davemackintosh/embedded_workshop_2021

Tools and setup

See here.

Block A

First Block: Running on and integrating with desktop OSes.

File

• Makefile
• Comparison of failure scenarios of C and Rust
• Platform agnositc APIs in C and Rust
• Highlight of problems with glibc versions

syscall

• Quick example showing basic usage of pointers
• Quick-and-dirty example to show that rust is no magic sauce (but the compiler helps)
• The same example again but with a bit more careful error handling in place.

C-Interoperability

Rust calls C

• Showcase of how a rust application can use an external C dependency. This was already done under the hood by the syscall example.
• We build the example with gcc

C calls Rust

• Basic example of a C application making use of some Rust library
• We use cbindgen to generate bindings to the Rust lib to expose a C API.

Bindgen + cc

• Showcase of combining bindgen and cc to compile a C library and create bindigns to it for Rust.
• These are two crates generated and generated_sys to mirror the separation found in most projects

Pi

We move to a different plattform, the RaspberryPi

blink

• The typical Hello World example used to make an LED blink
• We make use of a reaedy-made library rppal but encounter challenges with crosscompiling

blink_mem

• How does the rppal library make the led blink?
• We poke around the library to find out that we need to set some registers
• We use /dev/mem to write our own code doing so
• This is in preparation of a later example

Block B

Rust Java interop

• Interoperability of Java and Rust
• Small example of an integration between Java and Rust. This will be reused in the Android example

Rust C++ interop

• Interoperability of C++ and Rust
• Showcase demonstrating the use of the cxx crate.
• Whilst this is more powerful than the plain C interoperability, we also see some of the limitations.

no_std

No_std hello world

• After we learned where parts of the Rust ecosystem are located, we can make use of those present in the no_std world.
• Printing Hello World with no_std but using the OS nonetheless ist ridiculous and surprisingly hard
• We learn to get a feeling for no_std and its limitations but see some of Rusts beauty: The mighty features like the Ownership system can also be used in a no_std environment.
• Since we ditched the standard library, our resulting executable is tiny

bare_blink

• Remember the code from the blinkblink_mem making the LED blink by poking around the memory? We can do this without the OS with nearly the same code! Of course we need to provide a bit of glue around it, after all, we write a exceptionally simple OS-Kernel.

Block C & D