extract_flash.c will fail for large programs on dual-256K flash boards

[tomlogic]

IIRC, the memory layout of dual flash boards places the UserBlock and System ID Block at the top of the first flash. I think this was to allow for storing data on the second flash, or possibly an alternate firmware image (downloader on first flash, application on second flash).

The current version of Samples/extract_flash.c doesn't take that mapping into account, and won't be able to dump a large firmware image that skips over the UserBlock and System ID Block.

[tomlogic]

Note that firmware images spanning the second flash have padding in the area occupied by the User Data Block and System ID Block. I assume that RFU sends those pages, but the Pilot BIOS doesn't actually write them to flash.

I need to confirm the padding, and any tools that pull a firmware binary from a full flash dump should be sure to overwrite the dumped User Data and System ID with the preferred padding.