This allows more options to be overridden to 0 in an mpconfigboard.mk.
Improved:
* FRAMEBUFFERIO, FULL_BUILD, BITOPS, PWMIO, RGBMATRIX, OTARYIO, PULSEIO, WATCHDOG
Still problematic (pull requests welcome):
* RP2PIO & NEOPIXEL_WRITE, possibly only if a status neopixel is defined
* BITBANGIO, possibly only if BUSIO is enabled
* RTC
Incidentally, with RP2PIO & NEOPIXEL_WRITE, BITBANGIO, and RTC re-enabled I get
```
323956 bytes used, 720524 bytes free in flash firmware space out of 1044480 bytes (1020.0kB).
12072 bytes used, 250072 bytes free in ram for stack and heap out of 262144 bytes (256.0kB).
```
Closes#4515
This switches stage2 to C and uses Jinja to change the C code based
on flash settings from https://github.com/adafruit/nvm.toml. It
produces the fastest settings for the given set of external flashes.
Flash size is no longer hard coded so switching flashes with similar
capabilities but different sizes should *just work*.
This PR also places "ITCM" code in RAM to save the XIP cache for
code execution. Further optimization is possible. A blink code.py
still requires a number of flash fetches every blink.
Fixes#4041
The rp2040 is _very_ marginal for mp3 playback, and currently sometimes triggers a bug that gives garbled audio output. However, it does work for some limited situations.
Any two consecutive pins can be used for an IncrementalEncoder
Testing performed: Put a synthesized (few hundred counts per second) quadrature signal into GP2/3 and read the encoder out. Performed filesystem operations at the same time to stress test it.
The reasons for not using common_hal_rp2pio_statemachine_readinto are commented on.
This adds I2SOut and PDMIn support via PIO.
StateMachines can now:
* read and read while writing
* transfer in 1, 2 or 4 byte increments
* init pins based on expected defaults automatically
* be stopped and restarted
* rxfifo can be cleared and rxstalls detected (good for tracking when
the reading code isn't keeping up)
Fixes#4162
Also found a race condition between timer_disable and redraw, which
would happen if I debugger-paused inside common_hal_rgbmatrix_timer_disable
or put a delay or print inside it. That's what pausing inside reconstruct
fixes.
So that the "right timer" can be chosen, `timer_allocate` now gets the `self`
pointer. It's guaranteed at this point that the pin information is accurate,
so you can e.g., find a PWM unit related to the pins themselves.
This required touching each port to add the parameter even though it's
unused everywhere but raspberrypi.
The RP2040 is new microcontroller from Raspberry Pi that features
two Cortex M0s and eight PIO state machines that are good for
crunching lots of data. It has 264k RAM and a built in UF2
bootloader too.
Datasheet: https://pico.raspberrypi.org/files/rp2040_datasheet.pdf
