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Bugfixing
[tpg/acess2.git] / Kernel / arch / x86 / vm8086.c
diff --git a/Kernel/arch/x86/vm8086.c b/Kernel/arch/x86/vm8086.c
index 8ef7453..1f4f1f4 100644 (file)
--- a/Kernel/arch/x86/vm8086.c
+++ b/Kernel/arch/x86/vm8086.c
@@ -13,12 +13,14 @@
 #define VM8086_STACK_OFS       0x0AFE
 enum eVM8086_Opcodes
 {
-       VM8086_OP_PUSHF = 0x9C,
-       VM8086_OP_POPF  = 0x9D,
-       VM8086_OP_INT_I = 0xCD,
-       VM8086_OP_IRET  = 0xCF,
-       VM8086_OP_IN_AD = 0xEC,
-       VM8086_OP_IN_ADX= 0xED
+       VM8086_OP_PUSHF   = 0x9C,
+       VM8086_OP_POPF    = 0x9D,
+       VM8086_OP_INT_I   = 0xCD,
+       VM8086_OP_IRET    = 0xCF,
+       VM8086_OP_IN_AD   = 0xEC,
+       VM8086_OP_IN_ADX  = 0xED,
+       VM8086_OP_OUT_AD  = 0xEE,
+       VM8086_OP_OUT_ADX = 0xEF
 };
 #define VM8086_PAGES_PER_INST  4
 
@@ -45,13 +47,16 @@ MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
 tSpinlock      glVM8086_Process;
 tPID   gVM8086_WorkerPID;
 tTID   gVM8086_CallingThread;
-tVM8086        * volatile gpVM8086_State;
+tVM8086        volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
 
 // === FUNCTIONS ===
 int VM8086_Install(char **Arguments)
 {
        tPID    pid;    
        
+       // Lock to avoid race conditions
+       LOCK( &glVM8086_Process );
+       
        // Create BIOS Call process
        pid = Proc_Clone(NULL, CLONE_VM);
        if(pid == -1)
@@ -61,8 +66,8 @@ int VM8086_Install(char **Arguments)
        }
        if(pid == 0)
        {
-               Uint    *stacksetup;    // Initialising Stack
-               Uint16  *rmstack;       // Real Mode Stack
+               Uint    * volatile stacksetup;  // Initialising Stack
+               Uint16  * volatile rmstack;     // Real Mode Stack
                 int    i;
                 
                // Set Image Name
@@ -86,32 +91,32 @@ int VM8086_Install(char **Arguments)
                *(Uint8*)(0x100003) = 0xCB;     // RET FAR
                
                rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
-               *rmstack-- = 0xFFFF;    //CS
-               *rmstack-- = 0x0010;    //IP
+               rmstack--;      *rmstack = 0xFFFF;      //CS
+               rmstack--;      *rmstack = 0x0010;      //IP
                
                // Setup Stack
                stacksetup = (Uint*)0x101000;
-               *--stacksetup = VM8086_STACK_SEG;       // GS
-               *--stacksetup = VM8086_STACK_SEG;       // FS
-               *--stacksetup = VM8086_STACK_SEG;       // DS
-               *--stacksetup = VM8086_STACK_SEG;       // ES
-               *--stacksetup = VM8086_STACK_SEG;       // SS
-               *--stacksetup = VM8086_STACK_OFS-2;     // SP
-               *--stacksetup = 0x20202;        // FLAGS
-               *--stacksetup = 0xFFFF; // CS
-               *--stacksetup = 0x10;   // IP
-               *--stacksetup = 0xAAAA; // AX
-               *--stacksetup = 0xCCCC; // CX
-               *--stacksetup = 0xDDDD; // DX
-               *--stacksetup = 0xBBBB; // BX
-               *--stacksetup = 0x5454; // SP
-               *--stacksetup = 0xB4B4; // BP
-               *--stacksetup = 0x5151; // SI
-               *--stacksetup = 0xD1D1; // DI
-               *--stacksetup = 0x20|3; // DS - Kernel
-               *--stacksetup = 0x20|3; // ES - Kernel
-               *--stacksetup = 0x20|3; // FS
-               *--stacksetup = 0x20|3; // GS
+               stacksetup--;   *stacksetup = VM8086_STACK_SEG; // GS
+               stacksetup--;   *stacksetup = VM8086_STACK_SEG; // FS
+               stacksetup--;   *stacksetup = VM8086_STACK_SEG; // DS
+               stacksetup--;   *stacksetup = VM8086_STACK_SEG; // ES
+               stacksetup--;   *stacksetup = VM8086_STACK_SEG; // SS
+               stacksetup--;   *stacksetup = VM8086_STACK_OFS-2;       // SP
+               stacksetup--;   *stacksetup = 0x20202;  // FLAGS
+               stacksetup--;   *stacksetup = 0xFFFF;   // CS
+               stacksetup--;   *stacksetup = 0x10;     // IP
+               stacksetup--;   *stacksetup = 0xAAAA;   // AX
+               stacksetup--;   *stacksetup = 0xCCCC;   // CX
+               stacksetup--;   *stacksetup = 0xDDDD;   // DX
+               stacksetup--;   *stacksetup = 0xBBBB;   // BX
+               stacksetup--;   *stacksetup = 0x5454;   // SP
+               stacksetup--;   *stacksetup = 0xB4B4;   // BP
+               stacksetup--;   *stacksetup = 0x5151;   // SI
+               stacksetup--;   *stacksetup = 0xD1D1;   // DI
+               stacksetup--;   *stacksetup = 0x20|3;   // DS - Kernel
+               stacksetup--;   *stacksetup = 0x20|3;   // ES - Kernel
+               stacksetup--;   *stacksetup = 0x20|3;   // FS
+               stacksetup--;   *stacksetup = 0x20|3;   // GS
                __asm__ __volatile__ (
                "mov %%eax,%%esp;\n\t"  // Set stack pointer
                "pop %%gs;\n\t"
@@ -139,6 +144,11 @@ void VM8086_GPF(tRegs *Regs)
        if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
        && Threads_GetPID() == gVM8086_WorkerPID)
        {
+               if( gpVM8086_State == (void*)-1 ) {
+                       Log_Log("VM8086", "Worker thread ready and waiting");
+                       RELEASE( &glVM8086_Process );   // Release lock obtained in VM8086_Install
+                       gpVM8086_State = NULL;
+               }
                if( gpVM8086_State ) {
                        gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
                        gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
@@ -158,12 +168,12 @@ void VM8086_GPF(tRegs *Regs)
                }
                
