.. and enable it on atmel-samd and raspberrypi. On trinket_m0 this saves
96 net bytes of flash. There are 216 bytes actually saved by reducing
the flash storage size of the property descriptors, but added code in
several paths takes back over half of the 'raw savings'.
By organizing the "get-only" and "get-set" (but no delete) properties
each in a different section, we can represent then more efficiently.
Testing performed: that a get-only property can still be gotten but
can't be set or deleted; that a get-set property can sill be gotten or
set but can't be deleted. Tested on pygamer.
Because this requires linker file support, I only enabled it on two of
the ports.
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 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
Jeff Epler
Scott Shawcroft
microDev