I had installed the Hawking wireless function app on Yosemite and on update to El Capitan, a few weeks ago, I realized that it was no longer compatible. More annoyingly, my mac kept rebooting with kernel panic error and the backtrace pointed to the hk.uds.netusb.controller kernel extension. Googling traced the error back to the Hawking kernel module. First time round, I ended up booting into recovery mode and re-installing the OS.
Today, my mac gave the same issues, apparently the kernel module got installed again somehow (or it was never removed) and I was geared up to re-install. However, when booting into recovery mode ( press option while boot up) exploring a little i found that I could get a terminal open. I was relieved as I had not backed up the mac and was a little worried about re-install wiping my drive.
So I wondered if I could somehow remove the kernel module manually instead of re-installing like last time. I came across this post on the Apple forums.. the pointed that I could remove the kernel module. One point to remember is that your root is the recovery HD not your normal boot up disk. To get into your normal boot-up disk you need to actually cd into /Volumes/MacHD ( my startup disk was called MacHD) and then follow the instructions in the above post.. Basically move the /Library/Extensions/kudshawking.kext folder under /Volumes/MacHD somewhere else.
As an aside this might be also be a good time to back up, at least over the network using rsync or something, if needed… but of course i didn’t do it yet.
Then i came across this post on manually installing kernel extensions. However, I could not find the kext caches they referenced. Further Googling brought me to this post on someone trying to re-install a custom kernel and i found they used the kextcache command. The kextcache command has a -system-cache option that updates the system cache, but we need to point it to the right system cache ( in my case on MacHD) using the -u option. My final command was something like
kextcache -system-cache -u /Volumes/MacHD
and Voila !!!….after reboot my mac was back online again.
Hopefully this post is useful to someone… I think this might work for any kernel modules that break under El Capitan… the one thing that comes to mind is the NetGear Genie modules.