How do I compile a multiprocessor kernel?

You have to add some options to the kernel configuration file. Things are very easy in 4.3:

  1. Add 
    options         SMP                     # Symmetric MultiProcessor Kernel
options         APIC_IO                 # Symmetric (APIC) I/O
  2. Disable or remove the following two lines 
    cpu            I386_CPU
cpu            I486_CPU

You have to do more tinkering in previous releases. Try adding 

options         NCPU=2                  # number of CPUs
options         NBUS=6                  # number of busses
options         NAPIC=2                 # number of IO APICs
options         NINTR=39                # number of INTs
You will have to find out those values (or pick whatever and wait for the error messages, that are usually very informative.)

Felix Hernandez
Last modified: Thu Oct 18 00:21:16 EDT 2001