Good news!  Turns out even though I rewrote the clkintr code to use the cpu's
counter, I still needed to have locore ignore int4 from the R4030.  I made
use of the new "MIPS_DYNAMIC_STATUS_MASK" option to do exactly this, and it
appears to be working.  Now, I get to...

scsibus0: waiting 2 seconds for devices to settle...

...as the last message after autoconfig'ing is done, but it just sits there
forever (despite the supposed 2 second wait).  I currently don't have any
hard drive connected, but I'll try that next.  I would've thought it would
be smart enough to keep on going past this point to root-device selection
and the nfs-boot code, but alas.

More to come...
-Mark