[otlib] Add delay to QEMU monitor creation

Signed-off-by: James Wainwright <[email protected]>

Author: jwnrt

sw/host/opentitanlib/src/transport/qemu/mod.rs

@@ -12,6 +12,8 @@ pub mod uart;
 use std::cell::RefCell;
 use std::rc::Rc;
 use std::str::FromStr;
+use std::thread;
+use std::time::Duration;
 
 use anyhow::{Context, bail};
 
@@ -173,6 +175,10 @@ impl Qemu {
         let reset = QemuReset::new(Rc::clone(&monitor));
         let reset = Rc::new(reset);
 
+        // QEMU polls once per second to see if PTYs have been connected to. We must wait that
+        // full second to be sure that QEMU is watching all of them.
+        thread::sleep(Duration::from_secs(1));
+
         Ok(Qemu {
             monitor,
             reset,