boot directory prefix in grub-install (even with --root-directory)

boot directory prefix in grub-install (even with --root-directory)

[Grégoire Sutre]

Hi,

grub-install copies GRUB images into ${rootdir}/boot/grub (where 
${rootdir} is empty by default and can be changed with --root-directory).

To install GRUB files on a partition that contains a /boot file, one 
must specify a non-empty --root-directory, and grub files are then 
copied into /DIR/boot/grub.  Or one could mount the partition on a mount 
point of the form DIR/boot and specify --root-directory=DIR to force 
installation into the /grub directory of the partition.  Both solutions 
are not completely satisfactory.  Is there a better one?

The problem arises e.g. with NetBSD which uses /boot for its own 
bootloader.  The script util/grub-install.in contains lines to take care 
of that situation (lines 160-172), but these lines rely on a variable 
${host_os} that is not set.  This might be deprecated code from GRUB 
Legacy's grub-install, where ${host_os} is set by a configure substitution.

An alternative solution would be to have grub-install install in 
${rootdir}/grub, with ${rootdir} equal to /boot by default.  The default 
behavior (with no --root-directory) would be the same.

The following patch implements this alternative.

Thanks for your time,

Grégoire

--- util/grub-install.in.orig	2009-12-22 11:26:01.538833717 +0100
+++ util/grub-install.in	2009-12-22 12:48:55.979476412 +0100
@@ -39,8 +39,7 @@
  fi
  grub_mkdevicemap=${sbindir}/`echo grub-mkdevicemap | sed ${transform}`
  grub_probe=${sbindir}/`echo grub-probe | sed ${transform}`
-rootdir=
-grub_prefix=`echo /boot/grub | sed ${transform}`
+rootdir=/boot
  modules=

  install_device=
@@ -66,7 +65,7 @@
    -v, --version           print the version information and exit
    --modules=MODULES       pre-load specified modules MODULES
    --root-directory=DIR    install GRUB images under the directory DIR
-                          instead of the root directory
+                          instead of ${rootdir}
    --grub-setup=FILE       use FILE as grub-setup
    --grub-mkimage=FILE     use FILE as grub-mkimage
    --grub-mkdevicemap=FILE use FILE as grub-mkdevicemap
@@ -84,7 +83,7 @@

  INSTALL_DEVICE can be a GRUB device name or a system device filename.

-grub-install copies GRUB images into the DIR/boot directory specified by
+grub-install copies GRUB images into the DIR/`echo grub | sed 
${transform}` directory specified by
  --root-directory, and uses grub-setup to install grub into the boot
  sector.

@@ -157,21 +156,7 @@
      setup_verbose="--verbose"
  fi

-# Initialize these directories here, since ROOTDIR was initialized.
-case "$host_os" in
-netbsd* | openbsd*)
-    # Because /boot is used for the boot block in NetBSD and OpenBSD, 
use /grub
-    # instead of /boot/grub.
-    grub_prefix=`echo /grub | sed ${transform}`
-    bootdir=${rootdir}
-    ;;
-*)
-    # Use /boot/grub by default.
-    bootdir=${rootdir}/boot
-    ;;
-esac
-
-grubdir=${bootdir}/`echo grub | sed ${transform}`
+grubdir=${rootdir}/`echo grub | sed ${transform}`
  device_map=${grubdir}/device.map

  grub_probe="${grub_probe} --device-map=${device_map}"
@@ -204,8 +189,7 @@
  fi

  # Create the GRUB directory if it is not present.
-test -d "$bootdir" || mkdir "$bootdir" || exit 1
-test -d "$grubdir" || mkdir "$grubdir" || exit 1
+mkdir -p "$grubdir" || exit 1

  # If --recheck is specified, remove the device map, if present.
  if test $recheck = yes; then

Re: boot directory prefix in grub-install (even with --root-directory)

[Vladimir 'φ-coder/phcoder' Serbinenko]

