Merge pull request #4060 from dhalbert/regularize-extmod-modules

CIRCUITPY_* switches for JSON, RE, etc. Doc cleanup

23 files changed, 99 insertions, 524 deletions

diff --git a/README.rst b/README.rst
index 19992d284..f14cf41ff 100644
--- a/README.rst
+++ b/README.rst
@@ -125,7 +125,7 @@ Behavior
    get back into normal mode.
 -  RGB status LED indicating CircuitPython state, and errors through a sequence of colored flashes.
 -  Re-runs ``code.py`` or other main file after file system writes over USB mass storage. (Disable with
-   ``samd.disable_autoreload()``)
+   ``supervisor.disable_autoreload()``)
 -  Entering the REPL after the main code is finished requires a key press which enters the REPL and
    disables autoreload.
 -  Main is one of these: ``code.txt``, ``code.py``, ``main.py``,
diff --git a/docs/library/uerrno.rst b/docs/library/errno.rst
index 72f71f0aa..96777b205 100644
--- a/docs/library/uerrno.rst
+++ b/docs/library/errno.rst
@@ -1,9 +1,7 @@
-:mod:`uerrno` -- system error codes
+:mod:`errno` -- system error codes
 ===================================
 
-.. include:: ../templates/unsupported_in_circuitpython.inc
-
-.. module:: uerrno
+.. module:: errno
    :synopsis: system error codes
 
 |see_cpython_module| :mod:`cpython:errno`.
@@ -22,7 +20,7 @@ Constants
         try:
             os.mkdir("my_dir")
         except OSError as exc:
-            if exc.args[0] == uerrno.EEXIST:
+            if exc.args[0] == errno.EEXIST:
                 print("Directory already exists")
 
 .. data:: errorcode
@@ -30,5 +28,5 @@ Constants
     Dictionary mapping numeric error codes to strings with symbolic error
     code (see above)::
 
-        >>> print(uerrno.errorcode[uerrno.EEXIST])
+        >>> print(errno.errorcode[uerrno.EEXIST])
         EEXIST
diff --git a/docs/library/esp.rst b/docs/library/esp.rst
deleted file mode 100644
index 125aaa890..000000000
--- a/docs/library/esp.rst
+++ /dev/null
@@ -1,85 +0,0 @@
-:mod:`esp` --- functions related to the ESP8266
-===============================================
-
-.. include:: ../templates/unsupported_in_circuitpython.inc
-
-.. module:: esp
-    :synopsis: functions related to the ESP8266
-
-The ``esp`` module contains specific functions related to the ESP8266 module.
-
-
-Functions
----------
-
-.. function:: sleep_type([sleep_type])
-
-    Get or set the sleep type.
-
-    If the *sleep_type* parameter is provided, sets the sleep type to its
-    value. If the function is called without parameters, returns the current
-    sleep type.
-
-    The possible sleep types are defined as constants:
-
-        * ``SLEEP_NONE`` -- all functions enabled,
-        * ``SLEEP_MODEM`` -- modem sleep, shuts down the WiFi Modem circuit.
-        * ``SLEEP_LIGHT`` -- light sleep, shuts down the WiFi Modem circuit
-          and suspends the processor periodically.
-
-    The system enters the set sleep mode automatically when possible.
-
-.. function:: deepsleep(time=0)
-
-    Enter deep sleep.
-
-    The whole module powers down, except for the RTC clock circuit, which can
-    be used to restart the module after the specified time if the pin 16 is
-    connected to the reset pin. Otherwise the module will sleep until manually
-    reset.
-
-.. function:: flash_id()
-
-    Read the device ID of the flash memory.
-
-.. function:: flash_read(byte_offset, length_or_buffer)
-
-.. function:: flash_write(byte_offset, bytes)
-
-.. function:: flash_erase(sector_no)
-
-.. function:: set_native_code_location(start, length)
-
-    Set the location that native code will be placed for execution after it is
-    compiled.  Native code is emitted when the ``@micropython.native``,
-    ``@micropython.viper`` and ``@micropython.asm_xtensa`` decorators are applied
-    to a function.  The ESP8266 must execute code from either iRAM or the lower
-    1MByte of flash (which is memory mapped), and this function controls the
-    location.
-
-    If *start* and *length* are both ``None`` then the native code location is
-    set to the unused portion of memory at the end of the iRAM1 region.  The
-    size of this unused portion depends on the firmware and is typically quite
-    small (around 500 bytes), and is enough to store a few very small
-    functions.  The advantage of using this iRAM1 region is that it does not
-    get worn out by writing to it.
-
-    If neither *start* nor *length* are ``None`` then they should be integers.
-    *start* should specify the byte offset from the beginning of the flash at
-    which native code should be stored.  *length* specifies how many bytes of
-    flash from *start* can be used to store native code.  *start* and *length*
-    should be multiples of the sector size (being 4096 bytes).  The flash will
-    be automatically erased before writing to it so be sure to use a region of
-    flash that is not otherwise used, for example by the firmware or the
-    filesystem.
-
-    When using the flash to store native code *start+length* must be less
-    than or equal to 1MByte.  Note that the flash can be worn out if repeated
-    erasures (and writes) are made so use this feature sparingly.
-    In particular, native code needs to be recompiled and rewritten to flash
-    on each boot (including wake from deepsleep).
-
-    In both cases above, using iRAM1 or flash, if there is no more room left
-    in the specified region then the use of a native decorator on a function
-    will lead to `MemoryError` exception being raised during compilation of
-    that function.
diff --git a/docs/library/index.rst b/docs/library/index.rst
index e91387242..181ff0109 100644
--- a/docs/library/index.rst
+++ b/docs/library/index.rst
@@ -6,35 +6,21 @@ MicroPython libraries
 Python standard libraries and micro-libraries
 ---------------------------------------------
 
-These libraries are inherited from MicroPython.
-They are similar to the standard Python libraries with the same name
-or with the "u" prefix dropped.
+The libraries below are inherited from MicroPython.
+They are similar to the standard Python libraries with the same name.
 They implement a subset of or a variant of the corresponding
 standard Python library.
 
