Working on app data auto linking.

os/build.rs

@@ -0,0 +1,34 @@
+use std::io::{Result, Write};
+use std::fs::{File, read_dir};
+
+fn main() {
+    println!("cargo:rerun-if-changed=../user");
+    insert_app_data().unwrap();
+}
+
+static TARGET_PATH: &'static str = "../user/target/riscv64gc-unknown-none-elf/release/";
+
+fn insert_app_data() -> Result<()> {
+    let mut f = File::create("src/link_app.S").unwrap();
+    let apps: Vec<_> = read_dir("../user/src/bin")
+        .unwrap()
+        .into_iter()
+        .map(|dir_entry| {
+            let mut name_with_ext = dir_entry.unwrap().file_name().into_string().unwrap();
+            name_with_ext.drain(name_with_ext.find('.').unwrap()..name_with_ext.len());
+            name_with_ext
+        })
+        .collect();
+
+    for (idx, app_with_extension) in apps.iter().enumerate() {
+        writeln!(f, r#"
+    .section .data
+    .global app_{0}_start
+    .global app_{0}_end
+app_{0}_start:
+    .incbin "{2}{1}"
+app_{0}_end:
+        "#, idx, app_with_extension, TARGET_PATH)?;
+    }
+    Ok(())
+}