This allows to statically allocate the TCB (thread control block) and
thread stack in the BSS segment, reducing the need for dynamic memory
allocation.
Now only the bits that really need to be written in assembler are written
in it, otherwise C is used. This means that the assembler code no longer
needs to know about the global state structure which makes it much easier
to maintain.
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.
SA_SIGINFO allows the signal handler to access more information about
the signal, especially useful in a threaded environment. The extra
information is not currently used but it may prove useful in the future.
GC_EXIT() can cause a pending thread (waiting on the mutex) to be
scheduled right away. This other thread may trigger a garbage
collection. If the pointer to the newly-allocated block (allocated by
the original thread) is not computed before the switch (so it's just left
as a block number) then the block will be wrongly reclaimed.
This patch makes sure the pointer is computed before allowing any thread
switch to occur.
By using a single, global mutex, all memory-related functions (alloc,
free, realloc, collect, etc) are made thread safe. This means that only
one thread can be in such a function at any one time.
The linker flag --gc-sections is not available on the linker used on
Mac OS X which results in an error when linking micropython on Mac OS X.
Therefore move this option to the LDFLAGS_ARCH variable on non Darwin
systems. According to http://stackoverflow.com/a/17710056 the equivalent
to --gc-sections is -dead_strip thus this option is used for the
LDFLAGS_ARCH on Darwin systems.
In particular, the WeMOS D1 Mini board comes with a shield that has a
64x48 OLED display. This patch makes it display properly, with the upper
left pixel being at (0, 0) and not (32, 0).
I tried to do this with the configuration commands, but there doesn't
seem to be a command that would set the column offset (there is one for
the line offset, though).
Damien George