[PATCH] Improve EFI grub-install to handle non-Apple systems

[Colin Watson <cjwatson@ubuntu.com>]

At the moment, the EFI grub-install script only handles Apple Mac
systems.  This patch adds support for systems that conform to the UEFI
specification, while retaining support for Apple systems.

I couldn't find anything approaching a standard for where the EFI System
Partition should be mounted, so I chose to look for it in /boot/efi,
since I don't like creating new top-level directories.  If there's a
different convention then I'd be happy to add support for it.

Vladimir asked whether I could merge util/i386/efi/grub-install.in into
util/grub-install.in at the same time.  This is of course desirable but
I haven't got round to it yet, and I didn't want to stall this patch
indefinitely until I find time for that.

2010-07-12  Colin Watson  <cjwatson@ubuntu.com>

	* util/i386/efi/grub-install.in: Add support for systems that
	conform to the UEFI specification, as well as Apple systems.
	Currently looks for the EFI System Partition on /boot/efi.

=== modified file 'util/i386/efi/grub-install.in'
--- util/i386/efi/grub-install.in	2010-07-04 12:23:55 +0000
+++ util/i386/efi/grub-install.in	2010-07-12 11:43:20 +0000
@@ -24,6 +24,7 @@ exec_prefix=@exec_prefix@
 sbindir=@sbindir@
 bindir=@bindir@
 libdir=@libdir@
+sysconfdir=@sysconfdir@
 PACKAGE_NAME=@PACKAGE_NAME@
 PACKAGE_TARNAME=@PACKAGE_TARNAME@
 PACKAGE_VERSION=@PACKAGE_VERSION@
@@ -43,10 +44,14 @@ rootdir=
 grub_prefix=`echo /boot/grub | sed ${transform}`
 modules=
 
+efibootmgr=`which efibootmgr 2>/dev/null || true`
+
 no_floppy=
 force_lba=
 recheck=no
+removable=no
 debug=no
+efi_quiet=
 
 # Usage: usage
 # Print the usage.
@@ -65,6 +70,7 @@ Install GRUB on your EFI partition.
   --grub-probe=FILE       use FILE as grub-probe
   --no-floppy             do not probe any floppy drive
   --recheck               probe a device map even if it already exists
+  --removable             the installation device is removable
 
 $self copies GRUB images into the DIR/boot directory specified by
 --root-directory.
@@ -127,9 +133,14 @@ do
 	no_floppy="--no-floppy" ;;
     --recheck)
 	recheck=yes ;;
+    --removable)
+	removable=yes ;;
     # This is an undocumented feature...
     --debug)
 	debug=yes ;;
+    # Intentionally undocumented; for compatibility only.
+    -f | --force)
+	;;
     *)
 	echo "Unrecognized option \`$option'" 1>&2
 	usage
@@ -138,9 +149,13 @@ do
     esac
 done
 
+# for make_system_path_relative_to_its_root()
+. ${libdir}/grub/grub-mkconfig_lib
+
 # If the debugging feature is enabled, print commands.
 if test $debug = yes; then
     set -x
+    efi_quiet=-q
 fi
 
