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

[D. Hugh Redelmeier]

| From: Lennart Sorensen via talk <talk at gtalug.org>

| Using grub is way more flexible.

I sometimes find it convenient to edit the kernel parameters.  grub
allows this and UEFI firmware usually does not.

What else do you lose?

|  Having only one bootable kernel is
| not convinient which is what you essentially have if you make a UEFI
| boot entry pointing at a kernel directly.

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)

| Sure if your system has a UEFI shell (most desktop and laptop machines
| seem allergic to that concept)

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

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