Building the Linux 2.4 Kernel

The Linux kernel source and its OpenPGP signature from www.kernel.org
One time only: Import the current Linux Kernel Archives OpenPGP key to GnuPG (instructions at http://www.kernel.org/signature.html). You won't have to repeat this step until the key expires.

Verify

To verify the signature (and import the key in the last step above), you'll need to have GnuPG (http://www.gnupg.org) already installed. See http://www.kernel.org/signature.html for full instructions, but essentially once you've got GnuPG set up and the correct key imported, the command you want to use is:

gpg --verify linux-2.x.y.tar.gz.sign linux-2.x.y.tar.gz

Unless you have taken explicit steps to build a trust path to the Linux Kernel Archives Verification Key, you should expect to see a warning message, which is ok. What you want to look for is something similiar to "Good signature from..."

Prerequisites

Read the README file
Read the CHANGES files

Make sure you have no stale .o files and dependencies lying around:

$ cd /usr/src/linux-2.4.x $ make mrproper

Configure

$ make menuconfig

I would recommend the following, at a minimum:

Yes: Prompt for development and/or incomplete code/drivers (CONFIG_EXPERIMENTAL). You can always choose not to include any specific experimental module down the road, but this way you get to at least see what you are choosing to not include.
No: Enable loadable module support (CONFIG_MODULES). Not if you're a server connected to the Internet.. Too many of the root exploits are starting to involve loading modules to alter the kernel's behavior, making such exploits harder to detect. If you do use modules, you'll need to 'make modules' and 'make modules_install' after compiling the kernel.

Build

$ make dep $ make clean $ make bzImage $ cp arch/i386/boot/bzImage /dos/vmlinuz

Boot

Suppose you actually want to be able to boot to your new shiny kernel? Forget about LILO; use Loadlin instead. I've had nothing but headaches with LILO as a boot manager. On the other hand, I've never had any issues with LOADLIN. Using Loadlin is simple and effective. The instructions are fairly straight-forward, so I won't go into the details. Make sure to copy your shiny new bzImage file to your dos partition, using DOS 8.3 naming syntax. The source for Loadlin is available at ftp://elserv.ffm.fgan.de/pub/linux/loadlin-1.6/lodlin16.tgz

Here's the two file configurations I use. The first is from CONFIG.SYS:

[menu] menuitem=linux, Linux menuitem=single, Linux (single user mode) menuitem=dos menucolor=15,1 menudefault=linux, 10

[linux][single][dos]

And here's the corresponding AUTOEXEC.BAT file:

@echo off goto %config%

:linux c:\loadlin.exe c:\vmlinuz root=/dev/sda5 ro goto dos

:single c:\loadlin.exe c:\vmlinuz root=/dev/sda5 ro single

:dos