Created attachment 328236 [details]
This tool is widely used to determine the allocation/erase block size and page size of flash media in order to setup an optimal partition alignment.
There aren't any versioned tarballs and, annoyingly, the Gitweb snapshot feature sends a tarball with a different checksum each time. Someone has cloned it to GitHub though so that works as a source.
flashbench is in the tree now.