3 * - By John Hodge (thePowersGang)
11 #define VM8086_MAGIC_CS 0xFFFF
12 #define VM8086_MAGIC_IP 0x0010
13 #define VM8086_STACK_SEG 0x9F00
14 #define VM8086_STACK_OFS 0x0AFE
17 VM8086_OP_PUSHF = 0x9C,
18 VM8086_OP_POPF = 0x9D,
19 VM8086_OP_INT_I = 0xCD,
20 VM8086_OP_IRET = 0xCF,
21 VM8086_OP_IN_AD = 0xEC,
22 VM8086_OP_IN_ADX = 0xED,
23 VM8086_OP_OUT_AD = 0xEE,
24 VM8086_OP_OUT_ADX = 0xEF
26 #define VM8086_PAGES_PER_INST 4
28 #define VM8086_BLOCKSIZE 128
29 #define VM8086_BLOCKCOUNT ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
32 int Proc_Clone(Uint *Err, Uint Flags);
35 struct sVM8086_InternalData
38 Uint32 Bitmap; // 32 sections = 128 byte blocks
41 } AllocatedPages[VM8086_PAGES_PER_INST];
45 int VM8086_Install(char **Arguments);
46 void VM8086_GPF(tRegs *Regs);
47 //tVM8086 *VM8086_Init(void);
50 MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
51 tMutex glVM8086_Process;
52 tPID gVM8086_WorkerPID;
53 tTID gVM8086_CallingThread;
54 tVM8086 volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
55 Uint32 gaVM8086_MemBitmap[VM8086_BLOCKCOUNT/32];
58 int VM8086_Install(char **Arguments)
62 // Lock to avoid race conditions
63 Mutex_Acquire( &glVM8086_Process );
65 // Create BIOS Call process
66 pid = Proc_Clone(NULL, CLONE_VM);
69 Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
70 return MODULE_ERR_MISC;
74 Uint * volatile stacksetup; // Initialising Stack
75 Uint16 * volatile rmstack; // Real Mode Stack
79 Threads_SetName("VM8086");
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 MM_Map( 0, 0 ); // IVT / BDA
87 // Map (but allow allocation) of 0x1000 - 0x9F000
88 // - So much hack, it isn't funny
90 MM_Map( i * 0x1000, i * 0x1000 );
91 MM_DerefPhys( i * 0x1000 ); // Above
92 MM_DerefPhys( i * 0x1000 ); // Phys setup
94 MM_Map( 0x9F000, 0x9F000 ); // Stack / EBDA
95 // System Stack / Stub
96 if( MM_Allocate( 0x100000 ) == 0 ) {
97 Log_Error("VM8086", "Unable to allocate memory for stack/stub");
98 gVM8086_WorkerPID = 0;
102 *(Uint8*)(0x100000) = VM8086_OP_IRET;
103 *(Uint8*)(0x100001) = 0x07; // POP ES
104 *(Uint8*)(0x100002) = 0x1F; // POP DS
105 *(Uint8*)(0x100003) = 0xCB; // RET FAR
107 rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
108 rmstack--; *rmstack = 0xFFFF; //CS
109 rmstack--; *rmstack = 0x0010; //IP
112 stacksetup = (Uint*)0x101000;
113 stacksetup--; *stacksetup = VM8086_STACK_SEG; // GS
114 stacksetup--; *stacksetup = VM8086_STACK_SEG; // FS
115 stacksetup--; *stacksetup = VM8086_STACK_SEG; // DS
116 stacksetup--; *stacksetup = VM8086_STACK_SEG; // ES
117 stacksetup--; *stacksetup = VM8086_STACK_SEG; // SS
118 stacksetup--; *stacksetup = VM8086_STACK_OFS-2; // SP
119 stacksetup--; *stacksetup = 0x20202; // FLAGS
120 stacksetup--; *stacksetup = 0xFFFF; // CS
121 stacksetup--; *stacksetup = 0x10; // IP
122 stacksetup--; *stacksetup = 0xAAAA; // AX
123 stacksetup--; *stacksetup = 0xCCCC; // CX
124 stacksetup--; *stacksetup = 0xDDDD; // DX
125 stacksetup--; *stacksetup = 0xBBBB; // BX
126 stacksetup--; *stacksetup = 0x5454; // SP
127 stacksetup--; *stacksetup = 0xB4B4; // BP
128 stacksetup--; *stacksetup = 0x5151; // SI
129 stacksetup--; *stacksetup = 0xD1D1; // DI
130 stacksetup--; *stacksetup = 0x20|3; // DS - Kernel
131 stacksetup--; *stacksetup = 0x20|3; // ES - Kernel
132 stacksetup--; *stacksetup = 0x20|3; // FS
133 stacksetup--; *stacksetup = 0x20|3; // GS
134 __asm__ __volatile__ (
135 "mov %%eax,%%esp;\n\t" // Set stack pointer
141 "iret;\n\t" : : "a" (stacksetup));
142 for(;;); // Shouldn't be reached
145 gVM8086_WorkerPID = pid;
146 Log_Log("VM8086", "gVM8086_WorkerPID = %i", pid);
147 while( gpVM8086_State != NULL )
148 Threads_Yield(); // Yield to allow the child to initialise
150 // Worker killed itself
151 if( gVM8086_WorkerPID != pid ) {
152 return MODULE_ERR_MISC;
155 return MODULE_ERR_OK;
158 void VM8086_GPF(tRegs *Regs)
162 //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
164 if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
165 && Threads_GetPID() == gVM8086_WorkerPID)
167 if( gpVM8086_State == (void*)-1 ) {
168 Log_Log("VM8086", "Worker thread ready and waiting");
169 gpVM8086_State = NULL;
170 Mutex_Release( &glVM8086_Process ); // Release lock obtained in VM8086_Install
172 //Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
173 // gpVM8086_State, gVM8086_CallingThread);
174 if( gpVM8086_State ) {
175 gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
176 gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
177 gpVM8086_State->BP = Regs->ebp;
178 gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
179 gpVM8086_State->DS = Regs->ds; gpVM8086_State->ES = Regs->es;
180 gpVM8086_State = NULL;
182 Threads_WakeTID(gVM8086_CallingThread);
185 //Log_Log("VM8086", "Waiting for something to do");
186 __asm__ __volatile__ ("sti");
187 // Wait for a new task
188 while(!gpVM8086_State) {
190 //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
193 //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
194 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
195 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
196 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
197 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
198 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
