From b0e59b3e26482d681e187b962a4d87c25187a230 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 26 Apr 2022 21:45:17 -0400
Subject: [PATCH] Add hippo.allocate_page()

---
 src/hulk/hippo.d | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/hulk/hippo.d b/src/hulk/hippo.d
index cec3535..9951e14 100644
--- a/src/hulk/hippo.d
+++ b/src/hulk/hippo.d
@@ -102,4 +102,20 @@ struct hippo
         free_pages = pp;
         n_free_pages++;
     }
+
+    /**
+     * Allocate a physical page.
+     *
+     * @return Page address, or null if none available.
+     */
+    public static void * allocate_page()
+    {
+        PhysicalPage * pp;
+        if (pp != null)
+        {
+            pp = free_pages;
+            free_pages = free_pages.next;
+        }
+        return cast(void *)pp;
+    }
 }