Preventing overwrite of nonessential code during essential code update

摘要

Systems and methods are provided for downloading updated software from a head end to a cable modem that writes to flash memory an updated operating system code without overwriting the preexisting application code portion and also without overwriting the preexisting operating system code portion. Updated application code is not written until the updated operating system code has been verified as error-free.

主权项

1. A method for updating the software of a network communication device, the method comprising the steps of:
receiving the updated software code from a head end device, wherein the updated software code includes an essential code portion and a nonessential application code portion; and upon a determination that sufficient storage capacity exists within a flash memory device for the essential code portion while maintaining a preexisting essential code portion and a preexisting nonessential application code portion therein:
writing the essential code portion to the flash memory device such that both the preexisting essential code portion and the preexisting nonessential application code portion are not overwritten by the essential code portion;verifying that the essential code portion has been written to the flash memory device without error;updating a first pointer with an address corresponding to the essential code;writing the nonessential application code portion to the flash memory device such that the preexisting essential code portion is not overwritten; andupdating a second pointer with an address corresponding to the nonessential application code.