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 MM_Allocate( 0x100000 ); // System Stack / Stub
88 *(Uint8*)(0x100000) = VM8086_OP_IRET;
89 *(Uint8*)(0x100001) = 0x07; // POP ES
90 *(Uint8*)(0x100002) = 0x1F; // POP DS
91 *(Uint8*)(0x100003) = 0xCB; // RET FAR
93 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
94 rmstack--; *rmstack = 0xFFFF; //CS
95 rmstack--; *rmstack = 0x0010; //IP
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
127 "iret;\n\t" : : "a" (stacksetup));
128 for(;;); // Shouldn't be reached
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
136 return MODULE_ERR_OK;
139 void VM8086_GPF(tRegs *Regs)
143 //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
145 if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
146 && Threads_GetPID() == gVM8086_WorkerPID)
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;
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;
163 Threads_WakeTID(gVM8086_CallingThread);
166 //Log_Log("VM8086", "Waiting for something to do");
167 __asm__ __volatile__ ("sti");
168 // Wait for a new task
169 while(!gpVM8086_State) {
171 //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
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;
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;
193 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
197 case VM8086_OP_PUSHF: //PUSHF
199 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
201 Log_Debug("VM8086", "Emulated PUSHF");
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
209 Log_Debug("VM8086", "Emulated POPF");
213 case VM8086_OP_INT_I: //INT imm8
216 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
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;
222 Regs->cs = *(Uint16*)(4*id + 2);
223 Regs->eip = *(Uint16*)(4*id);
225 Log_Debug("VM8086", "Emulated INT 0x%x", id);
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;
234 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
239 case VM8086_OP_IN_AD: //IN AL, DX
240 Regs->eax &= 0xFFFFFF00;
241 Regs->eax |= inb(Regs->edx&0xFFFF);
243 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
246 case VM8086_OP_IN_ADX: //IN AX, DX
247 Regs->eax &= 0xFFFF0000;
248 Regs->eax |= inw(Regs->edx&0xFFFF);
250 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
254 case VM8086_OP_OUT_AD: //OUT DX, AL
255 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
257 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
260 case VM8086_OP_OUT_ADX: //OUT DX, AX
261 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
263 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
267 // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
274 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
277 case VM8086_OP_IN_ADX: //IN AX, DX
278 Regs->eax = ind(Regs->edx&0xFFFF);
280 Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
283 case VM8086_OP_OUT_ADX: //OUT DX, AX
284 outd(Regs->edx&0xFFFF, Regs->eax);
286 Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
290 Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
294 // Force an end to the call
295 Regs->cs = VM8086_MAGIC_CS;
296 Regs->eip = VM8086_MAGIC_IP;
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;
312 * \brief Create an instance of the VM8086 Emulator
314 tVM8086 *VM8086_Init(void)
317 ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
318 ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
322 void VM8086_Free(tVM8086 *State)
325 for( i = VM8086_PAGES_PER_INST; i --; )
326 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
330 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
335 Size = (Size + 127) & ~127;
336 nBlocks = Size / 128;
338 if(Size > 4096) return NULL;
340 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
342 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) continue;
345 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
349 // Scan the bitmap for a free block
350 for( j = 0; j < 32; j++ ) {
351 if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
357 if(rem == 0) // Goodie, there's a gap
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;
363 //Log_Debug("VM8086", "Allocated at #%i,%04x", i, base*128);
364 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
370 // No pages with free space?, allocate a new one
371 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
373 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) break;
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);
381 State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
382 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
383 State->Internal->AllocatedPages[i].Bitmap = 0;
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;
390 return (void*) State->Internal->AllocatedPages[i].VirtBase;
393 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
395 return (void*)( KERNEL_BASE + Segment*16 + Offset );
398 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
400 State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
401 State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
403 Mutex_Acquire( &glVM8086_Process );
405 gpVM8086_State = State;
406 gVM8086_CallingThread = Threads_GetTID();
407 Threads_WakeTID( gVM8086_WorkerPID );
409 while( gpVM8086_State != NULL ) Threads_Sleep();
411 Mutex_Release( &glVM8086_Process );