File grub-efi-large-memory-map.patch of Package grub

From: Mike Travis <travis@sgi.com>
Subject: [PATCH] Convert EFI memory map to E820 map for the operating system
Date: Thu, 19 Aug 2010 14:08:00 -0400

IT#1003573

Convert EFI memory map to E820 map for the operating system
This code is based on a Linux kernel patch submitted by Edgar Hucek 

diff --exclude='*.rej' --exclude='*.orig' --exclude='*~' -Naurp grub.a/efi/efimm.c grub.b/efi/efimm.c
--- grub.a/efi/efimm.c	2010-08-17 11:04:54.000000000 -0400
+++ grub.b/efi/efimm.c	2010-08-17 11:09:07.176704838 -0400
@@ -265,6 +265,9 @@ grub_efi_get_memory_map (grub_efi_uintn_
 
 /*
  * Add a memory region to the kernel e820 map.
+ *
+ * Convert EFI memory map to E820 map for the operating system
+ * This code is based on a Linux kernel patch submitted by Edgar Hucek 
  */
 static void
 add_memory_region (struct e820_entry *e820_map,
@@ -274,25 +277,49 @@ add_memory_region (struct e820_entry *e8
 		   unsigned int type)
 {
   int x = *e820_nr_map;
+  static unsigned long long estart = 0ULL;
+  static unsigned long esize = 0L;
+  static unsigned int etype = -1;
+  static int merge = 0;
 
-  if (x == E820_MAX)
-    {
-      grub_printf ("Too many entries in the memory map!\n");
-      return;
-    }
-
-  if (e820_map[x-1].addr + e820_map[x-1].size == start
+  /* merge adjacent regions of same type */
+  if ((x > 0) && e820_map[x-1].addr + e820_map[x-1].size == start
       && e820_map[x-1].type == type)
     {
       e820_map[x-1].size += size;
+      estart = e820_map[x-1].addr;
+      esize  = e820_map[x-1].size;
+      etype  = e820_map[x-1].type;
+      merge++;
+      return;
     }
-  else
+
+    /* fill up to E820_MAX */
+    if ( x < E820_MAX )
     {
       e820_map[x].addr = start;
       e820_map[x].size = size;
       e820_map[x].type = type;
       (*e820_nr_map)++;
+      merge=0;
+      return;
+    }
+
+    /* different type means another region didn't fit */
+    /* or same type, but there's a hole */
+    if (etype != type || (estart + esize) != start)
+    {
+      merge = 0;
+      estart = start;
+      esize = size;
+      etype = type;
+      return;
     }
+
+    /* same type and no hole, merge it */
+    estart += esize;
+    esize += size;
+    merge++;
 }
 
 /*