Re: [PATCH] grub-install: check for arm-efi as a default target

[dann frazier]

On Thu, Feb 21, 2019 at 12:42 PM Leif Lindholm <address@hidden> wrote:
>
> Hi Steve,
>
> On Mon, Feb 11, 2019 at 02:42:34AM +0000, Steve McIntyre wrote:
> > Much like on x86, we can work out if the system is running on top of
> > EFI firmware. If so, return "arm-efi". If not, fall back to
> > "arm-uboot" as previously.
>
> Right, this clearly needs a fix.
>
> > Heavily inspired by the existing code for x86.
>
> Mmm. I would much prefer if we could break out the efi test in a
> separate helper function. And clean it up while we're at it.

fyi, I made an attempt at this a while back:
http://lists.gnu.org/archive/html/grub-devel/2018-08/msg00082.html
http://lists.gnu.org/archive/html/grub-devel/2018-08/msg00081.html
http://lists.gnu.org/archive/html/grub-devel/2018-08/msg00083.html

  -dann

> > Signed-off-by: Steve McIntyre <address@hidden>
> > ---
> >  grub-core/osdep/basic/platform.c |  6 ++++++
> >  grub-core/osdep/linux/platform.c | 24 ++++++++++++++++++++++++
> >  include/grub/util/install.h      |  3 +++
> >  util/grub-install.c              |  2 +-
> >  4 files changed, 34 insertions(+), 1 deletion(-)
> >
> > diff --git a/grub-core/osdep/basic/platform.c 
> > b/grub-core/osdep/basic/platform.c
> > index 4b5502aeb..a7dafd85a 100644
> > --- a/grub-core/osdep/basic/platform.c
> > +++ b/grub-core/osdep/basic/platform.c
> > @@ -19,6 +19,12 @@
> >  #include <grub/util/install.h>
> >
> >  const char *
> > +grub_install_get_default_arm_platform (void)
> > +{
> > +  return "arm-uboot";
> > +}
> > +
> > +const char *
> >  grub_install_get_default_x86_platform (void)
> >  {
> >    return "i386-pc";
> > diff --git a/grub-core/osdep/linux/platform.c 
> > b/grub-core/osdep/linux/platform.c
> > index 775b6c031..a3f9e9d28 100644
> > --- a/grub-core/osdep/linux/platform.c
> > +++ b/grub-core/osdep/linux/platform.c
> > @@ -98,6 +98,30 @@ read_platform_size (void)
> >  }
> >
> >  const char *
> > +grub_install_get_default_arm_platform (void)
> > +{
> > +  /*
> > +     On Linux, we need the efivars kernel modules.
> > +     If no EFI is available this module just does nothing
> > +     besides a small hello and if we detect efi we'll load it
> > +     anyway later. So it should be safe to
> > +     try to load it here.
> > +   */
> > +  grub_util_exec_redirect_all ((const char * []){ "modprobe", "efivars", 
> > NULL },
> > +                            NULL, NULL, "/dev/null");
>
> So, I guess this is a "safe" operation. But efivars isn't the
> interface that should be used these days - efivarfs is.
> The efivars library will always use efivarfs
> (mounted on /sys/firmware/efi/efivars) in preference to efivars
> (available through /sys/firmware/efi/vars).
>
> Since it's safe, we may leave it in for someone running bleeding edge
> grub on an ancient system, or just using a misconfigured kernel.
> But the comment is misleading. I would suggest changing it to
> something like:
>
>   /*
>       Linux uses efivarfs (mounted on /sys/firmware/efi/efivars)
>       to access the EFI variable store.
>       Some legacy systems may still use the deprecated efivars
>       interface (accessed through /sys/firmware/efi/vars).
>       Where both are present, libefivar will use the former in
>       preference, so attempting to load efivars will not interfere
>       with later operations.
>   */
>
> /
>     Leif
>
> > +  grub_util_info ("Looking for /sys/firmware/efi ..");
> > +  if (is_not_empty_directory ("/sys/firmware/efi"))
> > +    {
> > +      grub_util_info ("...found");
> > +      return "arm-efi";
> > +    }
> > +
> > +  grub_util_info ("... not found");
> > +  return "arm-uboot";
> > +}
> > +
> > +const char *
> >  grub_install_get_default_x86_platform (void)
> >  {
> >    /*
> > diff --git a/include/grub/util/install.h b/include/grub/util/install.h
> > index af2bf65d7..80a51fcb1 100644
> > --- a/include/grub/util/install.h
> > +++ b/include/grub/util/install.h
> > @@ -209,6 +209,9 @@ void
> >  grub_install_create_envblk_file (const char *name);
> >
> >  const char *
> > +grub_install_get_default_arm_platform (void);
> > +
> > +const char *
> >  grub_install_get_default_x86_platform (void);
> >
> >  int
> > diff --git a/util/grub-install.c b/util/grub-install.c
> > index 4a0a66168..1d68cc5bb 100644
> > --- a/util/grub-install.c
> > +++ b/util/grub-install.c
> > @@ -319,7 +319,7 @@ get_default_platform (void)
> >  #elif defined (__ia64__)
> >     return "ia64-efi";
> >  #elif defined (__arm__)
> > -   return "arm-uboot";
> > +   return grub_install_get_default_arm_platform ();
> >  #elif defined (__aarch64__)
> >     return "arm64-efi";
> >  #elif defined (__amd64__) || defined (__x86_64__) || defined (__i386__)
> > --
> > 2.11.0
> >
> >
> > _______________________________________________
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> > address@hidden
> > https://lists.gnu.org/mailman/listinfo/grub-devel
>
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