FIRMWARE UPDATE SYSTEM, AND INFORMATION APPARATUS, AS WELL AS PROGRAM

The present invention provides a firmware update process capable of realizing both recovery from an interruption of update and saving of a capacity of nonvolatile memory used for backup and storing difference data. Thus, intermediate data is included for always holding a status of firmware in rewriting in addition to the new and old firmware. In a case of updating all blocks configuring the firmware in an arbitrary order, the process successively compares blocks of the intermediate data and new firmware with each other; calculates an address of data for recovery from an interruption of update and a backup capacity required therefor; extracts difference data to be distributed, calculates a capacity thereof and creates an update procedure; and derives a processing order whose total of the backup capacity and the difference data capacity is the minimum (see Figure 2 ).