3 * - By John Hodge (thePowersGang)
10 #include <semaphore.h>
15 #define VM8086_MAGIC_CS 0xFFFF
16 #define VM8086_MAGIC_IP 0x0010
17 #define VM8086_STACK_SEG 0x9F00
18 #define VM8086_STACK_OFS 0x0AFE
21 VM8086_OP_PUSHF = 0x9C,
22 VM8086_OP_POPF = 0x9D,
23 VM8086_OP_INT_I = 0xCD,
24 VM8086_OP_IRET = 0xCF,
25 VM8086_OP_IN_AD = 0xEC,
26 VM8086_OP_IN_ADX = 0xED,
27 VM8086_OP_OUT_AD = 0xEE,
28 VM8086_OP_OUT_ADX = 0xEF
30 #define VM8086_PAGES_PER_INST 4
32 #define VM8086_BLOCKSIZE 128
33 #define VM8086_BLOCKCOUNT ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
36 struct sVM8086_InternalData
39 Uint32 Bitmap; // 32 sections = 128 byte blocks
42 } AllocatedPages[VM8086_PAGES_PER_INST];
46 int VM8086_Install(char **Arguments);
47 void VM8086_GPF(tRegs *Regs);
48 //tVM8086 *VM8086_Init(void);
51 MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
52 tMutex glVM8086_Process;
53 tSemaphore gVM8086_TaskComplete;
54 tSemaphore gVM8086_TasksToDo;
55 tPID gVM8086_WorkerPID;
56 tTID gVM8086_CallingThread;
57 tVM8086 volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
58 Uint32 gaVM8086_MemBitmap[VM8086_BLOCKCOUNT/32];
59 int gbVM8086_ShadowIF = 0;
62 int VM8086_Install(char **Arguments)
66 Semaphore_Init(&gVM8086_TasksToDo, 0, 10, "VM8086", "TasksToDo");
68 // Lock to avoid race conditions
69 Mutex_Acquire( &glVM8086_Process );
71 // Create BIOS Call process
72 pid = Proc_Clone(CLONE_VM);
73 Log_Debug("VM8086", "pid = %i", pid);
76 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
77 return MODULE_ERR_MISC;
81 Uint * volatile stacksetup; // Initialising Stack
82 Uint16 * volatile rmstack; // Real Mode Stack
85 Log_Debug("VM8086", "Initialising worker");
88 Threads_SetName("VM8086");
91 for(i=0xA0;i<0x100;i++) {
92 MM_Map( i * 0x1000, i * 0x1000 );
94 MM_Map( 0, 0 ); // IVT / BDA
95 // Map (but allow allocation) of 0x1000 - 0x9F000
96 // - So much hack, it isn't funny
97 // TODO: Remove this and replce with something less hacky
99 MM_Map( i * 0x1000, i * 0x1000 );
100 while(MM_GetRefCount(i*0x1000))
101 MM_DerefPhys( i * 0x1000 );
103 MM_Map( 0x9F000, 0x9F000 ); // Stack / EBDA
104 // System Stack / Stub
105 if( MM_Allocate( 0x100000 ) == 0 ) {
106 Log_Error("VM8086", "Unable to allocate memory for stack/stub");
107 gVM8086_WorkerPID = 0;
111 *(Uint8*)(0x100000) = VM8086_OP_IRET;
112 *(Uint8*)(0x100001) = 0x07; // POP ES
113 *(Uint8*)(0x100002) = 0x1F; // POP DS
114 *(Uint8*)(0x100003) = 0xCB; // RET FAR
116 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
117 rmstack--; *rmstack = 0xFFFF; //CS
118 rmstack--; *rmstack = 0x0010; //IP
121 stacksetup = (Uint*)0x101000;
122 stacksetup--; *stacksetup = VM8086_STACK_SEG; // GS
123 stacksetup--; *stacksetup = VM8086_STACK_SEG; // FS
124 stacksetup--; *stacksetup = VM8086_STACK_SEG; // DS
125 stacksetup--; *stacksetup = VM8086_STACK_SEG; // ES
126 stacksetup--; *stacksetup = VM8086_STACK_SEG; // SS
127 stacksetup--; *stacksetup = VM8086_STACK_OFS-2; // SP
128 stacksetup--; *stacksetup = 0x20202; // FLAGS
129 stacksetup--; *stacksetup = 0xFFFF; // CS
130 stacksetup--; *stacksetup = 0x10; // IP
131 stacksetup--; *stacksetup = 0xAAAA; // AX
132 stacksetup--; *stacksetup = 0xCCCC; // CX
133 stacksetup--; *stacksetup = 0xDDDD; // DX
134 stacksetup--; *stacksetup = 0xBBBB; // BX
135 stacksetup--; *stacksetup = 0x5454; // SP
136 stacksetup--; *stacksetup = 0xB4B4; // BP
137 stacksetup--; *stacksetup = 0x5151; // SI
138 stacksetup--; *stacksetup = 0xD1D1; // DI
139 stacksetup--; *stacksetup = 0x20|3; // DS - Kernel
140 stacksetup--; *stacksetup = 0x20|3; // ES - Kernel
141 stacksetup--; *stacksetup = 0x20|3; // FS
142 stacksetup--; *stacksetup = 0x20|3; // GS
143 __asm__ __volatile__ (
144 "mov %%eax,%%esp;\n\t" // Set stack pointer
150 "iret;\n\t" : : "a" (stacksetup));
151 for(;;); // Shouldn't be reached
154 gVM8086_WorkerPID = pid;
156 // It's released when the GPF fires
157 Mutex_Acquire( &glVM8086_Process );
158 Mutex_Release( &glVM8086_Process );
160 // Worker killed itself
161 if( gVM8086_WorkerPID != pid ) {
