From ee9835938a27c7f8d3eb22192d4f3be9244f535e Mon Sep 17 00:00:00 2001
From: Paul Gardner-Stephen <paul@m-e-g-a.org>
Date: Sat, 31 May 2025 20:40:25 +0930
Subject: [PATCH] force CPU into hypervisor before updating HYPPO image #222

---
 src/tools/m65.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/tools/m65.c b/src/tools/m65.c
index 5daa70a0..de916763 100644
--- a/src/tools/m65.c
+++ b/src/tools/m65.c
@@ -2280,7 +2280,21 @@ int main(int argc, char **argv)
     if (hyppo) {
       log_info("replacing hyppo...");
       real_stop_cpu();
-      load_file(hyppo, 0xfff8000, patchKS);
+
+      // Reset CPU, and then stop it quickly so that we know it's still in the hypervisor
+      monitor_sync();
+      slow_write(fd, "\r!\r", 3);
+      usleep(100000);
+      slow_write(fd, "\rt1\r", 4);      
+      monitor_sync();
+      sleep(1);
+      
+      load_file(hyppo, 0xfff8000, patchKS);      
+
+      // Reset CPU after loading new HYPPO
+      slow_write(fd, "\r!\r", 3);
+      monitor_sync();
+      sleep(2);
     }
     if (flashmenufile) {
       log_info("replacing flashmenu");