1. Rise is recognized in identdcpu.c.
2. The TSC is not written to. A workaround for the CPU bug is being
applied to clock.c (the bug being that the mP6 has TSC enabled
in its CPUID-capabilities, but it only supports reading it. If we
try to write to it (MSR 16), a GPF occurs.) The new behavior is that
FreeBSD will _not_ zero the TSC. Instead, we do a bit of 64-bit
arithmetic.
Reviewed by: msmith
Obtained from: unfurl & msmith