 # Initialize these directories here, since ROOTDIR was initialized.
@@ -177,6 +192,106 @@ else
     exit 1
 fi
 
+# Get GRUB_DISTRIBUTOR.
+if test -f ${sysconfdir}/default/grub ; then
+    . ${sysconfdir}/default/grub
+fi
+
+# Find the EFI System Partition.
+efidir=
+if test -d ${bootdir}/efi; then
+    install_device=`$grub_mkdevicemap --device-map=/dev/stdout | $grub_probe --target=device --device-map=/dev/stdin ${bootdir}/efi`
+    # Is it a mount point?
+    if test "x$install_device" != "x`$grub_mkdevicemap --device-map=/dev/stdout | $grub_probe --target=device --device-map=/dev/stdin ${bootdir}`"; then
+	efidir=${bootdir}/efi
+    fi
+elif test -n "$rootdir" && test "x$rootdir" != "x/"; then
+    # The EFI System Partition may have been given directly using
+    # --root-directory.
+    install_device=`$grub_mkdevicemap --device-map=/dev/stdout | $grub_probe --target=device --device-map=/dev/stdin ${rootdir}`
+    # Is it a mount point?
+    if test "x$install_device" != "x`$grub_mkdevicemap --device-map=/dev/stdout | $grub_probe --target=device --device-map=/dev/stdin ${rootdir}/..`"; then
+	efidir=${rootdir}
+    fi
+fi
+
+if test -n "$efidir"; then
+    efi_fs=`$grub_probe --target=fs --device-map=${device_map} ${efidir}`
+    if test "x$efi_fs" = xfat; then :; else
+	echo "${efidir} doesn't look like an EFI partition." 1>&2
+	efidir=
+    fi
+fi
+
+if test -n "$efidir"; then
+    # The EFI specification requires that an EFI System Partition must
+    # contain an "EFI" subdirectory, and that OS loaders are stored in
+    # subdirectories below EFI.  Vendors are expected to pick names that do
+    # not collide with other vendors.  To minimise collisions, we use the
+    # name of our distributor if possible.
+    if test $removable = yes; then
+	# The specification makes stricter requirements of removable
+	# devices, in order that only one image can be automatically loaded
+	# from them.  The image must always reside under /EFI/BOOT, and it
+	# must have a specific file name depending on the architecture.
+	efi_distributor=BOOT
+	case "$target_cpu" in
+	i386)
+	    efi_file=BOOTIA32.EFI
+	    ;;
+	x86-64)
+	    efi_file=BOOTX64.EFI
+	    ;;
+	# GRUB does not yet support these architectures, but they're defined
+	# by the specification so we include them here to ease future
+	# expansion.
+	ia64)
+	    efi_file=BOOTIA64.EFI
+	    ;;
+	arm)
+	    efi_file=BOOTARM.EFI
+	    ;;
+	esac
+    else
+	efi_distributor="$(echo "$GRUB_DISTRIBUTOR" | tr '[A-Z]' '[a-z]' | cut -d' ' -f1)"
+	if test -z "$efi_distributor"; then
+	    efi_distributor=grub
+	fi
+	# It is convenient for each architecture to have a different
+	# efi_file, so that different versions can be installed in parallel.
+	case "$target_cpu" in
+	i386)
+	    efi_file=grubia32.efi
+	    ;;
+	x86-64)
+	    efi_file=grubx64.efi
+	    ;;
+	# GRUB does not yet support these architectures, but they're defined
+	# by the specification so we include them here to ease future
+	# expansion.
+	ia64)
+	    efi_file=grubia64.efi
+	    ;;
+	arm)
+	    efi_file=grubarm.efi
+	    ;;
+	*)
+	    efi_file=grub.efi
+	    ;;
+	esac
+	# TODO: We should also use efibootmgr, if available, to add a Boot
+	# entry for ourselves.
+    fi
+    efidir="$efidir/EFI/$efi_distributor"
+    mkdir -p "$efidir" || exit 1
+else
+    # We don't know what's going on.  Fall back to traditional
+    # (non-specification-compliant) behaviour.
+    efidir="$grubdir"
+    efi_distributor=
+    efi_file=grub.efi
+fi
+
 # Create the GRUB directory if it is not present.
 mkdir -p "$grubdir" || exit 1
 
@@ -221,13 +336,16 @@ for dir in ${localedir}/*; do
     fi
 done
 
+# Write device to a variable so we don't have to traverse /dev every time.
+grub_device=`$grub_probe --target=device --device-map=${device_map} ${grubdir}` || exit 1
+
 if ! test -f ${grubdir}/grubenv; then
     $grub_editenv ${grubdir}/grubenv create
 fi
 
 # Create the core image. First, auto-detect the filesystem module.
-fs_module=`$grub_probe --target=fs --device-map=${device_map} ${grubdir}`
-if test "x$fs_module" = xfat; then :; else
+fs_module=`$grub_probe --target=fs --device-map=${device_map} --device ${grub_device}`
+if test "$efidir" != "$grubdir" || test "x$fs_module" = xfat; then :; else
     echo "${grubdir} doesn't look like an EFI partition." 1>&2
     exit 1
 fi
@@ -236,17 +354,86 @@ fi
 # this command is allowed to fail (--target=fs already grants us that the
 # filesystem will be accessible).
 partmap_module=
-for x in `$grub_probe --target=partmap --device-map=${device_map} ${grubdir} 2> /dev/null`; do
+for x in `$grub_probe --target=partmap --device-map=${device_map} --device ${grub_device} 2> /dev/null`; do
    partmap_module="$partmap_module part_$x";
 done
 
