From: Piotr Krysiuk <piotras@gmail.com>
Date: Sun, 20 Apr 2014 13:58:45 +0000 (+0200)
Subject: Allow loading old kernels by placing GDT in conventional memory.
X-Git-Tag: 2.02-beta3~644
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5a6db38d62235094a903882b71ef2749b4c19cbb;p=thirdparty%2Fgrub.git

Allow loading old kernels by placing GDT in conventional memory.
---

diff --git a/ChangeLog b/ChangeLog
index 30d0cace4..1be8e5e64 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2014-04-20  Piotr Krysiuk  <piotras@gmail.com>
+
+	* grub-core/lib/i386/relocator.c: Allow loading old kernels by placing
+	GDT in conventional memory.
+
 2014-04-10  Colin Watson  <cjwatson@ubuntu.com>
 
 	* util/grub.d/30_os-prober.in: Tolerate devices with no filesystem
diff --git a/grub-core/lib/i386/relocator.c b/grub-core/lib/i386/relocator.c
index d2a1b27ae..ffaf25f08 100644
--- a/grub-core/lib/i386/relocator.c
+++ b/grub-core/lib/i386/relocator.c
@@ -81,10 +81,13 @@ grub_relocator32_boot (struct grub_relocator *rel,
   void *relst;
   grub_relocator_chunk_t ch;
 
-  err = grub_relocator_alloc_chunk_align (rel, &ch, 0,
-					  (0xffffffff - RELOCATOR_SIZEOF (32))
-					  + 1, RELOCATOR_SIZEOF (32), 16,
-					  GRUB_RELOCATOR_PREFERENCE_NONE,
+  /* Specific memory range due to Global Descriptor Table for use by payload
+     that we will store in returned chunk.  The address range and preference
+     are based on "THE LINUX/x86 BOOT PROTOCOL" specification.  */
+  err = grub_relocator_alloc_chunk_align (rel, &ch, 0x1000,
+					  0x9a000 - RELOCATOR_SIZEOF (32),
+					  RELOCATOR_SIZEOF (32), 16,
+					  GRUB_RELOCATOR_PREFERENCE_LOW,
 					  avoid_efi_bootservices);
   if (err)
     return err;