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, 57 insertions, 41 deletions

diff --git a/docs/library/machine.rst b/docs/library/machine.rst
index 7870da2ff..7ea7f565e 100644
--- a/docs/library/machine.rst
+++ b/docs/library/machine.rst
@@ -1,10 +1,23 @@
-:mod:`machine` --- functions related to the board
-=================================================
+:mod:`machine` --- functions related to the hardware
+====================================================
 
 .. module:: machine
-   :synopsis: functions related to the board
+   :synopsis: functions related to the hardware
 
-The ``machine`` module contains specific functions related to the board.
+The ``machine`` module contains specific functions related to the hardware
+on a particular board. Most functions in this module allow to achieve direct
+and unrestricted access to and control of hardware blocks on a system
+(like CPU, timers, buses, etc.). Used incorrectly, this can lead to
+malfunction, lockups, crashes of your board, and in extreme cases, hardware
+damage.
+
+.. _machine_callbacks:
+
+A note of callbacks used by functions and class methods of ``machine`` module:
+all these callbacks should be considered as executing in an interrupt context.
+This is true for both physical devices with IDs >= 0 and "virtual" devices
+with negative IDs like -1 (these "virtual" devices are still thin shims on
+top of real hardware and real hardware interrupts). See :ref:`isr_rules`.
 
 Reset related functions
 -----------------------
@@ -39,16 +52,7 @@ Power related functions
 
 .. function:: freq()
 
-    .. only:: not port_wipy
-
-        Returns CPU frequency in hertz.
-
-    .. only:: port_wipy
-
-        Returns a tuple of clock frequencies: ``(sysclk,)``
-        These correspond to:
-
-        - sysclk: frequency of the CPU
+    Returns CPU frequency in hertz.
 
 .. function:: idle()
 
@@ -81,13 +85,6 @@ Miscellaneous functions
 
 .. only:: port_wipy
 
-    .. function:: main(filename)
-
-        Set the filename of the main script to run after boot.py is finished.  If
-        this function is not called then the default file main.py will be executed.
-
-        It only makes sense to call this function from within boot.py.
-
     .. function:: rng()
 
         Return a 24-bit software generated random number.
@@ -105,12 +102,15 @@ Miscellaneous functions
    microseconds.  The `pulse_level` argument should be 0 to time a low pulse
    or 1 to time a high pulse.
 
-   The function first waits while the pin input is different to the `pulse_level`
-   parameter, then times the duration that the pin is equal to `pulse_level`.
+   If the current input value of the pin is different to `pulse_level`,
+   the function first (*) waits until the pin input becomes equal to `pulse_level`,
+   then (**) times the duration that the pin is equal to `pulse_level`.
    If the pin is already equal to `pulse_level` then timing starts straight away.
 
-   The function will raise an OSError with ETIMEDOUT if either of the waits is
-   longer than the given timeout value (which is in microseconds).
+   The function will return -2 if there was timeout waiting for condition marked
+   (*) above, and -1 if there was timeout during the main measurement, marked (**)
+   above. The timeout is the same for both cases and given by `timeout_us` (which
+   is in microseconds).
 
 .. _machine_constants:
 
@@ -118,37 +118,53 @@ Constants
 ---------
 
 .. data:: machine.IDLE
-.. data:: machine.SLEEP
-.. data:: machine.DEEPSLEEP
+          machine.SLEEP
+          machine.DEEPSLEEP
 
-    irq wake values
+    IRQ wake values.
 
 .. data:: machine.PWRON_RESET
-.. data:: machine.HARD_RESET
-.. data:: machine.WDT_RESET
-.. data:: machine.DEEPSLEEP_RESET
-.. data:: machine.SOFT_RESET
+          machine.HARD_RESET
+          machine.WDT_RESET
+          machine.DEEPSLEEP_RESET
+          machine.SOFT_RESET
 
-    reset causes
+    Reset causes.
 
 .. data:: machine.WLAN_WAKE
-.. data:: machine.PIN_WAKE
-.. data:: machine.RTC_WAKE
+          machine.PIN_WAKE
+          machine.RTC_WAKE
 
-    wake reasons
+    Wake-up reasons.
 
 Classes
 -------
 
-.. toctree::
+.. only:: not port_wipy
+
+ .. toctree::
    :maxdepth: 1
 
-   machine.ADC.rst
-   machine.I2C.rst
    machine.Pin.rst
-   machine.RTC.rst
-   machine.SD.rst
+   machine.Signal.rst
+   machine.UART.rst
    machine.SPI.rst
+   machine.I2C.rst
+   machine.RTC.rst
    machine.Timer.rst
+   machine.WDT.rst
+
+.. only:: port_wipy
+
+ .. toctree::
+   :maxdepth: 1
+
+   machine.Pin.rst
    machine.UART.rst
+   machine.SPI.rst
+   machine.I2C.rst
+   machine.RTC.rst
+   machine.Timer.rst
    machine.WDT.rst
+   machine.ADC.rst
+   machine.SD.rst