-.. warning::
-
-   Though these MicroPython-based libraries are available in CircuitPython,
-   their functionality may change in the future, perhaps significantly.
-   As CircuitPython continues to develop, new versions of these libraries will
-   be created that are more compliant with the standard Python libraries.
-   You may need to change your code later if you rely
-   on any non-standard functionality they currently provide.
-
 CircuitPython's long-term goal is that code written in CircuitPython
 using Python standard libraries will be runnable on CPython without changes.
 
-Some libraries below are not enabled on CircuitPython builds with
+These libraries are not enabled on CircuitPython builds with
 limited flash memory, usually on non-Express builds:
-``uerrno``, ``ure``.
-
-Some libraries are not currently enabled in any CircuitPython build, but may be in the future:
-``uio``, ``ujson``, ``uzlib``.
+``binascii``, ``errno``, ``json``, ``re``.
 
-Some libraries are only enabled only WiFi-capable ports (ESP8266, nRF)
-because they are typically used for network software:
-``binascii``, ``hashlib``, ``uheapq``, ``uselect``, ``ussl``.
-Not all of these are enabled on all WiFi-capable ports.
+These libraries are not currently enabled in any CircuitPython build, but may be in the future,
+with the ``u`` prefix dropped:
+``uctypes``, ``uhashlib``, ``uzlib``.
 
 .. toctree::
    :maxdepth: 1
@@ -44,13 +30,14 @@ Not all of these are enabled on all WiFi-capable ports.
    array.rst
    binascii.rst
    collections.rst
+   errno.rst
    gc.rst
    hashlib.rst
+   io.rst
+   json.rst
+   re.rst
    sys.rst
-   uerrno.rst
-   uio.rst
-   ujson.rst
-   ure.rst
+   uctypes.rst
    uselect.rst
    usocket.rst
    ussl.rst
@@ -59,8 +46,8 @@ Not all of these are enabled on all WiFi-capable ports.
 Omitted functions in the ``string`` library
 -------------------------------------------
 
-A few string operations are not enabled on CircuitPython
-M0 non-Express builds, due to limited flash memory:
+A few string operations are not enabled on small builds
+(usually non-Express), due to limited flash memory:
 ``string.center()``, ``string.partition()``, ``string.splitlines()``,
 ``string.reversed()``.
 
@@ -78,15 +65,3 @@ versions of CircuitPython.
    btree.rst
    framebuf.rst
    micropython.rst
-   network.rst
-   uctypes.rst
-
-Libraries specific to the ESP8266
----------------------------------
-
-The following libraries are specific to the ESP8266.
-
-.. toctree::
-  :maxdepth: 2
-
-  esp.rst
diff --git a/docs/library/uio.rst b/docs/library/io.rst
index d1f7c111f..37e3eb7c9 100644
--- a/docs/library/uio.rst
+++ b/docs/library/io.rst
@@ -1,9 +1,7 @@
-:mod:`uio` -- input/output streams
+:mod:`io` -- input/output streams
 ==================================
 
-.. include:: ../templates/unsupported_in_circuitpython.inc
-
-.. module:: uio
+.. module:: io
    :synopsis: input/output streams
 
 |see_cpython_module| :mod:`cpython:io`.
diff --git a/docs/library/ujson.rst b/docs/library/json.rst
index 4ed91f053..21574e556 100644
--- a/docs/library/ujson.rst
+++ b/docs/library/json.rst
@@ -1,9 +1,7 @@
-:mod:`ujson` -- JSON encoding and decoding
+:mod:`json` -- JSON encoding and decoding
 ==========================================
 
-.. include:: ../templates/unsupported_in_circuitpython.inc
-
-.. module:: ujson
+.. module:: json
    :synopsis: JSON encoding and decoding
 
