I am trying to customize ubuntu-14.04.2-server-amd64.iso, but I am unable to make it uefi bootable.
First I tried with original iso file:
dd if=/path/to/iso/ubuntu-14.04.2-server-amd64.iso of=/dev/sdc bs=16M
Everything is good at this point - I can boot flash in UEFI.
I have extracted iso content to /path/to/tmp folder and then I am trying to re-create iso (right now unmodified), but new iso does not work with uefi.
I am re-creating iso with this command:
mkisofs -r -V "Custom Ubuntu Install CD" -cache-inodes \
-J -l -b isolinux/isolinux.bin -c isolinux/boot.cat \
-no-emul-boot -boot-load-size 4 -boot-info-table \
-eltorito-alt-boot -e boot/grub/efi.img -no-emul-boot \
-o /path/to/tmp.iso /path/to/tmp
Then I am using same dd command to put new iso on usb. What is right command to make it uefi bootable?