I've had intermittent trouble with Devuan/EFI from day 1, when I got a new MB/SSD and found out I had to use EFI for my hardware to work.  Most recent was a bad grub update (you may recall that was a topic of conversation here a few months back.  Latest (yesterday) was my MB battery dying, and having to replace that!  I could not boot, no matter what settings I picked (the no legacy boot thing seems a little different in my most recent bios, but pretty sure I turned it off.)
Solution: I booted with a refind thumb drive, and followed the instructions here: https://wiki.debian.org/GrubEFIReinstall which may be all you need to do to get your system booting.  I found when I booted that /boot/efi was not mounted, even though it was in my fstab.  I mounted it when the instructions called for it, and everything else worked smoothly.  I was able to boot without my thumb drive, just now!
Perhaps this will help.  I used refind version 0.13.1 (downloaded in Feb, when I had trouble with the grub update).
After this, updates to Devuan work fine, and the boot loader works normally.

--Tim

    On Tuesday, May 25, 2021, 10:54:58 AM EDT, o1bigtenor via Dng <dng@???> wrote:  

On Mon, May 24, 2021 at 9:56 PM Patrick Bartek <nemommxiv@???> wrote:
>
> On Mon, 24 May 2021 20:46:06 -0500
> o1bigtenor via Dng <dng@???> wrote:
>
> > On Mon, May 24, 2021 at 4:51 PM o1bigtenor <o1bigtenor@???>
> > wrote:
> > >
> > > Greetings
> > >
> > > Tried a migration from Debian Buster to Beowulf - - - nope.
> > > Downloaded the DVD and got almost all the way through the install.
> > > Got stuck when the install demands a place to install grub and this
> > > is an EFI setup.
> > >
> >
> > Thought I'd check things.
> > You bet - - - - had it on legacy boot not efi boot.
> > Changed that and did another install.
> > At the boot after install - - - oops - - - no joy.
> >
> > Complaints of no run init: can't execute /sbin/init: no such file or
> > directory.
> >
> > Now this I have no ideas on how to fix - - - - please advise.
> >
> > (This is using the devuan dvd to install from. If this doesn't work
> > - - - - well - - -  I'm now out of my depth!)
>
> For my clean install of Beowulf, I had to use Expert Mode to get the
> EFI boot choice.  Having Legacy Mode on or off in BIOS made no
> difference.

Have now gone through a complete install twice using 'Expert Mode'.
>
> You also need a dedicated EFI partition (type ef00, EFI System type)
> formatted FAT32 mounted on /boot/efi which should show in the installer
> partitioner tool.  You don't need a dedicated /boot partition. The boot
> folder under / is sufficient.

Have an EFI partition (FAT32 IIRC) on the HDD. Said no for installing GRUB
to some independent partition.
>
> Thoroughly study the install instructions, especially about setting up
> efi.

I can find nothing for setting up efi on Devuan on any of the official pages.
If you know of such if you would please advise.

(I know devuan works, a buddy, now deceased a year, was a huge fan,
likely also involved in some maintenance - - - - just how do I get this
server testing system running Beowulf. Four installs now and still no
joy.
Have now done 4 installs and would like advice before I start #5.
Doing the same thing over and over hoping results will change is
not my idea of 'joy'.)

TIA
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