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 tMutex  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         Mutex_Acquire( &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         while( gpVM8086_State != NULL )
 134                 Threads_Yield();        // Yield to allow the child to initialise
 135
 136         return MODULE_ERR_OK;
 137 }
 138
 139 void VM8086_GPF(tRegs *Regs)
 140 {
 141         Uint8   opcode;
 142
 143         //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
 144
 145         if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
 146         && Threads_GetPID() == gVM8086_WorkerPID)
 147         {
 148                 if( gpVM8086_State == (void*)-1 ) {
 149                         Log_Log("VM8086", "Worker thread ready and waiting");
 150                         Mutex_Release( &glVM8086_Process );     // Release lock obtained in VM8086_Install
 151                         gpVM8086_State = NULL;
 152                 }
 153                 //Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
 154                 //      gpVM8086_State, gVM8086_CallingThread);
 155                 if( gpVM8086_State ) {
 156                         gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
 157                         gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
 158                         gpVM8086_State->BP = Regs->ebp;
 159                         gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
 160                         gpVM8086_State->DS = Regs->ds;  gpVM8086_State->ES = Regs->es;
 161                         gpVM8086_State = NULL;
 162                         // Wake the caller
 163                         Threads_WakeTID(gVM8086_CallingThread);
 164                 }
 165
 166                 //Log_Log("VM8086", "Waiting for something to do");
 167                 __asm__ __volatile__ ("sti");
 168                 // Wait for a new task
 169                 while(!gpVM8086_State) {
 170                         Threads_Sleep();
 171                         //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
 172                 }
 173
 174                 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
 175                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
 176                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
 177                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
 178                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
 179                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
 180                 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
 181
 182                 // Set Registers
 183                 Regs->eip = 0x11;       Regs->cs = 0xFFFF;
 184                 Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
 185                 Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
 186                 Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
 187                 Regs->ebp = gpVM8086_State->BP;
 188                 Regs->ds = 0x23;        Regs->es = 0x23;
 189                 Regs->fs = 0x23;        Regs->gs = 0x23;
 190                 return ;
 191         }
 192
 193         opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
 194         Regs->eip ++;
 195         switch(opcode)
 196         {
 197         case VM8086_OP_PUSHF:   //PUSHF
 198                 Regs->esp -= 2;
 199                 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
 200                 #if TRACE_EMU
 201                 Log_Debug("VM8086", "Emulated PUSHF");
 202                 #endif
 203                 break;
 204         case VM8086_OP_POPF:    //POPF
 205                 Regs->eflags &= 0xFFFF0002;
 206                 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0xFFFD;        // Changing IF is not allowed
 207                 Regs->esp += 2;
 208                 #if TRACE_EMU
 209                 Log_Debug("VM8086", "Emulated POPF");
 210                 #endif
 211                 break;
 212
 213         case VM8086_OP_INT_I:   //INT imm8
 214                 {
 215                  int    id;
 216                 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
 217                 Regs->eip ++;
 218
 219                 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
 220                 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
 221
 222                 Regs->cs = *(Uint16*)(4*id + 2);
 223                 Regs->eip = *(Uint16*)(4*id);
 224                 #if TRACE_EMU
 225                 Log_Debug("VM8086", "Emulated INT 0x%x", id);
 226                 #endif
 227                 }
 228                 break;
 229
 230         case VM8086_OP_IRET:    //IRET
 231                 Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 232                 Regs->cs  = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );     Regs->esp += 2;
 233                 #if TRACE_EMU
 234                 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
 235                 #endif
 236                 break;
 237
 238
 239         case VM8086_OP_IN_AD:   //IN AL, DX
 240                 Regs->eax &= 0xFFFFFF00;
 241                 Regs->eax |= inb(Regs->edx&0xFFFF);
 242                 #if TRACE_EMU
 243                 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 244                 #endif
 245                 break;
 246         case VM8086_OP_IN_ADX:  //IN AX, DX
 247                 Regs->eax &= 0xFFFF0000;
 248                 Regs->eax |= inw(Regs->edx&0xFFFF);
 249                 #if TRACE_EMU
 250                 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 251                 #endif
 252                 break;
 253
 254         case VM8086_OP_OUT_AD:  //OUT DX, AL
 255                 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
 256                 #if TRACE_EMU
 257                 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
 258                 #endif
 259                 break;
 260         case VM8086_OP_OUT_ADX: //OUT DX, AX
