Not sure if this is the right place, but anyway...
The Kobo firmware accepts incomplete KoboRoot.tgz (cancelled download, lost connection, ...) and corrupts itself when extracting them. This is because it uses zcat to verify the KoboRoot.tgz, which fails to raise any error for incomplete files, and tar subsequently extracts half an update and even leaves outright corrupted files (like half a library). Worst case the device is bricked. Using tar instead of zcat to verify the tar file would catch most of such errors.
(in /etc/init.d/rcS)
Code:
zcat /mnt/onboard/.kobo/KoboRoot.tgz > /dev/null && tar zxf /mnt/onboard/.kobo/KoboRoot.tgz -C /
should be
Code:
tar tzf /mnt/onboard/.kobo/KoboRoot.tgz > /dev/null && tar zxf /mnt/onboard/.kobo/KoboRoot.tgz -C /
# or alternatively
tar Ozf /mnt/onboard/.kobo/KoboRoot.tgz > /dev/null && tar zxf /mnt/onboard/.kobo/KoboRoot.tgz -C /
(same for Kobo.tgz)