initmsgbuf() call in cpu_startup(): msgbuf_paddr never set?

[Tad Hunt <tad%entrisphere.com@localhost>]

the first thing that cpu_startup() does is call

        initmsgbuf((caddr_t)msgbuf_paddr, round_page(MSGBUFSIZE));

However a quick examination makes it appear as though msgbuf_paddr
(which is in the bss segment) has never been initialized... Thus I
believe that the msgbuf will end up at address 0 -- Most likely
overwriting the exception vectors...

It used to be at 0x3000.  Is there any particular reason why it moved?

-Tad