3 * - By John Hodge (thePowersGang)
12 #define VM8086_MAGIC_CS 0xFFFF
13 #define VM8086_MAGIC_IP 0x0010
14 #define VM8086_STACK_SEG 0x9F00
15 #define VM8086_STACK_OFS 0x0AFE
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
27 #define VM8086_PAGES_PER_INST 4
29 #define VM8086_BLOCKSIZE 128
30 #define VM8086_BLOCKCOUNT ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
33 struct sVM8086_InternalData
36 Uint32 Bitmap; // 32 sections = 128 byte blocks
39 } AllocatedPages[VM8086_PAGES_PER_INST];
43 int VM8086_Install(char **Arguments);
44 void VM8086_GPF(tRegs *Regs);
45 //tVM8086 *VM8086_Init(void);
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];
56 int VM8086_Install(char **Arguments)
60 // Lock to avoid race conditions
61 Mutex_Acquire( &glVM8086_Process );
63 // Create BIOS Call process
64 pid = Proc_Clone(CLONE_VM);
67 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
68 return MODULE_ERR_MISC;
72 Uint * volatile stacksetup; // Initialising Stack
73 Uint16 * volatile rmstack; // Real Mode Stack
77 Threads_SetName("VM8086");
79 Log_Debug("VM8086", "Mapping memory");
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
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
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
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;
103 Log_Debug("VM8086", "Mapped low memory");
105 *(Uint8*)(0x100000) = VM8086_OP_IRET;
106 *(Uint8*)(0x100001) = 0x07; // POP ES
107 *(Uint8*)(0x100002) = 0x1F; // POP DS
108 *(Uint8*)(0x100003) = 0xCB; // RET FAR
110 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
111 rmstack--; *rmstack = 0xFFFF; //CS
112 rmstack--; *rmstack = 0x0010; //IP
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
144 "iret;\n\t" : : "a" (stacksetup));
145 for(;;); // Shouldn't be reached
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
153 // Worker killed itself
154 if( gVM8086_WorkerPID != pid ) {
155 return MODULE_ERR_MISC;
158 return MODULE_ERR_OK;
161 void VM8086_GPF(tRegs *Regs)
165 //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
167 if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
168 && Threads_GetPID() == gVM8086_WorkerPID)
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
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;
185 Threads_WakeTID(gVM8086_CallingThread);
188 //Log_Log("VM8086", "Waiting for something to do");
189 __asm__ __volatile__ ("sti");
190 // Wait for a new task
191 while(!gpVM8086_State) {
193 //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
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;
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;
215 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
219 case VM8086_OP_PUSHF: //PUSHF
221 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
223 Log_Debug("VM8086", "Emulated PUSHF");
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
231 Log_Debug("VM8086", "Emulated POPF");
235 case VM8086_OP_INT_I: //INT imm8
238 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
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;
244 Regs->cs = *(Uint16*)(4*id + 2);
245 Regs->eip = *(Uint16*)(4*id);
247 Log_Debug("VM8086", "Emulated INT 0x%x", id);
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;
256 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
261 case VM8086_OP_IN_AD: //IN AL, DX
262 Regs->eax &= 0xFFFFFF00;
263 Regs->eax |= inb(Regs->edx&0xFFFF);
265 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
268 case VM8086_OP_IN_ADX: //IN AX, DX
269 Regs->eax &= 0xFFFF0000;
270 Regs->eax |= inw(Regs->edx&0xFFFF);
272 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
276 case VM8086_OP_OUT_AD: //OUT DX, AL
277 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
279 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
282 case VM8086_OP_OUT_ADX: //OUT DX, AX
283 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
285 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
289 // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
296 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
299 case VM8086_OP_IN_ADX: //IN AX, DX
300 Regs->eax = ind(Regs->edx&0xFFFF);
302 Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
305 case VM8086_OP_OUT_ADX: //OUT DX, AX
306 outd(Regs->edx&0xFFFF, Regs->eax);
308 Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
312 Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
316 // Force an end to the call
317 Regs->cs = VM8086_MAGIC_CS;
318 Regs->eip = VM8086_MAGIC_IP;
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;
334 * \brief Create an instance of the VM8086 Emulator
336 tVM8086 *VM8086_Init(void)
339 ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
340 ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
344 void VM8086_Free(tVM8086 *State)
347 for( i = VM8086_PAGES_PER_INST; i --; )
348 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
352 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
357 Size = (Size + 127) & ~127;
358 nBlocks = Size / 128;
360 if(Size > 4096) return NULL;
362 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
364 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) continue;
367 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
371 // Scan the bitmap for a free block
372 for( j = 0; j < 32; j++ ) {
373 if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
379 if(rem == 0) // Goodie, there's a gap
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;
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 );
392 // No pages with free space?, allocate a new one
393 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
395 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) break;
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);
403 State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
404 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
405 State->Internal->AllocatedPages[i].Bitmap = 0;
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;
412 LOG(" - %x:%x", *Segment, *Offset);
413 return (void*) State->Internal->AllocatedPages[i].VirtBase;
416 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
418 return (void*)( KERNEL_BASE + Segment*16 + Offset );
421 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
423 State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
424 State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
426 Mutex_Acquire( &glVM8086_Process );
428 gpVM8086_State = State;
429 gVM8086_CallingThread = Threads_GetTID();
430 Threads_WakeTID( gVM8086_WorkerPID );
432 while( gpVM8086_State != NULL ) Threads_Sleep();
434 Mutex_Release( &glVM8086_Process );