make it work

test/init.c

@@ -1,11 +1,20 @@
-void _start(void)
+// <https://jborza.com/post/2021-05-11-riscv-linux-syscalls/>
+
+_Noreturn void __attribute__ ((noinline)) exit(int code)
 {
-    __asm__ volatile (
+    __asm__ volatile(
         "li a7, 93;" // exit
-        "li a0, 0;" // code 0
+        "mv a0, %0;"  // code
         "ecall"
         :
-        :
+        : "r"(code)
         : "a7", "a0", "memory"
     );
+    __builtin_unreachable();
+}
+
+_Noreturn void _start(void)
+{
+    
+    exit(10);
 }