rootninja

Mount your iso, then mount the image found inside and change it

First you’ll need to mount your distribution iso image.

# mount -o loop Fedora-13-x86_64-DVD.iso /mnt/level1

Go inside the distribution iso where you mounted it under /mnt/level1 and you should see an images directory with the install.img inside it. Images is at the same level as isolinux.

We have to go deeper

Mount that stage one image somewhere else. You should be able to mount it to another directory from where it’s already mounted at level1 itself, but if not, rsync is your friend. Just copy it somewhere else before you try to mount it.

# mount -o loop images/install.img /mnt/level2

Here’s what you have available during stage one right out of the box from a Fedora 13 DVD iso.

# ls -l /mnt/level2/
total 0
drwxr-xr-x. 20 root root  495 2010-08-24 10:52 etc
drwxr-xr-x.  2 root root    3 2010-08-24 10:52 firmware
drwxr-xr-x.  4 root root   74 2010-08-24 10:52 lib
drwxr-xr-x.  4 root root 2897 2010-08-24 10:48 lib64
drwxr-xr-x.  2 root root    3 2010-08-24 10:52 modules
drwxr-xr-x.  2 root root    3 2010-08-24 10:52 proc
drwxr-xr-x.  9 root root  149 2010-08-24 10:52 usr
drwxr-xr-x.  5 root root   50 2010-08-24 10:40 var

Inception Time

Now if you have an iso editor such as isomaster, you could rebuild the install.img and plop that inside the the outer iso, rebuilding that one too.

Need more libraries? Don’t like anaconda’s jpg/png’s? Add them in there and rebuild the install image using mksquashfs, then drop it in your distro image, and rebuild that using isomaster.

This has been oversimplified on purpose to keep it short and sweet. Don’t forget, you’re stuck with read-only file systems when you mount images with loopback, so you’ll need to copy the contents elsewhere and rebuild them.

Of course, an easier way to get the job done might just be to use a different set of commands if you find whatever it was you were hoping would be available during %pre install is missing.

For example, No fdisk? Try sfdisk or parted instead.