Debugging kernel code requires a dedicated computer, as bugs may result in the system crashing or worse. (such as corrupted or overwritten file systems) Rather than dedicating a physical machine, we will be using the free version of VMWare Server as our test platform in this class.

We will run a stripped-down Linux distribution, CRUX Linux (http://www.crux.nu), on the virtual machine, for two reasons: (a) it takes less disk space, and (b) it boots quickly - this is something we are going to be doing a lot of, either after installing a new kernel, or after crashing.

The following directions walk you through (a) installing VMWare, (b) installing the linux distribution, and (c) compiling and booting a new kernel.

Install VMWare

Get the free version of VMWare Server here
Register and get a license key. You may also want the following documentation:
VMware Server Administration Guide pdf
VMware Server Virtual Machine Guide pdf
Create a new virtual machine
guest operating system: "other 2.6.x linux kernel"
networking: "host-only"
disk: 2GB is more than enough. I use 1.25G in the example below.

note - if you have SElinux enabled (e.g. if you're running CentOS 4.3) you won't be able to install VMWare. Remove the selinux policies first:

  rpm -e selinux-policy-targeted

note for Macintosh users - this has been tested with a trial copy of build 1884 of Parallels for Mac, and with the appropriate substitutions (CD/ROM has to be primary slave to boot, so pass a kernel command line option; use IDE drive instead of SCSI) it seems to work.

Install Linux

Get the installation ISO image
cmpsci577a.iso.bin (the .bin prefix is to make our webserver serve it as binary - you may need to rename it to cmpsci577a.iso)
Boot the installation CD
Configure the CD/ROM device to use cmpsci577a.iso, boot, and log in as root. (if you're installing off a physical CD, then configure it to use the real CD/ROM drive)
Partition the disk
If you used the default configuration, your virtual disk is /dev/sda. (If you configured the virtual disk as an IDE drive, it will be /dev/hda) Use fdisk or cfdisk to partition the disk, creating two partitions:

                               cfdisk 2.12r

                          Disk Drive: /dev/sda
                     Size: 1342177280 bytes, 1342 MB
           Heads: 255   Sectors per Track: 63   Cylinders: 163

  Name        Flags      Part Type  FS Type      [Label]    Size (MB)
---------------------------------------------------------------------
  sda1                    Primary   Linux swap              254.99 
  sda2        Boot        Primary   Linux                   1085.74

     [Bootable]  [ Delete ]  [  Help  ]  [Maximize]  [ Print  ]
     [  Quit  ]  [  Type  ]  [ Units  ]  [ Write  ]

Be sure to (a) set the "Boot" flag on /dev/sda2 so you can boot from it, and (b) set the type of /dev/sda1 to "swap".

create and mount filesystem, swap:

  mkfs.ext3 /dev/sda2
  mount /dev/sda2 /mnt
  mkswap /dev/sda1
  swapon /dev/sda1

Run 'setup'
It will prompt you for the directory to install into (/mnt), the operation to perform (install), and then ask you to select packages. The default list of packages should be OK - it consists of only the required packages plus GDB.
"chroot" into the new installation

 $ mount --bind /dev /mnt/dev
 $ mount --bind /tmp /mnt/tmp
 $ mount -t proc proc /mnt/proc
 $ mount -t sysfs none /mnt/sys
 $ chroot /mnt /bin/bash

edit /etc/fstab
It needs to contain the following two lines:

  /dev/sda2  /   ext3    defaults        1 1
  /dev/sda1  swap swap   defaults        0 0

edit /etc/rc.conf
The hostname doesn't really matter, but you probably want to edit the SERVICES line so it reads:

  SERVICES=(net sshd)

You can add other services, but you probably don't need them.

Edit /etc/rc.d/net and /etc/hosts
Actually, you don't need to edit them, as by default it should be set up to use DHCP on eth0

Compile and install the kernel

Configure, compile, and install a new kernel
Note that there are two initial kernel configuration files in the directory /usr/src/linux-2.6.16.6. The easiest way to configure the kernel is to copy one of them to .config and then 'make oldconfig' to set up the configuration. The "small" configuration is recommended - it compiles quickly, and contains all the devices needed for VMWare Server.

 $ cd /usr/src/linux-2.6.15.6
 $ cp linux-2.6.15.6-small.config .config
 $ make oldconfig
 $ make 
 $ make modules_install
 $ cp arch/i386/boot/bzImage /boot/vmlinuz
 $ cp System.map /boot/System.map

Install the boot loader
Edit /boot/grub/menu.lst if necessary - by default it should boot /boot/vmlinuz with /dev/sda2 as the root partition. Then run grub:

  $ grub
  grub> root (hd0,1)
  grub> setup (hd0)
  grub> quit

NOTE - the standard CRUX instructions describe using LILO, an older linux boot loader, instead of Grub. In my experience this results in a virtual machine that will not boot.

Now you are done - you should be able to disconnect the CD/ROM (menu VM->CD/ROM->disconnect) and reboot into your newly installed virtual machine.

From OSLab

Intro: Installing your system

Install VMWare

Install Linux

Compile and install the kernel