 |see_cpython_module| :mod:`cpython:json`.
diff --git a/docs/library/network.rst b/docs/library/network.rst
deleted file mode 100644
index 3bd41150d..000000000
--- a/docs/library/network.rst
+++ /dev/null
@@ -1,278 +0,0 @@
-****************************************
-:mod:`network` --- network configuration
-****************************************
-
-.. include:: ../templates/unsupported_in_circuitpython.inc
-
-.. module:: network
-   :noindex:
-   :synopsis: network configuration
-
-This module provides network drivers and routing configuration. To use this
-module, a MicroPython variant/build with network capabilities must be installed.
-Network drivers for specific hardware are available within this module and are
-used to configure hardware network interface(s). Network services provided
-by configured interfaces are then available for use via the :mod:`usocket`
-module.
-
-For example::
-
-    # connect/ show IP config a specific network interface
-    # see below for examples of specific drivers
-    import network
-    import utime
-    nic = network.Driver(...)
-    if not nic.isconnected():
-        nic.connect()
-        print("Waiting for connection...")
-        while not nic.isconnected():
-            utime.sleep(1)
-    print(nic.ifconfig())
-
-    # now use usocket as usual
-    import usocket as socket
-    addr = socket.getaddrinfo('micropython.org', 80)[0][-1]
-    s = socket.socket()
-    s.connect(addr)
-    s.send(b'GET / HTTP/1.1\r\nHost: micropython.org\r\n\r\n')
-    data = s.recv(1000)
-    s.close()
-
-Common network adapter interface
-================================
-
-This section describes an (implied) abstract base class for all network
-interface classes implemented by ``MicroPython ports <MicroPython port>``
-for different hardware. This means that MicroPython does not actually
-provide ``AbstractNIC`` class, but any actual NIC class, as described
-in the following sections, implements methods as described here.
-
-.. class:: AbstractNIC(id=None, ...)
-
-Instantiate a network interface object. Parameters are network interface
-dependent. If there are more than one interface of the same type, the first
-parameter should be `id`.
-
-    .. method:: active([is_active])
-
-        Activate ("up") or deactivate ("down") the network interface, if
-        a boolean argument is passed. Otherwise, query current state if
-        no argument is provided. Most other methods require an active
-        interface (behavior of calling them on inactive interface is
-        undefined).
-
-    .. method:: connect([service_id, key=None, \*, ...])
-
-       Connect the interface to a network. This method is optional, and
-       available only for interfaces which are not "always connected".
-       If no parameters are given, connect to the default (or the only)
-       service. If a single parameter is given, it is the primary identifier
-       of a service to connect to. It may be accompanied by a key
-       (password) required to access said service. There can be further
-       arbitrary keyword-only parameters, depending on the networking medium
-       type and/or particular device. Parameters can be used to: a)
-       specify alternative service identifier types; b) provide additional
-       connection parameters. For various medium types, there are different
-       sets of predefined/recommended parameters, among them:
-
-       * WiFi: *bssid* keyword to connect to a specific BSSID (MAC address)
-
-    .. method:: disconnect()
-
-       Disconnect from network.
-
-    .. method:: isconnected()
-
-       Returns ``True`` if connected to network, otherwise returns ``False``.
-
-    .. method:: scan(\*, ...)
-
-       Scan for the available network services/connections. Returns a
-       list of tuples with discovered service parameters. For various
-       network media, there are different variants of predefined/
-       recommended tuple formats, among them:
-
-       * WiFi: (ssid, bssid, channel, RSSI, authmode, hidden). There
-         may be further fields, specific to a particular device.
-
-       The function may accept additional keyword arguments to filter scan
-       results (e.g. scan for a particular service, on a particular channel,
-       for services of a particular set, etc.), and to affect scan
-       duration and other parameters. Where possible, parameter names
-       should match those in connect().
-
-    .. method:: status()
-
-       Return detailed status of the interface, values are dependent
-       on the network medium/technology.
-
-    .. method:: ifconfig([(ip, subnet, gateway, dns)])
-
-       Get/set IP-level network interface parameters: IP address, subnet mask,
-       gateway and DNS server. When called with no arguments, this method returns
-       a 4-tuple with the above information. To set the above values, pass a
-       4-tuple with the required information.  For example::
-
-        nic.ifconfig(('192.168.0.4', '255.255.255.0', '192.168.0.1', '8.8.8.8'))
-
-    .. method:: config('param')
-                config(param=value, ...)
-
-       Get or set general network interface parameters. These methods allow to work
-       with additional parameters beyond standard IP configuration (as dealt with by
-       `ifconfig()`). These include network-specific and hardware-specific
-       parameters and status values. For setting parameters, the keyword argument
-       syntax should be used, and multiple parameters can be set at once. For
-       querying, a parameter name should be quoted as a string, and only one
-       parameter can be queried at a time::
-
-        # Set WiFi access point name (formally known as ESSID) and WiFi channel
-        ap.config(essid='My AP', channel=11)
-        # Query params one by one
-        print(ap.config('essid'))
-        print(ap.config('channel'))
-        # Extended status information also available this way
-        print(sta.config('rssi'))
-
-.. _network.WLAN:
-
-Functions
-=========
-
-.. function:: phy_mode([mode])
-
-    Get or set the PHY mode.
-
-    If the *mode* parameter is provided, sets the mode to its value. If
-    the function is called without parameters, returns the current mode.
-
-    The possible modes are defined as constants:
-        * ``MODE_11B`` -- IEEE 802.11b,
-        * ``MODE_11G`` -- IEEE 802.11g,
-        * ``MODE_11N`` -- IEEE 802.11n.
-
-class WLAN
-==========
-
-This class provides a driver for WiFi network processor in the ESP8266.  Example usage::
-
-    import network
-    # enable station interface and connect to WiFi access point
-    nic = network.WLAN(network.STA_IF)
-    nic.active(True)
-    nic.connect('your-ssid', 'your-password')
-    # now use sockets as usual
-
-Constructors
-------------
-.. class:: WLAN(interface_id)
-
-Create a WLAN network interface object. Supported interfaces are
-``network.STA_IF`` (station aka client, connects to upstream WiFi access
-points) and ``network.AP_IF`` (access point, allows other WiFi clients to
-connect). Availability of the methods below depends on interface type.
-For example, only STA interface may `connect()` to an access point.
-
-Methods
--------
-
-.. method:: wlan.active([is_active])
-
-    Activate ("up") or deactivate ("down") network interface, if boolean
-    argument is passed. Otherwise, query current state if no argument is
-    provided. Most other methods require active interface.
-
-.. method:: wlan.connect(ssid=None, password=None, \*, bssid=None)
-
-    Connect to the specified wireless network, using the specified password.
-    If *bssid* is given then the connection will be restricted to the
-    access-point with that MAC address (the *ssid* must also be specified
-    in this case).
-
-.. method:: wlan.disconnect()
-
-    Disconnect from the currently connected wireless network.
-
-.. method:: wlan.scan()
-
-    Scan for the available wireless networks.
-
-    Scanning is only possible on STA interface. Returns list of tuples with
-    the information about WiFi access points:
-
-        (ssid, bssid, channel, RSSI, authmode, hidden)
-
-    *bssid* is hardware address of an access point, in binary form, returned as
-    bytes object. You can use `binascii.hexlify()` to convert it to ASCII form.
-
-    There are five values for authmode:
-
-        * 0 -- open
-        * 1 -- WEP
-        * 2 -- WPA-PSK
-        * 3 -- WPA2-PSK
-        * 4 -- WPA/WPA2-PSK
-
-    and two for hidden:
-
-        * 0 -- visible
-        * 1 -- hidden
-
-.. method:: wlan.status()
-
-    Return the current status of the wireless connection.
-
-    The possible statuses are defined as constants:
-
-        * ``STAT_IDLE`` -- no connection and no activity,
-        * ``STAT_CONNECTING`` -- connecting in progress,
-        * ``STAT_WRONG_PASSWORD`` -- failed due to incorrect password,
-        * ``STAT_NO_AP_FOUND`` -- failed because no access point replied,
-        * ``STAT_CONNECT_FAIL`` -- failed due to other problems,
-        * ``STAT_GOT_IP`` -- connection successful.
-
-.. method:: wlan.isconnected()
-
-    In case of STA mode, returns ``True`` if connected to a WiFi access
-    point and has a valid IP address.  In AP mode returns ``True`` when a
-    station is connected. Returns ``False`` otherwise.
-
-.. method:: wlan.ifconfig([(ip, subnet, gateway, dns)])
-
-   Get/set IP-level network interface parameters: IP address, subnet mask,
-   gateway and DNS server. When called with no arguments, this method returns
-   a 4-tuple with the above information. To set the above values, pass a
-   4-tuple with the required information.  For example::
-
-    nic.ifconfig(('192.168.0.4', '255.255.255.0', '192.168.0.1', '8.8.8.8'))
-
-.. method:: wlan.config('param')
-            wlan.config(param=value, ...)
-
-   Get or set general network interface parameters. These methods allow to work
-   with additional parameters beyond standard IP configuration (as dealt with by
-   `wlan.ifconfig()`). These include network-specific and hardware-specific
-   parameters. For setting parameters, keyword argument syntax should be used,
-   multiple parameters can be set at once. For querying, parameters name should
-   be quoted as a string, and only one parameter can be queries at time::
-
-    # Set WiFi access point name (formally known as ESSID) and WiFi channel
-    ap.config(essid='My AP', channel=11)
-    # Query params one by one
-    print(ap.config('essid'))
-    print(ap.config('channel'))
-
-   Following are commonly supported parameters (availability of a specific parameter
-   depends on network technology type, driver, and ``MicroPython port``).
-
-   =============  ===========
-   Parameter      Description
-   =============  ===========
-   mac            MAC address (bytes)
-   essid          WiFi access point name (string)
-   channel        WiFi channel (integer)
-   hidden         Whether ESSID is hidden (boolean)
-   authmode       Authentication mode supported (enumeration, see module constants)
-   password       Access password (string)
-   dhcp_hostname  The DHCP hostname to use
-   =============  ===========
diff --git a/docs/library/ure.rst b/docs/library/re.rst
index 4af182b01..bdcc9f52c 100644
--- a/docs/library/ure.rst
+++ b/docs/library/re.rst
@@ -1,9 +1,7 @@
-:mod:`ure` -- simple regular expressions
+:mod:`re` -- simple regular expressions
 ========================================
 
