bsdinstall: use gpt/efiboot0 label in /etc/fstab

[asomers]

Summary

Otherwise, boot will hang if the numbering of disks has changed since
initial install.

MFC after: 2 weeks
Sponsored by: Axcient

Test Plan

Ran bsdinstall in a VM

[brd]

Thanks for this, I ran into it awhile back and didn't have time to run it down!

[imp]

So long as we don't have two disks with that label, we'll be fine...
So this is better than what we had, but not quite to where we need to get to....
Though the functionality we need to get there isn't in bsdinstall...

[asomers]

In D35309#800308, @imp wrote:

So long as we don't have two disks with that label, we'll be fine...
So this is better than what we had, but not quite to where we need to get to....
Though the functionality we need to get there isn't in bsdinstall...

Well, when using a mirrored setup at least bsdinstall creates a /dev/gpt/efiboot0 and a /dev/gpt/efiboot1. What functionality do you think we need?

[imp]

In D35309#800313, @asomers wrote:

In D35309#800308, @imp wrote:

So long as we don't have two disks with that label, we'll be fine...
So this is better than what we had, but not quite to where we need to get to....
Though the functionality we need to get there isn't in bsdinstall...

Well, when using a mirrored setup at least bsdinstall creates a /dev/gpt/efiboot0 and a /dev/gpt/efiboot1. What functionality do you think we need?

We should use the ESP we booted from with /dev/efi/esp.... which is a set of patches that aren't even half-assed yet in my tree...