10. Update the kernel and set up the X Window system

10.1. Why update the kernel

The kernel that comes with the system, 2.2.15 is a quite stable kernel. But there have been a lot of development since it came out, including just recently, frame buffer support for the internal IBM E15 graphics card. To get this to work we have to get some kernel sources and patches, and compile a new kernel.

As for the installation we just have done, X does work, but only when you boot from the boot disk. Would it not have been nice to be able to boot directly off the hard disk - and by the way, what about sound support? Let's set up this together as quickly as possible.

Before starting downloading files and compiling the kernel, check that you have these packages installed:

• make

• gcc

• cpp

• glibc

• glibc-devel

• ncurses-devel

• kernel-headers

• This list should probably be longer

10.2. What files to download

We'll use the 2.2.16 kernel sources. To add better support for our Carolina motherboard, well add two patches from David Monro's Carolina page. This may sound complicated, but believe me, it's not. Follow the steps below here, and we'll get you up in an hour or so.

Start out by making a brand new directory for the files in a appropriate place, like /usr/src/my_new_linux_kernel. (You have to be root to do this. Use su to become root, and issue the command 'mkdir /usr/src/my_new_linux_kernel' or something like that.) Download all files to this directory.

Begin with the linux-2.2.16.tar.gz source from the /pub/linux/kernel/v2.2 directory at ftp.kernel.org or a local mirror (recommended for faster download).

Then, get the Carolina patch and the IBM E15 frame buffer patch from David Monro's Carolina page at http://www.amberdata.demon.co.uk/carolina

10.3. Unpacking and patching the source

The next step is to unpack and patch the source files you just downloaded. cd to the directory where you downloaded the files, and unpack the kernel source by issuing these commands:

gunzip linux-2.2.16.tar.gz tar xvf linux-2.2.16.tar

(On some mirrors there are only bz2 files availble. If this is the issue, use bunzip2 instead of gunzip.) This will make a directory called "linux" with all the kernel source. Now we shall add the patches. If the patches have the extentions "gz", unpack them with gunzip like this:

gunzip carolina.diff.gz gunzip ibm_e15fb.diff.gz

Now add the carolina patch by issuing the commands:

mv linux new patch -p0 <carolina.diff

Last, add the IBM E15 patch by issuing the command:

patch -p0 <ibm_e15fb.diff

For a clean compile later, rename the kernel tree to its original name by issuing this command:

mv new linux

If you get through these steps succesfully, the kernel source is now ready for configuring.

10.4. Configuring the kernel

The details of configuring the kernel are way outside the scope of this document. To get more help, try The Kernel HOWTO. Here, we'll just cover the basics to get a working kernel. Download my kernel config file into the linux directory in the kernel tree top directory.

In the directory containing the linux kernel tree, start the configuration program by issuing these commands:

cd linux make menuconfig

Select the almost last option Load an Alternate Configuration File. Press backspace to remove the text in the box, type ingvar.config instead, and press enter. This config file has support for most you'll need on this box, including sound and the frame buffer device to run X. This should be enough to get the kernel to compile, but while you're in there, check over the different menus to get to know your possibilities. Don't be afraid to change anything. You can always load the configuration file again. A thing you really should check, and possibly change, is the Initial kernel command string, located in the General setup submenu. Change the value of the root device to the device where your root (/) filesystem is mounted. If unsure, press ALT+F2, log in and try the command mount. Press ALT+F1 to get back again (supposed that you are on virtual terminal 1). Also check your own preferences on filesystems and other stuff you might have special need for or interest in. If you for some reason don't want (or need) to run X, eg. because the console becomes much slower, remove support for the IBM E15 frame buffer in the Console drivers submenu.

In the main menu, save your new configuration for later use, if you like, and select exit. Answer Yes to the question about saving the changes. You are now ready to compile the kernel.

10.5. Compiling and installing the kernel

To compile the kernel is quite straightforward. If you're not in there already, enter the linux directory in the top level of the kernel tree, and issue this command series:

make dep && make clean && make zImage && make modules && make modules_install

Now, go and make yourself a cup of tea or coffee or have a beer or a bible study for some minutes. This can take some time. If everything is alright, you'll finally have a kernel to install when the text stops scrolling after maybe as much as 20 minutes, depending on your kernel configuration.

Now it's time to install your fresh-baked kernel. On RedHat-like systems like LinuxPPC, we keep kernels and their setupfiles in the /boot directory. Assuming you used /usr/src/my_new_linux_kernel previously, let's do some copying now:

cp /usr/src/my_new_linux_kernel/linux/arch/ppc/boot/zImage /boot/vmlinuz-2.2.16 cp /usr/src/my_new_linux_kernel/linux/System.map /boot/System.map-2.2.16

Assuming that sda1 is your boot device, install the new kernel by issuing this command:

dd if=/boot/zimage-2.2.16 of=/dev/sda1

We also need the System map link to point to our new System.map. Issue these commands:

mv /boot/System.map /boot/System.map.old ln -s /boot/System.map-2.2.16 /boot/System.map

There! You are ready to reboot. Light some candles, remove the boot disk, and issue the command:

reboot

If everything works out, the system will go down nicely, and (assuming you compiled in support for the E15 frame buffer) come up again with Tux, the Linux Penguin Mascot smiling to you while booting.

10.6. Set up X

In this chapter we will set up X, if it does not work properly already.

To set up X, check that you have installed the following packages:

• XFree86

• XFree86-FBDev

• XFree86-100dpi-fonts and/or XFree86-75dpi-fonts

• Xconfigurator

• Maybe more packages here...

        Xconfigurator