In order to update your Kernel you will need to download the lastest version from www.kernel.org or another appropriate location. To download the 2.2.19 Kernel you can either get the full kernel or the patch (the same can be done for the 2.4.x kernel series that is available here), the difference is that the patch version just updates the appropriate changes made in the new kernel where are the full source just contains everything you need for the latest kernel, we will be using the full kernel source version.

On the main page at kernel.org the tell you the latest stable and the latest pre release version of the kernel, this will be a 2.4.x version, they also provided changelogs that inform you of what modification and updates have been made in that particular version of the release. It is advisable that you read up on the kernel and updating documentation that is available on the site, this will help you to understand what you are doing.

Once you have selected the appropriate version then you need to download it, you can either just download it in Netscape (or whatever browser you prefer) or you can use a console based program like wget. We recommend that you download the files to the /usr/src/ directory as that is where you will be working in.

Now that you have downloaded the files you will need to extract them, this can be done by typing tar xzvf linux-2.2.19.tar.gz (or whatever the name of the file is that you have downloaded), this will extract all the appropriate files into a newly created directory, i.e. something like /usr/src/linux-2.2.19/, you will notice there is another directory with similar name, this is your old kernel source code, there is also a file linux in the directory, this is a symbolic link file to the kernel that the system uses, you will need to delete this file and point it to the new kernel directory, to do this rm linux then confirm yes, now create the new symbolic link by typing ln -s linux-2.2.19 linux..

Once you have extracted all the files then you can begin configuring the kernel so that it suits your system, to do this you want to go into the directory of the kernel (e.g. cd linux/). There are a number of ways of configuring your kernel, you can do it graphically in X-Windows by typing in make xconfig, you can also do it a number of ways in the console, select make config and it will prompt you will all the configuration questions, if you do a make oldconfig it will only ask you for the new options and configurations available in this kernel version. Unless you want to get down and dirty and understand Linux then we recommend doing just a make oldconfig. One the newer 2.4.x kernels you type in make menuconfig whcih will give you a graphics based configuration setup, this is for both the console and X-Windows.

Finally, when you have configured your kernel do a make dep to set up all the dependencies correctly.

If this is your first time with the 2.4.x kernel then you can download some example configuration files and edit them to suit, if you would like to do this than you can download them from here, all you need to do is select the config file that is best for your system and then copy it as .config to the /usr/src/linux-2.4.x/ directory that you ware compiling from. Once you have done this simply type in make config and change anything that you man need to, then simply follow the rest of the instructions. You can setup the 2.4.x kernel for either IPCHAINS support or IPTABLES, this is simply done by selecting Y or N when the CONFIG_NETFILER option is asked.

To make the new kernel image you need to type make zImage, this will create a new Linux kernal image. If your image is too big you will get an error saying "System is too big. Try using bzImage or modules.", this means that you will need to make a compressed image file, not to fear that is almost as easy, just type in make bzImage to compile the kernel. This is a good point to make sure that you have the backup kernel handy, make sure you know where it is as you might need this if the system doesn't want to boot, you especially don't want to delete the old image because that will cause a big problem if the system doesn't want to work.

The next thing to do is a make modules and then make modules_install, you can now move onto putting the new kernel into place. You will need to make sure that the appropriate modules for all your hardware are present, i.e. when compiling you would want to make sure that the modules for your network card are correct and present (this was the only problem that I had during this entire process).

In order to boot your new kernel, you'll need to copy the kernel image (found in /usr/src/linux/arch/i386/boot/zImage after compilation) to the place where your regular bootable kernel is found, this should be /boot/, copy the file and call it vmlinuz-2.2.19, you will then need to delete the symbolic link file vmlinuz and create a new one for the new kernel, ln -s vmlinuz-2.2.19 vmlinuz.

The kernel file you just compiled should be in the /usr/src/linux/arch/i386/boot/compressed/ directory and its called vmlinux. You will also want to copy this and put it in your boot directory, cp vmlinux /boot/vmlinux-2.2.19 should do it.

Now you need to modify your /etc/lilo.conf to add the new image and keep an entry for the old (just in case you need to use it).

boot=/dev/hda
map=/boot/map
install=/boot/boot.b
prompt
timeout=50
linear
default=linux

image=/boot/vmlinuz-2.2.19
     label=linux
     read-only
     root=/dev/hda1
     append="mem=128M"

image=/boot/vmlinuz-2.2.14-5.0
     label=linux.old
     read-only
     root=/dev/hda1
     append="mem=128M"

Your /etc/lilo.conf file should look something like the above when you have completed it. The BOLD text are the things that you will need to add. Now your ready for the final steps.

Reinstalling LILO is usually a matter of running /sbin/lilo. You should see something like the following:

Added linux *
Added linux.old

After reinstalling LILO, you should be all set. Shutdown the system, reboot, (you should know this by now, shutdown -r now) and enjoy!

One of the beauties of Linux is its total flexibility, if you have any problems with setting up your new kernel (i.e. it wont boot properly or you can't use any networking features) then you can resort to your old kernel. When you machine boots and your are at the LILO prompt, hit TAB, you should see linux and linux.old (or whatever images you setup in your lilo.conf file above), to boot your original (or old) configuration and kernel then just type in linux.old.

Once the machine has booted you will be using your old kernel (in this case 2.2.14-5.0) and you can fix any problems with the new kernel before rebooting again, you will be able to keep doing this until your machine is working properly. This is one of many features that make Linux such a diverse and flexible Operating System.