tree 037d8a1714819550dcbf9f05fb9b464850908d6e
parent 85ea4584260f9378719da9b0b3ad010042fdefbf
author Jon Flatley <jflat@google.com> 1582751927 -0500
committer Miguel O <miguelaosoriol@gmail.com> 1583257708 -0800

[sw, spiflash] Dramatically increase transfer rate

The spiflash tool has relied on a fixed delay for spacing the writes
between frames. This hasn't been a problem for small binary deployments
to the FPGA, but Tock release binaries take ~3m23s to flash, and debug
binaries take even longer.

Add flow control to spiflash by waiting for until the hash of the
current frame can be read back before writing the next frame. This
successfully allows Tock to be flashed to the FPGA in 6.7s, a 96.7%
decrease over the previous implementation.

Signed-off-by: Jon Flatley <jflat@google.com>