Add snake program skelton.

Author: thejpster

.vscode/settings.json

@@ -4,6 +4,7 @@
         "./samples/panic/Cargo.toml",
         "./samples/hello/Cargo.toml",
         "./samples/fault/Cargo.toml",
+        "./samples/snake/Cargo.toml",
         "./Cargo.toml"
     ]
 }

samples/Cargo.toml

@@ -3,6 +3,7 @@ members = [
     "fault",
     "hello",
     "input-test",
+    "snake",
     "panic",
 ]
 

samples/snake/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "snake"
+version = "0.1.0"
+edition = "2021"
+license = "MIT OR Apache-2.0"
+authors = ["Jonathan 'theJPster' Pallant <[email protected]>"]
+description = "ANSI Snake for Neotron systems"
+
+[dependencies]
+neotron-sdk = { path = "../.." }
+
+# See workspace for profile settings

samples/snake/build.rs

@@ -0,0 +1,21 @@
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `neotron-cortex-m.ld` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("neotron-cortex-m.ld"))
+        .unwrap()
+        .write_all(include_bytes!("../neotron-cortex-m.ld"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `neotron-cortex-m.ld`
+    // here, we ensure the build script is only re-run when
+    // `neotron-cortex-m.ld` is changed.
+    println!("cargo:rerun-if-changed=../neotron-cortex-m.ld");
+}

samples/snake/src/main.rs

@@ -0,0 +1,17 @@
+#![cfg_attr(target_os = "none", no_std)]
+#![cfg_attr(target_os = "none", no_main)]
+
+#[cfg(not(target_os = "none"))]
+fn main() {
+    neotron_sdk::init();
+}
+
+#[no_mangle]
+extern "C" fn neotron_main() -> i32 {
+    let stdout = neotron_sdk::stdout();
+    if stdout.write(b"Hello, world\n").is_ok() {
+        0
+    } else {
+        1
+    }
+}