println 实现

ch2/user/src/user_lang_items/user_console.rs

@@ -1,4 +1,5 @@
 use core::fmt::{Arguments, Write, Result};
+use crate::syscall::sys_write;
 
 struct Stdout;
 
@@ -6,7 +7,7 @@ const STDOUT: usize = 1;
 
 impl Write for Stdout {
     fn write_str(&mut self, s: &str) -> Result {
-        // ... todo 实现系统调用
+        sys_write(STDOUT, s.as_bytes());
         Ok(())
     }
 }

ch2/user/src/user_lang_items/user_panic.rs

@@ -1,16 +1,17 @@
 use core::panic::PanicInfo;
+use crate::println;
 
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
     if let Some(location) = info.location() {
-        // println!(
-        //     "Panicked at {}:{} {}",
-        //     location.file(),
-        //     location.line(),
-        //     info.message().unwrap()
-        // );
+        println!(
+            "Panicked at {}:{} {}",
+            location.file(),
+            location.line(),
+            info.message().unwrap()
+        );
     } else {
-        // println!("Panicked: {}", info.message().unwrap());
+        println!("Panicked: {}", info.message().unwrap());
     }
     loop {