Add support for pca10059 with REPL over tinyusb USB CDC.
The board also includes a board specific module that will
recover UICR->REGOUT0 in case this has been erased.
This initial support does not preserve any existing bootloader
on the pca10090 in case this was present, and expects to use all
available flash on the device.
Add nrf-port finyusb driver files. USB CDC can be activated
by board configuration files using the MICROPY_HW_USB_CDC.
Updating BLE driver, Makefile, nrfx-glue and main.c to plug
in the tinyusb stack.
The specific board can be selected with the BOARD makefile variable. This
defaults (if not specified) to BOARD=GENERIC, which is the original default
firmware build. For the 512k target use BOARD=GENERIC_512K.
On other ports (e.g. ESP32) they provide a complete Nimble implementation
(i.e. we don't need to use the code in extmod/nimble). This change
extracts out the bits that we don't need to use in other ports:
- malloc/free/realloc for Nimble memory.
- pendsv poll handler
- depowering the cywbt
Also cleans up the root pointer management.
In which case place the native function prelude in a bytes object, linked
from the const_table of that function. An architecture should define
N_PRELUDE_AS_BYTES_OBJ to 1 before including py/emitnative.c to emit
correct machine code, then enable MICROPY_EMIT_NATIVE_PRELUDE_AS_BYTES_OBJ
so the runtime can correctly handle the prelude being in a bytes object.
Such that args/return regs for the parent are different to args/return regs
for child calls. For an architecture to use this feature it should define
the REG_PARENT_xxx macros before including py/emitnative.c.