Kernel/x86 - Clean up some of the task switching code (possibly a little broken)
[tpg/acess2.git] / KernelLand / Kernel / arch / x86 / vm8086.c
index 44c60df..f1b5005 100644 (file)
@@ -1,6 +1,9 @@
 /*
- * Acess2 VM8086 Driver
+ * Acess2 Kernel (x86)
  * - By John Hodge (thePowersGang)
+ *
+ * vm8086.c
+ * - Virtual 8086 Mode Monitor
  */
 #define DEBUG  0
 #include <acess.h>
@@ -12,6 +15,8 @@
 // === CONSTANTS ===
 #define TRACE_EMU      0
 
+#define VM8086_USER_BASE       0x1000
+
 #define VM8086_MAGIC_CS        0xFFFF
 #define VM8086_MAGIC_IP        0x0010
 #define VM8086_STACK_SEG       0x9F00
@@ -33,13 +38,15 @@ enum eVM8086_Opcodes
 #define VM8086_BLOCKCOUNT      ((0x9F000-0x10000)/VM8086_BLOCKSIZE)
 
 // === TYPES ===
+struct sVM8086_InternalPages
+{
+       Uint32  Bitmap; // 32 sections = 128 byte blocks
+       char    *VirtBase;
+       tPAddr  PhysAddr;
+};
 struct sVM8086_InternalData
 {
-       struct {
-               Uint32  Bitmap; // 32 sections = 128 byte blocks
-               tVAddr  VirtBase;
-               tPAddr  PhysAddr;
-       }       AllocatedPages[VM8086_PAGES_PER_INST];
+       struct sVM8086_InternalPages    AllocatedPages[VM8086_PAGES_PER_INST];
 };
 
 // === PROTOTYPES ===
@@ -61,16 +68,14 @@ Uint32      gaVM8086_MemBitmap[VM8086_BLOCKCOUNT/32];
 // === FUNCTIONS ===
 int VM8086_Install(char **Arguments)
 {
-       tPID    pid;    
-
        Semaphore_Init(&gVM8086_TasksToDo, 0, 10, "VM8086", "TasksToDo");
        
        // Lock to avoid race conditions
        Mutex_Acquire( &glVM8086_Process );
        
        // Create BIOS Call process
-       pid = Proc_Clone(CLONE_VM);
-       Log_Debug("VM8086", "pid = %i", pid);
+       tPID pid = Proc_Clone(CLONE_VM);
+       LOG("pid = %i", pid);
        if(pid == -1)
        {
                Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
@@ -80,29 +85,31 @@ int VM8086_Install(char **Arguments)
        {
                Uint    * volatile stacksetup;  // Initialising Stack
                Uint16  * volatile rmstack;     // Real Mode Stack
-                int    i;
 
-               Log_Debug("VM8086", "Initialising worker");     
+               LOG("Initialising worker");
        
                // Set Image Name
                Threads_SetName("VM8086");
 
