVM8086_CallingThread;
  55 tVM8086 volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
  56 Uint32  gaVM8086_MemBitmap[VM8086_BLOCKCOUNT/32];
  57
  58 // === FUNCTIONS ===
  59 int VM8086_Install(char **Arguments)
  60 {
  61         tPID    pid;
  62
  63         Semaphore_Init(&gVM8086_TasksToDo, 0, 10, "VM8086", "TasksToDo");
  64
  65         // Lock to avoid race conditions
  66         Mutex_Acquire( &glVM8086_Process );
  67
  68         // Create BIOS Call process
  69         pid = Proc_Clone(CLONE_VM);
  70         Log_Debug("VM8086", "pid = %i", pid);
  71         if(pid == -1)
  72         {
  73                 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
  74                 return MODULE_ERR_MISC;
  75         }
  76         if(pid == 0)
  77         {
  78                 Uint    * volatile stacksetup;  // Initialising Stack
  79                 Uint16  * volatile rmstack;     // Real Mode Stack
  80                  int    i;
  81
  82                 Log_Debug("VM8086", "Initialising worker");
  83
  84                 // Set Image Name
  85                 Threads_SetName("VM8086");
  86
  87                 // Map ROM Area
  88                 for(i=0xA0;i<0x100;i++) {
  89                         MM_Map( i * 0x1000, i * 0x1000 );
  90                 }
  91                 MM_Map( 0, 0 ); // IVT / BDA
  92                 // Map (but allow allocation) of 0x1000 - 0x9F000
  93                 // - So much hack, it isn't funny
  94                 for(i=1;i<0x9F;i++) {
  95                         MM_Map( i * 0x1000, i * 0x1000 );
  96                         MM_DerefPhys( i * 0x1000 );     // Above
  97                         while(MM_GetRefCount(i*0x1000))
  98                                 MM_DerefPhys( i * 0x1000 );     // Phys setup
  99                 }
 100                 MM_Map( 0x9F000, 0x9F000 );     // Stack / EBDA
 101                 // System Stack / Stub
 102                 if( MM_Allocate( 0x100000 ) == 0 ) {
 103                         Log_Error("VM8086", "Unable to allocate memory for stack/stub");
 104                         gVM8086_WorkerPID = 0;
 105                         Threads_Exit(0, 1);
 106                 }
 107
 108                 *(Uint8*)(0x100000) = VM8086_OP_IRET;
 109                 *(Uint8*)(0x100001) = 0x07;     // POP ES
 110                 *(Uint8*)(0x100002) = 0x1F;     // POP DS
 111                 *(Uint8*)(0x100003) = 0xCB;     // RET FAR
 112
 113                 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
 114                 rmstack--;      *rmstack = 0xFFFF;      //CS
 115                 rmstack--;      *rmstack = 0x0010;      //IP
 116
 117                 // Setup Stack
 118                 stacksetup = (Uint*)0x101000;
 119                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // GS
 120                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // FS
 121                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // DS
 122                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // ES
 123                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // SS
 124                 stacksetup--;   *stacksetup = VM8086_STACK_OFS-2;       // SP
 125                 stacksetup--;   *stacksetup = 0x20202;  // FLAGS
 126                 stacksetup--;   *stacksetup = 0xFFFF;   // CS
 127                 stacksetup--;   *stacksetup = 0x10;     // IP
 128                 stacksetup--;   *stacksetup = 0xAAAA;   // AX
 129                 stacksetup--;   *stacksetup = 0xCCCC;   // CX
 130                 stacksetup--;   *stacksetup = 0xDDDD;   // DX
 131                 stacksetup--;   *stacksetup = 0xBBBB;   // BX
 132                 stacksetup--;   *stacksetup = 0x5454;   // SP
 133                 stacksetup--;   *stacksetup = 0xB4B4;   // BP
 134                 stacksetup--;   *stacksetup = 0x5151;   // SI
 135                 stacksetup--;   *stacksetup = 0xD1D1;   // DI
 136                 stacksetup--;   *stacksetup = 0x20|3;   // DS - Kernel
 137                 stacksetup--;   *stacksetup = 0x20|3;   // ES - Kernel
 138                 stacksetup--;   *stacksetup = 0x20|3;   // FS
 139                 stacksetup--;   *stacksetup = 0x20|3;   // GS
 140                 __asm__ __volatile__ (
 141                 "mov %%eax,%%esp;\n\t"  // Set stack pointer
 142                 "pop %%gs;\n\t"
 143                 "pop %%fs;\n\t"
 144                 "pop %%es;\n\t"
 145                 "pop %%ds;\n\t"
 146                 "popa;\n\t"
 147                 "iret;\n\t" : : "a" (stacksetup));
 148                 for(;;);        // Shouldn't be reached
 149         }
 150
 151         gVM8086_WorkerPID = pid;
 152
 153         // It's released when the GPF fires
 154         Mutex_Acquire( &glVM8086_Process );
 155         Mutex_Release( &glVM8086_Process );
 156
 157         // Worker killed itself
 158         if( gVM8086_WorkerPID != pid ) {
 159                 return MODULE_ERR_MISC;
 160         }
 161
 162         return MODULE_ERR_OK;
 163 }
 164
 165 void VM8086_GPF(tRegs *Regs)
 166 {
 167         Uint8   opcode;
 168
 169 //      Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
 170
 171         if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
 172         && Threads_GetPID() == gVM8086_WorkerPID)
 173         {
 174                 if( gpVM8086_State == (void*)-1 ) {
 175                         Log_Log("VM8086", "Worker thread ready and waiting");
 176                         gpVM8086_State = NULL;
 177                         Mutex_Release( &glVM8086_Process );     // Release lock obtained in VM8086_Install
