[PATCH] grub-setup Modify the conditionality of the copy of the partition table

[Mario Limonciello <mario_limonciello@dell.com>]

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 Hi:

I've discovered that in snapshots of GRUB2 in Ubuntu natty, you are no longer able to install GRUB2 to a partition and successfully boot on certain Dell E-series Latitudes.  This is a regression from the GRUB2 that was included in Ubuntu maverick.  The BIOS makes an assertion based on the content of the partition table section of the PBR and content that doesn't resemble a partition table will cause the the BIOS to get stuck in a loop and never complete POST.

I've identified the changeset that caused this to be r2751.  I've created a patch that modifies the conditionality of the partition table copy to not check for a partition table, but instead to verify it's not operating on a floppy disk.  This restores the previous behavior when installing to a partition, and still allows the new behavior for floppy disk installations.

Thanks,

-- 
*Mario Limonciello*
Linux Engineer
*Dell* | OS Engineering

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=== modified file 'ChangeLog'
--- ChangeLog	2011-03-23 19:29:17 +0000
+++ ChangeLog	2011-03-25 21:56:23 +0000
@@ -1,3 +1,11 @@
+2011-03-24  Mario Limonciello    <Mario_Limonciello@Dell.com>
+        * util/grub-setup.c: Conditionalize the partition map copy on floppy
+          support, not on whether the target contains partitions.
+
+          Otherwise, the BIOS on Dell Latitude E series laptops will freeze 
+          during POST if an invalid partition table is contained in the PBR
+          of the active partition when GRUB is installed to a partition.
+
 2011-03-23  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* grub-core/term/gfxterm.c (calculate_normal_character_width): Return 8

=== modified file 'util/grub-setup.c'
--- util/grub-setup.c	2011-01-07 12:27:34 +0000
+++ util/grub-setup.c	2011-03-25 21:51:56 +0000
@@ -399,25 +399,25 @@
       }
 #endif
 
-    if (! dest_partmap)
-      {
-	grub_util_warn (_("Attempting to install GRUB to a partitionless disk or to a partition.  This is a BAD idea."));
-	goto unable_to_embed;
-      }
-    if (multiple_partmaps || fs)
-      {
-	grub_util_warn (_("Attempting to install GRUB to a disk with multiple partition labels or both partition label and filesystem.  This is not supported yet."));
-	goto unable_to_embed;
-      }
-
     /* Copy the partition table.  */
-    if (dest_partmap)
+    if (!allow_floppy || !grub_util_biosdisk_is_floppy (dest_dev->disk))
       memcpy (boot_img + GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC,
 	      tmp_img + GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC,
 	      GRUB_BOOT_MACHINE_PART_END - GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC);
 
     free (tmp_img);
     
+    if (! dest_partmap)
+      {
+	grub_util_warn (_("Attempting to install GRUB to a partitionless disk or to a partition.  This is a BAD idea."));
+	goto unable_to_embed;
+      }
+    if (multiple_partmaps || fs)
+      {
+	grub_util_warn (_("Attempting to install GRUB to a disk with multiple partition labels or both partition label and filesystem.  This is not supported yet."));
+	goto unable_to_embed;
+      }
+
     if (!dest_partmap->embed)
       {
 	grub_util_warn ("Partition style '%s' doesn't support embeding",


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