A list of a few tools for firmware unpacking, repacking and analysis

binwalk: https://github.com/ReFirmLabs/binwalk
EMBA: https://github.com/e-m-b-a/emba
unblob: https://github.com/onekey-sec/unblob
ofrak: https://github.com/redballoonsecurity/ofrak
avatar2: https://github.com/avatartwo/avatar2