 178                 }
 179 //              Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
 180 //                      gpVM8086_State, gVM8086_CallingThread);
 181                 if( gpVM8086_State ) {
 182                         gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
 183                         gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
 184                         gpVM8086_State->BP = Regs->ebp;
 185                         gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
 186                         gpVM8086_State->DS = Regs->ds;  gpVM8086_State->ES = Regs->es;
 187                         gpVM8086_State = NULL;
 188                         // Wake the caller
 189                         Semaphore_Signal(&gVM8086_TaskComplete, 1);
 190                 }
 191
 192                 //Log_Log("VM8086", "Waiting for something to do");
 193                 __asm__ __volatile__ ("sti");
 194                 Semaphore_Wait(&gVM8086_TasksToDo, 1);
 195
 196                 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
 197                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
 198                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
 199                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
 200                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
 201                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
 202                 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
 203
 204                 // Set Registers
 205                 Regs->eip = 0x11;       Regs->cs = 0xFFFF;
 206                 Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
 207                 Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
 208                 Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
 209                 Regs->ebp = gpVM8086_State->BP;
 210                 Regs->ds = 0x23;        Regs->es = 0x23;
 211                 Regs->fs = 0x23;        Regs->gs = 0x23;
 212                 return ;
 213         }
 214
 215         opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
 216         Regs->eip ++;
 217         switch(opcode)
 218         {
 219         case VM8086_OP_PUSHF:   //PUSHF
 220                 Regs->esp -= 2;
 221                 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
 222                 #if TRACE_EMU
 223                 Log_Debug("VM8086", "Emulated PUSHF");
 224                 #endif
 225                 break;
 226         case VM8086_OP_POPF:    //POPF
 227                 // Changing IF is not allowed
 228                 Regs->eflags &= 0xFFFF0202;
 229                 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );
 230                 Regs->esp += 2;
 231                 #if TRACE_EMU
 232                 Log_Debug("VM8086", "Emulated POPF");
 233                 #endif
 234                 break;
 235
 236         case VM8086_OP_INT_I:   //INT imm8
 237                 {
 238                  int    id;
 239                 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
 240                 Regs->eip ++;
 241
 242                 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
 243                 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
 244
 245                 Regs->cs = *(Uint16*)(4*id + 2);
 246                 Regs->eip = *(Uint16*)(4*id);
 247                 #if TRACE_EMU
 248                 Log_Debug("VM8086", "Emulated INT 0x%x", id);
 249                 #endif
 250                 }
 251                 break;
 252
 253         case VM8086_OP_IRET:    //IRET
 254                 Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 255                 Regs->cs  = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 256                 #if TRACE_EMU
 257                 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
 258                 #endif
 259                 break;
 260
 261
 262         case VM8086_OP_IN_AD:   //IN AL, DX
 263                 Regs->eax &= 0xFFFFFF00;
 264                 Regs->eax |= inb(Regs->edx&0xFFFF);
 265                 #if TRACE_EMU
 266                 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 267                 #endif
 268                 break;
 269         case VM8086_OP_IN_ADX:  //IN AX, DX
 270                 Regs->eax &= 0xFFFF0000;
 271                 Regs->eax |= inw(Regs->edx&0xFFFF);
 272                 #if TRACE_EMU
 273                 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 274                 #endif
 275                 break;
 276
 277         case VM8086_OP_OUT_AD:  //OUT DX, AL
 278                 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
 279                 #if TRACE_EMU
 280                 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
 281                 #endif
 282                 break;
 283         case VM8086_OP_OUT_ADX: //OUT DX, AX
 284                 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 285                 #if TRACE_EMU
 286                 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 287                 #endif
 288                 break;
 289
 290         // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
 291         case 0xFA:      //CLI
 292                 break;
 293         case 0xFB:      //STI
 294                 break;
 295
 296         case 0x66:
 297                 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
 298                 switch( opcode )
 299                 {
