The motivation for doing this is so that we can allow
common_hal_mcu_disable_interrupts in IRQ context, something that works
on other ports, but not on nRF with SD enabled. This is because
when SD is enabled, calling sd_softdevice_is_enabled in the context
of an interrupt with priority 2 or 3 causes a HardFault. We have chosen
to give the USB interrupt priority 2 on nRF, the highest priority that
is compatible with SD.
Since at least SoftDevice s130 v2.0.1, sd_nvic_critical_region_enter/exit
have been implemented as inline functions and are safe to call even if
softdevice is not enabled. Reference kindly provided by danh:
https://devzone.nordicsemi.com/f/nordic-q-a/29553/sd_nvic_critical_region_enter-exit-missing-in-s130-v2
Switching to these as the default/only way to enable/disable interrupts
simplifies things, and fixes several problems and potential problems:
* Interrupts at priority 2 or 3 could not call common_hal_mcu_disable_interrupts
because the call to sd_softdevice_is_enabled would HardFault
* Hypothetically, the state of sd_softdevice_is_enabled
could change from the disable to the enable call, meaning the calls
would not match (__disable_irq() could be balanced with
sd_nvic_critical_region_exit).
This also fixes a problem I believe would exist if disable() were called
twice when SD is enabled. There is a single "is_nested_critical_region"
flag, and the second call would set it to 1. Both of the enable()
calls that followed would call critical_region_exit(1), and interrupts
would not properly be reenabled. In the new version of the code,
we use our own nesting_count value to track the intended state, so
now nested disable()s only call critical_region_enter() once, only
updating is_nested_critical_region once; and only the second enable()
call will call critical_region_exit, with the right value of i_n_c_r.
Finally, in port_sleep_until_interrupt, if !sd_enabled, we really do
need to __disable_irq, rather than using the common_hal_mcu routines;
the reason why is documented in a comment.
This commit adds time.ticks_ms/us support using RTC1 as the timebase. It
also adds the time.ticks_add/diff helper functions. This feature can be
enabled using MICROPY_PY_TIME_TICKS. If disabled the system uses the
legacy sleep methods and does not have any ticks functions.
In addition support for MICROPY_EVENT_POLL_HOOK was added to the
time.sleep_ms(x) function, making this function more power efficient and
allows support for select.poll/asyncio. To support this, the RTC's CCR0
was used to schedule a ~1msec event to wakeup the CPU.
Some important notes about the RTC timebase:
- Since the granularity of RTC1's ticks are approx 30usec, time.ticks_us is
not perfect, does not have 1us resolution, but is otherwise quite usable.
For tighter measurments the ticker's 1MHz counter should be used.
- time.ticks_ms(x) should *not* be called in an IRQ with higher prio than
the RTC overflow irq (3). If so it introduces a race condition and
possibly leads to wrong tick calculations.
See #6171 and #6202.
new file: ports/nrf/boards/raytac_mdbt50q-db-40/bootloader/6.0.0/pca10056_bootloader_6.0.0_s140.zip
new file: ports/nrf/boards/raytac_mdbt50q-db-40/mpconfigboard.h
new file: ports/nrf/boards/raytac_mdbt50q-db-40/mpconfigboard.mk
new file: ports/nrf/boards/raytac_mdbt50q-db-40/pins.c
When compiling for debug (-O0) the .text segment cannot fit the flash
region when MICROPY_ROM_TEXT_COMPRESSION=1, because the compiler does not
optimise away the large if-else chain used to select the correct compressed
string.
This commit enforces MICROPY_ROM_TEXT_COMPRESSION=0 when compiling for
debug (DEBUG=1).
The storage space of the advertisement name is not declared static, leading
to a random advertisement name. This commit fixes the issue by declaring
it static.
The Bluetooth link gets disconnected when connecting from a PC after 30-40
seconds. This commit adds handling of the data length update request. The
data length parameter pointer is set to NULL in the reply, letting the
SoftDevice automatically set values and use them in the data length update
procedure.
mp_keyboard_interrupt() triggers a compiler error because the function is
implicitly declared. This commit adds "py/runtime.h" to the includes.
Fixes issue #5732.
Testing performed: That a card is successfully mounted on Pygamer with
the built in SD card slot
This module is enabled for most FULL_BUILD boards, but is disabled for
samd21 ("M0"), litex, and pca10100 for various reasons.
* 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.