                //Log_Log("VM8086", "We have a task (%p)", gpVM8086_State);
-               Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
-               Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
-               Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
-               Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
-               Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
-               Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
+               Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
+               Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
+               Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
+               Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
+               Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
+               Regs->esp -= 2; *(Uint16*volatile)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
                
                // Set Registers
                Regs->eip = 0x11;       Regs->cs = 0xFFFF;
@@ -176,7 +186,7 @@ void VM8086_GPF(tRegs *Regs)
                return ;
        }
        
-       opcode = *(Uint8*)( KERNEL_BASE + (Regs->cs*16) + (Regs->eip) );
+       opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip) );
        Regs->eip ++;
        switch(opcode)
        {
@@ -202,8 +212,8 @@ void VM8086_GPF(tRegs *Regs)
                id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
                Regs->eip ++;
                
-               Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
-               Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
+               Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
+               Regs->esp -= 2; *(Uint16*volatile)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
                
                Regs->cs = *(Uint16*)(4*id + 2);
                Regs->eip = *(Uint16*)(4*id);
@@ -237,13 +247,13 @@ void VM8086_GPF(tRegs *Regs)
                #endif
                break;
                
-       case 0xEE:      //OUT DX, AL
+       case VM8086_OP_OUT_AD:  //OUT DX, AL
                outb(Regs->edx&0xFFFF, Regs->eax&0xFF);
                #if TRACE_EMU
                Log_Debug("VM8086", "Emulated OUT DX, AL (*0x%04x = 0x%02x)\n", Regs->edx&0xFFFF, Regs->eax&0xFF);
                #endif
                break;
-       case 0xEF:      //OUT DX, AX
+       case VM8086_OP_OUT_ADX: //OUT DX, AX
                outw(Regs->edx&0xFFFF, Regs->eax&0xFFFF);
                #if TRACE_EMU
                Log_Debug("VM8086", "Emulated OUT DX, AX (*0x%04x = 0x%04x)\n", Regs->edx&0xFFFF, Regs->eax&0xFFFF);
@@ -257,8 +267,31 @@ void VM8086_GPF(tRegs *Regs)
                break;
        
        case 0x66:
-               Log_Warning("VM8086", "Code at %04x:%04x attempted to use an operand override, ignored",
-                       Regs->cs, Regs->eip);
+               opcode = *(Uint8*)( (Regs->cs*16) + (Regs->eip&0xFFFF));
+               switch( opcode )
+               {
+               case VM8086_OP_IN_ADX:  //IN AX, DX
+                       Regs->eax = ind(Regs->edx&0xFFFF);
+                       #if TRACE_EMU
+                       Log_Debug("VM8086", "Emulated IN EAX, DX (Port 0x%x)\n", Regs->edx&0xFFFF);
+                       #endif
+                       break;
+               case VM8086_OP_OUT_ADX: //OUT DX, AX
+                       outd(Regs->edx&0xFFFF, Regs->eax);
+                       #if TRACE_EMU
+                       Log_Debug("VM8086", "Emulated OUT DX, EAX (*0x%04x = 0x%08x)\n", Regs->edx&0xFFFF, Regs->eax);
+                       #endif
+                       break;
+               default:
+                       Log_Error("VM8086", "Error - Unknown opcode 66 %02x caused a GPF at %04x:%04x",
+                               Regs->cs, Regs->eip,
+                               opcode
+                               );
+                       // Force an end to the call
+                       Regs->cs = VM8086_MAGIC_CS;
+                       Regs->eip = VM8086_MAGIC_IP;
+                       break;
+               }
                break;
        
        default:
Acess2 is a semi-POSIX-compatible home-brew OS.

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