tool: Add error for write locked

Add a new error for the case of trying to flash when security is enabled
and it is still locked and update the related docs.

Signed-off-by: Tim Crawford <tcrawford@system76.com>

tool/src/error.rs

@@ -29,6 +29,8 @@ pub enum Error {
     /// Encountered a hidapi::Error
     #[cfg(feature = "hidapi")]
     Hid(hidapi::HidError),
+    /// Writing to flash is disabled
+    WriteLocked,
 }
 
 #[cfg(feature = "std")]

tool/src/main.rs

@@ -170,6 +170,12 @@ unsafe fn flash(ec: &mut Ec<Box<dyn Access>>, path: &str, target: SpiTarget) ->
         println!("ec version: {:?}", str::from_utf8(ec_version));
     }
 
+    if let Ok(security) = ec.security_get() {
+        if security != SecurityState::Unlock {
+            return Err(Error::WriteLocked);
+        }
+    }
+
     if scratch {
         // Wait for any key releases
         eprintln!("Waiting 5 seconds for all keys to be released");
@@ -378,8 +384,6 @@ struct Args {
 }
 
 fn main() {
-    //.subcommand(Command::new("security").arg(Arg::new("state").value_parser(["lock", "unlock"])))
-
     let args = Args::parse();
 
     let get_ec = || -> Result<_, Error> {