SparrowOSTS_121127.ISO

SparrowOS/Demo/Lectures/PageTableEntries2.CPP

@@ -0,0 +1,46 @@
+I64 *addr=VGA_GRAPHIC_MEM_BASE,
+   *pte_addr=MemPtAtPageTableEntry(addr),
+   err_code=0,
+   *reported_fault_addr;
+
+
+/*
+  0[RBP]=old base ptr
+  8[RBP]=err code
+  16[RBP]=RIP
+  24[RBP]=RIP_SELECTOR
+  32[RBP]=RFLAGS
+  40[RBP]=RSP
+  48[RBP]=STK_SELECTOR
+*/
+
+interrupt U0 PageFault()
+{
+  I64 reg *rbp=GetBasePtr,reg *rsp=GetStkPtr,reg *src=rbp,reg *dst=rbp+1;
+  *pte_addr|=1;
+  InvlPg(addr);
+  err_code=rbp[1];
+asm {  MOV_RAX_CR2}
+  reported_fault_addr=GetRAX;
+//Remove err_code from stk
+//so IRET works right.
+  while (src>=rsp)
+    *dst--=*src--;
+  SetBasePtr(rbp+1);
+  SetStkPtr(rsp+1);
+}
+
+
+U0 PageTableDemo2()
+{
+  U8 *old_idte=IntEntrySet(I_PAGE_FAULT,&PageFault,0,IDTET_IRQ);
+  err_code=0;
+  *pte_addr &=~1; //Not present
+  InvlPg(addr);
+  WinMgrSync; //wait for VGA update
+  WinMgrSync;
+  IntEntrySet(I_PAGE_FAULT,old_idte,0,IDTET_IRQ);
+  "Err Code:%X Addr:%X\n",err_code,reported_fault_addr;
+}
+
+PageTableDemo2;