The kernel
configuration is saved in the /usr/src/linux/.config
file. There's a backup for it in
/boot/config-<version>
, it is a good
idea to keep it as a reference. But also save your own configurations for
different kernels, as this is just a matter of giving different names to
configuration files.
One possibility is to name configuration files after the kernel version. Say you modified your kernel version as shown in Section 4, “Configuring The Kernel”, then you can do:
# cp .config /root/config-2.6.10-foo
If you decide to upgrade
to 2.6.11
(for example), you will be able to reuse this
file, as the differences between the configuration of these two kernels
will be very small. Just use the backup copy:
# cp /root/config-2.6.10-foo .config
But copying the file back does not mean that the kernel is ready to be compiled just yet. You have to invoke make menuconfig (or whatever else you chose to use) again, because some of the files needed in order for the compilation to succeed are created and/or modified by these commands.
However, apart from the chore of going through all the menus again, you could possibly miss some interesting new option(s). You can avoid this by using make oldconfig. It has two advantages: