Setting Up Your Rust Embedded Toolchain

Before writing any code, we need to configure our development environment for cross-compiling to the RP2350 microcontroller. The RP2350 is a dual-core ARM Cortex-M33 microcontroller (with some special features we’ll discuss later). Rust, via rustup, can target this architecture easily.

1. Install Rust (stable) if you haven’t already, via rustup. Ensure you also have Cargo, which comes with Rust.
2. Update Rust to the latest stable version and self-update rustup (to avoid any surprises):

   rustup self update  
   rustup update stable
   

3. Add the target for RP2350: The Cortex-M33 core uses the ARMv8-M architecture with hardware floating-point. The correct Rust target triple is thumbv8m.main-none-eabihf. We’ll add that, and for completeness also add the ARMv6-M target used by older Pico (RP2040) and the RISC-V target (the RP2350 has a RISC-V mode, as we’ll mention). Run:

   rustup target add thumbv6m-none-eabi # (for RP2040, if needed)
   rustup target add thumbv8m.main-none-eabihf # RP2350 Arm Cortex-M33
   rustup target add riscv32imac-unknown-none-elf # (RP2350 RISC-V mode)
   

   Note: The RP2350 is unique in that each core can actually run as either an ARM Cortex-M33 or a RISC-V core (Hazard3) – a novel feature where the core type can be swapped at runtime . In this guide we’ll focus on the standard Cortex-M (ARM) mode. The RISC-V target is added just in case and for future exploration.

With these tools you will already be able to turn valid Rust code into a .elf file, which you can then flash onto the RP2350 using the methods described in the next chapter.