Add paging Entry flags

src/arch/aarch64/memory/paging/entry.rs

@@ -4,7 +4,20 @@ pub struct Entry(u64);
 
 bitflags! {
     pub struct EntryFlags: u64 {
-
+        const VALID          = 1 <<  0;
+        const TABLE          = 1 <<  1; // If set, a table entry, otherwise block entry
+        // ATTR_INDEX_MASK = 7 << 2;
+        const NON_SECURE     = 1 <<  5; // block/page descriptor lower attributes
+        const ACCESS         = 1 << 10; // block/page descriptor lower attributes
+        const NOT_GLOBAL     = 1 << 11; // nG, block/page descriptor lower attributes
+        const DIRTY          = 1 << 51; // block/page descriptor upper attributes
+        const CONTIGUOUS     = 1 << 52; // block/page descriptor upper attributes
+        const EL1_EXEC_NEVER = 1 << 53; // block/page descriptor upper attributes
+        const EXEC_NEVER     = 1 << 54; // block/page descriptor upper attributes
+        const PXN_TABLE      = 1 << 59; // table descriptor, next level table attributes
+        const XN_TABLE       = 1 << 60; // table descriptor, next level table attributes
+        const AP_TABLE       = 1 << 61; // table descriptor, next level table attributes, 2 bits
+        const NS_TABLE       = 1 << 63; // table descriptor, next level table attributes
     }
 }
 
@@ -22,12 +35,17 @@ impl Entry {
     }
 
     pub fn pointed_frame(&self) -> Option<Frame> {
-        if self.flags().contains(PRESENT) {
+        if self.flags().contains(EntryFlags::VALID) {
             Some(Frame::containing_address(
-                self.0 as usize & 0x000fffff_fffff000,
+                self.0 as usize & 0x0000_ffff_ffff_f000,
             ))
         } else {
             None
         }
     }
+
+    pub fn set(&mut self, frame: Frame, flags: EntryFlags) {
+        assert!(frame.start_address() & !0x0000_ffff_ffff_f000 == 0);
+        self.0 = (frame.start_address() as u64) | flags.bits();
+    }
 }