Merge #79

79: Replace manual assembly with nasm-rs and cc r=mkroening a=mkroening



Co-authored-by: Martin Kröning <mkroening@posteo.net>

Cargo.toml

@@ -18,6 +18,10 @@ x86 = { version = "0.47", default-features = false }
 [target.'cfg(target_arch = "aarch64")'.dependencies]
 aarch64 = "0.0.7"
 
+[build-dependencies]
+cc = "1.0"
+nasm-rs = "0.2"
+
 [profile.dev]
 opt-level = 1  # `opt-level = 0` makes bootloader to large for bootstrapping
 

build.rs

@@ -1,25 +1,21 @@
 use std::env;
-use std::path::Path;
-use std::process::Command;
 
-fn main() {
+fn main() -> Result<(), String> {
 	let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
 
 	if target_arch == "x86_64" {
-		let out_dir = env::var("OUT_DIR").unwrap();
+		let mut nasm = nasm_rs::Build::new();
+		nasm.file("src/arch/x86_64/entry.asm");
+		let objects = nasm.compile_objects()?;
 
-		Command::new("nasm")
-			.args(&["src/arch/x86_64/entry.asm", "-felf64", "-o"])
-			.arg(&format!("{}/entry.o", out_dir))
-			.status()
-			.expect("Could not start nasm. Is it installed?");
-		Command::new("ar")
-			.args(&["crus", "libentry.a", "entry.o"])
-			.current_dir(&Path::new(&out_dir))
-			.status()
-			.expect("Could not start ar. Is it installed?");
+		let mut cc = cc::Build::new();
+		for object in objects {
+			cc.object(object);
+		}
+		cc.compile("entry");
 
-		println!("cargo:rustc-link-search=native={}", out_dir);
 		println!("cargo:rustc-link-lib=static=entry");
 	}
+
+	Ok(())
 }