diff --git a/pvmfw/src/hvc/trng.rs b/pvmfw/src/hvc/trng.rs
new file mode 100644
index 0000000..d347693
--- /dev/null
+++ b/pvmfw/src/hvc/trng.rs
@@ -0,0 +1,65 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use crate::smccc;
+use core::fmt;
+use core::result;
+
+/// Standard SMCCC TRNG error values as described in DEN 0098 1.0 REL0.
+#[derive(Debug, Clone)]
+pub enum Error {
+    /// The call is not supported by the implementation.
+    NotSupported,
+    /// One of the call parameters has a non-supported value.
+    InvalidParameter,
+    /// Call returned without the requested entropy bits.
+    NoEntropy,
+    /// Negative values indicate error.
+    Unknown(i64),
+    /// The call returned a positive value when 0 was expected.
+    Unexpected(u64),
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::NotSupported => write!(f, "SMCCC TRNG call not supported"),
+            Self::InvalidParameter => write!(f, "SMCCC TRNG call received non-supported value"),
+            Self::NoEntropy => write!(f, "SMCCC TRNG call returned no entropy"),
+            Self::Unexpected(v) => write!(f, "Unexpected SMCCC TRNG return value {} ({0:#x})", v),
+            Self::Unknown(e) => write!(f, "Unknown SMCCC TRNG return value {} ({0:#x})", e),
+        }
+    }
+}
+
+pub type Result<T> = result::Result<T, Error>;
+
+pub fn hvc64(function: u32, args: [u64; 17]) -> Result<[u64; 18]> {
+    let res = smccc::hvc64(function, args);
+    match res[0] as i64 {
+        ret if ret >= 0 => Ok(res),
+        -1 => Err(Error::NotSupported),
+        -2 => Err(Error::InvalidParameter),
+        -3 => Err(Error::NoEntropy),
+        ret => Err(Error::Unknown(ret)),
+    }
+}
+
+pub fn hvc64_expect_zero(function: u32, args: [u64; 17]) -> Result<[u64; 18]> {
+    let res = hvc64(function, args)?;
+    match res[0] {
+        0 => Ok(res),
+        v => Err(Error::Unexpected(v)),
+    }
+}