Can you explain a bit more what setup_boot_reason_atag and setup_boot_mode_atag do?

I just wrote on the getbootstate/preinit thread asking you do allow bypassing bootreason and bootmode by using a kernel command line parameter, but just saw this in u-boot, which may (or not) be exactly what I wanted.

Can I do, e.g.
and this will be available in /proc/bootreason so it will be picked up by getbootstate?

If so, my request in the other thread is perhaps not necessary anymore, except for the bypassing of getbootstate by I could take care of that one (maybe I'll make an interactive version of getbootstate, so the user can choose while booting