                // Map ROM Area
-               for(i=0xA0;i<0x100;i++) {
-                       MM_Map( i * 0x1000, i * 0x1000 );
+               for(unsigned int i = 0xA0;i<0x100;i++) {
+                       MM_RefPhys(i * 0x1000);
+                       MM_Map( (void*)(i * 0x1000), i * 0x1000 );
                }
-               MM_Map( 0, 0 ); // IVT / BDA
-               // Map (but allow allocation) of 0x1000 - 0x9F000
-               // - So much hack, it isn't funny
-               // TODO: Remove this and replce with something less hacky
-               for(i=1;i<0x9F;i++) {
-                       MM_Map( i * 0x1000, i * 0x1000 );
-                       while(MM_GetRefCount(i*0x1000))
-                               MM_DerefPhys( i * 0x1000 );
+               MM_RefPhys(0);
+               MM_Map( (void*)0, 0 );  // IVT / BDA
+               if( MM_GetRefCount(0x00000) > 2 ) {
+                       Log_Notice("VM8086", "Ok, who's touched the IVT? (%i)",
+                               MM_GetRefCount(0x00000));
+               }
+               MM_RefPhys(0x9F000);
+               MM_Map( (void*)0x9F000, 0x9F000 );      // Stack / EBDA
+               if( MM_GetRefCount(0x9F000) > 2 ) {
+                       Log_Notice("VM8086", "And who's been playing with my EBDA? (%i)",
+                               MM_GetRefCount(0x9F000));
                }
-               MM_Map( 0x9F000, 0x9F000 );     // Stack / EBDA
                // System Stack / Stub
-               if( MM_Allocate( 0x100000 ) == 0 ) {
+               if( MM_Allocate( (void*)0x100000 ) == 0 ) {
                        Log_Error("VM8086", "Unable to allocate memory for stack/stub");
                        gVM8086_WorkerPID = 0;
                        Threads_Exit(0, 1);
@@ -140,6 +147,7 @@ int VM8086_Install(char **Arguments)
                stacksetup--;   *stacksetup = 0x20|3;   // ES - Kernel
                stacksetup--;   *stacksetup = 0x20|3;   // FS
                stacksetup--;   *stacksetup = 0x20|3;   // GS
+               LOG("stacksetup = %p, entering vm8086");
                __asm__ __volatile__ (
                "mov %%eax,%%esp;\n\t"  // Set stack pointer
                "pop %%gs;\n\t"
@@ -154,6 +162,7 @@ int VM8086_Install(char **Arguments)
        gVM8086_WorkerPID = pid;
 
        // It's released when the GPF fires
+       LOG("Waiting for worker %i to start", gVM8086_WorkerPID);
        Mutex_Acquire( &glVM8086_Process );
        Mutex_Release( &glVM8086_Process );
        
@@ -184,13 +193,25 @@ void VM8086_GPF(tRegs *Regs)
                }
 //             Log_Log("VM8086", "gpVM8086_State = %p, gVM8086_CallingThread = %i",
 //                     gpVM8086_State, gVM8086_CallingThread);
-               if( gpVM8086_State ) {
+               if( gpVM8086_State )
+               {
                        gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
                        gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
                        gpVM8086_State->BP = Regs->ebp;
                        gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
                        gpVM8086_State->DS = Regs->ds;  gpVM8086_State->ES = Regs->es;
+
+                       LOG("gpVM8086_State = %p", gpVM8086_State);
+                       LOG("gpVM8086_State->Internal = %p", gpVM8086_State->Internal);
+                       for( Uint i = 0; i < VM8086_PAGES_PER_INST; i ++ )
+                       {
+                               if( !gpVM8086_State->Internal->AllocatedPages[i].VirtBase )
+                                       continue ;
+                               MM_Deallocate( (tPage*)VM8086_USER_BASE + i );
+                       }
+
                        gpVM8086_State = NULL;
+                               
                        // Wake the caller
                        Semaphore_Signal(&gVM8086_TaskComplete, 1);
                }
@@ -199,6 +220,15 @@ void VM8086_GPF(tRegs *Regs)
                __asm__ __volatile__ ("sti");
                Semaphore_Wait(&gVM8086_TasksToDo, 1);
                
+               for( Uint i = 0; i < VM8086_PAGES_PER_INST; i ++ )
+               {
+                       if( !gpVM8086_State->Internal->AllocatedPages[i].VirtBase )
+                               continue ;
+                       MM_RefPhys( gpVM8086_State->Internal->AllocatedPages[i].PhysAddr );
+                       MM_Map( (tPage*)VM8086_USER_BASE + i, gpVM8086_State->Internal->AllocatedPages[i].PhysAddr );
+               }
+
+               
                //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;
@@ -252,6 +282,7 @@ 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->eflags;
                Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
                Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
                
@@ -389,14 +420,15 @@ tVM8086 *VM8086_Init(void)
 
 void VM8086_Free(tVM8086 *State)
 {
-        int    i;
-       for( i = VM8086_PAGES_PER_INST; i --; )
+       // TODO: Make sure the state isn't in use currently
+       for( Uint i = VM8086_PAGES_PER_INST; i --; )
                MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
        free(State);
 }
 
 void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
 {
+       struct sVM8086_InternalPages    *pages = State->Internal->AllocatedPages;
         int    i, j, base = 0;
         int    nBlocks, rem;
        
