Starting a new project

A recommendation when starting a RTIC project from scratch is to follow RTIC's defmt-app-template.

If you are targeting ARMv6-M or ARMv8-M-base architecture, check out the section Target Architecture for more information on hardware limitations to be aware of.

This will give you an RTIC application with support for RTT logging with defmt and stack overflow protection using flip-link. There is also a multitude of examples provided by the community:

For inspiration, you may look at the RTIC examples.

RTIC on RISC-V devices

Even though RTIC was initially developed for ARM Cortex-M, it is possible to use RTIC on RISC-V devices. However, the RISC-V ecosystem is more heterogeneous. To tackle this issue, currently, RTIC implements three different backends:

• riscv-esp32c3-backend: This backend provides support for the ESP32-C3 SoC. In these devices, RTIC is very similar to its Cortex-M counterpart.

• riscv-esp32c6-backend: This backend provides support for the ESP32-C6 SoC. In these devices, RTIC is very similar to its Cortex-M counterpart.

• riscv-mecall-backend: This backend provides support for any RISC-V device. In this backend, pending tasks trigger Machine Environment Call exceptions. The handler for this exception source dispatches pending tasks according to their priority. The behavior of this backend is equivalent to riscv-clint-backend. The main difference of this backend is that all the tasks must be software tasks. Additionally, it is not required to provide a list of dispatchers in the #[app] attribute, as RTIC will generate them at compile time.

• riscv-clint-backend: This backend supports devices with a CLINT peripheral. It is equivallent to riscv-mecall-backend, but instead of triggering exceptions, it triggers software interrupts via the MSIP register of the CLINT.