199 Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
202 Regs->eip = 0x11; Regs->cs = 0xFFFF;
203 Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
204 Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
205 Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
206 Regs->ebp = gpVM8086_State->BP;
207 Regs->ds = 0x23; Regs->es = 0x23;
208 Regs->fs = 0x23; Regs->gs = 0x23;
212 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
216 case VM8086_OP_PUSHF: //PUSHF
218 *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
220 Log_Debug("VM8086", "Emulated PUSHF");
223 case VM8086_OP_POPF: //POPF
224 Regs->eflags &= 0xFFFF0002;
225 Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0xFFFD; // Changing IF is not allowed
228 Log_Debug("VM8086", "Emulated POPF");
232 case VM8086_OP_INT_I: //INT imm8
235 id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
238 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
239 Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
241 Regs->cs = *(Uint16*)(4*id + 2);
242 Regs->eip = *(Uint16*)(4*id);
244 Log_Debug("VM8086", "Emulated INT 0x%x", id);
249 case VM8086_OP_IRET: //IRET
250 Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
251 Regs->cs = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
253 Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
258 case VM8086_OP_IN_AD: //IN AL, DX
259 Regs->eax &= 0xFFFFFF00;
260 Regs->eax |= inb(Regs->edx&0xFFFF);
262 Log_Debug("VM8086", "Emulated IN AL, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
265 case VM8086_OP_IN_ADX: //IN AX, DX
266 Regs->eax &= 0xFFFF0000;
267 Regs->eax |= inw(Regs->edx&0xFFFF);
269 Log_Debug("VM8086", "Emulated IN AX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
273 case VM8086_OP_OUT_AD: //OUT DX, AL
274 outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
276 Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
279 case VM8086_OP_OUT_ADX: //OUT DX, AX
280 outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
282 Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
286 // TODO: Decide on allowing VM8086 Apps to enable/disable interrupts
293 opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
296 case VM8086_OP_IN_ADX: //IN AX, DX
297 Regs->eax = ind(Regs->edx&0xFFFF);
299 Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
302 case VM8086_OP_OUT_ADX: //OUT DX, AX
303 outd(Regs->edx&0xFFFF, Regs->eax);
305 Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
309 Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
313 // Force an end to the call
314 Regs->cs = VM8086_MAGIC_CS;
315 Regs->eip = VM8086_MAGIC_IP;
321 Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
322 opcode, Regs->cs, Regs->eip);
323 // Force an end to the call
324 Regs->cs = VM8086_MAGIC_CS;
325 Regs->eip = VM8086_MAGIC_IP;
331 * \brief Create an instance of the VM8086 Emulator
333 tVM8086 *VM8086_Init(void)
336 ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
337 ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
341 void VM8086_Free(tVM8086 *State)
344 for( i = VM8086_PAGES_PER_INST; i --; )
345 MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
349 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
354 Size = (Size + 127) & ~127;
355 nBlocks = Size / 128;
357 if(Size > 4096) return NULL;
359 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
361 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) continue;
364 //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
368 // Scan the bitmap for a free block
369 for( j = 0; j < 32; j++ ) {
370 if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
376 if(rem == 0) // Goodie, there's a gap
378 for( j = 0; j < nBlocks; j++ )
379 State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
380 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
382 LOG("Allocated at #%i,%04x", i, base*128);
383 LOG(" - %x:%x", *Segment, *Offset);
384 return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
389 // No pages with free space?, allocate a new one
390 for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
392 if( State->Internal->AllocatedPages[i].VirtBase == 0 ) break;
394 // Darn, we can't allocate any more
395 if( i == VM8086_PAGES_PER_INST ) {
396 Log_Warning("VM8086", "Out of pages in %p", State);
400 State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
401 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
402 State->Internal->AllocatedPages[i].Bitmap = 0;
404 for( j = 0; j < nBlocks; j++ )
405 State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
406 LOG("AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
407 *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
409 LOG(" - %x:%x", *Segment, *Offset);
410 return (void*) State->Internal->AllocatedPages[i].VirtBase;
413 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
415 return (void*)( KERNEL_BASE + Segment*16 + Offset );
418 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
420 State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
421 State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
423 Mutex_Acquire( &glVM8086_Process );
425 gpVM8086_State = State;
426 gVM8086_CallingThread = Threads_GetTID();
427 Threads_WakeTID( gVM8086_WorkerPID );
429 while( gpVM8086_State != NULL ) Threads_Sleep();
431 Mutex_Release( &glVM8086_Process );