diff --git a/sys/amd64/debug.c b/sys/amd64/debug.c
index f98b795..47f347a 100644
--- a/sys/amd64/debug.c
+++ b/sys/amd64/debug.c
@@ -53,6 +53,8 @@ Debug_HaltIPI()
     MP_SetState(CPUSTATE_HALTED);
     __sync_fetch_and_add(&debugHalted, 1);
 
+    enable_interrupts();
+
     while (debugCmd == 0) {
 	pause();
     }
diff --git a/sys/amd64/mp.c b/sys/amd64/mp.c
index ebd0197..a60cdae 100644
--- a/sys/amd64/mp.c
+++ b/sys/amd64/mp.c
@@ -167,12 +167,13 @@ MP_CrossCallTrap()
 int
 MP_CrossCall(CrossCallCB cb, void *arg)
 {
-    CrossCallFrame frame;
+    volatile CrossCallFrame frame;
 
     // Setup frame
     memset(&frame, 0, sizeof(frame));
     frame.cb = cb;
     frame.arg = arg;
+    frame.count = 1;
 
     Critical_Enter();
 
@@ -187,7 +188,7 @@ MP_CrossCall(CrossCallCB cb, void *arg)
     frame.done[CPU()] = 1;
 
     // Wait for all to respond
-    while (frame.count != lastCPU) {
+    while (frame.count < lastCPU) {
 	// Check for timeout
 
 	// XXX: Should dump the crosscall frame