@@ -407,16 +439,18 @@ void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
        
        for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
        {
-               if( State->Internal->AllocatedPages[i].VirtBase == 0 )  continue;
-               
+               if( pages[i].VirtBase == 0 )    continue;
                
-               //Log_Debug("VM8086", "AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
+               //Log_Debug("VM8086", "pages[%i].Bitmap = 0b%b", i, pages[i].Bitmap);
                
                rem = nBlocks;
                base = 0;
                // Scan the bitmap for a free block
-               for( j = 0; j < 32; j++ ) {
-                       if( State->Internal->AllocatedPages[i].Bitmap & (1 << j) ) {
+               // - 32 blocks per page == 128 bytes per block == 8 segments
+               for( j = 0; j < 32; j++ )
+               {
+                       if( pages[i].Bitmap & (1 << j) )
+                       {
                                base = j+1;
                                rem = nBlocks;
                        }
@@ -425,12 +459,12 @@ void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
                        if(rem == 0)    // Goodie, there's a gap
                        {
                                for( j = 0; j < nBlocks; j++ )
-                                       State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
-                               *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
+                                       pages[i].Bitmap |= 1 << (base + j);
+                               *Segment = (VM8086_USER_BASE + i * 0x1000) / 16 + base * 8;
                                *Offset = 0;
-                               LOG("Allocated at #%i,%04x", i, base*128);
+                               LOG("Allocated at #%i,%04x", i, base*8*16);
                                LOG(" - %x:%x", *Segment, *Offset);
-                               return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
+                               return pages[i].VirtBase + base * 8 * 16;
                        }
                }
        }
@@ -438,7 +472,7 @@ void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
        // No pages with free space?, allocate a new one
        for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
        {
-               if( State->Internal->AllocatedPages[i].VirtBase == 0 )  break;
+               if( pages[i].VirtBase == 0 )    break;
        }
        // Darn, we can't allocate any more
        if( i == VM8086_PAGES_PER_INST ) {
@@ -446,22 +480,40 @@ void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
                return NULL;
        }
        
-       State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
-               1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
-       State->Internal->AllocatedPages[i].Bitmap = 0;
+       pages[i].VirtBase = MM_AllocDMA(1, -1, &pages[i].PhysAddr);
+       if( pages[i].VirtBase == 0 ) {
+               Log_Warning("VM8086", "Unable to allocate data page");
+               return NULL;
+       }
+       pages[i].Bitmap = 0;
+       LOG("AllocatedPages[%i].VirtBase = %p", i, pages[i].VirtBase);
+       LOG("AllocatedPages[%i].PhysAddr = %P", i, pages[i].PhysAddr);
                
        for( j = 0; j < nBlocks; j++ )
-               State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
-       LOG("AllocatedPages[%i].Bitmap = 0b%b", i, State->Internal->AllocatedPages[i].Bitmap);
-       *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
+               pages[i].Bitmap |= 1 << j;
+       LOG("AllocatedPages[%i].Bitmap = 0b%b", i, pages[i].Bitmap);
+       *Segment = (VM8086_USER_BASE + i * 0x1000) / 16;
        *Offset = 0;
-       LOG(" - %x:%x", *Segment, *Offset);
-       return (void*) State->Internal->AllocatedPages[i].VirtBase;
+       LOG(" - %04x:%04x", *Segment, *Offset);
+       return pages[i].VirtBase;
 }
 
 void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
 {
-       return (void*)( KERNEL_BASE + Segment*16 + Offset );
+       Uint32  addr = Segment * 16 + Offset;
+       
+       if( VM8086_USER_BASE <= addr && addr < VM8086_USER_BASE + VM8086_PAGES_PER_INST*0x1000 )
+       {
+               int pg = (addr - VM8086_USER_BASE) / 0x1000;
+               if( State->Internal->AllocatedPages[pg].VirtBase == 0)
+                       return NULL;
+               else
+                       return State->Internal->AllocatedPages[pg].VirtBase + (addr & 0xFFF);
+       }
+       else
+       {
+               return (void*)( KERNEL_BASE + addr );
+       }
 }
 
 void VM8086_Int(tVM8086 *State, Uint8 Interrupt)

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