This is a pristine copy (actually a subset of files) of upstream FreeRTOS
v9.0.0.
Modifications to the previous version of FreeRTOS (v8.1.2) included
addition of __attribute__ ((section (".boot"))) to the following
functions:
pxPortInitialiseStack
prvTaskExitError
prvPortStartFirstTask
xPortStartScheduler
vPortSetupTimerInterrupt
xTaskGenericCreate
vTaskStartScheduler
prvInitialiseTCBVariables
prvInitialiseTaskLists
prvAllocateTCBAndStack
This attribute will need to be reinstated on a case-by-case basis
because some of the above functions are now removed/changed.
This has implications all over the place. I have to admit that
you can instantly see that usability improves, but it costs 3K.
At the same time I took the oportunity to rename the '/SFLASH'
drive to '/flash' which improves compatibility with the pyboard.
Such functions are never used after MicroPython has started, and they
remain in RAM wasting space. Now they are placed in a special section
named "boot" which sits just before the heap, allowing us to extend
the effective heap area up to the new boot section. Right now, this
gives us back ~1K, but in the future, more functions might end up in
there as well.
The port currently implements support for GPIO, RTC, ExtInt and the WiFi
subsystem. A small file system is available in the serial flash. A
bootloader which makes OTA updates possible, is also part of this initial
implementation.