On 2020-10-12 12:26 AM, "Jack" <ostrof...@users.sourceforge.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, pe...@prh.myzen.co.uk wrote: > > > >> Date: Sun, 11 Oct 2020 19:21:49 > >> From: pe...@prh.myzen.co.uk > >> Reply-To: gentoo-user@lists.gentoo.org > >> To: gentoo-user@lists.gentoo.org > >> 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. >
