Allow passing Sercomm PID from file. Until now, Sercomm PID could only be passed as an array of hex bytes. Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Header consists in Sercomm PID bytes, followed by a SHA256 hash of the input binary. Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>