acoshf, asinhf, atanhf were added from musl. mathsincos.c was
split up into its original, separate files (from newlibe-nano-2).
tan was added.
All of the important missing float functions are now implemented,
and pyboard now passes tests/float/math_fun.py (finally!).
This patch adds a configuration option (MICROPY_CAN_OVERRIDE_BUILTINS)
which, when enabled, allows to override all names within the builtins
module. A builtins override dict is created the first time the user
assigns to a name in the builtins model, and then that dict is searched
first on subsequent lookups. Note that this implementation doesn't
allow deleting of names.
This patch also does some refactoring of builtins code, creating the
modbuiltins.c file.
Addresses issue #959.
The function is modeled after traceback.print_exception(), but unbloated,
and put into existing module to save overhead on adding another module.
Compliant traceback.print_exception() is intended to be implemented in
micropython-lib in terms of sys.print_exception().
This change required refactoring mp_obj_print_exception() to take pfenv_t
interface arguments.
Addresses #751.
Remove include of stm32f4xx_hal.h, replace by include of MICROPY_HAL_H
where needed, and make it compile without float support. This makes
these 3 modules much more generic and usable by other ports.
mp_obj_int_get_truncated is used as a "fast path" int accessor that
doesn't check for overflow and returns the int truncated to the machine
word size, ie mp_int_t.
Use mp_obj_int_get_truncated to fix struct.pack when packing maximum word
sized values.
Addresses issues #779 and #998.
mp_lexer_t type is exposed, mp_token_t type is removed, and simple lexer
functions (like checking current token kind) are now inlined.
This saves 784 bytes ROM on 32-bit unix, 348 bytes on stmhal, and 460
bytes on bare-arm. It also saves a tiny bit of RAM since mp_lexer_t
is a bit smaller. Also will run a bit more efficiently.
This patch overhauls the network driver interface. A generic NIC must
provide a set of C-level functions to implement low-level socket control
(eg socket, bind, connect, send, recv). Doing this, the network and
usocket modules can then use such a NIC to implement proper socket
control at the Python level.
This patch also updates the CC3K and WIZNET5K drivers to conform to the
new interface, and fixes some bugs in the drivers. They now work
reasonably well.
pyb.delay and pyb.udelay now use systick if IRQs are enabled, otherwise
they use a busy loop. Thus they work correctly when IRQs are disabled.
The busy loop is computed from the current CPU frequency, so works no
matter the CPU frequency.
The reason for having this delay is to reduce power consumption at the
REPL (HAL_Delay calls __WFI to idle the CPU). But stdin_rx_chr has a
__WFI in it anyway, so this delay call is not needed.
By removing this call, the readline input can consume characters much
more quickly (before was limited to 1000 chrs/s), and has much reduced
dependency on the specific port.
Also restrict higher frequencies to have a VCO_OUT frequency below
432MHz, as specified in the datasheet.
Docs improved to list allowed frequencies, and explain about USB
stability.
This is experimental support. API is subject to changes. RTS/CTS
available on UART(2) and UART(3) only. Use as:
uart = pyb.UART(2, 9600, flow=pyb.UART.RTS | pyb.UART.CTS)
This patch also enables non-blocking streams on stmhal port.
One can now make a USB-UART pass-through function:
def pass_through(usb, uart):
while True:
select.select([usb, uart], [], [])
if usb.any():
uart.write(usb.read(256))
if uart.any():
usb.write(uart.read(256))
pass_through(pyb.USB_VCP(), pyb.UART(1, 9600))
Improvements are:
2 ctrl-C's are now needed to truly kill running script on pyboard, so
make CDC interface allow multiple ctrl-C's through at once (ie sending
b'\x03\x03' to pyboard now counts as 2 ctrl-C's).
ctrl-C in friendly-repl can now stop multi-line input.
In raw-repl mode, use ctrl-D to indicate end of running script, and also
end of any error message. Thus, output of raw-repl is always at least 2
ctrl-D's and it's much easier to parse.
pyboard.py is now a bit faster, handles exceptions from pyboard better
(prints them and exits with exit code 1), prints out the pyboard output
while the script is running (instead of waiting till the end), and
allows to follow the output of a previous script when run with no
arguments.
