How to completely, disable UUID= and other dynamic probing in grub2? Basically, autodetect will never work on this computer. I've been using a hand-hacked lilo to handle booting because all of the grub instructions resulting in trying to do dynamic probing.
I currently have the bios set to legacy boot, but the bios claims to support UEFI. Anyway, the way this works is you get passed a hard disk identifier in dl. That's the hard disk to boot. Don't try scanning drives, you'll fine multiple copies, most of which are insane. I literally see the extra paths inside the OS as well. You should not try to access any other disks at all until the kernel is booted. The correct root device is in /etc/fstab, so update-grub can build the proper kernel command line. /boot is not a separate filesystem but is / (which simplifies this problem). Peeling off the partition number does yield the correct volume as a kernel device. You don't even want to think about how this works. It just does. The device to boot is in dl at boot time. The root device is in /etc/fstab. I do in fact know the entire disk device if it calls for putting it in a config file. Everybody's saying don't edit /boot/grub/grub.cfg; edit the config files in /etc/grub. Doesn't matter though. I can't figure out how to express this in the config at all, grub.cfg or the files handled by update-grub.
