[syslinux] Custom CentOS DVD, isolinux.bin, and isohybrid...

Trey Blancher
2012-06-22T11:20:44Z

I was given a custom CentOS 5.4 DVD, containing some Digium software for one of
our customers.  I need to turn this burned DVD into an image that can be written
to a USB thumb drive.  First, I ripped the DVD to an ISO image.  That part works
OK, my testing VM can load and run the custom kickstart script on the image.
After totally frying my unetbootin install, I decided to try and use isohybrid
on the ripped image so I can use dd to copy it to USB.

Unfortunately the isolinux information on the ripped ISO is old enough (looks
like it's from syslinux 3.11) so the isohybrid program on my Debian wheezy
workstation doesn't work.  It either doesn't like the boot catalog, or
doesn't like the isolinux.bin binary.  I replaced it with the isolinux.bin
from the syslinux 4.0.5 install on my workstation, rebuilt the ISO, and
successfully ran isohybrid.  However, the kickstart file runs into a snag.

When I load my rebuilt ISO image in my test VM, the image boots, and it finds
the kickstart file.  The problem is that for whatever reason, the installer
cannot find the CentOS CD files.  What's baffling is the only file I am
changing for this stage is isolinux.bin (and rebuilding the boot catalog with
genisoimage), so I wouldn't expect the process to be any different for the
rebuilt ISO.  I figure I must be missing something about how isolinux.bin works.
It appears that the ripped ISO is using isolinux 3.11, and the version I'm
trying load is 4.0.5.  I'm guessing that there's something different
enough about the environment set up by isolinux that it's causing this
problem.

Once I get the rebuilt image to load OK in my virtual machine, the next step is
to configure isolinux.cfg and the kickstart.cfg to launch from the USB key, but
that's not a question for this list.

Trey Blancher
Digium, Inc. | Technician II, Technical Support
dCAP - Digium Certified Asterisk Professional
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
toll-free:  1 877-DIGIUM-1 (1.877.344.4861)
direct: +1 256-428-6161
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