counters. These counters do not exist on all CPUs, but where they
do exist, can be used for counting events such as dcache misses that
would otherwise be difficult or impossible to instrument by code
inspection or hardware simulation.
pmc(9) is meant to be a general interface. Initially, the Intel XScale
counters are the only ones supported.
maps it with BTLB entries, to minimize the number of BTLB entries
needed.
Because the CPU type was often guessed incorrectly, the mapping of
HP board number to system name now includes information about the
expected CPU type.
be properly used by any misc. cloning device. While here, correct
a comment to indicate that "open" is the only entry point and that
everything else is handled with fileops.