3 * - By John Hodge (thePowersGang)
10 #include <semaphore.h>
13 #define VM8086_MAGIC_CS 0xFFFF
14 #define VM8086_MAGIC_IP 0x0010
15 #define VM8086_STACK_SEG 0x9F00
16 #define VM8086_STACK_OFS 0x0AFE
19 VM8086_OP_PUSHF = 0x9C,
20 VM8086_OP_POPF = 0x9D,
21 VM8086_OP_INT_I = 0xCD,
22 VM8086_OP_IRET = 0xCF,
23 VM8086_OP_IN_AD = 0xEC,
24 VM8086_OP_IN_ADX = 0xED,
25 VM8086_OP_OUT_AD = 0xEE,
26 VM8086_OP_OUT_ADX = 0xEF
28 #define VM8086_PAGES_PER_INST 4
30 #define VM8086_BLOCKSIZE 128
31 #define VM8086_BLOCKCOUNT ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
34 struct sVM8086_InternalData
37 Uint32 Bitmap; // 32 sections = 128 byte blocks
40 } AllocatedPages[VM8086_PAGES_PER_INST];
44 int VM8086_Install(char **Arguments);
45 void VM8086_GPF(tRegs *Regs);
46 //tVM8086 *VM8086_Init(void);
49 MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
50 tMutex glVM8086_Process;
51 tSemaphore gVM8086_TaskComplete;
52 tSemaphore gVM8086_TasksToDo;
53 tPID gVM8086_WorkerPID;
54 tTID gVM8086_CallingThread;
55 tVM8086 volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
56 Uint32 gaVM8086_MemBitmap[VM8086_BLOCKCOUNT/32];
59 int VM8086_Install(char **Arguments)
63 Semaphore_Init(&gVM8086_TasksToDo, 0, 10, "VM8086", "TasksToDo");
65 // Lock to avoid race conditions
66 Mutex_Acquire( &glVM8086_Process );
68 // Create BIOS Call process
69 pid = Proc_Clone(CLONE_VM);
70 Log_Debug("VM8086", "pid = %i", pid);
73 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
74 return MODULE_ERR_MISC;
78 Uint * volatile stacksetup; // Initialising Stack
79 Uint16 * volatile rmstack; // Real Mode Stack
82 Log_Debug("VM8086", "Initialising worker");
85 Threads_SetName("VM8086");
88 for(i=0xA0;i<0x100;i++) {
89 MM_Map( i * 0x1000, i * 0x1000 );
91 MM_Map( 0, 0 ); // IVT / BDA
92 // Map (but allow allocation) of 0x1000 - 0x9F000
93 // - So much hack, it isn't funny
95 MM_Map( i * 0x1000, i * 0x1000 );
96 MM_DerefPhys( i * 0x1000 ); // Above
97 while(MM_GetRefCount(i*0x1000))
98 MM_DerefPhys( i * 0x1000 ); // Phys setup
100 MM_Map( 0x9F000, 0x9F000 ); // Stack / EBDA
101 // System Stack / Stub
102 if( MM_Allocate( 0x100000 ) == 0 ) {
103 Log_Error("VM8086", "Unable to allocate memory for stack/stub");
104 gVM8086_WorkerPID = 0;
108 *(Uint8*)(0x100000) = VM8086_OP_IRET;
109 *(Uint8*)(0x100001) = 0x07; // POP ES
110 *(Uint8*)(0x100002) = 0x1F; // POP DS
111 *(Uint8*)(0x100003) = 0xCB; // RET FAR
113 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
114 rmstack--; *rmstack = 0xFFFF; //CS
115 rmstack--; *rmstack = 0x0010; //IP
118 stacksetup = (Uint*)0x101000;
119 stacksetup--; *stacksetup = VM8086_STACK_SEG; // GS
120 stacksetup--; *stacksetup = VM8086_STACK_SEG; // FS
121 stacksetup--; *stacksetup = VM8086_STACK_SEG; // DS
122 stacksetup--; *stacksetup = VM8086_STACK_SEG; // ES
123 stacksetup--; *stacksetup = VM8086_STACK_SEG; // SS
124 stacksetup--; *stacksetup = VM8086_STACK_OFS-2; // SP
125 stacksetup--; *stacksetup = 0x20202; // FLAGS
126 stacksetup--; *stacksetup = 0xFFFF; // CS
127 stacksetup--; *stacksetup = 0x10; // IP
128 stacksetup--; *stacksetup = 0xAAAA; // AX
129 stacksetup--; *stacksetup = 0xCCCC; // CX
130 stacksetup--; *stacksetup = 0xDDDD; // DX
131 stacksetup--; *stacksetup = 0xBBBB; // BX
132 stacksetup--; *stacksetup = 0x5454; // SP
133 stacksetup--; *stacksetup = 0xB4B4; // BP
134 stacksetup--; *stacksetup = 0x5151; // SI
135 stacksetup--; *stacksetup = 0xD1D1; // DI
136 stacksetup--; *stacksetup = 0x20|3; // DS - Kernel
137 stacksetup--; *stacksetup = 0x20|3; // ES - Kernel
138 stacksetup--; *stacksetup = 0x20|3; // FS
139 stacksetup--; *stacksetup = 0x20|3; // GS
140 __asm__ __volatile__ (
141 "mov %%eax,%%esp;\n\t" // Set stack pointer
147 "iret;\n\t" : : "a" (stacksetup));
148 for(;;); // Shouldn't be reached
151 gVM8086_WorkerPID = pid;
153 // It's released when the GPF fires
154 Mutex_Acquire( &glVM8086_Process );
155 Mutex_Release( &glVM8086_Process );
157 // Worker killed itself
158 if( gVM8086_WorkerPID != pid ) {
159 return MODULE_ERR_MISC;
162 return MODULE_ERR_OK;
165 void VM8086_GPF(tRegs *Regs)
169 // Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
171 if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
172 && Threads_GetPID() == gVM8086_WorkerPID)
174 if( gpVM8086_State == (void*)-1 ) {
175 Log_Log("VM8086", "Worker thread ready and waiting");
176 gpVM8086_State = NULL;
177 Mutex_Release( &glVM8086_Process ); // Release lock obtained in VM8086_Install
179 // Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
180 // gpVM8086_State, gVM8086_CallingThread);
181 if( gpVM8086_State ) {
182 gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
183 gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
184 gpVM8086_State->BP = Regs->ebp;
185 gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
186 gpVM8086_State->DS = Regs->ds; gpVM8086_State->ES = Regs->es;
187 gpVM8086_State = NULL;
189 Semaphore_Signal(&gVM8086_TaskComplete, 1);
192 //Log_Log("VM8086", "Waiting for something to do");
193 __asm__ __volatile__ ("sti");
194 Semaphore_Wait(&gVM8086_TasksToDo, 1);
