From 8ac3a0e4ad335171cc67c4b8bc37e0d344ccb199 Mon Sep 17 00:00:00 2001
From: Mike Fleetwood <mike.fleetwood@googlemail.com>
Date: Fri, 3 Jun 2016 20:34:09 +0100
Subject: [PATCH] Recognise GRUB2 core.img (#766989)

Recognise GRUB2 core.img boot code written to a partition without a file
system.  Such setups are possible/likely with GPT partitioned disks as
there is a specific partition type reserved for it [1][2]:
    21686148-6449-6E6F-744E-656564454649  (BIOS Boot partition)

[1] GUID Partition Table, Partition types
    https://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs

[2] BIOS boot partition
    https://en.wikipedia.org/wiki/BIOS_boot_partition

Bug 766989 - zfsonline support - need file system name support for ZFS
             type codes
---
 include/Utils.h     | 13 +++++++------
 src/GParted_Core.cc | 32 ++++++++++++++++++++------------
 src/Utils.cc        |  2 ++
 3 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/include/Utils.h b/include/Utils.h
index 22567881..e14a5279 100644
--- a/include/Utils.h
+++ b/include/Utils.h
@@ -90,14 +90,15 @@ enum FILESYSTEM
 
 	// Recognised signatures but otherwise unsupported file system types
 	FS_BITLOCKER       = 25,
-	FS_LINUX_SWRAID    = 26,
-	FS_LINUX_SWSUSPEND = 27,
-	FS_REFS            = 28,
-	FS_ZFS             = 29,
+	FS_GRUB2_CORE_IMG  = 26,
+	FS_LINUX_SWRAID    = 27,
+	FS_LINUX_SWSUSPEND = 28,
+	FS_REFS            = 29,
+	FS_ZFS             = 30,
 
 	// Partition space usage colours
-	FS_USED            = 30,
-	FS_UNUSED          = 31
+	FS_USED            = 31,
+	FS_UNUSED          = 32
 } ;
 
 enum SIZE_UNIT
diff --git a/src/GParted_Core.cc b/src/GParted_Core.cc
index 9768ab80..5b8c0a8c 100644
--- a/src/GParted_Core.cc
+++ b/src/GParted_Core.cc
@@ -1548,19 +1548,27 @@ FILESYSTEM GParted_Core::detect_filesystem_internal( PedDevice * lp_device, PedP
 		const char * sig2;
 		FILESYSTEM   fstype;
 	} signatures[] = {
-		//offset1, sig1          , offset2, sig2  , fstype
-		{ 65536LL, "ReIsEr4"     ,     0LL, NULL  , FS_REISER4   },
-		{   512LL, "LABELONE"    ,   536LL, "LVM2", FS_LVM2_PV   },
-		{     0LL, "LUKS\xBA\xBE",     0LL, NULL  , FS_LUKS      },
-		{ 65600LL, "_BHRfS_M"    ,     0LL, NULL  , FS_BTRFS     },
-		{     3LL, "-FVE-FS-"    ,     0LL, NULL  , FS_BITLOCKER },
-		{  1030LL, "\x34\x34"    ,     0LL, NULL  , FS_NILFS2    }
+		//offset1, sig1              , offset2, sig2  , fstype
+		{ 65536LL, "ReIsEr4"         ,     0LL, NULL  , FS_REISER4        },
+		{   512LL, "LABELONE"        ,   536LL, "LVM2", FS_LVM2_PV        },
+		{     0LL, "LUKS\xBA\xBE"    ,     0LL, NULL  , FS_LUKS           },
+		{ 65600LL, "_BHRfS_M"        ,     0LL, NULL  , FS_BTRFS          },
+		{     3LL, "-FVE-FS-"        ,     0LL, NULL  , FS_BITLOCKER      },
+		{  1030LL, "\x34\x34"        ,     0LL, NULL  , FS_NILFS2         },
+		{     0LL, "\x52\x56\xBE\x1B",     0LL, NULL  , FS_GRUB2_CORE_IMG },
+		{     0LL, "\x52\x56\xBE\x6F",     0LL, NULL  , FS_GRUB2_CORE_IMG },
+		{     0LL, "\x52\xE8\x28\x01",     0LL, NULL  , FS_GRUB2_CORE_IMG },
+		{     0LL, "\x52\xBF\xF4\x81",     0LL, NULL  , FS_GRUB2_CORE_IMG }
 	};
-	// Reference:
-	//   Detecting BitLocker
-	//   http://blogs.msdn.com/b/si_team/archive/2006/10/26/detecting-bitlocker.aspx
-	// Consider validation of BIOS Parameter Block fields as unnecessary for
-	// simple recognition only of BitLocker.
+	// For simple BitLocker recognition consider validation of BIOS Parameter block
+	// fields unnecessary.
+	// *   Detecting BitLocker
+	//     http://blogs.msdn.com/b/si_team/archive/2006/10/26/detecting-bitlocker.aspx
+	//
+	// Recognise GRUB2 core.img just by any of the possible first 4 bytes of x86 CPU
+	// instructions it starts with.
+	// *   bootinfoscript v0.74 line 1963  [GRUB2 core.img possible staring 4 bytes]
+	//     https://github.com/arvidjaar/bootinfoscript/blob/b1f711e39d7aa4021f4ad3d31468a8b1e1b3fda7/bootinfoscript#L1963
 
 	for ( unsigned int i = 0 ; i < sizeof( signatures ) / sizeof( signatures[0] ) ; i ++ )
 	{
diff --git a/src/Utils.cc b/src/Utils.cc
index 165c13bb..8a8da5e9 100644
--- a/src/Utils.cc
+++ b/src/Utils.cc
@@ -115,6 +115,7 @@ Glib::ustring Utils::get_color( FILESYSTEM filesystem )
 		case FS_UNUSED		: return "#FFFFFF" ;	//white
 		case FS_LVM2_PV		: return "#B39169" ;	//face skin dark
 		case FS_BITLOCKER	: return "#494066" ;	//purple shadow
+		case FS_GRUB2_CORE_IMG	: return "#666666" ;	//~ dark gray
 		case FS_LUKS		: return "#625B81" ;	//purple dark
 		case FS_LINUX_SWRAID   	: return "#5A4733" ;	// ~ dark brown
 		case FS_LINUX_SWSUSPEND	: return "#884631" ;	//red dark
@@ -291,6 +292,7 @@ Glib::ustring Utils::get_filesystem_string( FILESYSTEM filesystem )
 		case FS_UNUSED		: return _("unused") ;
 		case FS_LVM2_PV		: return "lvm2 pv" ;
 		case FS_BITLOCKER	: return "bitlocker" ;
+		case FS_GRUB2_CORE_IMG	: return "grub2 core.img";
 		case FS_LUKS		: return "luks";
 		case FS_LINUX_SWRAID	: return "linux-raid" ;
 		case FS_LINUX_SWSUSPEND	: return "linux-suspend" ;