rust lib

mission_rust/src/lib.rs

@@ -0,0 +1,43 @@
+#![no_std]
+
+use core::panic::PanicInfo;
+
+#[panic_handler]
+fn panic(_panic: &PanicInfo<'_>) -> ! {
+    loop {}
+}
+
+extern "C" {
+    pub fn outbyte(c: cty::c_char);
+}
+
+#[no_mangle]
+pub extern "C" fn rust_main(i: cty::c_double) {
+    mission(i);
+}
+
+struct Outbytes {}
+
+use core::fmt::{Error, Write};
+
+impl Write for Outbytes {
+    fn write_str(&mut self, s: &str) -> Result<(), Error> {
+        for c in s.as_bytes() {
+            unsafe {
+                outbyte(*c);
+            }
+        }
+        Ok(())
+    }
+}
+
+fn mission(i: f64) {
+    for byte in "abcd\n".bytes() {
+        unsafe {
+            outbyte(byte);
+        }
+    }
+    let mut stdout = Outbytes {};
+    
+    let _ok = writeln!(&mut stdout, "I got {}!", i);
+}