This allows to implement KeyboardInterrupt on unix, and a much safer
ctrl-C in stmhal port. First ctrl-C is a soft one, with hope that VM
will notice it; second ctrl-C is a hard one that kills anything (for
both unix and stmhal).
One needs to check for a pending exception in the VM only for jump
opcodes. Others can't produce an infinite loop (infinite recursion is
caught by stack check).
TIM2_CH1_ETR is really bundling 2 functions to the same pin:
TIM2_CH1 (where its used as a channel)
TIM2_ETR (where iss used as an external trigger).
I fixed most of these a while back, but it looks like I missed this one.
Also make cc3k.send and cc3k.recv independent functions (not wrapped by
stream write/read). Also make wiznet5k.recv more memory efficient.
This might address issue #920.
UART object now uses a stream-like interface: read, readall, readline,
readinto, readchar, write, writechar.
Timeouts are configured when the UART object is initialised, using
timeout and timeout_char keyword args.
The object includes optional read buffering, using interrupts. You can set
the buffer size dynamically using read_buf_len keyword arg. A size of 0
disables buffering.
This makes open() and _io.FileIO() more CPython compliant.
The mode kwarg is fully iplemented.
The encoding kwarg is allowed but not implemented; mainly to allow
the tests to specify encoding for CPython, see #874
When loading the ELF binary to the board with a debugger, the debugger
needs to know at which point to start executing the code. Currently the
entry point defaults to the start of the .text section.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
This fixed an issue with a certain SD card sometimes not initialising
first time round. See issue #822 for related, and thanks to
@iabdalkader for the idea.
Also, usocket.readinto(). Known issue is that .readinto() should be available
only for binary files, but micropython uses single method table for both
binary and text files.
os, time, select modules are now prefixed with u, but are still
available (via weak links) as their original names.
ure and ujson now available as re and json via weak links.
This patch enables output on the complimentary channels (TIMx_CHyN).
For timers 1 and 8, deadtime can also be inserted when the channels
transition. For the pyboard, TIM8_CH1/CH1N and TIM8_CH2/CH2N can
take advantage of this.
Found these by compiling stmhal with mp_uint_t of type uint32_t instead
of unsigned int. This actually makes a difference to the code, but just
a curiosity.
Timers now have the following new features:
- can init freq using floating point; eg tim.init(freq=0.1)
- tim.source_freq() added to get freq of timer clock source
- tim.freq() added to get/set freq
- print(tim) now prints freq
Eg pyb.freq(120000000) sets the CPU to 120MHz. The frequency can be set
at any point in the code, and can be changed as many times as you like.
Note that any active timers will need to be reconfigured after a freq
change.
Valid range is 24MHz to 168MHz (but not all freqs are supported). The
code maintains a 48MHz clock for the USB at all times and it's possible
to change the frequency at a USB REPL and keep the REPL alive (well,
most of the time it stays, sometimes it resets the USB for some reason).
Note that USB does not work with pyb.freq of 24MHz.
Remove reference to pyb.gc; add reference to pyb.millis.
There are lots of functions not listed when you run help(), but it would
be too much to list them all, so we list only some basic, useful ones.
Addresses issue #846.
As per issue #876, the network module is used to configure NICs
(hardware modules) and configure routing. The usocket module is
supposed to implement the normal Python socket module and selects the
underlying NIC using routing logic.
Right now the routing logic is brain dead: first-initialised,
first-used. And the routing table is just a list of registered NICs.
cc3k and wiznet5k work, but not at the same time due to C name clashes
(to be fixed).
Note that the usocket module has alias socket, so that one can import
socket and it works as normal. But you can also override socket with
your own module, using usocket at the backend.
In CPython IOError (and EnvironmentError) is deprecated and aliased to
OSError. All modules that used to raise IOError now raise OSError (or a
derived exception).
In Micro Python we never used IOError (except 1 place, incorrectly) and
so don't need to keep it.
See http://legacy.python.org/dev/peps/pep-3151/ for background.
Teensy doesn't need to worry about overflows since all of
its timers are only 16-bit.
For PWM, the pulse width needs to be able to vary from 0..period+1
(pulse-width == period+1 corresponds to 100% PWM)
I couldn't test the 0xffffffff cases since we can't currently get a
period that big in python. With a prescaler of 0, that corresponds
to a freq of 0.039 (i.e. cycle every 25.56 seconds), and we can't
set that using freq or period.
