... Right. After spending most of the last 10 days and some nights wrestling with the beast, I've got it fixed at last.
The Gentoo Handbook says to create a small unformatted partition at the beginning of the (primary?) disk, then to create a FAT-32 partition for /boot, then whatever other partitions are required. Neil said above that he doesn't do that; he omits the unformatted partition, and I believe that's quite popular. I tried following the same scheme, but that's what caused the difficulties I started this thread with: on this system I need both those partitions. The system will not boot without both of them. [1] The screen-shot of gparted I posted above shows the current layout once again. The handbook's description of partition creation on a UEFI system says to set the bios_grub flag on partition 1 and the boot flag on partition 2. I tried setting them both on the combined partition I was trying to get working, but the second one to be set cleared the first one, or else it just hid it from display. Either way, no boot. I found several other apparently authoritative pages detailing other /boot directory structures and file names; guessing which of them might work in any given case is not straightforward. Googling for "Gentoo EFI" or similar returns a list of them. For the record, this motherboard is an Asus X99-A, with UEFI BIOS 2.16.1242. It's interesting that, whenever the system failed to boot (and that often happened without showing me the boot selection menu) apparently the BIOS started the kernel stored in its data area, but it didn't find /boot/loader/ with its config files, so it didn't know where to look for the real kernel image. I still don't know what started this whole adventure (to coin a phrase); my DVI KVM switch came under suspicion at one stage, so I'll keep a wary eye on it. One remaining question: does it matter what kernel image is stored in UEFI data? I'm tempted to think not: it just has to get the initial boot step started. After that, /sbin/init "pivots" (whatever that means) to the real kernel under /boot. 1. I remember, dimly, that while commissioning this machine from new, I had trouble installing and running grub:2. I knew even less about UEFI systems then, so if I were to try it again now I might find a way. But I hate the damn thing, so as long as I don't need it it's not getting near my machines. -- Regards, Peter.