162 return MODULE_ERR_MISC;
165 return MODULE_ERR_OK;
168 void VM8086_GPF(tRegs *Regs)
173 // Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
175 LOG("VM8086 GPF at %04x:%04x", Regs->cs, Regs->eip);
177 if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
178 && Threads_GetPID() == gVM8086_WorkerPID)
180 if( gpVM8086_State == (void*)-1 ) {
181 Log_Log("VM8086", "Worker thread ready and waiting");
182 gpVM8086_State = NULL;
183 Mutex_Release( &glVM8086_Process ); // Release lock obtained in VM8086_Install
185 // Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
186 // gpVM8086_State, gVM8086_CallingThread);
187 if( gpVM8086_State ) {
188 gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
189 gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
190 gpVM8086_State->BP = Regs->ebp;
191 gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
192 gpVM8086_State->DS = Regs->ds; gpVM8086_State->ES = Regs->es;
193 gpVM8086_State = NULL;
195 Semaphore_Signal(&gVM8086_TaskComplete, 1);
198 //Log_Log("VM8086", "Waiting for something to do");
199 __asm__ __volatile__ ("sti");
200 Semaphore_Wait(&gVM8086_TasksToDo, 1);
202 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
203 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
204 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
205 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
206 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
207 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
208 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
211 Regs->eip = 0x11; Regs->cs = 0xFFFF;
212 Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
213 Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
214 Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
215 Regs->ebp = gpVM8086_State->BP;
216 Regs->ds = 0x23; Regs->es = 0x23;
217 Regs->fs = 0x23; Regs->gs = 0x23;
221 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
225 case VM8086_OP_PUSHF: //PUSHF
227 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
228 if( gbVM8086_ShadowIF )
229 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) |= 0x200;
231 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) &= ~0x200;
233 Log_Debug("VM8086", "%04x:%04x Emulated PUSHF (value 0x%x)",
234 Regs->cs, Regs->eip-1, Regs->eflags & 0xFFFF);
237 case VM8086_OP_POPF: //POPF
238 // Changing IF is not allowed
239 Regs->eflags &= 0xFFFF0202;
240 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );
241 gbVM8086_ShadowIF = !!(*(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0x200);
244 Log_Debug("VM8086", "%04x:%04x Emulated POPF (new value 0x%x)",
245 Regs->cs, Regs->eip-1, Regs->eflags & 0xFFFF);
249 case VM8086_OP_INT_I: //INT imm8
252 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
255 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
256 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
258 newcs = *(Uint16*)(4*id + 2);
259 newip = *(Uint16*)(4*id);
261 Log_Debug("VM8086", "%04x:%04x Emulated INT 0x%x (%04x:%04x) - AX=%04x,BX=%04x",
262 Regs->cs, Regs->eip-2, id, newcs, newip, Regs->eax, Regs->ebx);
269 case VM8086_OP_IRET: //IRET
270 newip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
271 newcs = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
273 Log_Debug("VM8086", "%04x:%04x IRET to %04x:%04x",
274 Regs->cs, Regs->eip-1, newcs, newip);
281 case VM8086_OP_IN_AD: //IN AL, DX
282 Regs->eax &= 0xFFFFFF00;
283 Regs->eax |= inb(Regs->edx&0xFFFF);
285 Log_Debug("VM8086", "%04x:%04x Emulated IN AL, DX (Port 0x%x [Val 0x%02x])",
286 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFF);
289 case VM8086_OP_IN_ADX: //IN AX, DX
290 Regs->eax &= 0xFFFF0000;
291 Regs->eax |= inw(Regs->edx&0xFFFF);
293 Log_Debug("VM8086", "%04x:%04x Emulated IN AX, DX (Port 0x%x [Val 0x%04x])",
294 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFFFF);
298 case VM8086_OP_OUT_AD: //OUT DX, AL
299 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
301 Log_Debug("VM8086", "%04x:%04x Emulated OUT DX, AL (*0x%04x = 0x%02x)",