196 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
197 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
198 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
199 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
200 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
201 Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
202 Regs->esp -= 2; *(Uint16*)( (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 // Changing IF is not allowed
228 Regs->eflags &= 0xFFFF0202;
229 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) );
232 Log_Debug("VM8086", "Emulated POPF");
236 case VM8086_OP_INT_I: //INT imm8
239 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
242 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
243 Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
245 Regs->cs = *(Uint16*)(4*id + 2);
246 Regs->eip = *(Uint16*)(4*id);
248 Log_Debug("VM8086", "Emulated INT 0x%x", id);
253 case VM8086_OP_IRET: //IRET
254 Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
255 Regs->cs = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
257 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
262 case VM8086_OP_IN_AD: //IN AL, DX
263 Regs->eax &= 0xFFFFFF00;
264 Regs->eax |= inb(Regs->edx&0xFFFF);
266 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
269 case VM8086_OP_IN_ADX: //IN AX, DX
270 Regs->eax &= 0xFFFF0000;
271 Regs->eax |= inw(Regs->edx&0xFFFF);
273 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
277 case VM8086_OP_OUT_AD: //OUT DX, AL
278 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
280 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
283 case VM8086_OP_OUT_ADX: //OUT DX, AX
284 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
286 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
290 // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
297 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
300 case VM8086_OP_IN_ADX: //IN AX, DX
301 Regs->eax = ind(Regs->edx&0xFFFF);
303 Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
306 case VM8086_OP_OUT_ADX: //OUT DX, AX
307 outd(Regs->edx&0xFFFF, Regs->eax);
309 Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
313 Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
317 // Force an end to the call
318 Regs->cs = VM8086_MAGIC_CS;
319 Regs->eip = VM8086_MAGIC_IP;
325 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
326 opcode, Regs->cs, Regs->eip);
327 // Force an end to the call
328 Regs->cs = VM8086_MAGIC_CS;
329 Regs->eip = VM8086_MAGIC_IP;
335 * \brief Create an instance of the VM8086 Emulator
337 tVM8086 *VM8086_Init(void)
340 ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
341 ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
345 void VM8086_Free(tVM8086 *State)
348 for( i = VM8086_PAGES_PER_INST; i --; )
349 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
353 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
358 Size = (Size + 127) & ~127;
359 nBlocks = Size / 128;
361 if(Size > 4096) return NULL;
363 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
365 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) continue;
368 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
372 // Scan the bitmap for a free block
373 for( j = 0; j < 32; j++ ) {
374 if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
380 if(rem == 0) // Goodie, there's a gap
382 for( j = 0; j < nBlocks; j++ )
383 State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
384 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
386 LOG("Allocated at #%i,%04x", i, base*128);
387 LOG(" - %x:%x", *Segment, *Offset);
388 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
393 // No pages with free space?, allocate a new one
394 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
396 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) break;
398 // Darn, we can't allocate any more
399 if( i == VM8086_PAGES_PER_INST ) {
400 Log_Warning("VM8086", "Out of pages in %p", State);
404 State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
405 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
406 State->Internal->AllocatedPages[i].Bitmap = 0;
408 for( j = 0; j < nBlocks; j++ )
409 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
410 LOG("AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
411 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
413 LOG(" - %x:%x", *Segment, *Offset);
414 return (void*) State->Internal->AllocatedPages[i].VirtBase;
417 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
419 return (void*)( KERNEL_BASE + Segment*16 + Offset );
422 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
424 State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
425 State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
427 // Log_Debug("VM8086", "Software interrupt %i to %04x:%04x", Interrupt, State->CS, State->IP);
429 Mutex_Acquire( &glVM8086_Process );
431 gpVM8086_State = State;
432 gVM8086_CallingThread = Threads_GetTID();
433 Semaphore_Signal(&gVM8086_TasksToDo, 1);
435 Semaphore_Wait(&gVM8086_TaskComplete, 1);
437 Mutex_Release( &glVM8086_Process );