Changes

{{WarningMessage|text='''Please note that, in case of problems (e.g. power failures) in the middle of U-Boot upgrading, the system might get in an unrecoverable state.'''}}

== U-Boot-based upgrading ==

With the help of the U-Boot commands (tftpload, protect, erase and cp) we can download and store kernel images, file system images and U-Boot itself in the target system. The main disadvantage is that this procedure usually requires to physically access the system, attaching to the serial console through a serial cable and using a PC with a terminal emulator software.

== Linux-based upgrading ==