-.. include:: ../templates/unsupported_in_circuitpython.inc
-
-.. module:: ure
+.. module:: re
    :synopsis: regular expressions
 
 |see_cpython_module| :mod:`cpython:re`.
@@ -77,7 +75,7 @@ Regex objects
 -------------
 
 Compiled regular expression. Instances of this class are created using
-`ure.compile()`.
+`re.compile()`.
 
 .. method:: regex.match(string)
             regex.search(string)
diff --git a/docs/shared_bindings_matrix.py b/docs/shared_bindings_matrix.py
index f38c0b64a..e62b1d218 100644
--- a/docs/shared_bindings_matrix.py
+++ b/docs/shared_bindings_matrix.py
@@ -30,7 +30,7 @@ import sys
 
 from concurrent.futures import ThreadPoolExecutor
 
-SUPPORTED_PORTS = ['atmel-samd', 'esp32s2', 'litex', 'mimxrt10xx', 'nrf', 'stm']
+SUPPORTED_PORTS = ['atmel-samd', 'cxd56', 'esp32s2', 'litex', 'mimxrt10xx', 'nrf', 'raspberrypi', 'stm']
 
 def get_circuitpython_root_dir():
     """ The path to the root './circuitpython' directory
@@ -44,7 +44,7 @@ def get_shared_bindings():
     """ Get a list of modules in shared-bindings based on folder names
     """
     shared_bindings_dir = get_circuitpython_root_dir() / "shared-bindings"
-    return [item.name for item in shared_bindings_dir.iterdir()] + ["ulab"]
+    return [item.name for item in shared_bindings_dir.iterdir()] + ["binascii", "errno", "json", "re", "ulab"]
 
