Merge tag 'v1.9.1'2.0.0-alpha.0

Fixes for stmhal USB mass storage, lwIP bindings and VFS regressions

This release provides an important fix for the USB mass storage device in
the stmhal port by implementing the SCSI SYNCHRONIZE_CACHE command, which
is now require by some Operating Systems.  There are also fixes for the
lwIP bindings to improve non-blocking sockets and error codes.  The VFS has
some regressions fixed including the ability to statvfs the root.

All changes are listed below.

py core:
- modbuiltins: add core-provided version of input() function
- objstr: catch case of negative "maxsplit" arg to str.rsplit()
- persistentcode: allow to compile with complex numbers disabled
- objstr: allow to compile with obj-repr D, and unicode disabled
- modsys: allow to compile with obj-repr D and PY_ATTRTUPLE disabled
- provide mp_decode_uint_skip() to help reduce stack usage
- makeqstrdefs.py: make script run correctly with Python 2.6
- objstringio: if created from immutable object, follow copy on write policy

extmod:
- modlwip: connect: for non-blocking mode, return EINPROGRESS
- modlwip: fix error codes for duplicate calls to connect()
- modlwip: accept: fix error code for non-blocking mode
- vfs: allow to statvfs the root directory
- vfs: allow "buffering" and "encoding" args to VFS's open()
- modframebuf: fix signed/unsigned comparison pendantic warning

lib:
- libm: use isfinite instead of finitef, for C99 compatibility
- utils/interrupt_char: remove support for KBD_EXCEPTION disabled

tests:
- basics/string_rsplit: add tests for negative "maxsplit" argument
- float: convert "sys.exit()" to "raise SystemExit"
- float/builtin_float_minmax: PEP8 fixes
- basics: convert "sys.exit()" to "raise SystemExit"
- convert remaining "sys.exit()" to "raise SystemExit"

unix port:
- convert to use core-provided version of built-in import()
- Makefile: replace references to make with $(MAKE)

windows port:
- convert to use core-provided version of built-in import()

qemu-arm port:
- Makefile: adjust object-file lists to get correct dependencies
- enable micropython.mem_*() functions to allow more tests

stmhal port:
- boards: enable DAC for NUCLEO_F767ZI board
- add support for NUCLEO_F446RE board
- pass USB handler as parameter to allow more than one USB handler
- usb: use local USB handler variable in Start-of-Frame handler
- usb: make state for USB device private to top-level USB driver
- usbdev: for MSC implement SCSI SYNCHRONIZE_CACHE command
- convert from using stmhal's input() to core provided version

cc3200 port:
- convert from using stmhal's input() to core provided version

teensy port:
- convert from using stmhal's input() to core provided version

esp8266 port:
- Makefile: replace references to make with $(MAKE)
- Makefile: add clean-modules target
- convert from using stmhal's input() to core provided version

zephyr port:
- modusocket: getaddrinfo: Fix mp_obj_len() usage
- define MICROPY_PY_SYS_PLATFORM (to "zephyr")
- machine_pin: use native Zephyr types for Zephyr API calls

docs:
- machine.Pin: remove out_value() method
- machine.Pin: add on() and off() methods
- esp8266: consistently replace Pin.high/low methods with .on/off
- esp8266/quickref: polish Pin.on()/off() examples
- network: move confusingly-named cc3200 Server class to its reference
- uos: deconditionalize, remove minor port-specific details
- uos: move cc3200 port legacy VFS mounting functions to its ref doc
- machine: sort machine classes in logical order, not alphabetically
- network: first step to describe standard network class interface

examples:
- embedding: use core-provided KeyboardInterrupt object

1 files changed, 29 insertions, 55 deletions

diff --git a/docs/library/uhashlib.rst b/docs/library/uhashlib.rst
index 223c72dfe..6b9a764ba 100644
--- a/docs/library/uhashlib.rst
+++ b/docs/library/uhashlib.rst
@@ -1,63 +1,41 @@
-:mod:`uhashlib` -- hashing algorithm
-====================================
+:mod:`uhashlib` -- hashing algorithms
+=====================================
 
