feat(kernel): add RequestPages and ReleasePages syscalls

crates/types/src/address.rs

@@ -1,12 +1,42 @@
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct EntryPoint(usize);
 
+impl EntryPoint {
+    pub fn from_raw(addr: usize) -> Self {
+        Self(addr)
+    }
+
+    pub fn raw(&self) -> usize {
+        self.0
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct StackPointer(usize);
 
+impl StackPointer {
+    pub fn from_raw(addr: usize) -> Self {
+        Self(addr)
+    }
+
+    pub fn raw(&self) -> usize {
+        self.0
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct VirtualAddress(usize);
 
+impl VirtualAddress {
+    pub fn from_raw(addr: usize) -> Self {
+        Self(addr)
+    }
+
+    pub fn raw(&self) -> usize {
+        self.0
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub struct PhysicalAddress(usize);
 
@@ -29,3 +59,12 @@ pub struct DataRef {
     addr: VirtualAddress,
     len: usize,
 }
+
+impl DataRef {
+    pub fn empty() -> Self {
+        Self {
+            addr: VirtualAddress::from_raw(0),
+            len: 0,
+        }
+    }
+}