UEFI boot doesn't work in Rocky 9.3 installer using mkksiso

[gerry666uk]

See also my recent post:

Can't install from Rocky boot media, and BOOTX64.EFI

A friend has a PC, ASUS Z97M-PLUS, happily running CentOS 8.x. It was originally installed in UEFI mode (with secure boot) using media ‘CentOS-8-x86_64-1905-dvd1.iso’. I want to install Rocky (8 or 9), but it fails straight away with the error: Invalid image Failed to read header: Unsupported Failed to load image: Unsupported start_image() returned Unsupported I know this is partly to do with the EFI firmware being old, but I think it’s also to do with the “shim”, BOOTX64.EFI. The Fedora …