avr-hal

There are several microcontroller architectures within the Arduino family officially as well as compatible ones that are also called Arduino-something. The classic (and oldest) are the AVR microcontrollers (ATmega), which are not supported by embassy nor rtic at the moment AFAIK. They are supported by Rust, though. see: https://github.com/rahix/avr-hal. However, there are several other Arduino microcontrollers that are supported. For example the Arduino Nano RP2040, Arduino Nano 33 BLE (nRF), the Arduino MKR ones as well as the STM32duino (STM32F103, the one in the hugely popular $2 blue-pill boards) are all based on the ARM cortex-m architecture, which is supported by both embassy as well as rtic. For espressif chips (like the esp32), support is being worked on by the manufacturer itself: https://github.com/embassy-rs/embassy/issues/745

I would like to see that avr-unknown-gnu-atmega328 works with the latest compiler. Some bug in LLVM broke it[1], because it didn't work starting with versions after nightly-2021-01-07[2]. I know that rust team has nothing to do with this, but they should improve the gcc codegen[3] to be able to run rust on more embedded devices than LLVM has support for. Someone wanted to port his libc written in rust to ia64 and the gcc codegen broke and couldn't compile that. [1] https://reviews.llvm.org/D114611 [2] https://github.com/Rahix/avr-hal/issues/124 [3] https://github.com/rust-lang/rustc_codegen_gcc