This release brings general improvements and bug fixes to the core and various ports, as well as documentation additions, clean-ups and better consistency. And effort has been made to clean up the source code to make it more consistent across the core and all ports.

There is a new tool "mpy_bin2res.py" to convert arbitrary (binary) files to Python resources for inclusion in source code (frozen or otherwise).

The ussl module has seen improvements, including implementation of server_hostname (for axtls) and server_side mode (for mbedtls).

There is now a double-precision float math library and stmhal has support to build firmware with software or hardware double-precision.

A detailed list of changes follows.

py core:

• formatfloat: fix number of digits and exponent sign when rounding
• modthread: raise RuntimeError in release() if lock is not acquired
• compile: raise SyntaxError if positional args are given after /*
• objint: support "big" byte-order in int.to_bytes()
• objint: in to_bytes(), allow length arg to be any int and check sign
• compile: fix bug with break/continue in else of optimised for-range
• compile: optimise emitter label indices to save a word of heap
• builtinimport: remove unreachable code for relative imports
• objnamedtuple: simplify and remove use of alloca building namedtuple
• mpprint: remove unreachable check for neg return of mp_format_float
• binary: add missing "break" statements
• runtime: mark m_malloc_fail() as NORETURN
• objstr: remove unnecessary "sign" variable in formatting code
• vm: make "if" control flow more obvious in YIELD_FROM opcode
• modmath: check for zero division in log with 2 args
• makeversionhdr.py: update to parse new release line in docs/conf.py
• objdict: factorise dict accessor helper to reduce code size
• change mp_uint_t to size_t in builtins code
• repl: change mp_uint_t to size_t in repl helpers
• compile: combine arith and bit-shift ops into 1 compile routine
• compile: use switch-case to match token and operator
• objgenerator: allow to hash generators and generator instances
• gc: refactor assertions in gc_free function
• vm: make n_state variable local to just set-up part of VM
• asmx64: support moving a 64-bit immediate to one of top 8 registers
• modmicropython: cast stack_limit value so it prints correctly
• builtinevex: add typechecking of globals/locals args to eval/exec
• py.mk: make berkeley-db C-defs apply only to relevant source files
• mperrno: allow mperrno.h to be correctly included before other hdrs
• mpz: make mpz_is_zero() an inline function
• implement raising a big-int to a negative power
• mkrules.mk: show frozen modules sizes together with executable size
• objtuple: allow to use inplace-multiplication operator on tuples
• objstr: raise an exception for wrong type on RHS of str binary op
• modsys: initial implementation of sys.getsizeof()
• binary.c: fix bug when packing big-endian 'Q' values
• add verbose debug compile-time flag MICROPY_DEBUG_VERBOSE
• binary: change internal bytearray typecode from 0 to 1
• objstringio: prevent offset wraparound for io.BytesIO objects
• objstringio: fix regression with handling SEEK_SET
• stream: seek: Consistently handle negative offset for SEEK_SET
• mkrules.mk: use "find -path" when searching for frozen obj files
• compile: remove unused pn_colon code when compiling func params
• objcomplex: remove unnecessary assignment of variable
• formatfloat: don't post-increment variable that won't be used again
• use "static inline" for funcs that should be inline
• asmthumb: use existing macro to properly clear the D-cache

extmod:

• modussl_axtls: update for axTLS 2.1.3
• modussl_axtls: implement server_hostname arg to wrap_socket()
• move modonewire.c from esp8266 to extmod directory
• modure: if input string is bytes, return bytes results too
• modubinascii: add check for empty buffer passed to hexlify
• modussl_axtls: allow to close ssl stream multiple times
• modussl_mbedtls: support server_side mode
• modussl_mbedtls: when reading and peer wants to close, return 0
• modframebuf: fix invalid stride for odd widths in GS4_HMSB fmt
• modussl_mbedtls: make socket.close() free all TLS resources
• modframebuf: consistently use "col" as name for colour variables
• modussl_mbedtls: implement non-blocking SSL sockets
• machine_signal: fix parsing of invert arg when Pin is first arg
• modframebuf: use correct initialization for .locals_dict
• modlwip: implement setsockopt(IP_ADD_MEMBERSHIP)
• modussl_mbedtls.c: add ussl.getpeercert() method
• modubinascii: rewrite mod_binascii_a2b_base64
• modubinascii: don't post-increment variable that won't be used
• modonewire: rename public module to mp_module_onewire
• for uos.stat interpret st_size member as an unsigned int
• use "static inline" for funcs that should be inline

lib:

