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                 //      MM_SetFlags( i * 0x1000, MM_PFLAG_RO, MM_PFLAG_RO );    // Set Read Only
  85                 }
  86                 Log_Debug("VM8086", "ROM area mapped");
  87                 MM_Map( 0, 0 ); // IVT / BDA
  88                 // Map (but allow allocation) of 0x1000 - 0x9F000
  89                 // - So much hack, it isn't funny
  90                 for(i=1;i<0x9F;i++) {
  91                         MM_Map( i * 0x1000, i * 0x1000 );
  92                         MM_DerefPhys( i * 0x1000 );     // Above
  93                         if(MM_GetRefCount(i*0x1000))
  94                                 MM_DerefPhys( i * 0x1000 );     // Phys setup
  95                 }
  96                 MM_Map( 0x9F000, 0x9F000 );     // Stack / EBDA
  97                 // System Stack / Stub
  98                 if( MM_Allocate( 0x100000 ) == 0 ) {
  99                         Log_Error("VM8086", "Unable to allocate memory for stack/stub");
 100                         gVM8086_WorkerPID = 0;
 101                         Threads_Exit(0, 1);
 102                 }
 103                 Log_Debug("VM8086", "Mapped low memory");
 104
 105                 *(Uint8*)(0x100000) = VM8086_OP_IRET;
 106                 *(Uint8*)(0x100001) = 0x07;     // POP ES
 107                 *(Uint8*)(0x100002) = 0x1F;     // POP DS
 108                 *(Uint8*)(0x100003) = 0xCB;     // RET FAR
 109
 110                 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
 111                 rmstack--;      *rmstack = 0xFFFF;      //CS
 112                 rmstack--;      *rmstack = 0x0010;      //IP
 113
 114                 // Setup Stack
 115                 stacksetup = (Uint*)0x101000;
 116                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // GS
 117                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // FS
 118                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // DS
 119                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // ES
 120                 stacksetup--;   *stacksetup = VM8086_STACK_SEG; // SS
 121                 stacksetup--;   *stacksetup = VM8086_STACK_OFS-2;       // SP
 122                 stacksetup--;   *stacksetup = 0x20202;  // FLAGS
 123                 stacksetup--;   *stacksetup = 0xFFFF;   // CS
 124                 stacksetup--;   *stacksetup = 0x10;     // IP
 125                 stacksetup--;   *stacksetup = 0xAAAA;   // AX
 126                 stacksetup--;   *stacksetup = 0xCCCC;   // CX
 127                 stacksetup--;   *stacksetup = 0xDDDD;   // DX
 128                 stacksetup--;   *stacksetup = 0xBBBB;   // BX
 129                 stacksetup--;   *stacksetup = 0x5454;   // SP
 130                 stacksetup--;   *stacksetup = 0xB4B4;   // BP
 131                 stacksetup--;   *stacksetup = 0x5151;   // SI
 132                 stacksetup--;   *stacksetup = 0xD1D1;   // DI
 133                 stacksetup--;   *stacksetup = 0x20|3;   // DS - Kernel
 134                 stacksetup--;   *stacksetup = 0x20|3;   // ES - Kernel
 135                 stacksetup--;   *stacksetup = 0x20|3;   // FS
 136                 stacksetup--;   *stacksetup = 0x20|3;   // GS
 137                 __asm__ __volatile__ (
 138                 "mov %%eax,%%esp;\n\t"  // Set stack pointer
 139                 "pop %%gs;\n\t"
 140                 "pop %%fs;\n\t"
 141                 "pop %%es;\n\t"
 142                 "pop %%ds;\n\t"
 143                 "popa;\n\t"
 144                 "iret;\n\t" : : "a" (stacksetup));
 145                 for(;;);        // Shouldn't be reached
 146         }
 147
 148         gVM8086_WorkerPID = pid;
 149         Log_Log("VM8086", "gVM8086_WorkerPID = %i", pid);
 150         while( gpVM8086_State != NULL )
 151                 Threads_Yield();        // Yield to allow the child to initialise
 152
 153         // Worker killed itself
 154         if( gVM8086_WorkerPID != pid ) {
 155                 return MODULE_ERR_MISC;
 156         }
 157
 158         return MODULE_ERR_OK;
 159 }
 160
 161 void VM8086_GPF(tRegs *Regs)
 162 {
 163         Uint8   opcode;
 164
 165         //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
 166
 167         if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
 168         && Threads_GetPID() == gVM8086_WorkerPID)
 169         {
 170                 if( gpVM8086_State == (void*)-1 ) {
 171                         Log_Log("VM8086", "Worker thread ready and waiting");
 172                         gpVM8086_State = NULL;
 173                         Mutex_Release( &glVM8086_Process );     // Release lock obtained in VM8086_Install
 174                 }
 175                 //Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
 176                 //      gpVM8086_State, gVM8086_CallingThread);
 177                 if( gpVM8086_State ) {
 178                         gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
