Re: [gentoo-user] Re: grub weirdness

[Wolf Canis]

Sven Köhler wrote:
>> When you emerged grub-0.97-r5, this was displayed on your console:
>> WARN: postinst
>> *** IMPORTANT NOTE: you must run grub and install
>> the new version's stage1 to your MBR.  Until you do,
>> stage1 and stage2 will still be the old version, but
>> later stages will be the new version, which could
>> cause problems such as an unbootable system.
>
> Yes, the ebuild writes that to the screen.
>
> But silently, in the background (because every output is piped to
> /dev/null - how evil!), the ebuild calls grub with some commands
> inside your grub.conf.

I just updated grub to version 0.97-r5 and this was,
at the end, displayed:

 To avoid automounting and autoinstalling with /boot,
 just export the DONT_MOUNT_BOOT variable.


 Your boot partition was not mounted as /boot, but portage
 was able to mount it without additional intervention.
 Files will be installed there for grub to function correctly.

 *** IMPORTANT NOTE: you must run grub and install
 the new version's stage1 to your MBR.  Until you do,
 stage1 and stage2 will still be the old version, but
 later stages will be the new version, which could
 cause problems such as an unbootable system.
 Copying files from /lib/grub and /usr/lib/grub to //boot/grub
 To install grub files to another device (like a usb stick), just run:
    emerge --config =grub-0.97-r5

>
> If there's a setup-command in your grub.conf, it is indeed executed.
> So if that command is outdated (something you won't notice, since that
> command is not used by grub in any situation i know), the ebuild will
> execute that setup-command and write to some device's boot sector. How
> evil, again!
>
> Regards,
>   Sven
>
> P.S.: here's the code from grub-0.97-r5.ebuild:
>
>         if [[ -e ${dir}/grub.conf ]] ; then
>                 egrep \
>                         -v
> '^[[:space:]]*(#|$|default|fallback|initrd|password|splashimage|timeout|title)'
> \
>                         "${dir}"/grub.conf | \
>                 /sbin/grub --batch \
>                         --device-map="${dir}"/device.map \
>                         > /dev/null
>         fi
And following the code of the functions which does the job:
found in ebuild: /usr/portage/sys-boot/grub/grub-0.97-r5.ebuild

setup_boot_dir() {
    local boot_dir=$1
    local dir=${boot_dir}

    [[ ! -e ${dir} ]] && die "${dir} does not exist!"
    [[ ! -L ${dir}/boot ]] && ln -s . "${dir}/boot"
    dir="${dir}/grub"
    if [[ ! -e ${dir} ]] ; then
        mkdir "${dir}" || die "${dir} does not exist!"
    fi

    # change menu.lst to grub.conf
    if [[ ! -e ${dir}/grub.conf ]] && [[ -e ${dir}/menu.lst ]] ; then
        mv -f "${dir}"/menu.lst "${dir}"/grub.conf
        ewarn
        ewarn "*** IMPORTANT NOTE: menu.lst has been renamed to grub.conf"
        ewarn
    fi

    if [[ -e ${dir}/stage2 ]] ; then
        mv "${dir}"/stage2{,.old}
        ewarn "*** IMPORTANT NOTE: you must run grub and install"
        ewarn "the new version's stage1 to your MBR.  Until you do,"
        ewarn "stage1 and stage2 will still be the old version, but"
        ewarn "later stages will be the new version, which could"
        ewarn "cause problems such as an unbootable system."
        ebeep
    fi

    einfo "Copying files from /lib/grub and /usr/lib/grub to ${dir}"
    for x in "${ROOT}"/lib*/grub/*/* "${ROOT}"/usr/lib*/grub/*/* ; do
        [[ -f ${x} ]] && cp -p "${x}" "${dir}"/
    done

    if [[ -e ${dir}/grub.conf ]] ; then
        egrep \
            -v
'^[[:space:]]*(#|$|default|fallback|initrd|password|splashimage|timeout|title)'
\
            "${dir}"/grub.conf | \
        /sbin/grub --batch \
            --device-map="${dir}"/device.map \
            > /dev/null
    fi

    # the grub default commands silently piss themselves if
    # the default file does not exist ahead of time
    if [[ ! -e ${dir}/default ]] ; then
        grub-set-default --root-directory="${boot_dir}" default
    fi
}


How you can see isn't the message piped to /dev/null, only
the command "/sbin/grub -batch -device-map...".

Have fun,
W. Canis