[gentoo-user] Re: [gentoo-user] UEFI booting again

On 2020-10-12 12:26 AM, "Jack" <ostroffjh@×××××××××××××××××.net> wrote:
> On 10/11/20 7:37 PM, Jude DaShiell wrote:
> > If you followed the handbook /dev/sda2 would be where the boot record lives.
>
> I don't think so, but the terminology is certainly confusing. Peter
> asked where efibootmgr writes something.  What is on /dev/sda2 could be
> grub.cfg if it were mounted at /boot, and the grub booting stub (I
> forget the correct name, but grubx64.efi) might be on /dev/sda2 if it
> were mounted at /boot/EFI.  However, efibootmgr doesn't mess with either
> of those.  It deals with what is stored in the UEFI boot firmware.  That
> entry, which is read by the UEFI at boot time, runs the entry in the EFI
> disk partition (usually under /boot/EFI), which then runs the kernel
> (and possibly initramfs) in /boot.  Unfortunately, "boot record" is
> probably too general a term.

Yes, I meant the equivalent of that in an MBR system. Where the bootable kernel image lives is another matter. 

I haven't been using grub, just efibootmgr to declare the image to the UEFI BIOS, and bootctl from systemd-boot to show a list of boot options. 

I assume there's something like an EEPROM on the motherboard to contain pointers (what I called boot records) to the the bootable kernel images. That's what I was asking about. I'm pretty sure that that table doesn't live on the disk. (Followers of this tale may remember that I had a problem with the NVMe disk; it turned out to be faulty, and I've replaced it. Windows could still boot on another disk without any intervention by me.)

Can someone confirm or refute those ideas? 

>
> Jack
>
> > On Sun, 11 Oct 2020, peter@××××××××××××.uk wrote:
> >
> >> Date: Sun, 11 Oct 2020 19:21:49
> >> From: peter@××××××××××××.uk
> >> Reply-To: gentoo-user@l.g.o
> >> To: gentoo-user@l.g.o
> >> Subject: [gentoo-user] UEFI booting again
> >>
> >> I'm still wrestling with my system and its not booting.
> >>
> >> Can anyone please tell me precisely where 'efibootmgr -c ...' writes a boot record, or whatever it's called? My machine seems unable to store what I give it, and I suspect that the BIOS ROM has failed. Big expense if so.
> >>
> >> TiA.
>