 300                 case VM8086_OP_IN_ADX:  //IN AX, DX
 301                         Regs->eax = ind(Regs->edx&0xFFFF);
 302                         #if TRACE_EMU
 303                         Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 304                         #endif
 305                         break;
 306                 case VM8086_OP_OUT_ADX: //OUT DX, AX
 307                         outd(Regs->edx&0xFFFF, Regs->eax);
 308                         #if TRACE_EMU
 309                         Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
 310                         #endif
 311                         break;
 312                 default:
 313                         Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
 314                                 Regs->cs, Regs->eip,
 315                                 opcode
 316                                 );
 317                         // Force an end to the call
 318                         Regs->cs = VM8086_MAGIC_CS;
 319                         Regs->eip = VM8086_MAGIC_IP;
 320                         break;
 321                 }
 322                 break;
 323
 324         default:
 325                 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
 326                         opcode, Regs->cs, Regs->eip);
 327                 // Force an end to the call
 328                 Regs->cs = VM8086_MAGIC_CS;
 329                 Regs->eip = VM8086_MAGIC_IP;
 330                 break;
 331         }
 332 }
 333
 334 /**
 335  * \brief Create an instance of the VM8086 Emulator
 336  */
 337 tVM8086 *VM8086_Init(void)
 338 {
 339         tVM8086 *ret;
 340         ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
 341         ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
 342         return ret;
 343 }
 344
 345 void VM8086_Free(tVM8086 *State)
 346 {
 347          int    i;
 348         for( i = VM8086_PAGES_PER_INST; i --; )
 349                 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
 350         free(State);
 351 }
 352
 353 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
 354 {
 355          int    i, j, base = 0;
 356          int    nBlocks, rem;
 357
 358         Size = (Size + 127) & ~127;
 359         nBlocks = Size / 128;
 360
 361         if(Size > 4096) return NULL;
 362
 363         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 364         {
 365                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  continue;
 366
 367
 368                 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 369
 370                 rem = nBlocks;
 371                 base = 0;
 372                 // Scan the bitmap for a free block
 373                 for( j = 0; j < 32; j++ ) {
 374                         if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
 375                                 base = j+1;
 376                                 rem = nBlocks;
 377                         }
 378
 379                         rem --;
 380                         if(rem == 0)    // Goodie, there's a gap
 381                         {
 382                                 for( j = 0; j < nBlocks; j++ )
 383                                         State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
 384                                 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
 385                                 *Offset = 0;
 386                                 LOG("Allocated at #%i,%04x", i, base*128);
 387                                 LOG(" - %x:%x", *Segment, *Offset);
 388                                 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
 389                         }
 390                 }
 391         }
 392
 393         // No pages with free space?, allocate a new one
 394         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 395         {
 396                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  break;
 397         }
 398         // Darn, we can't allocate any more
 399         if( i == VM8086_PAGES_PER_INST ) {
 400                 Log_Warning("VM8086", "Out of pages in %p", State);
 401                 return NULL;
 402         }
 403
 404         State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
 405                 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
 406         State->Internal->AllocatedPages[i].Bitmap = 0;
 407
 408         for( j = 0; j < nBlocks; j++ )
 409                 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
 410         LOG("AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 411         *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
 412         *Offset = 0;
 413         LOG(" - %x:%x", *Segment, *Offset);
 414         return (void*) State->Internal->AllocatedPages[i].VirtBase;
 415 }
 416
 417 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
 418 {
 419         return (void*)( KERNEL_BASE + Segment*16 + Offset );
 420 }
 421
 422 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
 423 {
 424         State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
 425         State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
 426
 427 //      Log_Debug("VM8086", "Software interrupt %i to %04x:%04x", Interrupt, State->CS, State->IP);
 428
 429         Mutex_Acquire( &glVM8086_Process );
 430
 431         gpVM8086_State = State;
 432         gVM8086_CallingThread = Threads_GetTID();
 433         Semaphore_Signal(&gVM8086_TasksToDo, 1);
 434
 435         Semaphore_Wait(&gVM8086_TaskComplete, 1);
 436
 437         Mutex_Release( &glVM8086_Process );
 438 }