Early kernel boot log?

Hi

So I believe the reason I'm not seeing and printf output in dmesg is that
it is too early in some functions.
For example
machdep.s
 getmemsize()
 add_efi_map_entries()
 etc

However, these functions do contain debug printf statements so if they're
logging to somewhere, where/how can I see this?

I also tried booting in bhyve too see if I could get any output via serial
console but nothing there either.

printfs in cpu_startup() does give me output in dmesg.

Cheers