Apple Inc.

William M Galcher

Ronald Ray Hochsprung

Cameron J Esfahani

Paul M Resch

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 is stored as a compressed ROM image on a disk or other mass storage device, which may be located remotely from the computer system. Upon power-up or reset of the computer system, the code in the ROM is executed to read the compressed ROM image into random access memory (RAM) of the computer system. The compressed image is then decompressed and executed as part of the boot sequence. Once decompressed, the portion of RAM storing the intermediate-level code is write-protected in the memory map, and the code in boot ROM is deleted from the memory map. Memory space in RAM that is allocated to the intermediate-level code but not used is returned to the operating system for use as part of system RAM.

Growing community of inventors

Mt. View, CA, United States of America

William M Galcher