• axtls: upgrade to axTLS 2.1.3 + MicroPython patchset
• libm/math: remove implementations of float conversion functions
• add libm_dbl, a double-precision math library, from musl-1.1.16

drivers:

• onewire: move onewire.py, ds18x20.py from esp8266 to drivers
• onewire: enable pull-up when init'ing the 1-wire pin

tools:

• gen-cpydiff: use case description as 3rd-level heading
• pyboard: add license header
• mpy_bin2res: tools to convert binary resources to Python module
• mpy-tool.py: don't generate const_table if it's empty
• mpy-tool.py: fix missing argument in dump() function

tests:

• net_inet/test_tls_sites.py: integration test for SSL connections
• net_inet: add tests for accept and connect in nonblocking mode
• basics: add tests for for-else statement
• net_inet: move tests which don't require full Internet to net_hosted
• connect_nonblock: refactor towards real net_hosted test
• auto detect floating point capabilites of the target
• import: add a test for the builtin import function
• import: update comment now that uPy raises correct exception
• basics/namedtuple1: add test for creating with pos and kw args
• unix/extra_coverage: add test for mp_vprintf with bad fmt spec
• basics: add tests for arithmetic operators precedence
• cpydiff/modules_deque: elaborate workaround
• cpydiff/core_class_mro: move under Classes, add workaround
• cpydiff/core_arguments: move under Functions subsection
• cpydiff/core_class_supermultiple: same cause as core_class_mro
• cpydiff: improve wording, add more workarounds
• cpydiff: add case for str.ljust/rjust
• rename exec1.py to builtin_exec.py
• basics/builtin_exec: test various globals/locals args to exec()

minimal port:

• Makefile: enable gc-sections to remove unused code
• remove unused stmhal include from Makefile
• use size_t for mp_builtin_open argument

unix port:

• modtime: replace strftime() with localtime()
• mpconfigport.mk: update descriptions of readline and TLS options
• Makefile: disable assertions in the standard unix executable
• modjni: convert to mp_rom_map_elem_t
• for uos.stat interpret st_size member as an unsigned int

stmhal port:

• mpconfigport.h: remove config of PY_THREAD_GIL to use default
• make error messages more consistent across peripherals
• add initial implementation of Pin.irq() method
• add .value() method to Switch object, to mirror Pin and Signal
• move pybstdio.c to lib/utils/sys_stdio_mphal.c for common use
• add "quiet timing" enter/exit functions
• make available the _onewire module, for low-level bus control
• modules: provide sym-link to onewire.py driver
• boards/stm32f405.ld: increase FLASH_TEXT to end of 1MiB flash
• sdcard: allow a board to customise the SDIO pins
• add possibility to build with double-precision floating point
• boards: enable double-prec FP on F76x boards
• Makefile: use hardware double-prec FP for MCUs that support it
• Makefile: rename FLOAT_IMPL to MICROPY_FLOAT_IMPL to match C name
• Makefile: add CFLAGS_EXTRA to CFLAGS so cmdline can add options
• mpconfigport.h: allow MICROPY_PY_THREAD to be overridden
• boards: add configuration files for NUCLEO_F429ZI
• boards/NUCLEO_F429ZI: change USB config from HS to FS peripheral
• reduce size of ESPRUINO_PICO build so it fits in flash
• servo: make pyb.Servo(n) map to Pin('Xn') on all MCUs
• servo: don't compile servo code when it's not enabled
• use "static inline" for funcs that should be inline

cc3200 port:

• modusocket: simplify socket.makefile() function
• make non-zero socket timeout work with connect/accept/send
• modusocket: fix connect() when in non-blocking or timeout mode
• use the name MicroPython consistently in code

esp8266 port:

