Customize Centos Installation Boot Menu
I have a CentOS 7 kickstart disc that should be usable on either BIOS or EFI systems. I'm trying to customize the boot menu installation choices. Editing isolinux/isolinux.cfg file reflects changes when the system is installed on a BIOS system. Editing EFI/BOOT/grub.cfg is supposed to modify the boot menu for EFI systems, but it does not; I'm getting the original default boot menu in this case. What do I need to do to make changes to the EFI boot menu on the installation disc?
Found the answer. Although the Red Hat and CentOS documentation says to modify EFI/BOOT/grub.cfg, this isn't quite correct. They neglect to mention that there are two versions of this path and file on the installation ISO: one at the top level, which I was modifying and which does nothing, and another stored in images/efiboot.img. Mount this image file, and you'll find the same path and filename; modifying THAT grub.cfg file changes the boot menu display as desired when installing on EFI systems.