 
 def read_mpconfig():
diff --git a/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.h b/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.h
index 4b0c324fa..1586a3289 100644
--- a/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.h
+++ b/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.h
@@ -43,5 +43,3 @@
 // USB is always used internally so skip the pin objects for it.
 #define IGNORE_PIN_PA24     1
 #define IGNORE_PIN_PA25     1
-
-#define MICROPY_PY_URE 0
diff --git a/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.mk b/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.mk
index f754f3513..aace5c0cb 100644
--- a/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.mk
@@ -18,6 +18,7 @@ CIRCUITPY_FREQUENCYIO = 0
 CIRCUITPY_I2CPERIPHERAL = 0
 CIRCUITPY_MSGPACK = 0
 CIRCUITPY_PIXELBUF = 0
+CIRCUITPY_RE = 0
 CIRCUITPY_ROTARYIO = 0
 CIRCUITPY_RTC = 0
 # So not all of displayio, sorry!
diff --git a/ports/atmel-samd/mpconfigport.h b/ports/atmel-samd/mpconfigport.h
index bce89e0b9..d2a529485 100644
--- a/ports/atmel-samd/mpconfigport.h
+++ b/ports/atmel-samd/mpconfigport.h
@@ -45,11 +45,7 @@
 #define MICROPY_PY_BUILTINS_COMPLEX                 (0)
 #define MICROPY_PY_BUILTINS_NOTIMPLEMENTED          (0)
 #define MICROPY_PY_FUNCTION_ATTRS                   (0)
-// MICROPY_PY_UJSON depends on MICROPY_PY_IO
-#define MICROPY_PY_IO                               (0)
 #define MICROPY_PY_REVERSE_SPECIAL_METHODS          (0)
-#define MICROPY_PY_UBINASCII                        (0)
-#define MICROPY_PY_UJSON                            (0)
 #define MICROPY_PY_COLLECTIONS_ORDEREDDICT          (0)
 #define MICROPY_PY_UERRNO_LIST \
     X(EPERM) \
@@ -84,9 +80,6 @@
 #define SPI_FLASH_MAX_BAUDRATE 24000000
 #define MICROPY_PY_BUILTINS_NOTIMPLEMENTED          (1)
 #define MICROPY_PY_FUNCTION_ATTRS                   (1)
-// MICROPY_PY_UJSON depends on MICROPY_PY_IO
-#define MICROPY_PY_IO                               (1)
-#define MICROPY_PY_UJSON                            (1)
 //      MICROPY_PY_UERRNO_LIST - Use the default
 
 #endif // SAM_D5X_E5X
diff --git a/ports/atmel-samd/mpconfigport.mk b/ports/atmel-samd/mpconfigport.mk
index 17e3995bf..fb9cdf2e6 100644
--- a/ports/atmel-samd/mpconfigport.mk
+++ b/ports/atmel-samd/mpconfigport.mk
@@ -20,26 +20,16 @@ endif
 
 # Put samd21-only choices here.
 ifeq ($(CHIP_FAMILY),samd21)
-# frequencyio not yet verified as working on SAMD21, though make it possible to override.
-ifndef CIRCUITPY_AUDIOMIXER
-CIRCUITPY_AUDIOMIXER = 0
-endif
-
-ifndef CIRCUITPY_AUDIOMP3
-CIRCUITPY_AUDIOMP3 = 0
-endif
-
-ifndef CIRCUITPY_BUILTINS_POW3
-CIRCUITPY_BUILTINS_POW3 = 0
-endif
 
-ifndef CIRCUITPY_FREQUENCYIO
-CIRCUITPY_FREQUENCYIO = 0
-endif
+# The ?='s allow overriding in mpconfigboard.mk.
 
-ifndef CIRCUITPY_TOUCHIO_USE_NATIVE
-CIRCUITPY_TOUCHIO_USE_NATIVE = 1
-endif
+CIRCUITPY_AUDIOMIXER ?= 0
+CIRCUITPY_BINASCII ?= 0
+CIRCUITPY_AUDIOMP3 ?= 0
+CIRCUITPY_BUILTINS_POW3 ?= 0
+CIRCUITPY_FREQUENCYIO ?= 0
+CIRCUITPY_JSON ?= 0
+CIRCUITPY_TOUCHIO_USE_NATIVE ?= 1
 
 # No room for HCI _bleio on SAMD21.
 CIRCUITPY_BLEIO_HCI = 0
@@ -71,27 +61,13 @@ ifeq ($(CHIP_FAMILY),samd51)
 # No native touchio on SAMD51.
 CIRCUITPY_TOUCHIO_USE_NATIVE = 0
 
-# The ifndef's allow overriding in mpconfigboard.mk.
-
-ifndef CIRCUITPY_NETWORK
-CIRCUITPY_NETWORK = 0
-endif
-
-ifndef CIRCUITPY_PS2IO
-CIRCUITPY_PS2IO = 1
-endif
-
-ifndef CIRCUITPY_SAMD
-CIRCUITPY_SAMD = 1
-endif
-
-ifndef CIRCUITPY_RGBMATRIX
-CIRCUITPY_RGBMATRIX = $(CIRCUITPY_FULL_BUILD)
-endif
+# The ?='s allow overriding in mpconfigboard.mk.
 
