esp-hal/esp32s2-hal/build.rs

use std::{env, error::Error, fs::File, io::Write, path::PathBuf};

fn main() -> Result<(), Box<dyn Error>> {
    // Put the linker script somewhere the linker can find it
    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
    println!("cargo:rustc-link-search={}", out.display());

    let memory_extras = generate_memory_extras();
    File::create(out.join("memory_extras.x"))?.write_all(&memory_extras)?;

    // Only re-run the build script when memory.x is changed,
    // instead of when any part of the source code changes.
    println!("cargo:rerun-if-changed=ld/memory.x");

    #[cfg(feature = "defmt")]
    println!("cargo:rustc-link-arg=-Tdefmt.x");

    Ok(())
}

fn generate_memory_extras() -> Vec<u8> {
    let reserved_cache = if cfg!(feature = "psram") {
        "0x4000"
    } else {
        "0x2000"
    };

    format!(
        "
        /* reserved at the start of DRAM/IRAM */
        RESERVE_CACHES = {reserved_cache};
        "
    )
    .as_bytes()
    .to_vec()
}