Apple Inc.

Paul M Resch

Joseph Sokol, Jr

Cameron J Esfahani

Craig Harvey Prouse

Ronald Ray Hochsprung

William M Galcher

Byron W Pang

C K Haun

Christopher K Haun

C K Hahn

A method and apparatus are provided for supplying a reliable and maintainable operating system in a net-booted environment. According to one embodiment, a network computer (NC) client boots from a boot image provided by an NC server. The boot image includes information identifying the location of one or more system volumes on the NC server that contain operating system software. In response to an attempt to modify the contents of the one or more system volumes, the NC client causes information identifying the modification to be recorded on the NC server separate from the one or more system volumes in a storage area associated with the NC client.

Providing a reliable operating system for clients of a net-booted environment

One embodiment of the present invention provides a system that facilitates communicating between device drivers within a computing system. The system first determines a need to invoke a function on a remote device from a local device driver, wherein the local device driver is not able to perform the function on the remote device. Once the need has been determined, the system obtains a unique identifier for a remote device driver capable of performing the function on the remote device, and uses the unique identifier to facilitate invoking the function in the remote device driver from the local device driver.

Method and apparatus for communicating between device drivers in a computer system

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.

Computer operating system using compressed ROM image in RAM

Methods and apparatuses for controlling power consumption in a digital processing system. In one aspect of the invention, an exemplary method includes using a non-volatile memory of the digital processing system (DPS) as a virtual memory of a volatile random access memory (RAM) of the DPS, determining a selection of a reduced power consumption state, storing, in response to the selection and through a virtual memory process, data from the volatile RAM to the non-volatile memory, and reducing power to at least one element of the data processing system after the storing, wherein the storing includes determining whether to store the data to the non-volatile memory by determining if first data previously stored as virtual memory in the non-volatile memory is valid (not dirty) after the selection.

Growing community of inventors

Santa Clara, CA, United States of America

Paul M Resch