 179                         gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
 180                         gpVM8086_State->BP = Regs->ebp;
 181                         gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
 182                         gpVM8086_State->DS = Regs->ds;  gpVM8086_State->ES = Regs->es;
 183                         gpVM8086_State = NULL;
 184                         // Wake the caller
 185                         Threads_WakeTID(gVM8086_CallingThread);
 186                 }
 187
 188                 //Log_Log("VM8086", "Waiting for something to do");
 189                 __asm__ __volatile__ ("sti");
 190                 // Wait for a new task
 191                 while(!gpVM8086_State) {
 192                         Threads_Sleep();
 193                         //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
 194                 }
 195
 196                 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
 197                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
 198                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
 199                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
 200                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
 201                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
 202                 Regs->esp -= 2; *(Uint16*volatile)( (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                 Regs->eflags &= 0xFFFF0002;
 228                 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0xFFFD;        // Changing IF is not allowed
 229                 Regs->esp += 2;
 230                 #if TRACE_EMU
 231                 Log_Debug("VM8086", "Emulated POPF");
 232                 #endif
 233                 break;
 234
 235         case VM8086_OP_INT_I:   //INT imm8
 236                 {
 237                  int    id;
 238                 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
 239                 Regs->eip ++;
 240
 241                 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
 242                 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
 243
 244                 Regs->cs = *(Uint16*)(4*id + 2);
 245                 Regs->eip = *(Uint16*)(4*id);
 246                 #if TRACE_EMU
 247                 Log_Debug("VM8086", "Emulated INT 0x%x", id);
 248                 #endif
 249                 }
 250                 break;
 251
 252         case VM8086_OP_IRET:    //IRET
 253                 Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 254                 Regs->cs  = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 255                 #if TRACE_EMU
 256                 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
 257                 #endif
 258                 break;
 259
 260
 261         case VM8086_OP_IN_AD:   //IN AL, DX
 262                 Regs->eax &= 0xFFFFFF00;
 263                 Regs->eax |= inb(Regs->edx&0xFFFF);
 264                 #if TRACE_EMU
 265                 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 266                 #endif
 267                 break;
 268         case VM8086_OP_IN_ADX:  //IN AX, DX
 269                 Regs->eax &= 0xFFFF0000;
 270                 Regs->eax |= inw(Regs->edx&0xFFFF);
 271                 #if TRACE_EMU
 272                 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 273                 #endif
 274                 break;
 275
 276         case VM8086_OP_OUT_AD:  //OUT DX, AL
 277                 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
 278                 #if TRACE_EMU
 279                 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
 280                 #endif
 281                 break;
 282         case VM8086_OP_OUT_ADX: //OUT DX, AX
 283                 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 284                 #if TRACE_EMU
 285                 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 286                 #endif
 287                 break;
 288
 289         // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
 290         case 0xFA:      //CLI
 291                 break;
 292         case 0xFB:      //STI
 293                 break;
 294
 295         case 0x66:
 296                 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
 297                 switch( opcode )
 298                 {
 299                 case VM8086_OP_IN_ADX:  //IN AX, DX
 300                         Regs->eax = ind(Regs->edx&0xFFFF);
 301                         #if TRACE_EMU
 302                         Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 303                         #endif
 304                         break;
 305                 case VM8086_OP_OUT_ADX: //OUT DX, AX
 306                         outd(Regs->edx&0xFFFF, Regs->eax);
 307                         #if TRACE_EMU
 308                         Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
