When the configure script ends, it also tells you to `make dep'
and (possibly) `clean'.
So, do the `make dep'. This insures that all of the
dependencies, such the include files, are in place. It does not take long,
unless your computer is fairly slow to begin with.
For older versions of the kernel, when finished, you should do a
`make clean'.
This removes all of the object files and some other things
that an old version leaves behind. In any case,
do not forget this step before attempting to recompile a kernel.
After depending and cleaning, you may now `make
bzImage' or `make bzdisk' (this is the part that takes a long
time.).
`make bzImage' will compile the kernel, and leave
a file in arch/i386/boot called `bzImage'
(among other things). This is the new compressed kernel. `make bzdisk'
does the same thing, but also places the new bzImage
on a floppy disk which you hopefully put in drive ``A:''.
`bzdisk' is fairly handy for testing new
kernels; if it bombs (or just doesn't work right), just remove the floppy
and boot with
your old kernel. It can also be a handy way to boot if you accidentally
remove your kernel (or something equally as dreadful). You can also use it
to install new systems when you just dump the contents of one disk onto the
other (``all this and more! NOW how much would you pay?'').
All even halfway reasonably recent kernels are compressed, hence the
`bz' in front of the names. A compressed kernel automatically
decompresses itself when executed.
In older kernels, you don't have the option to build a bzImage; it
was simply a zImage. That option is at the moment still available,
however, given the code size of newer kernels, it is now more or
less mandatory to build a bzImage because the older methods can't
handle a kernel that's just too large.
`make mrproper' will do a more extensive `clean'ing.
It is sometimes necessary; you may wish to do it at every patch. `make
mrproper' will also delete your configuration file, so you might want
to make a backup of it (.config) if you see it as valuable.
`make oldconfig' will attempt to configure the kernel from an old
configuration file; it will run through the `make config' process
for you. If you haven't ever compiled a kernel before or don't have an old
config file, then you probably shouldn't do this, as you will most likely
want to change the default configuration.
See the section on modules for a description of `make modules'.
After you have a new kernel that seems to work the way you want it
to, it's time to install it. Most people use LILO (Linux Loader) for
this. `make bzlilo' will install the kernel, run LILO on it,
and get you all ready to boot, BUT ONLY if lilo is configured in the
following way on your system: kernel is
/vmlinuz, lilo is in /sbin, and your lilo config
(/etc/lilo.conf) agrees with this.
Otherwise, you need to use LILO directly. It's a fairly easy package to
install and work with, but it has a tendency to
confuse people with the configuration file.
Look at the config file (either /etc/lilo/config for older
versions or /etc/lilo.conf for new versions), and see what the
current setup is. The config file looks like this:
image = /vmlinuz
label = Linux
root = /dev/hda1
...
The `image =' is set to the currently installed kernel.
Most people use /vmlinuz. `label'
is used by lilo to determine which kernel or operating system to
boot, and `root' is the / of that particular operating
system. Make a backup
copy of your old kernel and copy the bzImage
which you just
made into place (you would say `cp bzImage /vmlinuz' if you
use `/vmlinuz'). Then, rerun lilo -- on newer systems, you can
just run `lilo', but on older stuff, you might have to do an
/etc/lilo/install or even an
/etc/lilo/lilo -C /etc/lilo/config.
If you would like to know more about LILO's configuration, or you don't have LILO, get the newest version from your favorite ftp site and follow the instructions.
To boot one of your old kernels off the hard disk
(another way to save yourself in case you screw up the new kernel),
copy the lines below (and including) `image = xxx' in the LILO config
file to the bottom of the file, and change the `image = xxx' to
`image = yyy', where `yyy' is the full pathname of
the file you saved your
backup kernel to. Then, change the `label = zzz' to
`label = linux-backup' and rerun lilo. You may need to
put a line in
the config file saying `delay=x', where x is an amount in tenths of a
second, which tells LILO to wait that much time before booting, so that you
can interrupt it (with the shift key, for example), and type in the label
of the backup boot image (in case unpleasant things happen).