Started to implement syscall.rs

test/userlib/sys.s

@@ -65,7 +65,7 @@ __start:
 
 		.globl Halt
 	.type	__Halt, @function
-Halt:
+Shutdown:
 	addi a7,zero,SC_HALT
 	ecall
 	jr	ra

test/userlib/syscall.rs

@@ -0,0 +1,21 @@
+pub struct Burritos_Time {
+    seconds: i64,
+    nanos: i64
+}
+pub struct ThreadId{
+    id: u64
+}
+pub struct t_error{
+    t: i32
+}
+extern "C"{
+    fn Shutdown() -> ();
+    fn SysTime(t: Burritos_Time) -> ();
+    fn Exit(status: i32) -> ();
+    fn Exec(name: String) -> ThreadId;
+    fn newThread(debug_name: String, func: i32, arg: i32) -> ThreadId;
+    fn Join (id: ThreadId) -> t_error;
+    fn Yield() -> ();
+    fn Perror(mess: String) -> ();
+
+}