3 * - By John Hodge (thePowersGang)
10 #define VM8086_MAGIC_CS 0xFFFF
11 #define VM8086_MAGIC_IP 0x0010
12 #define VM8086_STACK_SEG 0x9F00
13 #define VM8086_STACK_OFS 0x0AFE
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
25 #define VM8086_PAGES_PER_INST 4
28 int Proc_Clone(Uint *Err, Uint Flags);
31 struct sVM8086_InternalData
34 Uint32 Bitmap; // 32 sections = 128 byte blocks
37 } AllocatedPages[VM8086_PAGES_PER_INST];
41 int VM8086_Install(char **Arguments);
42 void VM8086_GPF(tRegs *Regs);
43 //tVM8086 *VM8086_Init(void);
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
53 int VM8086_Install(char **Arguments)
57 // Lock to avoid race conditions
58 Mutex_Acquire( &glVM8086_Process );
60 // Create BIOS Call process
61 pid = Proc_Clone(NULL, CLONE_VM);
64 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
65 return MODULE_ERR_MISC;
69 Uint * volatile stacksetup; // Initialising Stack
70 Uint16 * volatile rmstack; // Real Mode Stack
74 Threads_SetName("VM8086");
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
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 );
85 MM_Map( 0x9F000, 0x9F000 ); // Stack / EBDA
86 // System Stack / Stub
87 if( MM_Allocate( 0x100000 ) == 0 ) {
88 Log_Error("VM8086", "Unable to allocate memory for stack/stub");
89 gVM8086_WorkerPID = 0;
93 *(Uint8*)(0x100000) = VM8086_OP_IRET;
94 *(Uint8*)(0x100001) = 0x07; // POP ES
95 *(Uint8*)(0x100002) = 0x1F; // POP DS
96 *(Uint8*)(0x100003) = 0xCB; // RET FAR
98 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
99 rmstack--; *rmstack = 0xFFFF; //CS
100 rmstack--; *rmstack = 0x0010; //IP
103 stacksetup = (Uint*)0x101000;
104 stacksetup--; *stacksetup = VM8086_STACK_SEG; // GS
105 stacksetup--; *stacksetup = VM8086_STACK_SEG; // FS
106 stacksetup--; *stacksetup = VM8086_STACK_SEG; // DS
107 stacksetup--; *stacksetup = VM8086_STACK_SEG; // ES
108 stacksetup--; *stacksetup = VM8086_STACK_SEG; // SS
109 stacksetup--; *stacksetup = VM8086_STACK_OFS-2; // SP
110 stacksetup--; *stacksetup = 0x20202; // FLAGS
111 stacksetup--; *stacksetup = 0xFFFF; // CS
112 stacksetup--; *stacksetup = 0x10; // IP
113 stacksetup--; *stacksetup = 0xAAAA; // AX
114 stacksetup--; *stacksetup = 0xCCCC; // CX
115 stacksetup--; *stacksetup = 0xDDDD; // DX
116 stacksetup--; *stacksetup = 0xBBBB; // BX
117 stacksetup--; *stacksetup = 0x5454; // SP
118 stacksetup--; *stacksetup = 0xB4B4; // BP
119 stacksetup--; *stacksetup = 0x5151; // SI
120 stacksetup--; *stacksetup = 0xD1D1; // DI
121 stacksetup--; *stacksetup = 0x20|3; // DS - Kernel
122 stacksetup--; *stacksetup = 0x20|3; // ES - Kernel
123 stacksetup--; *stacksetup = 0x20|3; // FS
124 stacksetup--; *stacksetup = 0x20|3; // GS
125 __asm__ __volatile__ (
126 "mov %%eax,%%esp;\n\t" // Set stack pointer
132 "iret;\n\t" : : "a" (stacksetup));
133 for(;;); // Shouldn't be reached
136 gVM8086_WorkerPID = pid;
137 Log_Log("VM8086", "gVM8086_WorkerPID = %i", pid);
138 while( gpVM8086_State != NULL )
139 Threads_Yield(); // Yield to allow the child to initialise
141 // Worker killed itself
142 if( gVM8086_WorkerPID != pid ) {
143 return MODULE_ERR_MISC;
146 return MODULE_ERR_OK;
149 void VM8086_GPF(tRegs *Regs)
153 //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
155 if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
156 && Threads_GetPID() == gVM8086_WorkerPID)
158 if( gpVM8086_State == (void*)-1 ) {
159 Log_Log("VM8086", "Worker thread ready and waiting");
160 Mutex_Release( &glVM8086_Process ); // Release lock obtained in VM8086_Install
161 gpVM8086_State = NULL;
163 //Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
164 // gpVM8086_State, gVM8086_CallingThread);
165 if( gpVM8086_State ) {
166 gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
167 gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
168 gpVM8086_State->BP = Regs->ebp;
169 gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
170 gpVM8086_State->DS = Regs->ds; gpVM8086_State->ES = Regs->es;
171 gpVM8086_State = NULL;
173 Threads_WakeTID(gVM8086_CallingThread);
176 //Log_Log("VM8086", "Waiting for something to do");
177 __asm__ __volatile__ ("sti");
178 // Wait for a new task
179 while(!gpVM8086_State) {
181 //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
184 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
185 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
186 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
187 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
188 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
189 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
190 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
193 Regs->eip = 0x11; Regs->cs = 0xFFFF;
194 Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
195 Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
196 Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
