The flash-IRQ handler is used to flush the storage cache, ie write
outstanding block data from RAM to flash. This is triggered by a timeout,
or by a direct call to flush all storage caches.
Prior to this commit, a timeout could trigger the cache flushing to occur
during the execution of a read/write to external SPI flash storage. In
such a case the storage subsystem would break down.
SPI storage transfers are already protected against USB IRQs, so by
changing the priority of the flash IRQ to that of the USB IRQ (what is
done in this commit) the SPI transfers can be protected against any
timeouts triggering a cache flush (the cache flush would be postponed until
after the transfer finished, but note that in the case of SPI writes the
timeout is rescheduled after the transfer finishes).
The handling of internal flash sync'ing needs to be changed to directly
call flash_bdev_irq_handler() sync may be called with the IRQ priority
already raised (eg when called from a USB MSC IRQ handler).
MCUs that have a PLLSAI can use it to generate a 48MHz clock for USB, SDIO
and RNG peripherals. In such cases the SYSCLK is not restricted to values
that allow the system PLL to generate 48MHz, but can be any frequency.
This patch allows such configurability for F7 MCUs, allowing the SYSCLK to
be set in 2MHz increments via machine.freq(). PLLSAI will only be enabled
if needed, and consumes about 1mA extra. This fine grained control of
frequency is useful to get accurate SPI baudrates, for example.
If bytearray is constructed from str, a second argument of encoding is
required (in CPython), and third arg of Unicode error handling is allowed,
e.g.:
bytearray("str", "utf-8", "strict")
This is similar to bytes:
bytes("str", "utf-8", "strict")
This patch just allows to pass 2nd/3rd arguments to bytearray, but
doesn't try to validate them to not impact code size. (This is also
similar to how bytes constructor is handled, though it does a bit
more validation, e.g. check that in case of str arg, encoding argument
is passed.)
This removes the need for a separate axtls build stage, and builds all
axtls object files along with other code. This simplifies and cleans up
the build process, automatically builds axtls when needed, and puts the
axtls object files in the correct $(BUILD) location.
The MicroPython axtls configuration file is provided in
extmod/axtls-include/config.h
A recent version of arm-none-eabi-gcc (8.2.0) will warn about unused packed
attributes in USB_WritePacket and USB_ReadPacket. This patch suppresses
such warnings for this file only.
This patch adds full support for unwinding jumps to the native emitter.
This means that return/break/continue can be used in try-except,
try-finally and with statements. For code that doesn't use unwinding jumps
there is almost no overhead added to the generated code.
The native emitter keeps the current exception in a slot in its C stack
(instead of on its Python value stack), so when it catches an exception it
must explicitly clear that slot so the same exception is not reraised later
on.
Back in 8047340d75 basic support was added in
the VM to handle return statements within a finally block. But it didn't
cover all cases, in particular when some finally's were active and others
inactive when the "return" was executed.
This patch adds further support for return-within-finally by correctly
managing the currently_in_except_block flag, and should fix all cases. The
main point is that finally handlers remain on the exception stack even if
they are active (currently being executed), and the unwind return code
should only execute those finally's which are inactive.
New tests are added for the cases which now pass.
PEP479 (see https://www.python.org/dev/peps/pep-0479/) prohibited raising
StopIteration from within a generator (it is turned into a RuntimeError).
This behaviour was introduced in Python 3.5 and in 3.7 was made compulsory.
Until uPy implements PEP479, this patch adds .py.exp files for the relevant
tests so they can be run under Python 3.7.
In Python 3.7 the behaviour of repr() of an exception with one argument
changed: it no longer prints a trailing comma in the argument list. See
https://bugs.python.org/issue30399
This patch modifies tests that rely on this behaviour to not rely on it.
And the python34.py test is updated to include a test for this behaviour
with a .exp file.
Prior to this patch, native code would use a full nlr_buf_t for each
exception handler (try-except, try-finally, with). For nested exception
handlers this would use a lot of C stack and be rather inefficient.
This patch changes how exceptions are handled in native code by setting up
only a single nlr_buf_t context for the entire function, and then manages a
state machine (using the PC) to work out which exception handler to run
when an exception is raised by an nlr_jump. This keeps the C stack usage
at a constant level regardless of the depth of Python exception blocks.
The patch also fixes an existing bug when local variables are written to
within an exception handler, then their value was incorrectly restored if
an exception was raised (since the nlr_jump would restore register values,
back to the point of the nlr_push).
And it also gets nested try-finally+with working with the viper emitter.
Broadly speaking, efficiency of executing native code that doesn't use
any exception blocks is unchanged, and emitted code size is only slightly
increased for such function. C stack usage of all native functions is
either equal or less than before. Emitted code size for native functions
that use exception blocks is increased by roughly 10% (due in part to
fixing of above-mentioned bugs).
But, most importantly, this patch allows to implement more Python features
in native code, like unwind jumps and yielding from within nested exception
blocks.
