Write default linker script if no overlay were specified

src/Tools/mkoverlay/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+tool_helper = {path = "../tool_helper"}

src/Tools/mkoverlay/src/creator/ldscript.rs

@@ -0,0 +1,21 @@
+use super::super::types::OverlaySlot;
+use tool_helper::{Error, format_if_error, Output};
+use std::io::Write;
+
+const DEFAULT_LD_SCRIPT:&'static str = r#"
+__heap_base = __bss_end;
+"#;
+
+pub fn write(output: &mut Output, overlay_desc: &Vec<OverlaySlot>) -> Result<(), Error> {
+    if overlay_desc.is_empty() {
+        return write_default(output);
+    }
+
+    format_if_error!(write!(output, "Dino\n"), "Writing test output failed with: {error_text}")?;
+    return Ok(());
+}
+
+fn write_default(output: &mut Output) -> Result<(), Error> {
+    format_if_error!(output.write(DEFAULT_LD_SCRIPT.as_bytes()), "Writing default LD Script failed with: {error_text}")?;
+    Ok(())
+}

src/Tools/mkoverlay/src/creator/mod.rs

@@ -0,0 +1,2 @@
+pub mod ldscript;
+pub mod makefile;

src/Tools/mkoverlay/src/lib.rs

@@ -1 +1,2 @@
 pub mod types;
+pub mod creator;

src/Tools/mkoverlay/src/main.rs

@@ -1,4 +1,5 @@
 use mkoverlay::types::{OverlaySection, OverlaySlot};
+use tool_helper::{Error, open_output};
 
 fn generate_file() -> Vec<OverlaySlot> {
     let mut slots   = Vec::new();
@@ -13,6 +14,16 @@ fn generate_file() -> Vec<OverlaySlot> {
     slots
 }
 
+fn run_main() -> Result<(), Error> {
+    let     input  = generate_file();
+    let mut output = open_output(None)?;
+
+    mkoverlay::creator::ldscript::write(&mut output, &input)
+}
+
 fn main() {
-    println!("Blubbi: {:?}", generate_file());
+    match run_main() {
+        Ok(())     => println!("Planschbecken!!"),
+        Err(error) => println!("{}", error),
+    }
 }