Rename aster-frame to ostd

ostd/src/error.rs

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use crate::mm::page_table::PageTableError;
+
+/// The error type which is returned from the APIs of this crate.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum Error {
+    /// Invalid arguments provided.
+    InvalidArgs,
+    /// Insufficient memory available.
+    NoMemory,
+    /// Page fault occurred.
+    PageFault,
+    /// Access to a resource is denied.
+    AccessDenied,
+    /// Input/output error.
+    IoError,
+    /// Insufficient system resources.
+    NotEnoughResources,
+    /// Arithmetic Overflow occurred.
+    Overflow,
+    /// Memory mapping already exists for the given virtual address.
+    MapAlreadyMappedVaddr,
+}
+
+impl From<PageTableError> for Error {
+    fn from(_err: PageTableError) -> Error {
+        Error::AccessDenied
+    }
+}