Minor - use wait_irq() instead of irq_enable()/hlt() in apm.
diff --git a/src/apm.c b/src/apm.c
index 6efead0..2ca2c64 100644
--- a/src/apm.c
+++ b/src/apm.c
@@ -9,7 +9,7 @@
 #include "farptr.h" // GET_VAR
 #include "bregs.h" // struct bregs
 #include "ioport.h" // outb
-#include "util.h" // irq_enable
+#include "util.h" // wait_irq
 #include "config.h" // CONFIG_*
 #include "biosvar.h" // GET_GLOBAL
 
@@ -94,8 +94,7 @@
 static void
 handle_155305(struct bregs *regs)
 {
-    irq_enable();
-    hlt();
+    wait_irq();
     set_success(regs);
 }