Add check that PIT ISR is firing

src/hulk/hulk.d

@@ -24,6 +24,7 @@ import hulk.rtc;
 import hulk.serial;
 import hulk.usb;
 import hulk.pit;
+import hulk.time;
 
 extern extern(C) __gshared ubyte _hulk_bss_size;
 
@@ -87,6 +88,15 @@ void hulk_start()
     Usb.initialize();
     sti();
 
+    /* Check that PIT millisecond interrupt is firing. */
+    size_t uptime = Time.uptime();
+    while (Time.uptime() <= uptime)
+    {
+    }
+    Klog.writefln("\a5HULK Initialization Complete!");
+
+    /* Idle loop. */
+    Time.msleep(1);
     for (;;)
     {
         hlt();

src/hulk/time.d

@@ -23,7 +23,7 @@ struct Time
      */
     public static @property ulong uptime()
     {
-        return s_uptime;
+        return volatileLoad(&s_uptime);
     }
 
     /**
@@ -35,7 +35,7 @@ struct Time
     public static void msleep(ulong count)
     {
         ulong wait_for = s_uptime + count + 1;
-        while (volatileLoad(&s_uptime) < wait_for)
+        while (uptime() < wait_for)
         {
         }
     }