• Makefile: bump axTLS TLS record buffer size to 5K
• Makefile: allow FROZEN_DIR,FROZEN_MPY_DIR to be overridden
• Makefile: add LIB_SRC_C variable to qstr auto-extraction list
• make onewire module and support code usable by other ports
• modonewire: move low-level 1-wire bus code to modonewire.c
• modonewire: make timings static and remove onewire.timings func
• reinstate 1-wire scripts by sym-linking to drivers/onewire/
• move mp_hal_pin_open_drain from esp_mphal.c to machine_pin.c
• enable MICROPY_ENABLE_FINALISER
• README: make "Documentation" a top-level section
• machine_rtc: use correct arithmetic for aligning RTC mem len
• mpconfigport_512k: use terse error messages to get 512k to fit
• mpconfigport.h: make socket a weak link
• modesp: remove unused constants: STA_MODE, etc
• general: add known issue of WiFi RX buffers overflow
• use size_t for mp_builtin_open argument
• fix UART stop bit constants

zephyr port:

• Makefile: rework dependencies and "clean" target
• Makefile: revert prj.conf construction rule to the previous state
• remove long-obsolete machine_ptr_t typedef's
• Makefile: explicitly define default target as "all"
• modusocket: allow to use socketized net_context in upstream
• modusocket: socket, close: switch to native Zephyr socket calls
• modusocket: bind, connect, listen, accept: Swtich to native sockets
• modusocket: send: switch to native sockets
• modusocket: recv: switch to native sockets
• modusocket: fully switch to native Zephyr sockets
• modzephyr: add current_tid() and stacks_analyze() functions
• prj_base.conf: enable CONFIG_INIT_STACKS
• modusocket: update struct sockaddr family field name
• prj_96b_carbon.conf: re-enable networking on Carbon
• modzephyr: add shell_net_iface() function

docs:

• btree: add hints about opening db file and need to flush db
• select: rename to uselect, to match the actual module name
• license: update copyright year
• esp8266/tutorial/intro: discourage use of 512kb firmwares
• esp8266/tutorial/intro: Sphinx requires blank lines around literal blocks
• conf.py: include 3 levels of ToC in latexpdf output
• gc: mark mem_alloc()/mem_free() as uPy-specific
• gc: document gc.threshold() function
• builtins: list builtin exceptions
• conf.py: set default_role = 'any'
• lcd160cr: group related constants together and use full sentences
• ref/speed_python: update and make more hardware-neutral
• library/gc: fix grammar and improve readability of gc.threshold()
• move all ports docs to the single ToC
• topindex.html: remove link to wipy.io, it's no longer available
• conf.py: add .venv dir to exclude_patterns
• move topindex.html to templates/ subdir
• differences/index_template: use consistent heading casing
• builtins: add AssertionError, SyntaxError, ZeroDivisionError
• add glossary
• conf.py: switch to "new" format of intersphinx_mapping
• conf.py: add file for global replacements definition
• library: add CPython docs xref to each pertinent module
• replace.inc: add |see_cpython|, to xref individual symbols from CPython
• conf.py: set "version" and "release" to the same value
• *_index: drop "Indices and tables" pseudo-section
• pyboard: move hardware info into General Info chapter
• uerrno: document "uerrno" module
• esp8266/general.rst: fix name of NTP module
• pyboard: move info about using Windows from topindex to general
• uzlib: update description of decompress() and mention DecompIO
• pyboard/tutorial/amp_skin: add example for playing large WAV files
• library/ubinascii: update base64 docs
• library/usocket: move socket.error to its own section
• library/usocket: describe complete information on address formats
• glossary: elaborate on possible MicroPython port differences
• glossary: fix typos in micropython-lib paragraph
• index: rewrite introduction paragraph to avoid confusion
• use the name MicroPython consistently in documentation
• consistently link to micropython-lib in glossary

all:

• make more use of mp_raise_{msg,TypeError,ValueError} helpers
• unify header guard usage
• remove trailing spaces, per coding conventions
• don't include system errno.h when it's not needed
• use the name MicroPython consistently in comments
• make use of $(TOP) variable in Makefiles, instead of ".."
• raise exceptions via mp_raise_XXX
• make static dicts use mp_rom_map_elem_t type and MP_ROM_xxx macros

README:

• mention support for bytecode and frozen bytecode
• improve description of precompiled bytecode; mention mpy-cross

CODECONVENTIONS:

• clarify MicroPython changes sign-off process
• start to describe docs conventions
• describe docs use of markup for None/True/False

travis:

• build STM32F769DISC board instead of F7DISC to test dbl-prec FP
• pin cpp-coveralls at 0.3.12