A set of microprocessors may be set to a common mode in which the
microprocessors utilize features that are common to all microprocessors.
The common mode facilitates proper multiprocessor operation and permits a
fix to be applied to each of the microprocessors based on this common
mode. Firmware or software can detect whether microprocessors are set to
run in different modes in a multiprocessor system. If not, the
microprocessors are allowed to run in their normal mode, such as by
writing a value to a configuration register associated with each
microprocessor. If features are mixed, a different value can be written
which tells each microprocessor to revert to a common mode of operation
for that family of microprocessors. A common set of microcode patches may
be downloaded to the microprocessors. Alternatively, the various
microprocessors may also be instructed to run in a particular mode that
emulates a particular stepping.