 # Device abstraction module, if any (lvm, raid).
-devabstraction_module=`$grub_probe --target=abstraction --device-map=${device_map} ${grubdir}`
+devabstraction_module=`$grub_probe --target=abstraction --device-map=${device_map} --device ${grub_device}`
 
 # The order in this list is critical.  Be careful when modifying it.
 modules="$modules $fs_module $partmap_module $devabstraction_module"
 
-$grub_mkimage -O ${target_cpu}-efi --output=${grubdir}/grub.efi $modules || exit 1
+relative_grubdir=`make_system_path_relative_to_its_root ${grubdir}` || exit 1
+if [ "x${relative_grubdir}" = "x" ] ; then
+    relative_grubdir=/
+fi
+
+prefix_drive=
+config_opt=
+
+if [ "x${devabstraction_module}" = "x" ] ; then
+    if [ x"${install_device}" != x ]; then
+      if echo "${install_device}" | grep -qx "(.*)" ; then
+        install_drive="${install_device}"
+      else
+        install_drive="`$grub_probe --target=drive --device-map=${device_map} --device ${install_device}`" || exit 1
+      fi
+      install_drive="`echo ${install_drive} | sed -e s/,[a-z0-9,]*//g`"
+    fi
+    grub_drive="`$grub_probe --target=drive --device-map=${device_map} --device ${grub_device}`" || exit 1
+
+    # Strip partition number
+    grub_drive="`echo ${grub_drive} | sed -e s/,[a-z0-9,]*//g`"
+    if [ "x${grub_drive}" != "x${install_drive}" ] ; then
+        uuid="`$grub_probe --target=fs_uuid --device ${grub_device}`"
+        if [ "x${uuid}" = "x" ] ; then
+          echo "You attempted a cross-disk install, but the filesystem containing ${grubdir} does not support UUIDs." 1>&2
+          exit 1
+        fi
+        echo "search.fs_uuid ${uuid} root " > ${grubdir}/load.cfg
+	echo 'set prefix=($root)'"${relative_grubdir}" >> ${grubdir}/load.cfg
+	config_opt="-c ${grubdir}/load.cfg "
+        modules="$modules search_fs_uuid"
+    fi
+else
+    prefix_drive=`$grub_probe --target=drive --device ${grub_device}` || exit 1
+fi
+
+$grub_mkimage ${config_opt} -O ${target_cpu}-efi --output=${efidir}/${efi_file} --prefix=${prefix_drive}${relative_grubdir} $modules || exit 1
+
+# Try to make this image bootable using the EFI Boot Manager, if available.
+if test "$removable" = no && test -n "$efi_distributor" && \
+   test -n "$efibootmgr"; then
+    # On Linux, we need the efivars kernel modules.
+    case "$host_os" in
+    linux*)
+	modprobe -q efivars 2>/dev/null || true
+	;;
+    esac
+
+    # Delete old entries from the same distributor.
+    for bootnum in `efibootmgr | grep '^Boot[0-9]' | \
+		    fgrep " $efi_distributor" | cut -b5-8`; do
+	efibootmgr $efi_quiet -b "$bootnum" -B
+    done
+
+    # Add a new entry for the image we just created.  efibootmgr needs to be
+    # given the disk device and partition number separately, so we have to
+    # fiddle about with grub-probe to get hold of this reasonably reliably.
+    # Use fresh device map text to avoid any problems with stale data, since
+    # all we need here is a one-to-one mapping.
+    clean_devmap="$($grub_mkdevicemap --device-map=/dev/stdout)"
+    efidir_drive="$(echo "$clean_devmap" | $grub_probe --target=drive --device-map=/dev/stdin "$efidir")"
+    if test -z "$efidir_drive"; then
+	echo "Can't find GRUB drive for $efidir; unable to create EFI Boot Manager entry." >&2
+    else
+	efidir_disk="$(echo "$clean_devmap" | grep "^$(echo "$efidir_drive" | sed 's/,[^)]*//')" | cut -f2)"
+	efidir_part="$(echo "$efidir_drive" | sed 's/^([^,]*,[^0-9]*//; s/[^0-9].*//')"
+	efibootmgr $efi_quiet -c -d "$efidir_disk" -p "$efidir_part" -w \
+	    -L "$GRUB_DISTRIBUTOR" -l "\\EFI\\$efi_distributor\\$efi_file"
+    fi
+fi
 
 # Prompt the user to check if the device map is correct.
 echo "Installation finished. No error reported."

Thanks,

-- 
Colin Watson                                       [cjwatson@ubuntu.com]