197 Regs->ebp = gpVM8086_State->BP;
198 Regs->ds = 0x23; Regs->es = 0x23;
199 Regs->fs = 0x23; Regs->gs = 0x23;
203 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
207 case VM8086_OP_PUSHF: //PUSHF
209 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
211 Log_Debug("VM8086", "Emulated PUSHF");
214 case VM8086_OP_POPF: //POPF
215 Regs->eflags &= 0xFFFF0002;
216 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0xFFFD; // Changing IF is not allowed
219 Log_Debug("VM8086", "Emulated POPF");
223 case VM8086_OP_INT_I: //INT imm8
226 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
229 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
230 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
232 Regs->cs = *(Uint16*)(4*id + 2);
233 Regs->eip = *(Uint16*)(4*id);
235 Log_Debug("VM8086", "Emulated INT 0x%x", id);
240 case VM8086_OP_IRET: //IRET
241 Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
242 Regs->cs = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
244 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
249 case VM8086_OP_IN_AD: //IN AL, DX
250 Regs->eax &= 0xFFFFFF00;
251 Regs->eax |= inb(Regs->edx&0xFFFF);
253 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
256 case VM8086_OP_IN_ADX: //IN AX, DX
257 Regs->eax &= 0xFFFF0000;
258 Regs->eax |= inw(Regs->edx&0xFFFF);
260 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
264 case VM8086_OP_OUT_AD: //OUT DX, AL
265 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
267 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
270 case VM8086_OP_OUT_ADX: //OUT DX, AX
271 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
273 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
277 // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
284 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
287 case VM8086_OP_IN_ADX: //IN AX, DX
288 Regs->eax = ind(Regs->edx&0xFFFF);
290 Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
293 case VM8086_OP_OUT_ADX: //OUT DX, AX
294 outd(Regs->edx&0xFFFF, Regs->eax);
296 Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
300 Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
304 // Force an end to the call
305 Regs->cs = VM8086_MAGIC_CS;
306 Regs->eip = VM8086_MAGIC_IP;
312 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
313 opcode, Regs->cs, Regs->eip);
314 // Force an end to the call
315 Regs->cs = VM8086_MAGIC_CS;
316 Regs->eip = VM8086_MAGIC_IP;
322 * \brief Create an instance of the VM8086 Emulator
324 tVM8086 *VM8086_Init(void)
327 ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
328 ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
332 void VM8086_Free(tVM8086 *State)
335 for( i = VM8086_PAGES_PER_INST; i --; )
336 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
340 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
345 Size = (Size + 127) & ~127;
346 nBlocks = Size / 128;
348 if(Size > 4096) return NULL;
350 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
352 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) continue;
355 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
359 // Scan the bitmap for a free block
360 for( j = 0; j < 32; j++ ) {
361 if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
367 if(rem == 0) // Goodie, there's a gap
369 for( j = 0; j < nBlocks; j++ )
370 State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
371 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
373 //Log_Debug("VM8086", "Allocated at #%i,%04x", i, base*128);
374 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
380 // No pages with free space?, allocate a new one
381 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
383 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) break;
385 // Darn, we can't allocate any more
386 if( i == VM8086_PAGES_PER_INST ) {
387 Log_Warning("VM8086", "Out of pages in %p", State);
391 State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
392 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
393 State->Internal->AllocatedPages[i].Bitmap = 0;
395 for( j = 0; j < nBlocks; j++ )
396 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
397 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
398 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
400 return (void*) State->Internal->AllocatedPages[i].VirtBase;
403 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
405 return (void*)( KERNEL_BASE + Segment*16 + Offset );
408 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
410 State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
411 State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
413 Mutex_Acquire( &glVM8086_Process );
415 gpVM8086_State = State;
416 gVM8086_CallingThread = Threads_GetTID();
417 Threads_WakeTID( gVM8086_WorkerPID );
419 while( gpVM8086_State != NULL ) Threads_Sleep();
421 Mutex_Release( &glVM8086_Process );