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Working on MP build (now can run, just crashes due to CPUs treading on each other...
[tpg/acess2.git] / Kernel / arch / x86 / vm8086.c
diff --git a/Kernel/arch/x86/vm8086.c b/Kernel/arch/x86/vm8086.c
index 1816eac..86f440d 100644 (file)
--- a/Kernel/arch/x86/vm8086.c
+++ b/Kernel/arch/x86/vm8086.c
@@ -47,7 +47,7 @@ MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
 tSpinlock      glVM8086_Process;
 tPID   gVM8086_WorkerPID;
 tTID   gVM8086_CallingThread;
-tVM8086        * volatile gpVM8086_State = (void*)-1;  // Set to -1 to avoid race conditions
+tVM8086        volatile * volatile gpVM8086_State = (void*)-1; // Set to -1 to avoid race conditions
 
 // === FUNCTIONS ===
 int VM8086_Install(char **Arguments)
@@ -66,8 +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
@@ -91,32 +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"
@@ -130,7 +130,8 @@ int VM8086_Install(char **Arguments)
        
        gVM8086_WorkerPID = pid;
        Log_Log("VM8086", "gVM8086_WorkerPID = %i", pid);
-       Threads_Yield();        // Yield to allow the child to initialise
+       while( gpVM8086_State != NULL )
+               Threads_Yield();        // Yield to allow the child to initialise
        
        return MODULE_ERR_OK;
 }
@@ -149,6 +150,8 @@ void VM8086_GPF(tRegs *Regs)
                        RELEASE( &glVM8086_Process );   // Release lock obtained in VM8086_Install
                        gpVM8086_State = NULL;
                }
+               //Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
+               //      gpVM8086_State, gVM8086_CallingThread);
                if( gpVM8086_State ) {
                        gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
                        gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
@@ -156,7 +159,9 @@ void VM8086_GPF(tRegs *Regs)
                        gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
                        gpVM8086_State->DS = Regs->ds;  gpVM8086_State->ES = Regs->es;
                        gpVM8086_State = NULL;
-                       Threads_WakeTID(gVM8086_CallingThread);
+                       // Ensure the caller wakes
+                       //while(Threads_WakeTID(gVM8086_CallingThread) == -EALREADY)
+                       //      Threads_Yield();
                }
                
                //Log_Log("VM8086", "Waiting for something to do");
@@ -168,12 +173,12 @@ 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;
@@ -212,8 +217,8 @@ 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);
@@ -402,7 +407,7 @@ void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
        gVM8086_CallingThread = Threads_GetTID();
        Threads_WakeTID( gVM8086_WorkerPID );
        while( gpVM8086_State != NULL )
-               Threads_Sleep();
+               Threads_Yield();
        
        RELEASE( &glVM8086_Process );
 }
Acess2 is a semi-POSIX-compatible home-brew OS.

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