I also tested both stmhal and teensy with floats disabled, which
required a few other code changes to compile.
Pulled in and modified work done by mux/iabdalkader on cc3k driver, from
iabdalkader-cc3k-update branch. That branch was terribly messy and had
too many conflicts to merge neatly.
Fix stmhal and teensy print routines to report actual prescaler an period.
Fix teensy build to use soft-float
Add USE_ARDUINO_TOOLCHAIN option to teensy build
mp_parse_node_free now frees the memory associated with non-interned
strings. And the parser calls mp_parse_node_free when discarding a
non-used node (such as a doc string).
Also, the compiler now frees the parse tree explicitly just before it
exits (as opposed to relying on the caller to do this).
Addresses issue #708 as best we can.
Stack is full descending and must be 8-byte aligned. It must start off
pointing to just above the last byte of RAM.
Previously, stack started pointed to last byte of RAM (eg 0x2001ffff)
and so was not 8-byte aligned. This caused a bug in combination with
alloca.
This patch also updates some debug printing code.
Addresses issue #872 (among many other undiscovered issues).
This allows to set the pulse width (for PWM mode) as a ratio relative to
the period of the timer. Eg, 0.5 is a 50% duty cycle. You can set the
ratio in the channel init, or using channel.pulse_width_ratio; the
latter can also read the pulse width as a ratio.
By measuring SD card addresses in blocks and not bytes, one can get away
with using 32-bit numbers.
This patch also uses proper atomic lock/unlock around SD card
read/write, adds SD.info() function, and gives error code for failed
read/writes.
sys.exit always raises SystemExit so doesn't need a special
implementation for each port. If C exit() is really needed, use the
standard os._exit function.
Also initialise mp_sys_path and mp_sys_argv in teensy port.
Allows to create socket objects that support TCP and UDP in server and
client mode. Interface is very close to standard Python socket class,
except bind and accept do not work the same (due to hardware not
supporting them in the usual way).
Not compiled by default. To compile this module, use:
make MICROPY_PY_WIZNET5K=1
Top-level lib directory is for standard C libraries that we want to
provide our own versions of (for efficiency and stand-alone reasons).
It currently has libm in it for math functions.
Also add atanf and atan2f, which addresses issue #837.
SysTick IRQ now increases millisecond counter directly (ie without
calling HAL_IncTick). Provide our own version of HAL_Delay that does a
wfi while waiting. This more than halves power consumption when running
a loop containing a pyb.delay call. It used to be like this, but new
version of HAL library regressed this feature.
I also removed trailing spaces from modpyb.c which affected a couple
of lines technically not part of this patch.
Tested using: https://github.com/dhylands/upy-examples/blob/master/micros_test.py
which eventually fails due to wraparound issues (I could fix the test to compensate
but didn't bother)
These functions are generally 1 machine instruction, and are used in
critical code, so makes sense to have them inline.
Also leave these functions uninverted (ie 0 means enable, 1 means
disable) and provide macro constants if you really need to distinguish
the states. This makes for smaller code as well (combined with
inlining).
Applied to teensy port as well.
Because (for Thumb) a function pointer has the LSB set, pointers to
dynamic functions in RAM (eg native, viper or asm functions) were not
being traced by the GC. This patch is a comprehensive fix for this.
Addresses issue #820.
It's still "safe" because no scripts are run. Remove the SD card if you
want to access the internal flash filesystem. Addresses issue #616.
Also: remove obsolete pyb.source_dir setting, and reset pyb.main and
pyb.usb_mode settings on soft-reset.
Converts generted pins to use qstrs instead of string pointers.
This patch also adds the following functions:
pyb.Pin.names()
pyb.Pin.af_list()
pyb.Pin.gpio()
dir(pyb.Pin.board) and dir(pyb.Pin.cpu) also produce useful results.
pyb.Pin now takes kw args.
pyb.Pin.__str__ now prints more useful information about the pin
configuration.
I found the following functions in my boot.py to be useful:
```python
def pins():
for pin_name in dir(pyb.Pin.board):
pin = pyb.Pin(pin_name)
print('{:10s} {:s}'.format(pin_name, str(pin)))
def af():
for pin_name in dir(pyb.Pin.board):
pin = pyb.Pin(pin_name)
print('{:10s} {:s}'.format(pin_name, str(pin.af_list())))
```
This patch updates ST's HAL to the latest version, V1.3.0, dated 19 June
2014. Files were copied verbatim from the ST package. Only change was
to suppress compiler warning of unused variables in 4 places.
