Add Hurl.debug_lookup()

src/hulk/hurl.d

@@ -8,6 +8,7 @@ module hulk.hurl;
 import hos.cpu;
 import hulk.hippo;
 import hos.memory;
+import hulk.klog;
 
 /** HULK virtual base address. */
 enum ulong HULK_VIRTUAL_BASE_ADDRESS = 0xFFFF_8000_0000_0000u;
@@ -34,6 +35,7 @@ struct Hurl
     private struct PageTableEntry
     {
         private ulong m_entry;
+        alias m_entry this;
 
         this(ulong address, ulong flags)
         {
@@ -130,4 +132,27 @@ struct Hurl
             map(address, address, flags);
         }
     }
+
+    public static void debug_lookup(void * address)
+    {
+        klog.writefln("Debugging page table lookup of 0x%x", address);
+        PageTable * pt = m_pt_base;
+        for (size_t level = 0; level < 4u; level++)
+        {
+            PageTableEntry entry = (*pt)[address, level];
+            klog.writefln("Level %u, entry = 0x%x", level, entry);
+            if (entry.present)
+            {
+                pt = entry.follow();
+            }
+            else
+            {
+                break;
+            }
+            if ((entry & MAP_HUGE_PAGE) != 0u)
+            {
+                break;
+            }
+        }
+    }
 }