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Grégoire Sutre wrote:
> Hi,
>
> grub-install copies GRUB images into ${rootdir}/boot/grub (where
> ${rootdir} is empty by default and can be changed with --root-directory).
>
> To install GRUB files on a partition that contains a /boot file, one
> must specify a non-empty --root-directory, and grub files are then
> copied into /DIR/boot/grub.  Or one could mount the partition on a
> mount point of the form DIR/boot and specify --root-directory=DIR to
> force installation into the /grub directory of the partition.  Both
> solutions are not completely satisfactory.  Is there a better one?
>
> The problem arises e.g. with NetBSD which uses /boot for its own
> bootloader.  The script util/grub-install.in contains lines to take
> care of that situation (lines 160-172), but these lines rely on a
> variable ${host_os} that is not set.  This might be deprecated code
> from GRUB Legacy's grub-install, where ${host_os} is set by a
> configure substitution.
>
> An alternative solution would be to have grub-install install in
> ${rootdir}/grub, with ${rootdir} equal to /boot by default.  The
> default behavior (with no --root-directory) would be the same.
The main problem is with scripts already using --root-directory and
relying on existing behaviour. I propose add a new option
--grub-directory=DIR
which defaults to ROOTDIR/boot/grub
What do you think about this?
>
> The following patch implements this alternative.
>
> Thanks for your time,
>
> Grégoire
>
> --- util/grub-install.in.orig    2009-12-22 11:26:01.538833717 +0100
> +++ util/grub-install.in    2009-12-22 12:48:55.979476412 +0100
> @@ -39,8 +39,7 @@
>  fi
>  grub_mkdevicemap=${sbindir}/`echo grub-mkdevicemap | sed ${transform}`
>  grub_probe=${sbindir}/`echo grub-probe | sed ${transform}`
> -rootdir=
> -grub_prefix=`echo /boot/grub | sed ${transform}`
> +rootdir=/boot
>  modules=
>
>  install_device=
> @@ -66,7 +65,7 @@
>    -v, --version           print the version information and exit
>    --modules=MODULES       pre-load specified modules MODULES
>    --root-directory=DIR    install GRUB images under the directory DIR
> -                          instead of the root directory
> +                          instead of ${rootdir}
>    --grub-setup=FILE       use FILE as grub-setup
>    --grub-mkimage=FILE     use FILE as grub-mkimage
>    --grub-mkdevicemap=FILE use FILE as grub-mkdevicemap
> @@ -84,7 +83,7 @@
>
>  INSTALL_DEVICE can be a GRUB device name or a system device filename.
>
> -grub-install copies GRUB images into the DIR/boot directory specified by
> +grub-install copies GRUB images into the DIR/`echo grub | sed
> ${transform}` directory specified by
>  --root-directory, and uses grub-setup to install grub into the boot
>  sector.
>
> @@ -157,21 +156,7 @@
>      setup_verbose="--verbose"
>  fi
>
> -# Initialize these directories here, since ROOTDIR was initialized.
> -case "$host_os" in
> -netbsd* | openbsd*)
> -    # Because /boot is used for the boot block in NetBSD and OpenBSD,
> use /grub
> -    # instead of /boot/grub.
> -    grub_prefix=`echo /grub | sed ${transform}`
> -    bootdir=${rootdir}
> -    ;;
> -*)
> -    # Use /boot/grub by default.
> -    bootdir=${rootdir}/boot
> -    ;;
> -esac
> -
> -grubdir=${bootdir}/`echo grub | sed ${transform}`
> +grubdir=${rootdir}/`echo grub | sed ${transform}`
>  device_map=${grubdir}/device.map
>
>  grub_probe="${grub_probe} --device-map=${device_map}"
> @@ -204,8 +189,7 @@
>  fi
>
>  # Create the GRUB directory if it is not present.
> -test -d "$bootdir" || mkdir "$bootdir" || exit 1
> -test -d "$grubdir" || mkdir "$grubdir" || exit 1
> +mkdir -p "$grubdir" || exit 1
>
>  # If --recheck is specified, remove the device map, if present.
>  if test $recheck = yes; then
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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Re: boot directory prefix in grub-install (even with --root-directory)

[Grégoire Sutre]

Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> The main problem is with scripts already using --root-directory and
> relying on existing behaviour.

Yes, you're right.


> I propose add a new option
> --grub-directory=DIR
> which defaults to ROOTDIR/boot/grub
> What do you think about this?

Nice, I'm looking forward to it.  Thanks :-)

Grégoire

Re: boot directory prefix in grub-install (even with --root-directory)

[Robert Millan]

On Tue, Dec 22, 2009 at 12:53:46PM +0100, Grégoire Sutre wrote:
> The problem arises e.g. with NetBSD which uses /boot for its own  
> bootloader.  The script util/grub-install.in contains lines to take care  
> of that situation (lines 160-172), but these lines rely on a variable  
> ${host_os} that is not set.  This might be deprecated code from GRUB  
> Legacy's grub-install, where ${host_os} is set by a configure 
> substitution.

It derives from GRUB Legacy, but it's not deprecated.  I just fixed $host_os
initialization (in Bazaar trunk).

-- 
Robert Millan

  "Be the change you want to see in the world" -- Gandhi

Re: boot directory prefix in grub-install (even with --root-directory)

[Robert Millan]

On Tue, Dec 22, 2009 at 01:18:42PM +0100, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> Grégoire Sutre wrote:
> > Hi,
> >
> > grub-install copies GRUB images into ${rootdir}/boot/grub (where
> > ${rootdir} is empty by default and can be changed with --root-directory).
> >
> > To install GRUB files on a partition that contains a /boot file, one
> > must specify a non-empty --root-directory, and grub files are then
> > copied into /DIR/boot/grub.  Or one could mount the partition on a
> > mount point of the form DIR/boot and specify --root-directory=DIR to
> > force installation into the /grub directory of the partition.  Both
> > solutions are not completely satisfactory.  Is there a better one?
> >
> > The problem arises e.g. with NetBSD which uses /boot for its own
> > bootloader.  The script util/grub-install.in contains lines to take
> > care of that situation (lines 160-172), but these lines rely on a
> > variable ${host_os} that is not set.  This might be deprecated code
> > from GRUB Legacy's grub-install, where ${host_os} is set by a
> > configure substitution.
> >
> > An alternative solution would be to have grub-install install in
> > ${rootdir}/grub, with ${rootdir} equal to /boot by default.  The
> > default behavior (with no --root-directory) would be the same.
> The main problem is with scripts already using --root-directory and
> relying on existing behaviour. I propose add a new option
> --grub-directory=DIR
> which defaults to ROOTDIR/boot/grub
> What do you think about this?

If we do this, I'd just replace the old option completely.  But a standalone
--grub-directory is a bit more complex.

It seems to me that the current scheme is laid out this way because we didn't
have grub-mkrelpath / make_path_relative_to_its_root() when designing it.  A
proper solution would be to accept --grub-directory, then extract the relative
prefix from it.

-- 
Robert Millan

  "Be the change you want to see in the world" -- Gandhi