1 files changed, 115 insertions, 0 deletions
diff --git a/kernel/src/mm/addr.rs b/kernel/src/mm/addr.rs
new file mode 100644
index 0000000..0e848a6
--- /dev/null
+++ b/kernel/src/mm/addr.rs
@@ -0,0 +1,115 @@
+use core::{ops::Deref, sync::atomic::Ordering};
+
+use atomic::Atomic;
+use bytemuck::{Pod, Zeroable};
+
+static KERNEL_VIRTUAL_BASE: Atomic<PhysicalMemoryAddress> = Atomic::new(PhysicalMemoryAddress(0));
+
+pub fn init(kernel_virtual_base: PhysicalMemoryAddress) {
+    KERNEL_VIRTUAL_BASE.store(kernel_virtual_base, Ordering::Relaxed);
+}
+
+#[derive(Clone, Copy, Pod, Zeroable)]
+#[repr(transparent)]
+pub struct VirtualMemoryAddress(pub usize);
+
+impl Deref for VirtualMemoryAddress {
+    type Target = usize;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<usize> for VirtualMemoryAddress {
+    fn from(value: usize) -> Self {
+        Self(value)
+    }
+}
+
+impl From<VirtualMemoryAddress> for usize {
+    fn from(value: VirtualMemoryAddress) -> Self {
+        *value
+    }
+}
+
+impl From<PhysicalMemoryAddress> for VirtualMemoryAddress {
+    fn from(value: PhysicalMemoryAddress) -> Self {
+        VirtualMemoryAddress(*value + *KERNEL_VIRTUAL_BASE.load(Ordering::Relaxed))
+    }
+}
+
+#[derive(Clone, Copy, Pod, Zeroable)]
+#[repr(transparent)]
+pub struct PhysicalMemoryAddress(pub usize);
+
+impl Deref for PhysicalMemoryAddress {
+    type Target = usize;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<usize> for PhysicalMemoryAddress {
+    fn from(value: usize) -> Self {
+        PhysicalMemoryAddress(value)
+    }
+}
+
+impl From<PhysicalMemoryAddress> for usize {
+    fn from(value: PhysicalMemoryAddress) -> Self {
+        *value
+    }
+}
+
+impl From<VirtualMemoryAddress> for PhysicalMemoryAddress {
+    fn from(value: VirtualMemoryAddress) -> Self {
+        PhysicalMemoryAddress(*value - *KERNEL_VIRTUAL_BASE.load(Ordering::Relaxed))
+    }
+}
+
+#[derive(Clone, Copy)]
+pub enum MemoryAddress {
+    Virtual(VirtualMemoryAddress),
+    Physical(PhysicalMemoryAddress),
+}
+
+impl From<VirtualMemoryAddress> for MemoryAddress {
+    fn from(value: VirtualMemoryAddress) -> Self {
+        MemoryAddress::Virtual(value)
+    }
+}
+
+impl From<PhysicalMemoryAddress> for MemoryAddress {
+    fn from(value: PhysicalMemoryAddress) -> Self {
+        MemoryAddress::Physical(value)
+    }
+}
+
+impl From<MemoryAddress> for usize {
+    fn from(value: MemoryAddress) -> Self {
+        match value {
+            MemoryAddress::Virtual(v) => *v,
+            MemoryAddress::Physical(p) => *p,
+        }
+    }
+}
+
+impl From<MemoryAddress> for VirtualMemoryAddress {
+    fn from(value: MemoryAddress) -> Self {
+        match value {
+            MemoryAddress::Virtual(v) => v,
+            MemoryAddress::Physical(p) => p.into(),
+        }
+    }
+}
+
+impl From<MemoryAddress> for PhysicalMemoryAddress {
+    fn from(value: MemoryAddress) -> Self {
+        match value {
+            MemoryAddress::Virtual(v) => v.into(),
+            MemoryAddress::Physical(p) => p,
+        }
+    }
+}