This small script is compatible with Fujitsu Quaderno 2nd Gen A4 and A5. I also pack the needed public and private keys alongside the script.
Usage: unpacker.sh {your_pkg_path} {output_path}
The public and private keys can be dumped from the device's rawdata partation. The structure of the update package is different from the first Gen of the Fujitsu Quaderno (Sony DPT)
http://www.fmworld.net/download/digital-paper/sw/FwUpdater_gen2_1.1.00.26010FP.pkg
http://www.fmworld.net/download/digital-paper/sw/FwUpdater_gen2_1.1.00.24160FP.pkg
http://www.fmworld.net/download/digital-paper/sw/FwUpdater_gen2_1.1.00.21150FP.pkg
http://www.fmworld.net/download/digital-paper/sw/FwUpdater_gen2_1.1.00.17310FP.pkg
http://www.fmworld.net/download/digital-paper/sw/FwUpdater_gen2_1.1.00.15020FP.pkg
http://www.fmworld.net/download/digital-paper/sw/FwUpdater_gen2_1.1.00.09240FP.pkg
http://www.fmworld.net/download/digital-paper/sw/FwUpdater_gen2_1.0.00.17060FP.pkg