>from sys/arch/sparc/sparc/cpu.c
>
>/* Machines with "buserr-type" 1 have a bug in the cache chip that affects
>traps. */
>
>The "cache chip bug; trap page uncached" message is the kernel activating
>a workaround for this bug.

For whatever it is worth, this comment and code is mine.  I put it in
on, as I recall, advice from John Gilmore, who said that some sun4c
CPUs had this bug.  The "buserr-type" test was my best guess at how
such CPUs were identified.  I have never seen any official document
saying whether this is actually right, but it did seem to work.

Chris