A lot of the changes from ST are cosmetic: comments and white space.
Some small code changes here and there, and addition of F411 header.
Main code change is how SysTick interrupt is set: it now has a
configuration variable to set the priority, so we no longer need to work
around this (originall in system_stm32f4xx.c).
Make a clearer distinction between init functions that must be done
before any scripts can run (xxx_init0) and those that can be safely
deferred (xxx_init).
Fix bug initialising USB VCP exception. Addresses issue #788.
Re-order some init function to improve reliability of
reset/soft-reset.
qstr_init is always called exactly before mp_init, so makes sense to
just have mp_init call it. Similarly with
mp_init_emergency_exception_buf. Doing this makes the ports simpler and
less error prone (ie they can no longer forget to call these).
Some important changes to the way the file system is structured on the
pyboard:
1. 0: and 1: drive names are now replaced with POSIX inspired
directories, namely /flash and /sd.
2. Filesystem now supports the notion of a current working directory.
Supports the standard Python way of manipulating it: os.chdir and
os.getcwd.
3. On boot up, current directory is /flash if no SD inserted, else /sd
if SD inserted. Then runs boot.py and main.py from the current dir.
This is the same as the old behaviour, but is much more consistent and
flexible (eg you can os.chdir in boot.py to change where main.py is run
from).
4. sys.path (for import) is now set to '' (current dir), plus /flash
and /flash/lib, and then /sd and /sd/lib if SD inserted. This, along
with CWD, means that import now works properly. You can import a file
from the current directory.
5. os.listdir is fixed to return just the basename, not the full path.
See issue #537 for background and discussion.
For accel to start-up reliably, need to wait 30ms between on/off, and
30ms for it to enter active mode. With this fix the accel can be read
immediately after initialising it.
Addresses issue #763.
Before, pyb.stdin/pyb.stdout allowed some kind of access to the USB VCP
device, but it was basic access.
This patch adds a proper USB_VCP class and object with much more control
over the USB VCP device. Create an object with pyb.USB_VCP(), then use
this object as if it were a UART object. It has send, recv, read,
write, and other methods. send and recv allow a timeout to be specified.
Addresses issue 774.
The user code should call micropython.alloc_emergency_exception_buf(size)
where size is the size of the buffer used to print the argument
passed to the exception.
With the test code from #732, and a call to
micropython.alloc_emergenncy_exception_buf(100) the following error is
now printed:
```python
>>> import heartbeat_irq
Uncaught exception in Timer(4) interrupt handler
Traceback (most recent call last):
File "0://heartbeat_irq.py", line 14, in heartbeat_cb
NameError: name 'led' is not defined
```
Recent changes to builtin print meant that print was printing to the
mp_sys_stdout_obj, which was sending data raw to the USB CDC device.
The data should be cooked so that \n turns into \r\n.
With unicode enabled, this patch allows reading a fixed number of
characters from text-mode streams; eg file.read(5) will read 5 unicode
chars, which can made of more than 5 bytes.
For an ASCII stream (ie no chars > 127) it only needs to do 1 read. If
there are lots of non-ASCII chars in a stream, then it needs multiple
reads of the underlying object.
Adds a new test for this case. Enables unicode support by default on
unix and stmhal ports.
Conflicts:
stmhal/pin_named_pins.c
stmhal/readline.c
Renamed HAL_H to MICROPY_HAL_H. Made stmhal/mphal.h which intends to
define the generic Micro Python HAL, which in stmhal sits above the ST
HAL.
As stack checking is enabled by default, ports which don't call
stack_ctrl_init() are broken now (report RuntimeError on startup). Save
them trouble and just init stack control framework in interpreter init.
As we are building with -nostdlib gcc features like the stack protector
will fail linking, because the failure handlers are in gcc's internal
libs. Such features are implicitly disabled during compilation when
-nostdlib is used in CFLAGS too.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
-nostdlib is the correct option, gcc recognizes the double dash version
when in link-only mode, but not when compiling.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
This adds a hook to get/set pyb_uart_global_debug from Python, using
pyb.repl_uart(). You can set it to an arbitrary UART object, and then
the REPL (in and out) is repeated on this UART object (as well as on USB
CDC).
