Re: Grub-install documentation or override?

[Andrei Borzenkov]

В Fri, 26 Jun 2015 18:08:14 +0000
<address@hidden> пишет:

> 
> I am automating the build with the following goals:
> 
>    1) Not to add any additional dependencies into the LFS system itself 
> beyond what is standard, so the LFS system uses GRUB but does not have LVM.
>    2) To have minimal impact on the host system, so installing grub to the 
> host if they don't have it is not an option.
>    3) It needs to be able to be installed to an actual drive or to a disk 
> image, at the choice of the end user.
> 
> The only part of this causing me pain is grub-install at the very end of the 
> build.
> 

Try mounting / as separate loop device. It will give you suboptimal
GRUB configuration (where it will need to search for root instead of
encoding partition directly) but you can redo grub-install later from
booted system.

address@hidden:~> sudo losetup --find --show /tmp/floppy
/dev/loop0
address@hidden:~> sudo losetup --find --show -o 1048576 /tmp/floppy
/dev/loop1
address@hidden:~> sudo mount /dev/loop1 /mnt
address@hidden:~> sudo rm -rf /mnt/grub
address@hidden:~/build/grub> sudo pkgdatadir=$PWD ./grub-install -d grub-core 
--boot-directory=/mnt --modules=part_msdos /dev/loop0
Installing for i386-pc platform.
Installation finished. No error reported.
address@hidden:~/build/grub> 
address@hidden:~> ll /mnt/grub/
итого 28
drwxr-xr-x 2 root root  2048 июн 27 09:17 fonts
-rwxr-xr-x 1 root root  1024 июн 27 09:17 grubenv
drwxr-xr-x 2 root root 20480 июн 27 09:17 i386-pc
drwxr-xr-x 2 root root  2048 июн 27 09:17 locale
drwxr-xr-x 3 root root  2048 июн 27 09:17 themes


Replace part_msdos with part_gpt if needed.

The reason to explicitly include partition driver is that in this case
GRUB does not know that filesystem is located on partition at all, so
it cannot automatically detect and add it. And that is very good
illustration why GRUB must be able to correctly relate your
device-mapper "partition" to parent device.