define CIRCUITPY_BOOT_OUTPUT_FILE will cause mp_hal_stdout_tx_strn() to
invoke before serial_init() is called. Solution is skipped output to
serial if it is not inited.
gcc 8.0 supports the naked attribute for x86 systems so it can now be used
here. And in fact it is necessary to use this for nlr_push because gcc 8.0
no longer generates a prelude for this function (even without the naked
attribute).
- moving Makefile to parent folder. This resolves some of the weird path/build issues
- remove trace references to cpydiff and original file (no longer used anywhere)
- converting SOURCEDIR to a changeable variable, passed through all sphinx-build calls
- adding path to conf.py, in case it moves again
- making `-v` default with VERBOSE
- making `-E` default with FORCE
- creating BASEOPTS to store all the dirs, paths, and settings, passing them to sphinx-build in one long chain, instead of individually
- updating README to use the make command as default. Also added text explaining some of the customization you can add into a make command
This patch adds the configuration MICROPY_HW_USB_ENABLE_CDC2 which enables
a new USB device configuration at runtime: VCP+VCP+MSC. It will give two
independent VCP interfaces available via pyb.USB_VCP(0) and pyb.USB_VCP(1).
The first one is the usual one and has the REPL on it. The second one is
available for general use.
This configuration is disabled by default because if the mode is not used
then it takes up about 2200 bytes of RAM. Also, F4 MCUs can't support this
mode on their USB FS peripheral (eg PYBv1.x) because they don't have enough
endpoints. The USB HS peripheral of an F4 supports it, as well as both the
USB FS and USB HS peripherals of F7 MCUs.
The documentation (including the examples) for elapsed_millis and
elapsed_micros can be found in docs/library/pyb.rst so doesn't need to be
written in full in the source code.
When disabled, the pyb.I2C class saves around 8k of code space and 172
bytes of RAM. The same functionality is now available in machine.I2C
(for F4 and F7 MCUs).
It is still enabled by default.
