From the change:
// xtensa has more registers than an instruction can address. The 16 that
// can be addressed are called the "window". When a function is called or
// returns the window rotates. This allows for more efficient function calls
// because ram doesn't need to be used. It's only used if the window wraps
// around onto itself. At that point values are "spilled" to empty spots in
// the stack that were set aside. When the window rotates back around (on
// function return), the values are restored into the register from ram.
// So, in order to read the values in the stack scan we must make sure all
// of the register values we care about have been spilled to RAM. Luckily,
// there is a HAL call to do it. There is a bit of a race condition here
// because the register value could change after it's been restored but that
// is unlikely to happen with a heap pointer while we do a GC.
Fixes#2907
* Fix flash writes that don't end on a sector boundary. Fixes#2944
* Fix enum incompatibility with IDF.
* Fix printf output so it goes out debug UART.
* Increase stack size to 8k.
* Fix sleep of less than a tick so it doesn't crash.
If interrupts are disabled, then calling sd_* functions will hardfault.
Instead, assume that it's safe to write if interrupts are disabled.
Signed-off-by: Sean Cross <sean@xobs.io>
ARM recommends issuing a DSB instruction propr to issuing WFI, as it is
required on many parts suchas Cortex-M7. This is effectively a no-op on
the Cortex-M4 used in most NRF parts, however it ensures that we won't
be surprised when new parts come out.
See
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dai0321a/BIHICBGB.html
for more information.
Signed-off-by: Sean Cross <sean@xobs.io>
In order to ensure we don't have any outstanding requests, disable
interrupts prior to issuing `WFI`.
As part of this process, check to see if there are any pending USB
requests, and only execute the `WFI` if there is no pending data.
This fixes#2855 on NRF.
Signed-off-by: Sean Cross <sean@xobs.io>
On NRF, the `rtc_reset()` function is never called. As a result,
calls to `time.time()` return a cryptic error>
```
>>> import time
>>> time.time()
'' object has no attribute 'datetime'
>>>
```
This is because `MP_STATE_VM(rtc_time_source)` is not initialized
due to `rtc_reset()` never being called.
If `CIRCUITPY_RTC` is enabled, call `rtc_reset()` as part of the
`reset_port()` call. This ensures that `time.time()` works as expected.
Signed-off-by: Sean Cross <sean@xobs.io>
