Specifications

Remote Booting Linux on Intel Processors (CERN Variant)
Concurrent Technologies Page 16 of 30
How to create a PXE Image
• Ensure the PXELINUX configuration files “/tftpboot/pxelinux.cfg/C04354AB” and
“/tftpboot/pxelinux.cfg/C04354AB” have the correct “APPEND initrd=rootfs.gz
root=/dev/ram rw” statement, or if you are using a board without a VGA adapter, or
simply wish to use a serial console then use “APPEND console=ttyS0,9600
initrd=rootfs.gz root=/dev/ram rw”
• “cp /root/netboot/bzImage /tftpboot/”
• “cp /root/netboot/rootfs.gz /tftpboot/”
NOTE: If using a VP 31x/02x replace ttys0 with ttys2 in the above to specify the serial port
located on the processor board’s front panel.
15. Reboot the Client machine. It should execute a BOOTP or DHCP request, TFTP the boot
image, and start the Linux kernel mounting its root file system from RamDisk. When the
client has finished booting you may remove the network connection and work independently.
16. If you are using a Concurrent Technologies board that has on board flash then you may also
boot the Linux image made in this section from flash. Making the Client board entirely self-
contained. See the “Concurrent Technologies Etherboot Extensions Package” section below.
Ramdisk and NFS
1. If a network connection will always be present the best system performance will be given by
having the root file system that is divided between both RamDisk and NFS. By having a
small RamDisk contain the most commonly accessed files network traffic is kept to a
minimum, optimising both Client and network response times.
2. Create a RamDisk file system following steps 2 - 8 in the “RamDisk Only (For Embedded
Systems)” section above. In addition to the BusyBox “Config.h” edits described in step 4,
edit and modify the “//#define BB_FEATURE_NFSMOUNT” line to “#define
BB_FEATURE_NFSMOUNT”. This will include the NFS mount code into BusyBox.
3. Empty the “/tftpboot/RamDiskFs/usr” directory,
• “cd “/tftpboot/RamDiskFs/usr”
• “rm –rf *”
4. Edit the “/tftpboot/RamDiskFs/etc/fstab” file to look like this,
/dev/ram / ext2 defaults 1 1
192.67.84.170:/usr /usr nfs 0 0
192.67.84.170:/home /home nfs 0 0
none /proc proc defaults 0 0
none /dev/pts devpts gid=5,mode=620 0 0
The simplified RamDisk file system we have created for this example does not include a port
mapper daemon, and so we need specify “nolock” as an NFS mount option. Moreover, the
BusyBox mount operation only understands type two NFS mounts, and so we need to specify
“nfsvers=2” as an NFS mount option.
5. Create an empty file system file,
• “cd /root/netboot”