build.rs

use std::path::PathBuf;
use std::{env, fs};

fn main() {
    // Put the memory definitions somewhere the linker can find it
    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
    println!("cargo:rustc-link-search={}", out_dir.display());

    let boards: Vec<_> = env::vars()
        .filter_map(|(key, _value)| {
            if key.starts_with("CARGO_FEATURE_BOARD") {
                Some(key[20..].to_ascii_lowercase()) // Strip 'CARGO_FEATURE_BOARD_'
            } else {
                None
            }
        })
        .collect();

    if boards.is_empty() {
        panic!("No board features selected");
    }
    if boards.len() > 1 {
        panic!("More than one board feature selected: {:?}", boards);
    }

    let board = boards.first().unwrap();

    match board.as_str() {
        "hifive1" => {
            fs::copy("memory-hifive1.x", out_dir.join("hifive1-memory.x")).unwrap();
            println!("cargo:rerun-if-changed=memory-hifive1.x");
        }
        "hifive1_revb" | "redv" => {
            fs::copy("memory-hifive1-revb.x", out_dir.join("hifive1-memory.x")).unwrap();
            println!("cargo:rerun-if-changed=memory-hifive1-revb.x");
        }
        "lofive" | "lofive_r1" => {
            fs::copy("memory-lofive-r1.x", out_dir.join("hifive1-memory.x")).unwrap();
            println!("cargo:rerun-if-changed=memory-lofive-r1.x");
        }

        other => panic!("Unknown board: {}", other),
    }

    fs::copy("hifive1-link.x", out_dir.join("hifive1-link.x")).unwrap();
    println!("cargo:rerun-if-changed=hifive1-link.x");

    // Copy library with flash setup code
    let name = env::var("CARGO_PKG_NAME").unwrap();
    fs::copy("bin/flash.a", out_dir.join(format!("lib{}.a", name))).unwrap();
    println!("cargo:rustc-link-lib=static={}", name);
    println!("cargo:rerun-if-changed=bin/flash.a");
}