 261                 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 262                 #if TRACE_EMU
 263                 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
 264                 #endif
 265                 break;
 266
 267         // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
 268         case 0xFA:      //CLI
 269                 break;
 270         case 0xFB:      //STI
 271                 break;
 272
 273         case 0x66:
 274                 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
 275                 switch( opcode )
 276                 {
 277                 case VM8086_OP_IN_ADX:  //IN AX, DX
 278                         Regs->eax = ind(Regs->edx&0xFFFF);
 279                         #if TRACE_EMU
 280                         Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
 281                         #endif
 282                         break;
 283                 case VM8086_OP_OUT_ADX: //OUT DX, AX
 284                         outd(Regs->edx&0xFFFF, Regs->eax);
 285                         #if TRACE_EMU
 286                         Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
 287                         #endif
 288                         break;
 289                 default:
 290                         Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
 291                                 Regs->cs, Regs->eip,
 292                                 opcode
 293                                 );
 294                         // Force an end to the call
 295                         Regs->cs = VM8086_MAGIC_CS;
 296                         Regs->eip = VM8086_MAGIC_IP;
 297                         break;
 298                 }
 299                 break;
 300
 301         default:
 302                 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
 303                         opcode, Regs->cs, Regs->eip);
 304                 // Force an end to the call
 305                 Regs->cs = VM8086_MAGIC_CS;
 306                 Regs->eip = VM8086_MAGIC_IP;
 307                 break;
 308         }
 309 }
 310
 311 /**
 312  * \brief Create an instance of the VM8086 Emulator
 313  */
 314 tVM8086 *VM8086_Init(void)
 315 {
 316         tVM8086 *ret;
 317         ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
 318         ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
 319         return ret;
 320 }
 321
 322 void VM8086_Free(tVM8086 *State)
 323 {
 324          int    i;
 325         for( i = VM8086_PAGES_PER_INST; i --; )
 326                 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
 327         free(State);
 328 }
 329
 330 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
 331 {
 332          int    i, j, base = 0;
 333          int    nBlocks, rem;
 334
 335         Size = (Size + 127) & ~127;
 336         nBlocks = Size / 128;
 337
 338         if(Size > 4096) return NULL;
 339
 340         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 341         {
 342                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  continue;
 343
 344
 345                 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 346
 347                 rem = nBlocks;
 348                 base = 0;
 349                 // Scan the bitmap for a free block
 350                 for( j = 0; j < 32; j++ ) {
 351                         if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
 352                                 base = j;
 353                                 rem = nBlocks;
 354                         }
 355                         else {
 356                                 rem --;
 357                                 if(rem == 0)    // Goodie, there's a gap
 358                                 {
 359                                         for( j = 0; j < nBlocks; j++ )
 360                                                 State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
 361                                         *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
 362                                         *Offset = 0;
 363                                         //Log_Debug("VM8086", "Allocated at #%i,%04x", i, base*128);
 364                                         return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
 365                                 }
 366                         }
 367                 }
 368         }
 369
 370         // No pages with free space?, allocate a new one
 371         for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
 372         {
 373                 if( State->Internal->AllocatedPages[i].VirtBase == 0 )  break;
 374         }
 375         // Darn, we can't allocate any more
 376         if( i == VM8086_PAGES_PER_INST ) {
 377                 Log_Warning("VM8086", "Out of pages in %p", State);
 378                 return NULL;
 379         }
 380
 381         State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
 382                 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
 383         State->Internal->AllocatedPages[i].Bitmap = 0;
 384
 385         for( j = 0; j < nBlocks; j++ )
 386                 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
 387         //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
 388         *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
 389         *Offset = 0;
 390         return (void*) State->Internal->AllocatedPages[i].VirtBase;
 391 }
 392
 393 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
 394 {
 395         return (void*)( KERNEL_BASE + Segment*16 + Offset );
 396 }
 397
 398 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
 399 {
 400         State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
 401         State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
 402
 403         Mutex_Acquire( &glVM8086_Process );
 404
 405         gpVM8086_State = State;
 406         gVM8086_CallingThread = Threads_GetTID();
 407         Threads_WakeTID( gVM8086_WorkerPID );
 408         Threads_Sleep();
 409         while( gpVM8086_State != NULL ) Threads_Sleep();
 410
 411         Mutex_Release( &glVM8086_Process );
 412 }