//! This build script copies the `memory.x` file from the crate root into //! a directory where the linker can always find it at build time. //! For many projects this is optional, as the linker always searches the //! project root directory -- wherever `Cargo.toml` is. However, if you //! are using a workspace or have a more complicated build setup, this //! build script becomes required. Additionally, by requesting that //! Cargo re-run the build script whenever `memory.x` is changed, //! updating `memory.x` ensures a rebuild of the application with the //! new memory settings. //! //! The build script also sets the linker flags to tell it which link script to use. use std::env; use std::fs::File; use std::io::Write; use std::path::PathBuf; fn main() { // Put `memory.x` in our output directory and ensure it's // on the linker search path. let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap()); File::create(out.join("memory.x")) .unwrap() .write_all(include_bytes!("memory.x")) .unwrap(); println!("cargo:rustc-link-search={}", out.display()); // By default, Cargo will re-run a build script whenever // any file in the project changes. By specifying `memory.x` // here, we ensure the build script is only re-run when // `memory.x` is changed. println!("cargo:rerun-if-changed=memory.x"); // Specify linker arguments. // `--nmagic` is required if memory section addresses are not aligned to 0x10000, // for example the FLASH and RAM sections in your `memory.x`. // See https://github.com/rust-embedded/cortex-m-quickstart/pull/95 println!("cargo:rustc-link-arg=--nmagic"); // Set the linker script to the one provided by cortex-m-rt. println!("cargo:rustc-link-arg=-Tlink.x"); println!("cargo:rustc-linker=flip-link"); println!("cargo:rustc-link-arg=-Tdefmt.x"); }