 309                         #endif
 310                         break;
 311                 default:
 312                         Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
 313                                 Regs->cs, Regs->eip,
 314                                 opcode
 315                                 );
 316                         // Force an end to the call
 317                         Regs->cs = VM8086_MAGIC_CS;
 318                         Regs->eip = VM8086_MAGIC_IP;
 319                         break;
 320                 }
 321                 break;
 322
 323         default:
 324                 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
 325                         opcode, Regs->cs, Regs->eip);
 326                 // Force an end to the call
 327                 Regs->cs = VM8086_MAGIC_CS;
 328                 Regs->eip = VM8086_MAGIC_IP;
 329                 break;
 330         }
 331 }
 332
 333 /**
 334  * \brief Create an instance of the VM8086 Emulator
 335  */
 336 tVM8086 *VM8086_Init(void)
 337 {
 338         tVM8086 *ret;
 339         ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
 340         ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
 341         return ret;
 342 }
 343
 344 void VM8086_Free(tVM8086 *State)
 345 {
 346          int    i;
 347         for( i = VM8086_PAGES_PER_INST; i --; )
 348                 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
 349         free(State);
 350 }
 351
 352 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
 353 {
 354          int    i, j, base = 0;
 355          int    nBlocks, rem;
 356
 357         Size = (Size + 127) & ~127;
 358         nBlocks = Size / 128;
 359
 360         if(Size > 4096) return NULL;
 361
 362         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 363         {
 364                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  continue;
 365
 366
 367                 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 368
 369                 rem = nBlocks;
 370                 base = 0;
 371                 // Scan the bitmap for a free block
 372                 for( j = 0; j < 32; j++ ) {
 373                         if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
 374                                 base = j+1;
 375                                 rem = nBlocks;
 376                         }
 377
 378                         rem --;
 379                         if(rem == 0)    // Goodie, there's a gap
 380                         {
 381                                 for( j = 0; j < nBlocks; j++ )
 382                                         State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
 383                                 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
 384                                 *Offset = 0;
 385                                 LOG("Allocated at #%i,%04x", i, base*128);
 386                                 LOG(" - %x:%x", *Segment, *Offset);
 387                                 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
 388                         }
 389                 }
 390         }
 391
 392         // No pages with free space?, allocate a new one
 393         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 394         {
 395                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  break;
 396         }
 397         // Darn, we can't allocate any more
 398         if( i == VM8086_PAGES_PER_INST ) {
 399                 Log_Warning("VM8086", "Out of pages in %p", State);
 400                 return NULL;
 401         }
 402
 403         State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
 404                 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
 405         State->Internal->AllocatedPages[i].Bitmap = 0;
 406
 407         for( j = 0; j < nBlocks; j++ )
 408                 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
 409         LOG("AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 410         *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
 411         *Offset = 0;
 412         LOG(" - %x:%x", *Segment, *Offset);
 413         return (void*) State->Internal->AllocatedPages[i].VirtBase;
 414 }
 415
 416 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
 417 {
 418         return (void*)( KERNEL_BASE + Segment*16 + Offset );
 419 }
 420
 421 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
 422 {
 423         State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
 424         State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
 425
 426         Mutex_Acquire( &glVM8086_Process );
 427
 428         gpVM8086_State = State;
 429         gVM8086_CallingThread = Threads_GetTID();
 430         Threads_WakeTID( gVM8086_WorkerPID );
 431         Threads_Sleep();
 432         while( gpVM8086_State != NULL ) Threads_Sleep();
 433
 434         Mutex_Release( &glVM8086_Process );
 435 }