-ifndef CIRCUITPY_FRAMEBUFFERIO
-CIRCUITPY_FRAMEBUFFERIO = $(CIRCUITPY_FULL_BUILD)
-endif
+CIRCUITPY_NETWORK ?= 0
+CIRCUITPY_PS2IO ?= 1
+CIRCUITPY_SAMD ?= 1
+CIRCUITPY_RGBMATRIX ?= $(CIRCUITPY_FULL_BUILD)
+CIRCUITPY_FRAMEBUFFERIO ?= $(CIRCUITPY_FULL_BUILD)
 
 endif # samd51
 
diff --git a/ports/esp32s2/mpconfigport.h b/ports/esp32s2/mpconfigport.h
index 9c0fd9da3..0cf695bc9 100644
--- a/ports/esp32s2/mpconfigport.h
+++ b/ports/esp32s2/mpconfigport.h
@@ -30,7 +30,6 @@
 
 #define MICROPY_NLR_THUMB                   (0)
 
-#define MICROPY_PY_UJSON                    (1)
 #define MICROPY_USE_INTERNAL_PRINTF         (0)
 #define MICROPY_PY_SYS_PLATFORM             "Espressif ESP32-S2"
 
diff --git a/ports/litex/mpconfigport.h b/ports/litex/mpconfigport.h
index a7caf8526..5f739e49e 100644
--- a/ports/litex/mpconfigport.h
+++ b/ports/litex/mpconfigport.h
@@ -31,8 +31,6 @@
 #define CIRCUITPY_INTERNAL_NVM_SIZE         (0)
 #define MICROPY_NLR_THUMB                   (0)
 #define MICROPY_PY_REVERSE_SPECIAL_METHODS  (1)
-#define MICROPY_PY_UBINASCII                (1)
-#define MICROPY_PY_UJSON                    (1)
 
 #include "py/circuitpy_mpconfig.h"
 
diff --git a/ports/mimxrt10xx/mpconfigport.h b/ports/mimxrt10xx/mpconfigport.h
index 7496256d0..51e0ef9ff 100644
--- a/ports/mimxrt10xx/mpconfigport.h
+++ b/ports/mimxrt10xx/mpconfigport.h
@@ -41,8 +41,6 @@ extern uint8_t _ld_default_stack_size;
 #define CIRCUITPY_DEFAULT_STACK_SIZE                ((uint32_t) &_ld_default_stack_size)
 #define MICROPY_PY_BUILTINS_NOTIMPLEMENTED          (0)
 #define MICROPY_PY_FUNCTION_ATTRS                   (0)
-#define MICROPY_PY_IO                               (1)
-#define MICROPY_PY_UJSON                            (1)
 #define MICROPY_PY_REVERSE_SPECIAL_METHODS          (1)
 
 
diff --git a/ports/nrf/boards/simmel/mpconfigboard.mk b/ports/nrf/boards/simmel/mpconfigboard.mk
index 4eb6c98c7..032caac40 100644
--- a/ports/nrf/boards/simmel/mpconfigboard.mk
+++ b/ports/nrf/boards/simmel/mpconfigboard.mk
@@ -13,11 +13,13 @@ INTERNAL_FLASH_FILESYSTEM = 1
 
 CIRCUITPY_AESIO = 1
 CIRCUITPY_AUDIOMP3 = 0
+CIRCUITPY_BUSDEVICE = 0
 CIRCUITPY_BUSIO = 1
 CIRCUITPY_DISPLAYIO = 0
+CIRCUITPY_ERRNO = 0
 CIRCUITPY_FRAMEBUFFERIO = 0
-CIRCUITPY_MSGPACK = 0
 CIRCUITPY_GAMEPAD = 0
+CIRCUITPY_MSGPACK = 0
 CIRCUITPY_NEOPIXEL_WRITE = 0
 CIRCUITPY_NVM = 0
 CIRCUITPY_PIXELBUF  = 0
@@ -28,7 +30,6 @@ CIRCUITPY_SDCARDIO = 0
 CIRCUITPY_TOUCHIO = 0
 CIRCUITPY_ULAB = 0
 CIRCUITPY_WATCHDOG = 1
-CIRCUITPY_BUSDEVICE = 0
 
 # Enable micropython.native
 #CIRCUITPY_ENABLE_MPY_NATIVE = 1
diff --git a/ports/nrf/mpconfigport.h b/ports/nrf/mpconfigport.h
index 4ed42cd82..3ac41a5e4 100644
--- a/ports/nrf/mpconfigport.h
+++ b/ports/nrf/mpconfigport.h
@@ -35,11 +35,8 @@
 #include "peripherals/nrf/nvm.h" // for FLASH_PAGE_SIZE
 
 #define MICROPY_PY_FUNCTION_ATTRS                (1)
-#define MICROPY_PY_IO                            (1)
 #define MICROPY_PY_REVERSE_SPECIAL_METHODS       (1)
 #define MICROPY_PY_SYS_STDIO_BUFFER              (1)
-#define MICROPY_PY_UBINASCII                     (1)
-#define MICROPY_PY_UJSON                         (1)
 
 // 24kiB stack
 #define CIRCUITPY_DEFAULT_STACK_SIZE            (24*1024)
diff --git a/ports/raspberrypi/mpconfigport.h b/ports/raspberrypi/mpconfigport.h
index 3fdc8febb..743151931 100644
--- a/ports/raspberrypi/mpconfigport.h
+++ b/ports/raspberrypi/mpconfigport.h
@@ -27,8 +27,6 @@
 #ifndef __INCLUDED_MPCONFIGPORT_H
 #define __INCLUDED_MPCONFIGPORT_H
 
-#define MICROPY_PY_UJSON                            (1)
-
 #define CIRCUITPY_INTERNAL_NVM_SIZE 0
 
 #define CIRCUITPY_DEFAULT_STACK_SIZE                (24*1024)
diff --git a/ports/stm/mpconfigport.h b/ports/stm/mpconfigport.h
index 9489b4765..7cdab04f6 100644
--- a/ports/stm/mpconfigport.h
+++ b/ports/stm/mpconfigport.h
@@ -31,9 +31,7 @@
 #include <stdint.h>
 
