Make a Cisco ISO Bootable (non-bootable)

By Vince

I am going to run through a quick procedure to make the downloadable Cisco CUCM ISO images bootable. When you download them they are non-bootable for some reason. Use this at your own risk, and you must have a support contract to use any Cisco products. I am not liable for anything you do or mess up!

Cisco is nice enough to include the boot options and ISOLINUX files and configuration necessary to boot it. They just don’t add the boot sector to the ISO file.

Prerequisites:

  1. A unix machine, macOS in this example, get to a terminal window
  2. Brew installed - download from http://brew.sh to get it. Package manager for macOS
  3. Download the ISO file you need from support.cisco.com (search for callmanager, in this example I am using 11.5)
brew update
brew install cdrtools

#Change this path to the path of your ISO file you downloaded
hdiutil mount ~/Downloads/UCSInstall_UCOS_11.5.1.12900-21.sgn.iso

#Make a directory to copy the ISO contents to
mkdir ~/Downloads/CUCMiso

#copy all the ISO contents to the directory (we are going to re-package it)
cp -aR /Volumes/CDROM/ ~/Downloads/CUCMiso/

#make some files writable
chmod u+w ~/Downloads/CUCMiso/.
chmod u+w ~/Downloads/CUCMiso/isolinux/isolinux.bin 

#create the new ISO file. 
#Replace "cucm-11.5-bootable.iso" with whatever name you would like
#you must be inside the cd-rom directory to make this work properly
cd ~/Downloads/CUCMiso

mkisofs -R -no-emul-boot -boot-load-size 4 \
-boot-info-table -joliet-long \
-o ~/Downloads/cucm-11.5-bootable2.iso \
-b isolinux/isolinux.bin -c isolinux/boot.cat \
-V "CUCM 11.5 Bootable" .