Abstract: A computer-implemented method and apparatus for restoring operating systems within a set-top box system. The restoration provides for operating a first operating system in a first memory. An application program is operated in a second memory. The first operating system is stored in a second memory so that a second operating system is loaded into the first memory. When a predetermined condition which is associated with the second operating system is detected, the first operating system is loaded into the first memory in response to the detected predetermined condition. Such a system provides such non-limiting advantages to the set-top box as the ability to robustly recover from errors or anomalies associated with downloading an operating system.

Abstract: A system for preprocessing computer programs before downloading them into terminals includes a packager which processes certain information contained in compiled but unlinked programs. The packager partially resolves undefined symbols and relocations based on knowledge of a dispatch table in the destination terminal and other information known prior to the downloading process. Additionally, the packager determines the sizes of separate code, data, dispatch table and temporary symbol areas, incorporates this size information into a header, and transmits a data stream including the header and the aforementioned areas, including partially resolved symbols, to one or more terminals such as home communication terminals (HCTs) in a cable television network. Each receiving terminal extracts the size information and allocates only as much memory as is needed to store each of the separate areas, thus avoiding the need for a temporary holding buffer.