[GTALUG] long war story: growing the ESP (/boot/efi)

[Lennart Sorensen]

On Fri, Jul 09, 2021 at 03:40:19PM -0400, D. Hugh Redelmeier via talk wrote:
> I readily admit that too many UEFI implementations make it awkward to
> choose what to boot.  But the UEFI standard seems to support multiple
> kernels in the same ESP.  (At least some ThinkCentre firmware is bad in
> this repsect; XPS 15 firmware is good.)
> 
> efibootmgr seems to support setting this up (it might not be the best
> tool).  Here's what this machine's entry for fedora looks like.  It's
> got enough stuff that you could create a distinct entry for each
> kernel of interest.
> 
> Boot0000* Fedora	HD(2,GPT,f66e4ede-1301-47fd-af96-7f45aee7bc28,0x40800,0xb4000)/File(\EFI\fedora\shimx64.efi)

I seem to recall reading that certain implementations of UEFI would die
if you wrote to the nvram too many times.  Updating boot entries in UEFI
each time you upgrade the kernel might be a bad idea in that case.

> Apparently Microsoft dictated that if you wish to be considered
> Windows-ready, you must not ship with the UEFI shell.

Yes amazingly stupid to mandate one of the most convinient repair tools
isn't allowed on the system.

> You can build one -- the source is available.  But I haven't ever done
> so.

-- 
Len Sorensen