There are 3 repositories under portapack topic.
Custom firmware for the HackRF+PortaPack H1/H2
Custom firmware for the HackRF SDR + PortaPack H1 addon
An addon module for portapack to add extra sensors to it for more fun.
My own custom firmware for the HackRF SDR + PortaPack H1 addon - Not for the faint-hearted.
Portapack Mayhem all in one debian/linux compilation utility