1 files changed, 58 insertions, 0 deletions
diff --git a/src/smccc/arch/error.rs b/src/smccc/arch/error.rs
new file mode 100644
index 0000000..fa2fd4b
--- /dev/null
+++ b/src/smccc/arch/error.rs
@@ -0,0 +1,58 @@
+// Copyright 2023 the authors.
+// This project is dual-licensed under Apache 2.0 and MIT terms.
+// See LICENSE-APACHE and LICENSE-MIT for details.
+
+//! Error codes for standard Arm Architecture SMCCC calls.
+
+pub use crate::smccc::error::SUCCESS;
+use core::fmt::{self, Display, Formatter};
+
+pub const NOT_SUPPORTED: i32 = -1;
+pub const NOT_REQUIRED: i32 = -2;
+pub const INVALID_PARAMETER: i32 = -3;
+
+/// Errors for standard Arm Architecture calls.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Error {
+    /// The call is not supported by the implementation.
+    NotSupported,
+    /// The call is deemed not required by the implementation.
+    NotRequired,
+    /// One of the call parameters has a non-supported value.
+    InvalidParameter,
+    /// There was an unexpected return value.
+    Unknown(i32),
+}
+
+impl From<Error> for i32 {
+    fn from(error: Error) -> i32 {
+        match error {
+            Error::NotSupported => NOT_SUPPORTED,
+            Error::NotRequired => NOT_REQUIRED,
+            Error::InvalidParameter => INVALID_PARAMETER,
+            Error::Unknown(value) => value,
+        }
+    }
+}
+
+impl From<i32> for Error {
+    fn from(value: i32) -> Self {
+        match value {
+            NOT_SUPPORTED => Error::NotSupported,
+            NOT_REQUIRED => Error::NotRequired,
+            INVALID_PARAMETER => Error::InvalidParameter,
+            _ => Error::Unknown(value),
+        }
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match self {
+            Self::NotSupported => write!(f, "SMCCC call not supported"),
+            Self::NotRequired => write!(f, "SMCCC call not required"),
+            Self::InvalidParameter => write!(f, "SMCCC call received non-supported value"),
+            Self::Unknown(e) => write!(f, "Unknown SMCCC return value {} ({0:#x})", e),
+        }
+    }
+}