 #define MICROPY_PY_FUNCTION_ATTRS                (1)
-#define MICROPY_PY_IO                            (1)
 #define MICROPY_PY_REVERSE_SPECIAL_METHODS       (1)
-#define MICROPY_PY_UJSON                         (1)
 
 extern uint8_t _ld_default_stack_size;
 
diff --git a/py/circuitpy_mpconfig.h b/py/circuitpy_mpconfig.h
index 35f1227a9..ee23c7156 100644
--- a/py/circuitpy_mpconfig.h
+++ b/py/circuitpy_mpconfig.h
@@ -195,21 +195,12 @@ typedef long mp_off_t;
 #define MICROPY_PY_BUILTINS_STR_CENTER        (CIRCUITPY_FULL_BUILD)
 #define MICROPY_PY_BUILTINS_STR_PARTITION     (CIRCUITPY_FULL_BUILD)
 #define MICROPY_PY_BUILTINS_STR_SPLITLINES    (CIRCUITPY_FULL_BUILD)
-#define MICROPY_PY_UERRNO                     (CIRCUITPY_FULL_BUILD)
 #ifndef MICROPY_PY_COLLECTIONS_ORDEREDDICT
 #define MICROPY_PY_COLLECTIONS_ORDEREDDICT    (CIRCUITPY_FULL_BUILD)
 #endif
-#ifndef MICROPY_PY_UBINASCII
-#define MICROPY_PY_UBINASCII                  (CIRCUITPY_FULL_BUILD)
-#endif
-// Opposite setting is deliberate.
-#define MICROPY_PY_UERRNO_ERRORCODE           (!CIRCUITPY_FULL_BUILD)
-#ifndef MICROPY_PY_URE
-#define MICROPY_PY_URE                        (CIRCUITPY_FULL_BUILD)
-#endif
-#define MICROPY_PY_URE_MATCH_GROUPS           (CIRCUITPY_FULL_BUILD)
-#define MICROPY_PY_URE_MATCH_SPAN_START_END   (CIRCUITPY_FULL_BUILD)
-#define MICROPY_PY_URE_SUB                    (CIRCUITPY_FULL_BUILD)
+#define MICROPY_PY_URE_MATCH_GROUPS           (CIRCUITPY_RE)
+#define MICROPY_PY_URE_MATCH_SPAN_START_END   (CIRCUITPY_RE)
+#define MICROPY_PY_URE_SUB                    (CIRCUITPY_RE)
 
 // LONGINT_IMPL_xxx are defined in the Makefile.
 //
@@ -301,6 +292,13 @@ extern const struct _mp_obj_module_t audiopwmio_module;
 #define AUDIOPWMIO_MODULE
 #endif
 
+#if CIRCUITPY_BINASCII
+#define MICROPY_PY_UBINASCII CIRCUITPY_BINASCII
+#define BINASCII_MODULE        { MP_ROM_QSTR(MP_QSTR_binascii), MP_ROM_PTR(&mp_module_ubinascii) },
+#else
+#define BINASCII_MODULE
+#endif
+
 #if CIRCUITPY_BITBANGIO
 #define BITBANGIO_MODULE       { MP_OBJ_NEW_QSTR(MP_QSTR_bitbangio), (mp_obj_t)&bitbangio_module },
 extern const struct _mp_obj_module_t bitbangio_module;
@@ -399,6 +397,16 @@ extern const struct _mp_obj_module_t terminalio_module;
 #define TERMINALIO_MODULE
 #endif
 
+#if CIRCUITPY_ERRNO
+#define MICROPY_PY_UERRNO (1)
+// Uses about 80 bytes.
+#define MICROPY_PY_UERRNO_ERRORCODE (1)
+#define ERRNO_MODULE           { MP_ROM_QSTR(MP_QSTR_errno), MP_ROM_PTR(&mp_module_uerrno) },
+#else
+#define ERRNO_MODULE
+#
+#endif
+
 #if CIRCUITPY_ESPIDF
 extern const struct _mp_obj_module_t espidf_module;
 #define ESPIDF_MODULE            { MP_OBJ_NEW_QSTR(MP_QSTR_espidf),(mp_obj_t)&espidf_module },
@@ -470,6 +478,18 @@ extern const struct _mp_obj_module_t ipaddress_module;
 #define IPADDRESS_MODULE
 #endif
 
+#if CIRCUITPY_JSON
+#define MICROPY_PY_UJSON (1)
+#define MICROPY_PY_IO (1)
+#define JSON_MODULE            { MP_ROM_QSTR(MP_QSTR_json), MP_ROM_PTR(&mp_module_ujson) },
+#else
+#ifndef MICROPY_PY_IO
+// We don't need MICROPY_PY_IO unless someone else wants it.
+#define MICROPY_PY_IO (0)
+#endif
+#define JSON_MODULE
+#endif
+
 #if CIRCUITPY_MATH
 extern const struct _mp_obj_module_t math_module;
 #define MATH_MODULE            { MP_OBJ_NEW_QSTR(MP_QSTR_math), (mp_obj_t)&math_module },
@@ -588,6 +608,13 @@ extern const struct _mp_obj_module_t random_module;
 #define RANDOM_MODULE
 #endif
 
