message: error if architecture is unknown
diff: @@ -43,7 +43,8 @@ pub fn convert_elf(cli: &Cli, platform: &str) -> OutFiles {
  let elf = cli.elf.as_os_str();
  let mut tbf_path = cli.elf.clone();
  tbf_path.set_extension("tbf");
  - let architecture = get_platform_architecture(platform);
  + let architecture =
  + get_platform_architecture(platform).expect("Failed to determine ELF's architecture");
  if cli.verbose {
  println!("ELF file: {:?}", elf);
  println!("TBF path: {}", tbf_path.display());
  @@ -73,11 +74,7 @@ pub fn convert_elf(cli: &Cli, platform: &str) -> OutFiles {
  "-o".as_ref(), tab_path.as_os_str(),
  "--protected-region-size".as_ref(), protected_size.as_ref(),
  "--stack".as_ref(), stack_size.as_ref(),
  - format!("{}{}", elf.to_str().unwrap(), if let Some(ref architecture) = architecture {
  - format!(",{}", architecture)
  - } else {
  - "".to_string()
  - }).as_ref(),
  + format!("{},{}", elf.to_str().unwrap(), architecture).as_ref(),
  ]);
  if cli.verbose {
  command.arg("-v");
  