If rootdev is set, use it as currdev.

[imp]

Summary

PR: 229770

[ish_amail.plala.or.jp]

I confirmed this patch was working fine.

P.S. I found this patch is working with rEFInd but not working with loader alone.

See below comment.

[tsoome]

stand/efi/loader/main.c

287

const char *rootdev.

[ish_amail.plala.or.jp]

Sorry, although this patch is good working from rEFInd, it is not working for loader prompt.
While showing boot menu, press '3' and go to loader prompt.
OK set rootdev=disk0pX
OK boot
The OS is booted from currdev, not from rootdev.

[tsoome]

In D16322#346807, @ish_amail.plala.or.jp wrote:

Sorry, although this patch is good working from rEFInd, it is not working for loader prompt.
While showing boot menu, press '3' and go to loader prompt.
OK set rootdev=disk0pX
OK boot
The OS is booted from currdev, not from rootdev.

it cannot - the rootdev is only consulted in very early startup. from prompt set currdev directly. However, if you do change currdev, you also probably want to re-initialize the configuration, for that you need:
ok unload \ unload loaded kernel/modules if there are any
ok free-module-options \ this will release memory from internal module config
ok start \ this will read all the config from new currdev

[ish_amail.plala.or.jp]

In D16322#346808, @tsoome wrote:

it cannot - the rootdev is only consulted in very early startup. from prompt set currdev directly. However, if you do change currdev, you also probably want to re-initialize the configuration, for that you need:
ok unload \ unload loaded kernel/modules if there are any
ok free-module-options \ this will release memory from internal module config
ok start \ this will read all the config from new currdev

Thank you. I understood.
I think it should display 'free-module-options' and 'start' when running '?'(lists available commands) with loader prompt.
Also, I think that the sequence of 'set currdev', 'unload', 'free-module-options', 'start' and 'boot' should be explained in the loader (8) man page.
It is very useful information.
Now I can change to the zfs boot from the ufs boot on loader prompt with the sequence of 'set currdev', 'unload', 'free-module-options', 'start' and 'boot'.