Add support for CMD25 to write multiple sequential blocks in one go, in
an attempt to speed up uploads. It still needs to be benchmarked if this
actually results in a meaningful speedup.
Also fix logging from SD driver to be visible even when running under
micropython.
Signed-off-by: Matthias Blankertz <matthias@blankertz.org>
Add a read test to the SD tests in standalone_mp3, and also apply the
drive strength setup and higher clockrate from board_Rev1.py.
Signed-off-by: Matthias Blankertz <matthias@blankertz.org>
Add write support to rp2_sd driver.
Cleanup standalone-mp3 test tool and add write test mode.
Signed-off-by: Matthias Blankertz <matthias@blankertz.org>
