NASM to FASM

build.rs

@@ -1,5 +1,19 @@
+use std::{process::Command, env};
+
 fn main() {
     println!("cargo:rerun-if-changed=src/syscalls.S");
-    nasm_rs::compile_library_args("libsyscalls.a", &["src/syscalls.S"], &["-f elf32"])
-        .expect("failed to compile assembly");
+
+    let out_dir = env::var("OUT_DIR").unwrap();
+    
+    Command::new("fasm")
+        .arg("src/syscalls.S")
+        .arg(&format!("{}/libsyscalls.a", out_dir))
+        .status().unwrap();
+    Command::new("ar")
+        .arg("crus")
+        .arg(&format!("{}/libsyscalls.a", out_dir))
+        .arg(&format!("{}/libsyscalls.o", out_dir))
+        .status().unwrap();
+
+    println!("cargo:rustc-link-search={}", out_dir)
 }

src/syscalls.S

@@ -1,13 +1,13 @@
-BITS 32
+format ELF
 
-section .text
-    global _exit
-    global _start_window_draw
-    global _end_window_draw
-    global _define_window
-    global _display_message
-    global _wait_event
-    global _pressed_key
+section '.text'
+    public _exit
+    public _start_window_draw
+    public _end_window_draw
+    public _define_window
+    public _display_message
+    public _wait_event
+    public _pressed_key
 
 _exit:
     mov eax, -1