feat(app): nolibc hello world

app/nolibc.c

@@ -0,0 +1,18 @@
+void *syscall5(void *number, void *arg1, void *arg2, void *arg3, void *arg4,
+               void *arg5);
+
+typedef unsigned long int size_t;
+typedef long int ssize_t;
+
+static ssize_t write(int fd, void const *data, size_t nbytes) {
+  return (ssize_t)syscall5((void *)1, /* SYS_write, call number 1 */
+                           (void *)(size_t)fd, (void *)data, (void *)nbytes,
+                           0, /* Ignored */
+                           0  /* Ignored */
+  );
+}
+
+int main() {
+  write(0, "Hello World!\n", 13);
+  return 0;
+}