Re: [gentoo-user] Kernel upgrade confusion

[Mick]

Hi Jalus,

On Saturday, 30 December 2017 18:43:12 GMT Jalus Bilieyich wrote:
> Recently there was a kernel update and I don't want to reconfigure it
> from scratch. In the official documentation, it told me to move the old
> .config into the new kernel source tree and type
> make oldconfig
>
> This is where I'm confused; which .config file (/proc/config.gz or
> /boot/config) and where in the kernel source tree do I put this file in.

You will need to *copy* your old/existing kernel .config file to the new 
kernel source directory.

Where you copy it from depends on where you have stored your previous kernel 
.config file.  It may be in your /boot, if you have copied it there from /usr/
src/linux/.config last time you compiled your kernel.  It should be in /usr/
src/linux/ if this symlink is still pointing to your previous kernel.  You may 
be able to obtain it from your /proc/config.gz if you have configured your 
kernel to use this option.

So, as root you would for example do:

cp /usr/src/linux-4.4.87-r1/.config /usr/src/linux/4.9.49-r1/ && \
rm /usr/src/linux && \
ln -s /usr/src/linux-4.9.49-r1 linux && \
cd /usr/src/linux && \
make oldconfig

to copy the existing .config into the new kernel sources directory,
to remove the symlink pointing to the previous kernel,
to create a new symlink to the new kernel sources directory,
to change your working directory into the new kernel source tree, and
finally to run make oldconfig in order to configure any new options available 
in kernel 4.9.49-r1, without having to reconfigure each and every option 
already set in your kernel 4.4.87-r1.

If you have a /proc/config.gz you can unpack it and redirect it to your new 
kernel source directory:

zcat /proc/config.gz > /usr/src/linux-4.9.49-r1/.config

before you proceed with the last four steps I showed above.

HTH.
-- 
Regards,
Mick