Hello Mr. Rees
Mine is a Libreboot laptop. When I select boot from an isolinux image from a CD/ DVD, the CD is read, but after some time, the cursor drops back to the same menu line. When I checked the contents of this CD, what is mentioned in the below email were available...
Libreboot boots other CD with isolinux images

On Fri, 22 May 2020, 1:28 am Max Rees, <maxcrees@me.com> wrote:
On Thu May 21 03:33 PM, Sanjay Mysore wrote:
> Hello
> contents of the CD (.ISO image burned) are
> 1. Boot folder (grub)
> 2. system folder
> 3. bzimage_x86_64 (is this the one that should boot)
> 4. efi.img
> 5. initrd_x86_64 zip file
> 6. x86_64squash.fs
>
> This CD does not boot. Kindly clarify if the contents listed above on this
> Cd is correct or something is missing

Can you elaborate on what you mean by it "does not boot"? Do you at
least see a GRUB menu at some point? Are you running this in legacy/BIOS
mode or EFI mode on the machine in question?

There is a known bug[1] for EFI boot in our images, so it could be that.
That bug essentially results in the kernel not being able to display
anything because GRUB is misconfigured in the ISOs.

Max

[1] https://code.foxkit.us/adelie/image/merge_requests/5