Missing Ubuntu tools on KernelBuild page

[Alan Perry]

Hi,

I am trying out the kernel building instructions in 
https://kernelnewbies.org/KernelBuild with Ubuntu 20.04 and found 
missing/incomplete info. I would fix it myself but I only just got here 
and don't have access to do so.

With regards to the "What tools do I need?" section, on Ubuntu, I found 
that I also needed to install flex, bison, and libefi-dev.

Also, setting up the kernel configuration by duplicating my current 
config, there were broken paths to key files in the "Certificates for 
signature checking" section. Getting around that involves obtaining the 
files by installing linux-source and changing the paths to point to the 
appropriate files there.

As I said, I am willing to make the changes to the wiki if given access 
to do so, but, if not, I hope that someone with access can make the changes.

alan