+#if CIRCUITPY_RE
+#define MICROPY_PY_URE (1)
+#define RE_MODULE            { MP_ROM_QSTR(MP_QSTR_re), MP_ROM_PTR(&mp_module_ure) },
+#else
+#define RE_MODULE
+#endif
+
 #if CIRCUITPY_RGBMATRIX
 extern const struct _mp_obj_module_t rgbmatrix_module;
 #define RGBMATRIX_MODULE        { MP_OBJ_NEW_QSTR(MP_QSTR_rgbmatrix),(mp_obj_t)&rgbmatrix_module },
@@ -730,25 +757,6 @@ extern const struct _mp_obj_module_t ustack_module;
 #define USTACK_MODULE
 #endif
 
-// These modules are not yet in shared-bindings, but we prefer the non-uxxx names.
-#if MICROPY_PY_UBINASCII
-#define BINASCII_MODULE        { MP_ROM_QSTR(MP_QSTR_binascii), MP_ROM_PTR(&mp_module_ubinascii) },
-#else
-#define BINASCII_MODULE
-#endif
-
-#if MICROPY_PY_UERRNO
-#define ERRNO_MODULE           { MP_ROM_QSTR(MP_QSTR_errno), MP_ROM_PTR(&mp_module_uerrno) },
-#else
-#define ERRNO_MODULE
-#endif
-
-#if MICROPY_PY_UJSON
-#define JSON_MODULE            { MP_ROM_QSTR(MP_QSTR_json), MP_ROM_PTR(&mp_module_ujson) },
-#else
-#define JSON_MODULE
-#endif
-
 #if defined(CIRCUITPY_ULAB) && CIRCUITPY_ULAB
 // ulab requires reverse special methods
 #if defined(MICROPY_PY_REVERSE_SPECIAL_METHODS) && !MICROPY_PY_REVERSE_SPECIAL_METHODS
@@ -760,12 +768,6 @@ extern const struct _mp_obj_module_t ustack_module;
 #define ULAB_MODULE
 #endif
 
-#if MICROPY_PY_URE
-#define RE_MODULE { MP_ROM_QSTR(MP_QSTR_re), MP_ROM_PTR(&mp_module_ure) },
-#else
-#define RE_MODULE
-#endif
-
 // This is not a top-level module; it's microcontroller.watchdog.
 #if CIRCUITPY_WATCHDOG
 extern const struct _mp_obj_module_t watchdog_module;
diff --git a/py/circuitpy_mpconfig.mk b/py/circuitpy_mpconfig.mk
index 5bc44fa21..b8fe73eea 100644
--- a/py/circuitpy_mpconfig.mk
+++ b/py/circuitpy_mpconfig.mk
@@ -86,6 +86,9 @@ endif
 endif
 CFLAGS += -DCIRCUITPY_AUDIOMP3=$(CIRCUITPY_AUDIOMP3)
 
+CIRCUITPY_BINASCII ?= $(CIRCUITPY_FULL_BUILD)
+CFLAGS += -DCIRCUITPY_BINASCII=$(CIRCUITPY_BINASCII)
+
 CIRCUITPY_BITBANGIO ?= $(CIRCUITPY_FULL_BUILD)
 CFLAGS += -DCIRCUITPY_BITBANGIO=$(CIRCUITPY_BITBANGIO)
 
@@ -124,6 +127,9 @@ CFLAGS += -DCIRCUITPY_COUNTIO=$(CIRCUITPY_COUNTIO)
 CIRCUITPY_DISPLAYIO ?= $(CIRCUITPY_FULL_BUILD)
 CFLAGS += -DCIRCUITPY_DISPLAYIO=$(CIRCUITPY_DISPLAYIO)
 
+CIRCUITPY_ERRNO ?= $(CIRCUITPY_FULL_BUILD)
+CFLAGS += -DCIRCUITPY_ERRNO=$(CIRCUITPY_ERRNO)
+
 # CIRCUITPY_ESPIDF is handled in the esp32s2 tree.
 # Only for ESP32S chips.
 # Assume not a ESP build.
@@ -158,6 +164,9 @@ CFLAGS += -DCIRCUITPY_I2CPERIPHERAL=$(CIRCUITPY_I2CPERIPHERAL)
 CIRCUITPY_IPADDRESS ?= $(CIRCUITPY_WIFI)
 CFLAGS += -DCIRCUITPY_IPADDRESS=$(CIRCUITPY_IPADDRESS)
 
+CIRCUITPY_JSON ?= $(CIRCUITPY_FULL_BUILD)
+CFLAGS += -DCIRCUITPY_JSON=$(CIRCUITPY_JSON)
+
 CIRCUITPY_MATH ?= 1
 CFLAGS += -DCIRCUITPY_MATH=$(CIRCUITPY_MATH)
 
@@ -204,6 +213,9 @@ CFLAGS += -DCIRCUITPY_PWMIO=$(CIRCUITPY_PWMIO)
 CIRCUITPY_RANDOM ?= 1
 CFLAGS += -DCIRCUITPY_RANDOM=$(CIRCUITPY_RANDOM)
 
+CIRCUITPY_RE ?= $(CIRCUITPY_FULL_BUILD)
+CFLAGS += -DCIRCUITPY_RE=$(CIRCUITPY_RE)
+
 # CIRCUITPY_RP2PIO is handled in the raspberrypi tree.
 # Only for rp2 chips.
 # Assume not a rp2 build.
diff --git a/shared-bindings/support_matrix.rst b/shared-bindings/support_matrix.rst
index 1b75e0256..a2fb7987d 100644
--- a/shared-bindings/support_matrix.rst
+++ b/shared-bindings/support_matrix.rst
@@ -1,7 +1,7 @@
 .. _module-support-matrix:
 
-Support Matrix
-===============
+Module Support Matrix - Which Modules Are Available on Which Boards
+===================================================================
 
 The following table lists the available built-in modules for each CircuitPython
 capable board.