302 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFF);
305 case VM8086_OP_OUT_ADX: //OUT DX, AX
306 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
308 Log_Debug("VM8086", "%04x:%04x Emulated OUT DX, AX (*0x%04x = 0x%04x)",
309 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax&0xFFFF);
313 // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
316 Log_Debug("VM8086", "%04x:%04x Ignored CLI",
317 Regs->cs, Regs->eip);
319 gbVM8086_ShadowIF = 0;
323 Log_Debug("VM8086", "%04x:%04x Ignored STI",
324 Regs->cs, Regs->eip);
326 gbVM8086_ShadowIF = 1;
330 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
334 case VM8086_OP_IN_ADX: //IN AX, DX
335 Regs->eax = ind(Regs->edx&0xFFFF);
337 Log_Debug("VM8086", "%04x:%04x Emulated IN EAX, DX (Port 0x%x [Val 0x%08x])",
338 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax);
341 case VM8086_OP_OUT_ADX: //OUT DX, AX
342 outd(Regs->edx&0xFFFF, Regs->eax);
344 Log_Debug("VM8086", "%04x:%04x Emulated OUT DX, EAX (*0x%04x = 0x%08x)",
345 Regs->cs, Regs->eip-1, Regs->edx&0xFFFF, Regs->eax);
349 Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
350 Regs->cs, Regs->eip-2,
353 // Force an end to the call
354 Regs->cs = VM8086_MAGIC_CS;
355 Regs->eip = VM8086_MAGIC_IP;
361 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
362 opcode, Regs->cs, Regs->eip-1);
363 // Force an end to the call
364 Regs->cs = VM8086_MAGIC_CS;
365 Regs->eip = VM8086_MAGIC_IP;
371 * \brief Create an instance of the VM8086 Emulator
373 tVM8086 *VM8086_Init(void)
376 ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
377 ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
381 void VM8086_Free(tVM8086 *State)
384 for( i = VM8086_PAGES_PER_INST; i --; )
385 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
389 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
394 Size = (Size + 127) & ~127;
395 nBlocks = Size / 128;
397 if(Size > 4096) return NULL;
399 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
401 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) continue;
404 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
408 // Scan the bitmap for a free block
409 for( j = 0; j < 32; j++ ) {
410 if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
416 if(rem == 0) // Goodie, there's a gap
418 for( j = 0; j < nBlocks; j++ )
419 State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
420 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
422 LOG("Allocated at #%i,%04x", i, base*128);
423 LOG(" - %x:%x", *Segment, *Offset);
424 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
429 // No pages with free space?, allocate a new one
430 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
432 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) break;
434 // Darn, we can't allocate any more
435 if( i == VM8086_PAGES_PER_INST ) {
436 Log_Warning("VM8086", "Out of pages in %p", State);
440 State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
441 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
442 State->Internal->AllocatedPages[i].Bitmap = 0;
444 for( j = 0; j < nBlocks; j++ )
445 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
446 LOG("AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
447 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
449 LOG(" - %x:%x", *Segment, *Offset);
450 return (void*) State->Internal->AllocatedPages[i].VirtBase;
453 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
455 return (void*)( KERNEL_BASE + Segment*16 + Offset );
458 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
460 State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
461 State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
463 // Log_Debug("VM8086", "Software interrupt %i to %04x:%04x", Interrupt, State->CS, State->IP);
465 Mutex_Acquire( &glVM8086_Process );
467 gpVM8086_State = State;
468 gVM8086_CallingThread = Threads_GetTID();
469 Semaphore_Signal(&gVM8086_TasksToDo, 1);
471 Semaphore_Wait(&gVM8086_TaskComplete, 1);
473 Mutex_Release( &glVM8086_Process );