Re: [PATCH] Add multiboot2 header

[Marc Dunivan]

Actually, I'm trying from the hard disk. I can boot from the cdrom and
have a working console if I choose "Legacy BIOS" in the bios
options. But I couldn't install Debian GNU/Linux this way, if I recall
correctly, so now I'm trying to keep uefi.

You probably already have addressed this, so you can ignore this.  UEFI support for MBR partitions is quite confusing.

Shouldn't the disk have a GPT partition, not an MBR partition, to boot in UEFI without BIOS legacy mode (Compatibility Support Module)?  Doesn't Secure Boot need to be turned off in the firmware too?  I think Debian is using shim for Secure Boot to work (as the root of trust).  Also, doesn't the EFI System Partition(FAT32) need both the grub-efi file (\EFI\debian\grubia*.efi) and bootloader file (\EFI\boot\boot*.efi)*?--there other options for not having a boot file which are probably being used.

https://wiki.debian.org/UEFI
https://wiki.debian.org/SecureBoot
https://uefi.org/specifications/