The C nearbyint function has exactly the semantics that Python's round()
requires, whereas C's round() requires extra steps to handle rounding of
numbers half way between integers. So using nearbyint reduces code size
and potentially eliminates any source of errors in the handling of half-way
numbers.
Also, bare-metal implementations of nearbyint can be more efficient than
round, so further code size is saved (and efficiency improved).
nearbyint is provided in the C99 standard so it should be available on all
supported platforms.
The -ansi flag is used for C dialect selection and it is equivalent to -std=c90.
Because it goes right before -std=gnu99 it is ignored as for conflicting flags
GCC always uses the last one.
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.
Previously they used historical "pyb" affix causing confusion and
inconsistency (there's no "pyb" module in modern ports; but people
took esp8266 port as an example, and "pyb" naming kept proliferating,
while other people complained that source structure is not clear).
To build, "make 512k".
Disabled are FatFs support (no space for filesystem), Python functionality
related to files, btree module, and recently enabled features. With all
this, there's only one free FlashROM page.
SDK 2.0.0 goes into boot loop if a firmware is programmed over erased flash,
causing problems with user experience. This change implements behavior
similar to older SDKs': if clean flash is detected, default system
parameters are used.
Added options to make deploy so it can be used for ESP8266 boards with
other flash configurations. For example NodeMCU DEVKIT V1.0 can now use:
$ make FLASH_MODE=dio FLASH_SIZE=32m deploy
This new config option allows to control whether MicroPython uses its own
internal printf or not (if not, an external one should be linked in).
Accompanying this new option is the inclusion of lib/utils/printf.c in the
core list of source files, so that ports no longer need to include it
themselves.
modpybhspi now does the needed multiplexing, calling out to modpybspi
(bitbanging SPI) for suitable peripheral ID's. modmachinespi (previous
multiplexer class) thus not needed and removed.
modpybhspi also updated to following standard SPI peripheral naming:
SPI0 is used for FlashROM and thus not supported so far. SPI1 is available
for users, and thus needs to be instantiated as:
spi = machine.SPI(1, ...)
This extra forward slash for the starting-point directory is unnecessary
and leads to additional slashes on Max OS X which mean that the frozen
files cannot be imported.
Fixes#2374.
To start with, the critical scripts _boot.py and flashbdev.py are frozen
to improve performance and reduce RAM consumption.
Saves about 1000 bytes of heap RAM for a bare boot with filesystem.
Based on my experience, there's rather non-zero chance to have an image be
flashed incorrectly. As --verify option is now works well in teh latest
esptool.py, enable it by default.
All functionality of the pyb module is available in other modules, like
time, machine and os. The only outstanding function, info(), is
(temporarily) moved to the esp module and the pyb module is removed.