+// MM_DumpTables(0, -1L);
+}
+
+void MM_FinishVirtualInit(void)
+{
+ PAGEMAPLVL4(0) = 0;
+}
+
+/**
+ * \brief Called on a page fault
+ */
+void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
+{
+ // TODO: Implement Copy-on-Write
+ #if 1
+ if( PAGEMAPLVL4(Addr>>39) & PF_PRESENT
+ && PAGEDIRPTR (Addr>>30) & PF_PRESENT
+ && PAGEDIR (Addr>>21) & PF_PRESENT
+ && PAGETABLE (Addr>>12) & PF_PRESENT
+ && PAGETABLE (Addr>>12) & PF_COW )
+ {
+ tPAddr paddr;
+ if(MM_GetRefCount( PAGETABLE(Addr>>12) & PADDR_MASK ) == 1)
+ {
+ PAGETABLE(Addr>>12) &= ~PF_COW;
+ PAGETABLE(Addr>>12) |= PF_PRESENT|PF_WRITE;
+ }
+ else
+ {
+ //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
+ paddr = MM_AllocPhys();
+ if( !paddr ) {
+ Threads_SegFault(Addr);
+ return ;
+ }
+ {
+ void *tmp = (void*)MM_MapTemp(paddr);
+ memcpy( tmp, (void*)(Addr & ~0xFFF), 0x1000 );
+ MM_FreeTemp( (tVAddr)tmp );
+ }
+ MM_DerefPhys( PAGETABLE(Addr>>12) & PADDR_MASK );
+ PAGETABLE(Addr>>12) &= PF_USER;
+ PAGETABLE(Addr>>12) |= paddr|PF_PRESENT|PF_WRITE;
+ }
+
+ INVLPG( Addr & ~0xFFF );
+ return;
+ }
+ #endif
+
+ // If it was a user, tell the thread handler
+ if(ErrorCode & 4) {
+ Warning("User %s %s memory%s",
+ (ErrorCode&2?"write to":"read from"),
+ (ErrorCode&1?"bad/locked":"non-present"),
+ (ErrorCode&16?" (Instruction Fetch)":"")
+ );
+ Warning("User Pagefault: Instruction at %04x:%p accessed %p",
+ Regs->CS, Regs->RIP, Addr);
+ __asm__ __volatile__ ("sti"); // Restart IRQs
+ Threads_SegFault(Addr);
+ return ;
+ }
+
+ // Kernel #PF
+ Debug_KernelPanic();
+ // -- Check Error Code --
+ if(ErrorCode & 8)
+ Warning("Reserved Bits Trashed!");
+ else
+ {
+ Warning("Kernel %s %s memory%s",
+ (ErrorCode&2?"write to":"read from"),
+ (ErrorCode&1?"bad/locked":"non-present"),
+ (ErrorCode&16?" (Instruction Fetch)":"")
+ );
+ }
+
+ Log("Code at %p accessed %p", Regs->RIP, Addr);
+ // Print Stack Backtrace
+ Error_Backtrace(Regs->RIP, Regs->RBP);
+
+ MM_DumpTables(0, -1);