From b096dcee78665128c4a7713b434c73f9205302ad Mon Sep 17 00:00:00 2001
From: Yifan Wu <shinbokuow@163.com>
Date: Fri, 12 Feb 2021 13:03:08 +0800
Subject: [PATCH] Update app loader.

---
 os/build.rs      |  2 +-
 os/src/loader.rs | 52 ++++++++++++++++++++++++------------------------
 2 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/os/build.rs b/os/build.rs
index 2c006876..6038c95b 100644
--- a/os/build.rs
+++ b/os/build.rs
@@ -38,7 +38,7 @@ _num_app:
     .global _app_names
 _app_names:"#)?;
     for app in apps.iter() {
-        writeln!(f, r#"    .string "{}\n""#, app)?;
+        writeln!(f, r#"    .string "{}""#, app)?;
     }
 
     for (idx, app) in apps.iter().enumerate() {
diff --git a/os/src/loader.rs b/os/src/loader.rs
index d49cf694..6f302adb 100644
--- a/os/src/loader.rs
+++ b/os/src/loader.rs
@@ -1,4 +1,5 @@
 use alloc::vec::Vec;
+use lazy_static::*;
 
 pub fn get_num_app() -> usize {
     extern "C" { fn _num_app(); }
@@ -21,41 +22,40 @@ pub fn get_app_data(app_id: usize) -> &'static [u8] {
     }
 }
 
+lazy_static! {
+    static ref APP_NAMES: Vec<&'static str> = {
+        let num_app = get_num_app();
+        extern "C" { fn _app_names(); }
+        let mut start = _app_names as usize as *const u8;
+        let mut v = Vec::new();
+        unsafe {
+            for _ in 0..num_app {
+                let mut end = start;
+                while end.read_volatile() != '\0' as u8 {
+                    end = end.add(1);
+                }
+                let slice = core::slice::from_raw_parts(start, end as usize - start as usize);
+                let str = core::str::from_utf8(slice).unwrap();
+                v.push(str);
+                start = end.add(1);
+            }
+        }
+        v
+    };
+}
+
+
 #[allow(unused)]
 pub fn get_app_data_by_name(name: &str) -> Option<&'static [u8]> {
     let num_app = get_num_app();
-    let app_names = app_names();
     (0..num_app)
-        .find(|&i| app_names[i] == name)
+        .find(|&i| APP_NAMES[i] == name)
         .map(|i| get_app_data(i))
 }
 
-#[allow(unused)]
-fn app_names() -> Vec<&'static str> {
-    let num_app = get_num_app();
-    extern "C" { fn _app_names(); }
-    let mut start = _app_names as usize as *const u8;
-    let mut v = Vec::new();
-    unsafe {
-        for _ in 0..num_app {
-            let mut end = start;
-            while end.read_volatile() != '\n' as u8 {
-                end = end.add(1);
-            }
-            let slice = core::slice::from_raw_parts(start, end as usize - start as usize);
-            let str = core::str::from_utf8(slice).unwrap();
-            v.push(str);
-            // Mention that there is a extra char between names
-            start = end.add(2);
-        }
-    }
-    v
-}
-
 pub fn list_apps() {
-    let apps = app_names();
     println!("/**** APPS ****");
-    for app in apps {
+    for app in APP_NAMES.iter() {
         println!("{}", app);
     }
     println!("**************/")