Raspberry Pi 2: How to upgrade kernel?

I installed kali-2.1.2-rpi2.img on an SD card to try out on my Raspberry Pi. It works OK, but I need to compile a driver for my wifi card. For that I need kernel headers. And the kernel headers for the kernel that came pre-installed, 4.1.19-v7, don't seem to be available.

So I did what I usually do, install a new linux-image. I installed linux-image-4.9.0-kali3-armmp. (Version number is shown as 4.9.13-1kali3). I can see that that's what's in /boot. But when I reboot, it just comes back as 4.1.19-v7. Is there something else I need to do to upgrade the kernel?

Perhaps I need to install a new kernel.img on the boot partition, but I can't find clear instructions on doing that. Other distributions I've used on the Raspberry Pi haven't needed anything except apt-get.

Good question, I'd like know the answer too.

The kernel has to be purpose build for the Raspberry Pi. A stock arm build won't do.
Why don't you use my kernel?

https://whitedome.com.au/re4son/re4son-kernel/

That's based on the latest Raspberry Pi source with some Kali tweaks.

Happy hacking,
Re4son

So... random person saying "hey, why don't you download and install my custom kernel on your security audit build" kinda sounds like someone's testing me ;-) Probably fine, but bad hygiene all the same.

Alternative question: where do I get the official kernel headers package that matches the kernel Kali actually distributes?

Hi Mary,

That's the spirit :D
I don't think a header package was created during the build of the image.
You can find the scripts that were used to build these images here: https://github.com/offensive-securit.../master/rpi.sh

To get the headers you can either build your own image, using the above scripts, and package up the headers in your build directories, or you can build your own kernel as described here:
https://www.raspberrypi.org/document...el/building.md

You can pm me if you have any questions.