A low-level portion of the operating system of a computer system is separated from an intermediate-level portion of the operating system. The low-level portion, including hardware-specific code, is stored in a relatively small read-only memory (ROM), while at least part of the intermediate-level portion...http://www.google.de/patents/US6434695?utm_source=gb-gplus-sharePatent US6434695 - Computer operating system using compressed ROM image in RAM
