Re: Having the configuration file embedded into core.img look for the grub partition by its label

From: Arbiel Perlacremaz <arbiel.perlacremaz@gmx.fr>
To: The development of GNU GRUB <grub-devel@gnu.org>
Subject: Re: Having the configuration file embedded into core.img look for the grub partition by its label
Date: Fri, 26 Sep 2014 23:02:44 +0200	[thread overview]
Message-ID: <5425D474.5010503@gmx.fr> (raw)
In-Reply-To: <5425B7D7.2010404@gmail.com>

Hi

Le 26/09/2014 21:00, Vladimir 'φ-coder/phcoder' Serbinenko a écrit :
> On 23.09.2014 10:11, Arbiel Perlacremaz wrote:
>> Having the grub directory on the external device is not what I'm looking
>> for.
>>
>> I indeed use several external devices and I've installed GRUB on each of
>> them so that it is always available, whatsoever my configuration is. To
>> avoid confusion when updating GRUB, all my fstab files mount a unique
>> directory, always the same, on /boot/grub. This is the reason why I want
>> GRUB on my hard drive.
>>
> Upgrading modules without rerunning grub-install on all devices is not
> supported. It may work for few revisions but when core functions change
> it will break.
Grub and grub's modules are located in none external device. They are
located on a single partition on my hard disk. On the external devices
are only recorded the grub bootloader in the MBR and core.img in the gap
between the MBR and the first partition.
Do you mean that in this situation, I will have to rerun grub-install on
all USB devices any time a grub module has been modified ? And how do I
know that a grub module has been modified ?
>> Le 23/09/2014 01:09, Vladimir 'φ-coder/phcoder' Serbinenko a écrit :
>>> On 22.09.2014 22:49, Arbiel Perlacremaz wrote:
>>>> Hi
>>>>
>>>> A way I'm using to avoid any Window's reinstallation to overwrite GRUB
>>>> in a multiboot environment is to install the later on the MBR of a USB
>>>> key. That way, when booting with no key pluged, the PC boots into
>>>> Windows and when booting with the key pluged, the PC boots according to
>>>> the choice of the user in the grub menu's.
>>>>
>>>> I do locate the grub.cfg file in a partition of the internal hard drive.
>>>> In such a situation, grub-install embeddes a config file which reads
>>>> something like
>>>>
>>>>     search.fs_uuid 367C9BBD7C9B75F9 root hd0,msdos1
>>>>     set prefix=($root)'/'
>>>>
>>>> This is great.
>>>>
>>>> However, any undesired modification by any piece of software of the
>>>> partition's uuid will prevent GRUB to find it and lead to a boot
>>>> failure. As the Windows partition is less prone to such modifications as
>>>> Linux partitions, I do locate the grub.cfg file in that Windows
>>>> partition. However it would be more straightforward to locate the file
>>>> into a Linux partition, and to have grub search this partition by its label.
>>>>
>>>> How could this be done ? If this can't presently be done, can it be
>>>> included in a future grub release ?
>>> use --boot-directory to place all files on usb stick and make it load
>>> any other grub.cfg you might want.
>>>> Regards
>>>>
>>>> Arbiel
>>>>
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>>>> https://lists.gnu.org/mailman/listinfo/grub-devel
>>>>
>>>
>>>
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>
>
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