Kernel/arch/x86/vm8086.c

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