Experiment: Devicetree and device driver access in Rust

cmake/modules/rust.cmake

@@ -43,7 +43,7 @@ function(rust_cargo_application)
   # For now, hard-code the Zephyr crate directly here.  Once we have
   # more than one crate, these should be added by the modules
   # themselves.
-  set(LIB_RUST_CRATES zephyr zephyr-build)
+  set(LIB_RUST_CRATES zephyr zephyr-build zephyr-sys)
 
   _rust_map_target()
   message(STATUS "Building Rust llvm target ${RUST_TARGET}")

lib/rust/zephyr-sys/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "zephyr-sys"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+[build-dependencies]
+bindgen = { version = "0.69.4", features = ["experimental"] }

lib/rust/zephyr-sys/build.rs

@@ -0,0 +1,21 @@
+use std::env;
+use std::path::PathBuf;
+
+fn main() {
+    let bindings = bindgen::Builder::default()
+        .clang_arg("-I/home/ubuntu/zephyrproject/zephyr/include")
+        .clang_arg("-I/home/ubuntu/zephyrproject/zephyr/build/zephyr/include/generated")
+        .clang_arg("-imacros/home/ubuntu/zephyrproject/zephyr/build/zephyr/include/generated/zephyr/autoconf.h")
+        .wrap_static_fns(true)
+        .allowlist_function("gpio_.*")
+        .header("wrapper.h")
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks::new()))
+        .generate()
+        .expect("Unable to generate bindings");
+
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+
+    bindings
+        .write_to_file(out_path.join("bindings.rs"))
+        .expect("Couldn't write bindings!");
+}

lib/rust/zephyr-sys/src/lib.rs

@@ -0,0 +1,5 @@
+#![allow(non_upper_case_globals)]
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+
+include!(concat!(env!("OUT_DIR"), "/bindings.rs"));

lib/rust/zephyr-sys/wrapper.h

@@ -0,0 +1 @@
+#include <zephyr/drivers/gpio.h>

lib/rust/zephyr/Cargo.toml

@@ -14,3 +14,4 @@ Functionality for Rust-based applications that run on Zephyr.
 # used by the core Zephyr tree, but are needed by zephyr applications.
 [build-dependencies]
 zephyr-build = "0.1.0"
+zephyr-sys = "0.1.0"