Adding @microbuilder as a reviewer, because he is best aware of the storage budget on nrf.

@jepler can you verify that you can still build the feather with SD 5.0.0 (make clean && make ... SOFTDEV_VERSION=5.0.0)

Because looking at https://travis-ci.org/adafruit/circuitpython/jobs/366250196#L1146 and https://github.com/adafruit/circuitpython/blob/master/ports/nrf/boards/feather52/custom_nrf52832_dfu_app_5.0.0.ld#L26, I'm not sure if it will fit.

Yes, it succeeds locally. But note that I am building with a different (older) arm-none-eabi toolchain than is recommended. (My bins are actually somewhat bigger)

I'm also sitting on a patch to enable lto for nrf52 (didn't actually test the resulting binary yet, and anyway I have the same toolchain concerns when it comes to local testing); it saves nearly 6kB of text so if I let you have that can I use up 2kB of the savings right away?

Also, remember there are still a few shared modules left on the list to try and get in #526. Not trying to shoot this down, just a reminder of the juggling act. 😄

I'd like to see these renamed to binascii and hashlib to match CPython too. Please verify they are strict subsets of the CPython versions too.

@tannewt how strict are we about strict subsets? For instance, within ubinascii the function names are a strict subset

>>> import ubinascii
>>> dir(ubinascii)
['__name__', 'hexlify', 'unhexlify', 'a2b_base64', 'b2a_base64']

but I quickly found that CP is more loose with type requirements than CPython3. CP:

>>> ubinascii.hexlify('12345')
b'3132333435'

Python 3.5.3:

>>> binascii.hexlify('12345')
TypeError: a bytes-like object is required, not 'str'

Similarly for hashlib:

>>> uhashlib.sha1("hi").digest()
b'\xc2+_\x91x4&\tB\x8doQ\xb2\xc5\xafL\x0b\xdejB'

vs

>>> hashlib.sha1("hi").digest()
TypeError: Unicode-objects must be encoded before hashing

Ideally we'd throw the same error. The goal would be that CircuitPython code will run in CPython just fine.

Okay, let's consider this to be in hold until I can work on making the module more cpython3 compatible. It'll be 2 weeks minimum.

The pull requests for python3 compatibility of binascii are in, the hashlib pull request has just been created.

@jepler Both PRs are in so please update this PR and we'll get it merged in. Thanks!

@tannewt updated. However, gentle reminder to consider that I'm competing with #526 on flash space. For @arturo182 I did verify that the compile still completes successfully when building using SOFTDEV_VERSION=5.0.0.