Difference between config, menuconfig and defconfig

[Valdis.Kletnieks at vt.edu]

On Mon, 19 Sep 2016 16:02:11 -0400, Aruna Hewapathirane said:

> Many times I have seriously screwed up my kernel to a point where it
> suddenly refuses to boot. Every single time this has happened to me what
> saved me was make defconfig. You may not have your internet connection
> working, your sound may be kaput, the webcam not functional BUT defconfig
> has invariably *every single time* given me back a kernel I can boot into.

Of course, the *correct* answer here is to keep around the known-working
config files for several previous kernels.  And the easiest way to do that
is to:

1) keep several kernels in /boot (I have enough room for the current kernel,
3 or 4 previous, and enough slack to do 12 or 13 builds for a 'git bisect'
without having to stop and clean up).

2) Set the following two things in your .config, so you can always boot
into an older kernel and retrieve its config from /proc/config.gz:

CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y

3) Make sure your kernel install process copies the .config used
to /boot/config-`uname -r` so you have it handy.

And of course:

4) Take regular backups of your system.  That will protect you from lots
of screw-ups - and hardware failures as well.  A 1 or 2 tera USB hard
drive isn't that expensive.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 484 bytes
Desc: not available
Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20160919/d07f9003/attachment.bin