export CPU_VARIANT=XXXX

FULL_CPU value is $CPU.$CPU_VARIANT.

• linux - openrisc with features required for Linux enabled.

Minimal - smallest possible resource usage version of the CPU

Metal - CPU configured for "bare metal" firmware. No MMU, syscall, etc stuff

OS - CPU configured to run a real OS such as Linux. Will have MMU and caches. OS configure expects SDRAM

• Size - optimise for smallest resource usage
  • Balanced - enable performance features which have a good resource to performance ratio
  • Performance - enable all features which increase performance
• +Debug - enable features which increase debug