Ultimately, this will be replaced with a proper Pythonic interface to
set sys.stdin and sys.stdout.
io.FileIO is binary I/O, ans actually optional. Default file type is
io.TextIOWrapper, which provides str results. CPython3 explicitly describes
io.TextIOWrapper as buffered I/O, but we don't have buffering support yet
anyway.
Addresses issue #558, but it's likely that other out-of-memory errors
could crash the pyboard. Reason is that qstrs use m_new and can raise
an exception within the parser.
Need to have a policy as to how far we go adding keyword support to
built ins. It's nice to have, and gets better CPython compatibility,
but hurts the micro nature of uPy.
Addresses issue #577.
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
This renames MICROPY_HW_HAS_WLAN to MICROPY_HW_ENABLE_CC3K (since it's a
driver, not a board feature) and wraps all CC3000 code in this #if.
It's disabled for all boards.
It's not enabled by default because it doesn't fully work. It can
connect to an AP, get an IP address and do a host-lookup, but not yet do
send or recv on a socket.
Decided to write own script to pull documentation from comments in C code.
Style for writing auto generated documentation is: start line with ///
and then use standard markdown to write the comment. Keywords
recognised by the scraper begin with backslash. See code for examples.
Running: python gendoc.py modpyb.c accel.c adc.c dac.c extint.c i2c.c
led.c pin.c rng.c servo.c spi.c uart.c usrsw.c, will generate a HTML
structure in gendoc-out/.
gendoc.py is crude but functional. Needed something quick, and this was
it.
Instead of pyb.switch() as a function, it's more consistent (with
respect to all the other modules and peripherals) to have
pyb.Switch() create a switch object. This then generalises to having
multiple switches. Call the object to get its state. Use sw.callback
to set the callback function for when the switch is pressed.
Simple but functional timer control. More sophistication will
eventually be added, or for now just use direct register access :)
Also added pyb.freq() function to get MCU clock frequencies.
It's really a UART because there is no external clock line (and hence no
synchronous ability, at least in the implementation of this module).
USART should be reserved for a module that has "S"ynchronous capabilities.
Also, UART is shorter and easier to type :)
The three classes I2C, SPI and USART now have a fairly uniform (Python)
API. All are constructed, initialised and deinitialised in the same
way. They can have most of their parameters set, using keyword arguments.
All have send and recv (although slightly different with I2C requiring an
address in master mode). recv can do inplace receiving (ie store the
data in a previously-created bytearray).
It's just polling mode at the moment, but interrupt and DMA would be
nice to add.
Main reason for expanding buffer protocol API was to support writes to a
buffer in ADC module (see read_timed). With this change you can now
create an array of arbitrary type and ADC.read_timed will store into
that array in the correct format (byte, int, float). I wonder though if
all these changes were really worth it to support just this function.
Hopefully this enhanced buffer protocol API (with typecode specified)
will be used elsewhere.
This is an attempt to clean up the Micro Python API on the pyboard.
Gpio functionality is now in the Pin object, which seems more natural.
Constants for MODE and PULL are now in pyb.Pin. Names of some
classes have been adjusted to conform to CamelCase. Other
miscellaneous changes and clean up here and there.
On stmhal, computed gotos make the binary about 1k bigger, but makes it
run faster, and we have the room, so why not. All tests pass on
pyboard using computed gotos.
Internal flash used for the filesystem is now written (from the cache)
only after a 5s delay, or when a file is closed, or when the drive is
unmounted from the host. This delay means that multiple writes can
accumulate in the cache, and leads to less writes to the flash, making
it last longer.
It's implemented by a high-priority interrupt that takes care of flash
erase and write, and flushing the cache.
This is still only an interim solution for the flash filesystem. It
eventually needs to be replaced with something that uses less RAM for
the cache, something that can use more of the flash, and something that
does proper wear levelling.
The autogenerated header files have been moved about, and an extra
include dir has been added, which means you can give a custom
BUILD=newbuilddir option to make, and everything "just works"
Also tidied up the way the different Makefiles build their include-
directory flags
Need to wait for the low-level USB driver to send the data over the USB
in-endpoint before the buffer can be used again. This patch adds a
check for this.
