Table of Contents

Making a gPXE-bootable CD/DVD using ISOLINUX

gPXE already offers an option to make a bootable iso image via make bin/gpxe.iso, but what if you also want to store files on the disc? Once you've written the <1MB image to the CD, you still have 701MB left, so you might as well put it to good use.

You will need

SYSLINUX - This is probably available with your distribution. If not, you can get a copy from http://syslinux.zytor.com/

genisoimage or mkisofs - Again, probably included with your distribution. If not, it's available as part of cdrkit: http://www.cdrkit.org/

Preparing the Files

First, you need to put all the files you want to burn to the CD into a folder. You can make it wherever you like, but for this howto, I'll assume that its in ~/filesToBurn

Next, you need an isolinux.cfg file in the root of the folder. Here's a command to write a simple configuration; consult the SYSLINUX documentation if you want something more complex: 

cat > ~/filesToBurn/isolinux.cfg << EOF
default gpxe
label gpxe
kernel /gpxe.lkr
EOF

The reason for the truncated filename will be explained later.

Next, you need to find the isolinux.bin file. Mine was /usr/share/syslinux/isolinux.bin but you can find yours using: 

locate isolinux.bin

Once you've found it, copy it to your directory of files to write: 

cp /usr/share/syslinux/isolinux.bin ~/filesToBurn/

Creating and installing the gPXE image

Enter the source directory (gpxe-*/src) and compile the lkrn image: 

make bin/gpxe.lkrn

Copy the image to the directory of files to burn, renaming it to gpxe.lkr: 

cp bin/gpxe.lkrn ~/filesToBurn/gpxe.lkr

This is because ISOLINUX only supports 8.3 filenames, so gpxe.lkrn would be invalid. Other files on the CD can still have long file names though.

Generating the image

Once you're happy that everything's in the right place, generate the .iso image like so: 

genisoimage -o gPXEimage.iso -b isolinux.bin -no-emul-boot \
-boot-load-size 4 -boot-info-table -J ~/filesToBurn/

If that doesn't work, try substituting genisoimage for mkisofs.

If you aren't planning on using the disk on a windows machine, feel free to use the “-r” flag rather than “-J”

You should now have an iso image gPXEimage.iso in the current directory, which you can write to a disk using your favourite CD-burning software. You should then be able to both boot gPXE and read files from the CD.