Exception handler clears and updates the screen now (so one can read the error message)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1146 a1c6a512-1295-4272-9138-f99709370657

firmware/system.c

@@ -323,12 +323,19 @@ void UIE (unsigned int pc) /* Unexpected Interrupt or Exception */
 
     asm volatile ("sts\tpr,%0" : "=r"(n));
 
+    /* clear screen */
+    lcd_clear_display ();
+    /* output exception */
     n = (n - (unsigned)UIE0 - 4)>>2; // get exception or interrupt number
     snprintf(str,sizeof(str),"I%02x:%s",n,irqname[n]);
     lcd_puts(0,0,str);
     snprintf(str,sizeof(str),"at %08x",pc);
     lcd_puts(0,1,str);
 
+#ifdef HAVE_LCD_BITMAP
+    lcd_update ();
+#endif
+
     while (1)
     {
         volatile int i;