ao-elftohex: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/ao-elftohex - from package: altos

You may install the required package with command apt-get install {package}

Error in other languages:
ao-elftohex: bevel nie gevind nie
ao-elftohex: comandă negăsită
ao-elftohex: comando não encontrado
ao-elftohex: commande introuvable
ao-elftohex: command not found
ao-elftohex: käsku ei ole
ao-elftohex: không tìm thấy lệnh
ao-elftohex: komanda nerasta
ao-elftohex: Kommando nicht gefunden.
ao-elftohex: kommandot finns inte
ao-elftohex: komut yok
ao-elftohex: nie znaleziono polecenia
ao-elftohex: níor aimsíodh an t-ordú
ao-elftohex: no se encontró la orden
ao-elftohex: no s'ha trobat l'ordre
ao-elftohex: opdracht niet gevonden
ao-elftohex: parancs nem található
ao-elftohex: perintah tidak ditemukan
ao-elftohex: príkaz nenájdený
ao-elftohex: příkaz nenalezen
ao-elftohex: команда не найдена
ao-elftohex: командата не е открита
ao-elftohex: 命令找不到
ao-elftohex: コマンドが見つかりません