* Enable dcache for OCRAM where the VM heap lives.
* Add CIRCUITPY_SWO_TRACE for pushing program counters out over the
SWO pin via the ITM module in the CPU. Exempt some functions from
instrumentation to reduce traffic and allow inlining.
* Place more functions in ITCM to handle errors using code in RAM-only
and speed up CP.
* Use SET and CLEAR registers for digitalio. The SDK does read, mask
and write.
* Switch to 2MiB reserved for CircuitPython code. Up from 1MiB.
* Run USB interrupts during flash erase and write.
* Allow storage writes from CP if the USB drive is disabled.
* Get perf bench tests running on CircuitPython and increase timeouts
so it works when instrumentation is active.
Only uppercase ASCII letters a-z. This saves ~900 bytes. Previously
written files with other unicode letters will only be accessible
from their upper cased path.
If an exception's chain or context can refer to a pointer from a different
VM, a crash would typically result.
This couldn't turn up on UNIX testing because the VM is never torn
down and rebuilt like it is on hardware.
Because in the 'static' case the GeneratorObject is now fully initialized
whenever it's raised, the initialization can be dropped, which reduces
the flash size slightly.
Closes: #7565
cpython actually makes sure the newly chained exception doesn't create
a cycle (even indirectly); see _PyErr_SetObject use of "Floyd's cycle
detection algo". We'll go for the simpler solution of just checking
one level deep until it's clear we need to do more.
Closes: #7414
This may help address #7409 if the underlying cause is the deterministic
volume ID. However, not all boards have working urandom (samd21
at least does not) so a couple of fallbacks are attempted when it fails.
I verified that on a pico_w, each `storage.erase_filesystem()` gives
a distinct 32-bit volume ID (pico_w's urandom can never fail)
The conversion of characters like _space_ in qstrs is a bit
ad-hoc. Because "_not_" stands for the logical negation character ¬
the recently added message was displayed incorrectly:
```
>>> socket.getaddrinfo('does.not.exist', 0)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
gaierror: (-2, 'Name or service_space¬space_known')
```
I had noticed this, but evidently failed to include the fix in
the problem in #7269.
