Re: Grub2, can the following be done

[Vladimir 'phcoder' Serbinenko]

On Wed, Apr 12, 2017, 13:26 Andrei Borzenkov <address@hidden> wrote:

12.04.2017 02:28, Vladimir 'phcoder' Serbinenko пишет:
> I documented this in the manual. See "standalone multi-OS setup"
>

There is no such section. You probably mean Configuration - Multi-boot
manual config.

Unfortunately this is not as simple.

1. Sourcing full configuration file from another distribution is not
safe. It may refer to components (modules, fonts, themes, ...) not
present in "parent" grub. We do not change $prefix when executing
different config. And even if we did we cannot obviously load modules
from completely different build.

I'm working on proposal for a new config language to be used in addition to current format to solve all of those problems.

2. The most generic is to load another GRUB, but for now there is no
cross-platform method to do it. Chainloader, multiboot, efi - pick your
choice. We probably need platform independent "grub" loader that
resolves to whatever method is valid for current platform.

For PCBIOS having each distribution install its GRUB in own partition
and chainloading it is well understood and established practice, but it
makes it rather hard to auto-detect and incorporate such boot blocks.

For EFI the problem starts already with the fact that we are using
distribution name as \EFI subdirectory, so it is impossible to install
several instances of the same distribution side by side. Some (like
SUSE) expose GRUB_DISTRIBUTOR in system configuration tools, but as it
is also used to build menu, we get something like

openSUSE_1 with linux ...

which is not ideal either. We probably need to have separate
configuration option for subdirectory that can be then set to something
like \EFI\<distro>\<UUID> where UUID is machine UUID or even simply root
filesystem.

Of course existence of secure boot and shim do not make auto-detection
easier.


> On Wed, Apr 12, 2017, 09:27 Leslie Satenstein <address@hidden>
> wrote:
>
>> Current-Setup
>> =============
>> SYSTEM-A Grub2 >-----+ Points to A,B,C,D,E
>>                      +-->SYSTEM-B Grub2 Points to B,A,C,D,E
>>                      +-->SYSTEM-C Grub2 Points to C,A,B,D,E
>>                      +-->SYSTEM-D Grub2 Points to D,A,B,C,E
>>                      +-->SYSTEM-E Grub2 Points to E,A,B,C,D
>>
>> Problem
>> =======
>> any update to A,B.C.D.E needs a recreation of grub.cfg for each (all)
>> the others
>>
>>
>> Is it possible to do the following?
>>
>> SYSTEM-A Grub2 >-----+A,[MASTER=Grub2]
>>                      +-->SYSTEM-B Grub2 Points to B,[MASTER=Grub2]
>>                      +-->SYSTEM-C Grub2 Points to C,[MASTER=Grub2]
>>                      +-->SYSTEM-D Grub2 Points to D,[MASTER=Grub2]
>>                      +-->SYSTEM-E Grub2 Points to E,[MASTER=Grub2]
>>
>> [Master-Grub2]
>>      Copy of all Grub.cfgs, neatly organized?
>>
>> Any update of any system must also update MASTER-GRUB2
>>
>>
>>
>> _______________________________________________
>> Grub-devel mailing list
>> address@hidden
>> https://lists.gnu.org/mailman/listinfo/grub-devel
>>
>
>
>
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