grub2-filemanager VS Super-UEFIinSecureBoot-Disk

If you don't accept this, and want to boot of multiple ISO files by a grub2 bootloader, whether from a thumbdrive or a hard drive, also check the old https://github.com/a1ive/grub2-filemanager (now archived)

You can edit UEFI drivers from the operating system's bootloader, and you can even flash the UEFI itself from the OS in most computers. While secure boot. Failing that, you can shim a preloader between the bootloader and the UEFI and load arbitrary drivers despite secure boot, like is done here : https://github.com/ValdikSS/Super-UEFIinSecureBoot-Disk

Any sufficiently motivated attacker can make a UEFI rootkit happen, and it's in the wild right now. TPM really do offer no protection to users, either against userspace malware, or rootkits. It's purely about DRM.

Badabing badaboom

I was able to get around this by using a signed grub bootloader instead. What I did was modify a minimal grub disk from here to point to my manjaro installation using the partition uuid in its grub config. Its basically used to bypass secure boot and chainload the default unsigned grub2 which will start the system.

Try this if you want FreeBSD on a Secure Boot PC. I do this on my work PC.

This project works pretty good getting around the forced secure boot with the VCS: https://github.com/ValdikSS/Super-UEFIinSecureBoot-Disk