The MSP430 timer prescaler can device the 16 MHz clock down to
(16 / 2^x) MHz, with 0 <= x < 4. So no slower than 2 MHz.
With the current ztimer config the clock would run at twice the speed.
This cleans up the USCI based UART and SPI implementations and allows
multiple instances of either interface to be configured by the
boards. In addition, it allows sharing the USCI peripherals to provide
multiple serial interfaces with the same hardware (round-robin).
The nRF52840DK is an excellent wireless dev board due to the
integrated debugger, the nRF52840-Dongle is missing the debugger and
therefore a suboptimal choice.
The nRF52840-Dongle is cheap and has an excellent form factor that
allows to easily plug it into e.g. an OpenWRT system to quickly provide
a border router. The nRF52840DK is too large and too expensive for that
use case.
It appears that the rows have just been switched by mistake, this
switches them back to be correct.
This fixes compilation issues in `tests/pkg/tinyusb_netdev` with
newer versions of the RISC-V toolchain due to two competing USB
stacks being pulled in. With the older toolchain the build system
warns:
The following features may conflict: periph_usbdev tinyusb_device
But builds fine (even though surprises at runtime are likely). The
newer toolchain takes an issue with the same symbol being linked
in more than once (and more than one instance not being `weak`).
Adds a separate board for native64 instead of the `NATIVE_64BIT` workaround.
The files in `boards/native64` are more or less dummy files and just include
the `boards/native` logic (similar to `openlabs-kw41z-mini-256kib`).
The main logic for native is in `makefiles/arch/native.inc.mk`, `cpu/native`
and `boards/native`.
The remaining changes concern the build system, and change native board checks
to native CPU checks to cover both boards.
Initial version to test 64 bit compatibility.
Instead of a separate board, the inital version for Linux/x86_64 is enabled
by setting the environment variable `NATIVE_64BIT=y` and compiling as usual.
Not currently implemented:
* Architectures other than x86_64 or operating systems other than Linux
* No FreeBSD support
* No Aarch support
* Rust support for x86_64
