>> Indeed. Wrappinge the mutex operations in msgbuf_putchar with if (!cold) >> makes the kernel boot again. > > Here is a diff for that.
After a bit more thinking, it might be worth introduce a msgbuf_putchar_unlocked() routine for the inner part only, and have initmsgbuf() use it, since: - it has made sure the magic value test will suceed. - this is the only use of msgbuf_putchar() on sparc64 until the proper curcpu mappings are set up; all output from pmap_bootstrap() carefully uses the prom routines (and do not end up in the message buffer). $.02
