Nerdy kernel source screensaver

This is how to have the Phosphor screensaver scroll through random .c files from the kernel source.

Install xscreensaver (the default gnome lacks some settings) and set the Program field to something like:

cat `ls /usr/src/linux-source/kernel/*.c|shuf`

It's in the Advanced tab under Text Manipulation.

I'm not sure, but it might be possible to do the same in gconf-editor for the Gnome version of the screensaver.

In the line above I have a soft link to the source files:

ln -s /usr/src/linux-source-2.6.27 /usr/src/linux-source

sudo visudo no password

To allow a user or group to sudo some commands without authentication:

Edit the /etc/sudoers file:

sudo visudo

Add a line with the username (or %group):

username ALL=NOPASSWD: HALT, REBOOT, /usr/bin/apt-get, /usr/bin/aptitude

Note: HALT and REBOOT are aliases you can add in the sudoers file, like this:

# Cmnd alias specification
Cmnd_Alias REBOOT = /sbin/reboot
Cmnd_Alias HALT = /sbin/halt

Just do 'which halt' to find the path to the executable

pxe linux network install

The steps are
1. install dhcp3-server and tftpd-hpa
2. get the netboot files
3. prepare the tftp dir
4. mount the cd images
5. share the cd mount dirs
6. edit the pxelinux.cfg/default file
7. restart services

1. install dhcp3-server and tftpd-hpa

sudo apt-get install dhcp3-server tftpd-hpa

My /etc/dhcp3/dhcpd.conf:

ddns-updates on;
option domain-name "vstrom.local";
option domain-name-servers 192.168.0.2;
default-lease-time 86400;
max-lease-time 86400;
authoritative;
log-facility local7;

# vstrom
subnet 192.168.0.0 netmask 255.255.255.0 {
        option domain-name-servers 192.168.0.2;
        option domain-name "vstrom.local vstrom";
        option subnet-mask 255.255.255.0;
        range 192.168.0.50 192.168.0.59;
        option routers 192.168.0.1;
        ddns-update-style ad-hoc;
        filename "pxelinux.0";
        next-server 192.168.0.2;
}

My /etc/default/tftpd-ha:

#Defaults for tftpd-hpa
RUN_DAEMON="yes"
OPTIONS="-l -s /var/lib/tftpboot"

2. get the netboot files

lftp -c "open http://archive.ubuntu.com/ubuntu/dists/intrepid/main/installer-i386/current/images/; mirror netboot/"
sudo mv netboot/* /var/lib/tftpboot
rm -r netboot

3. prepare the tftp dir

cd /var/lib/netboot

All I have in the tftp dir is pxelinux.0 and pxelinux.cfg so just delete the rest
Now create a distribution folder for the ubuntu installations

mkdir -p ubuntu/{intrepid,intrepid-live,jaunty,jaunty-live}

4. mount the cd images
I mount my cd images in /media/

mkdir -p /media/{intrepid,intrepid-live,jaunty,jaunty-live}

My /etc/fstab entries for the images:

ubuntu-8.10-desktop-i386.iso  /media/intrepid-live udf,iso9660 user,auto,loop 0 0
ubuntu-8.10-alternate-i386.iso  /media/intrepid udf,iso9660 user,auto,loop 0 0
jaunty-desktop-i386.iso  /media/jaunty-live   udf,iso9660 user,auto,loop 0 0
jaunty-alternate-i386.iso  /media/jaunty   udf,iso9660 user,auto,loop 0 0

(The paths to the isos are actually longer, like: /Public/OS/linux/...)

5. share the cd mount dirs
My /etc/exports entries (for nfs)

/media/intrepid-live   *(insecure,rw,no_root_squash,async,no_subtree_check)
/media/intrepid   *(insecure,rw,no_root_squash,async,no_subtree_check)
/media/jaunty-live     *(insecure,rw,no_root_squash,async,no_subtree_check)
/media/jaunty     *(insecure,rw,no_root_squash,async,no_subtree_check)

6. edit the pxelinux.cfg/default file
My /var/lib/tftpboot/pxelinux.cfg/default which is read by tftpd-hpa at start or reload

DISPLAY boot.txt

DEFAULT intrepid_live

LABEL intrepid-live
        kernel ubuntu/intrepid-live/vmlinuz
        append root=/dev/nfs boot=casper netboot=nfs nfsroot=192.168.0.2:/media/intrepid-live file=preseed/ubuntu.seed initrd=ubuntu/intrepid-live/initrd.gz --

LABEL intrepid
        kernel ubuntu/intrepid/linux
        append vga=normal initrd=ubuntu/intrepid/initrd.gz --

LABEL jaunty-live
        kernel ubuntu/jaunty-live/vmlinuz
        append root=/dev/nfs boot=casper netboot=nfs nfsroot=192.168.0.2:/media/intrepid-live file=preseed/ubuntu.seed initrd=ubuntu/jaunty-live/initrd.gz --

LABEL jaunty
        kernel ubuntu/jaunty/linux
        append vga=normal initrd=ubuntu/jaunty/initrd.gz --

LABEL gparted
        kernel gparted/vmlinuz1
        append initrd=gparted/initrd1.img boot=live union=aufs noswap noprompt vga=788 fetch=http://192.168.0.2/gparted/filesystem.squashfs

LABEL grml
        KERNEL grml/linux26
        APPEND root=/dev/nfs rw nfsroot=192.168.0.2:/media/grml boot=live lang=us nomce quiet apm=power-off nodhcp noprompt noeject initrd=grml/initrd.gz vga=791

My boot.txt, just to type the boot commands available

=============================================
Ubuntu 9.04 Jaunty Jackalope
  jaunty-live
  jaunty (alternative install)

Ubuntu 8.10 Intrepid Ibex
  intrepid-live
  intrepid (alternative install)

Tools
  gparted
  grml

7. restart services

sudo /etc/init.d/nfs-kernel-server restart
sudo /etc/init.d/tftpd-hpa restart