extflash_erase target

[BrianPugh]

No description provided.

[kbeckmann]

It'll be enough with 256 bytes because when you invoke flashapp like you do below, you will perform a Chip Erase. I guess the help text can be improved :).

flashapp.sh <binary to flash> [address in flash] [size] [erase=1] [erase_bytes=0] [chunk_idx] [chunk_count]
'erase_bytes': Number of bytes to erase, all if '0'. Default '0'.

It felt like a good idea to have it like so when starting out but maybe that might change in the future, so it could be a good idea to make it explicit:

# Create dummy file with one page of 0xFF.
SIZE = 256
/usr/bin/env python3 -c "with open('${DUMMY_FILE}', 'wb') as f: f.write(b'\xFF'*${SIZE})"

# Flash it to start of the extflash and perform a Chip Erase
${FLASHAPP} "${DUMMY_FILE}"  0 ${SIZE} 1 0