If a port defines MICROPY_READER_POSIX or MICROPY_READER_FATFS then
lexer.c now provides an implementation of mp_lexer_new_from_file using
the mp_reader_new_file function.
Implementations of persistent-code reader are provided for POSIX systems
and systems using FatFS. Macros to use these are MICROPY_READER_POSIX and
MICROPY_READER_FATFS respectively. If an alternative implementation is
needed then a port can define the function mp_reader_new_file.
Its addition was due to an early exploration on how to add CPython-like
stream interface. It's clear that it's not needed and just takes up
bytes in all ports.
If an I2C send/recv fails then the peripheral is now checked to see if
it's in a "stuck" state waiting for the stop bit, and if so then it is
reset so that the next I2C transaction can proceed.
This patch also de-inits the I2C peripheral in the init() method, before
init'ing it again.
New keyword option in constructor and init() method is "dma=<bool>".
DMA is now disabled by default for I2C transfers because it currently does
not handle I2C bus errors very well (eg if slave device doesn't ACK or
NACK correctly during a transfer).
The DMA state is always HAL_DMA_STATE_RESET because of the memset clearing
all the data, so prior to this patch HAL_DMA_DeInit was never called. Now
it is always called to make sure the DMA is properly reset.
Now, to use frozen bytecode all a port needs to do is define
FROZEN_MPY_DIR to the directory containing the .py files to freeze, and
define MICROPY_MODULE_FROZEN_MPY and MICROPY_QSTR_EXTRA_POOL.
In order to have more fine-grained control over how builtin functions are
constructed, the MP_DECLARE_CONST_FUN_OBJ macros are made more specific,
with suffix of _0, _1, _2, _3, _VAR, _VAR_BETEEN or _KW. These names now
match the MP_DEFINE_CONST_FUN_OBJ macros.
In particular, this makes the L4 .isr_vector section 16K in size so it's
the same as the F4/F7 MCUs. The patch also moves the L4 filesystem to
the end of flash, which allows for 512K filesystem on the 1Mb devices
like the STM32L476DISC.
The delay_half parameter must be specified by the port to set up the
timing of the software SPI. This allows the port to adjust the timing
value to better suit its timing characteristics, as well as provide a
more accurate printing of the baudrate.
It's simpler to just default to always using software SPI if no specific
peripheral id/name is given. To use hardware SPI users must specify a
hardware peripheral id as the first parameter to the SPI constructor.