 .. module:: uhashlib
-   :synopsis: hashing algorithm
+   :synopsis: hashing algorithms
 
-.. only:: port_pyboard
+This module implements binary data hashing algorithms. The exact inventory
+of available algorithms depends on a board. Among the algorithms which may
+be implemented:
 
-    This module implements binary data hashing algorithms. Currently, it
-    implements SHA256 algorithm. Choosing SHA256 was a deliberate choice,
-    as a modern, cryptographically secure algorithm. This means that a
-    single algorithm can cover both use cases of "any hash algorithm" and
-    security-related usage, and thus save space omitting legacy algorithms
-    like MD5 or SHA1.
+* SHA256 - The current generation, modern hashing algorithm (of SHA2 series).
+  It is suitable for cryptographically-secure purposes. Included in the
+  MicroPython core and any board is recommended to provide this, unless
+  it has particular code size constraints.
 
-.. only:: port_wipy
-
-    This module implements binary data hashing algorithms. Currently, it
-    implements SHA1 and SHA256 algorithms only. These two algorithms are
-    more than enough for today's web applications.
+* SHA1 - A previous generation algorithm. Not recommended for new usages,
+  but SHA1 is a part of number of Internet standards and existing
+  applications, so boards targeting network connectivity and
+  interoperatiability will try to provide this.
 
+* MD5 - A legacy algorithm, not considered cryptographically secure. Only
+  selected boards, targeting interoperatibility with legacy applications,
+  will offer this.
 
 Constructors
 ------------
 
-.. only:: port_pyboard
-
-    .. class:: uhashlib.sha256([data])
-    
-       Create a hasher object and optionally feed ``data`` into it.
-
-.. only:: port_wipy
-
-    .. class:: uhashlib.sha1([data[, block_size]])
-    
-       Create a sha1 hasher object and optionally feed ``data`` or ``data and block_size`` into it.
-
-    .. class:: uhashlib.sha256([data[, block_size]])
-    
-       Create a sha256 hasher object and optionally feed ``data`` or ``data and block_size`` into it.
-
-    .. admonition:: CPython extension
-       :class: attention
-   
-       Due to hardware implementation details of the WiPy, data must be buffered before being
-       digested, which would make it impossible to calculate the hash of big blocks of data that
-       do not fit in RAM. In this case, since most likely the total size of the data is known
-       in advance, the size can be passed to the constructor and hence the HASH hardware engine
-       of the WiPy can be properly initialized without needing buffering. If ``block_size`` is
-       to be given, an initial chunk of ``data`` must be passed as well. **When using this extension,
-       care must be taken to make sure that the length of all intermediate chunks (including the
-       initial one) is a multiple of 4 bytes.** The last chunk may be of any length.
-      
-       Example::
-      
-           hash = uhashlib.sha1('abcd1234', 1001)    # length of the initial piece is multiple of 4 bytes
-           hash.update('1234')                       # also multiple of 4 bytes
-           ...
-           hash.update('12345')                      # last chunk may be of any length
-           hash.digest()
+.. class:: uhashlib.sha256([data])
+
+    Create an SHA256 hasher object and optionally feed ``data`` into it.
+
+.. class:: uhashlib.sha1([data])
+
+    Create an SHA1 hasher object and optionally feed ``data`` into it.
+
+.. class:: uhashlib.md5([data])
+
+    Create an MD5 hasher object and optionally feed ``data`` into it.
 
 Methods
 -------
@@ -69,11 +47,7 @@ Methods
 .. method:: hash.digest()
 
    Return hash for all data passed through hash, as a bytes object. After this
-   method is called, more data cannot be fed into hash any longer.
-
-   .. only:: port_wipy
-   
-        SHA1 hashes are 20-byte long. SHA256 hashes are 32-byte long.
+   method is called, more data cannot be fed into the hash any longer.
 
 .. method:: hash.hexdigest()