The USB VID&PID are automatically extracted from usbd_desc_cdc_msc.c
and inserted into pybcdc_inf.template, ensuring that the same USB
IDs get used everywhere
Mac OS X sends a SCSI command to remove the medium when it unmounts a
drive. If this command is not honoured, then OS X will automatically
remount the drive, making it impossible to eject. This patch disables
the USB MSC when the right SCSI command is sent.
Reads ADC values into a bytearray (or similar) at a fixed rate. Needs a
better name and improved API. Also fix up DAC dma function (which also
needs a better name and API).
Also contains raw memory read/write functions, read8, read16, read32,
write8, write16, write32. Can now do:
stm.write16(stm.GPIOA + stm.GPIO_BSRRL, 1 << 13)
This turns on the red LED.
With the new constant folding, the above constants for the GPIO address
are actually compiled to constants (and the addition done) at compile
time. For viper code and inline assembler, this optimisation will make
a big difference. In the inline assembler, using these constants would
not be possible without this constant folding.
Full CPython compatibility with this requires actually parsing the
input so far collected, and if it fails parsing due to lack of tokens,
then continue collecting input. It's not worth doing it this way. Not
having compatibility at this level does not hurt the goals of Micro
Python.
This is to reduce ROM usage. stream_p is used in file and socket types
only (at the moment), so seems a good idea to make the protocol
functions a pointer instead of the actual structure.
It saves 308 bytes of ROM in the stmhal/ port, 928 in unix/.
Finishes addressing issue #424.
In the end this was a very neat refactor that now makes things a lot
more consistent across the py code base. It allowed some
simplifications in certain places, now that everything is a dict object.
Also converted builtins tables to dictionaries. This will be useful
when we need to turn builtins into a proper module.
This adds support for almost everything (the comma isn't currently
supported).
The "unspecified" type with floats also doesn't behave exactly like
python.
Tested under unix with float and double
Spot tested on stmhal
Pretty much everyone needs to include map.h, since it's such an integral
part of the Micro Python object implementation. Thus, the definitions
are now in obj.h instead. map.h is removed.
Mostly just a global search and replace. Except rt_is_true which
becomes mp_obj_is_true.
Still would like to tidy up some of the names, but this will do for now.
All board config macros now begin with MICROPY_HW_.
Renamed PYBv10 to PYBV10, since macros should be all uppercase.
Made SDCARD_DETECT configurable in mpconfigport.h, so that the SD
detect pin can be easily configured.
Can now choose at boot up whether the USB device is CDC+MSC or CDC+HID.
Choice is made by an option in boot.py, with default being CDC+MSC.
HID+MSC is not currently supported, but should be easy to implement.
Boot up now has ability to change the reset mode: hold down USR switch
while booting and LEDs will count from 1 to 7 to indicate the boot mode.
Release USR when correct mode is selected. Current modes are 1 (normal
boot), 2 (safe mode), 3 (reset FS mode).
Originally, .methods was used for methods in a ROM class, and
locals_dict for methods in a user-created class. That distinction is
unnecessary, and we can use locals_dict for ROM classes now that we have
ROMable maps.
This removes an entry in the bloated mp_obj_type_t struct, saving a word
for each ROM object and each RAM object. ROM objects that have a
methods table (now a locals_dict) need an extra word in total (removed
the methods pointer (1 word), no longer need the sentinel (2 words), but
now need an mp_obj_dict_t wrapper (4 words)). But RAM objects save a
word because they never used the methods entry.
Overall the ROM usage is down by a few hundred bytes, and RAM usage is
down 1 word per user-defined type/class.
There is less code (no need to check 2 tables), and now consistent with
the way ROM modules have their tables initialised.
Efficiency is very close to equivaluent.
Added support for the ADC channels and mappings to make_pins.py
I'm not sure if the hal properly deals with the channel 16/18 differences
between the 40x and 42x. It seems to deal with it partially. This particular
aspect will need testing on a 42x or 43x.
Late USB enumeration could clear settings after they had been set.
Now fixed by not clearing some settings on init.
RX was blocking if received characters were not being processed, so
CTRL-C would not be picked up. Now "fixed" by not blocking, but
instead discarding incoming characters if they overflow the buffer.
New USB HAL is quite a bit improved over previous one. Now has better
callbacks and flow control.
REPL over USB CDC now works as before, except for soft-reset (since USB
driver uses malloc...).
