TempleOSCDV4.06.ISO

Demo/Lectures/Mem/PageTableEntries.CPP

@@ -0,0 +1,37 @@
+I64 *addr=text.vga_alias,
+   *pte_addr=MemPageTable(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 haserrcode U0 IntPageFault()
+{
+  I64 reg *rbp=GetRBP;
+  *pte_addr|=1;
+  InvlPg(addr);
+  err_code=rbp[1];
+  MOV_RAX_CR2
+  reported_fault_addr=GetRAX;
+}
+
+U0 PageTableDemo()
+{
+  U8 *old_idte=IntEntrySet(I_PAGE_FAULT,&IntPageFault,IDTET_IRQ);
+  err_code=0;
+  *pte_addr &=~1; //Not present
+  InvlPg(addr);
+  WinMgrSync; //wait for VGA update
+  WinMgrSync;
+  IntEntrySet(I_PAGE_FAULT,old_idte,IDTET_IRQ);
+  "Err Code:%X Addr:%X\n",err_code,reported_fault_addr;
+}
+
+PageTableDemo;