.. the primary user of which will be the camera, since the framebuffers
must be allocated via esp-idf allocation function and never from the
gc heap.
A board can have a default value, and the value can also be set in the
/.env file using the key CIRCUITPY_RESERVED_PSRAM with the value being
the reserved size in bytes.
Co-authored-by: Dan Halbert <halbert@adafruit.com>
Removes:
* AUTORESET_DELAY_MS which never did anything but was introduced
somehow.
* CIRCUITPY_BOOT_BUTTON in all but one ESP board because they all have
them. There is a default based on the strapping pins.
* BOARD_USER_SAFE_MODE_ACTION because it was all the same for boards
with boot buttons. Now the safe mode code manages the message.
