diff --git a/.gitignore b/.gitignore
index 5daf2cb..28cb524 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,6 @@ target/
 
 # CMake
 **/cmake-build-debug
+
+# Firmware files.
+*.bin
diff --git a/firmware/src/bin/foundation-firmware.rs b/firmware/src/bin/foundation-firmware.rs
index f36cb64..829277f 100644
--- a/firmware/src/bin/foundation-firmware.rs
+++ b/firmware/src/bin/foundation-firmware.rs
@@ -31,6 +31,12 @@ fn main() -> Result<()> {
     engine.input(&file_buf[header_len..]);
     let validation_hash = sha256d::Hash::from_engine(engine);
 
+    // This one is just for debugging.
+    let mut engine = sha256::Hash::engine();
+    engine.input(&header.information.serialize());
+    engine.input(&file_buf[header_len..]);
+    let single_hash = sha256::Hash::from_engine(engine);
+
     let firmware_length = file_buf.len() - header_len;
     if firmware_length != usize::try_from(header.information.length).unwrap() {
         bail!(
@@ -77,6 +83,10 @@ fn main() -> Result<()> {
         "  Validation Hash: {}",
         hex::encode(validation_hash.to_byte_array())
     );
+    println!(
+        "      Single Hash: {}",
+        hex::encode(single_hash.to_byte_array())
+    );
     println!();
 
     verify_signature(&SECP256K1, &header, &validation_hash, None)