The Itsybitsy exposes the SWD pins on an unpopulated header on the end
of the board. Add a OpenOCD config and document how to use it.
Signed-off-by: Michael Hope <mlhx@google.com>
The preceeding patches causes bossac to automatically pull the flash
address from DeviceTree, so drop the explicit flag.
Signed-off-by: Michael Hope <mlhx@google.com>
The Adafruit ItsyBitsy M4 express is a small (36 mm x 18 mm) ARM
development board with an onboard RGB LED, USB port, 2 MiB of SPI
flash, and range of I/O broken out onto 23 GPIO pins.
Signed-off-by: Michael Hope <mlhx@google.com>