+ *
+ * If the old value of BUCSR is non-zero, this thread has run
+ * before. Thus, we assume we are coming from kexec or a similar
+ * scenario, and PIR is already set to the correct value. This
+ * is a bit of a hack, but there are limited opportunities for
+ * getting information into the thread and the alternatives
+ * seemed like they'd be overkill. We can't tell just by looking
+ * at the old PIR value which state it's in, since the same value
+ * could be valid for one thread out of reset and for a different
+ * thread in Linux.