Re: Grub-install documentation or override?

[Andrei Borzenkov]

В Thu, 25 Jun 2015 17:20:23 +0000
<address@hidden> пишет:

> I have a 15GB image file partitioned using fdisk with a single MBR partition 
> and containing an ext4 file system which contains my LFS system. I used 
> kpartx on this to create /dev/loop0 and /dev/mapper/loop0p1. The file system 
> in /dev/loop0p1 is mounted on /mnt. I am chrooted into /mnt

How exactly? chroot must have at least /dev, /sys and /proc available
for device detection to work. 

 where my LFS system resides. Grub in the LFS system was built with the
 following (from LFS documentation):
> 
> ./configure --prefix=/usr          \
>             --sbindir=/sbin        \
>             --sysconfdir=/etc      \
>             --disable-grub-emu-usb \
>             --disable-efiemu       \
>             --disable-werror
> 
> Command used:
>  grub-install --target=i386-pc /dev/loop0
>

I do not have environment to test chroot, but the following works
using current upstream master (sans two clean up patches):

address@hidden:~> sudo losetup --find --show /tmp/floppy
/dev/loop0
address@hidden:~> sudo kpartx -a /dev/loop0
address@hidden:~> sudo mount /dev/mapper/loop0p2 /mnt
address@hidden:~/build/grub> ./configure ; make
address@hidden:~/build/grub> sudo pkgdatadir=$PWD ./grub-install -d grub-core 
--boot-directory=/mnt /dev/loop0
Installing for i386-pc platform.
Installation finished. No error reported.
address@hidden:~/build/grub> 

As Jordan suggested, you may be missing libdevmapper dependency.
 
> When that failed, I also tried a number of variations on this command, all of 
> which also failed. I tried following examples on the net regarding creating a 
> device.map and populating it with (hd0) /dev/loop0
> Grub seems to read the file OK, but the install still fails.
> 
> The host machine is a 64-bit install of Debian 8, although that shouldn't 
> matter.
> 
> If I do this on a real drive instead of a mounted image it works, but that 
> doesn't help me. Shouldn't it be possible to install grub to a loopback 
> device?
> 
> Thanks in advance for any help.
> 
> 
> 
> 
> ---- Andrei Borzenkov <address@hidden> wrote: 
> > Please, describe your configuration, and provide exact command you used. 
> > Otherwise it is impossible to say anything.
> > 
> > Отправлено с iPhone
> > 
> > > 25 июня 2015 г., в 14:43, <address@hidden> <address@hidden> написал(а):
> > > 
> > > I absolutely cannot get grub-install to do what I need it to do: Install 
> > > to the MBR on a disk image that is loop mounted with kpartx, while 
> > > chrooted into an ext4 filesystem on the first partition of that image. 
> > > The image will be used on a BIOS machine but the physical host is EFI.
> > > 
> > > This is for a linux from scratch 7.7 build and so uses the grub version 
> > > found here: http://alpha.gnu.org/gnu/grub/grub-2.02~beta2.tar.xz
> > > 
> > > I discovered the "target" argument to override the architecture by 
> > > searching the web (it doesn't seem to be mentioned in any detail in the 
> > > Grub manual), but I can't get it to install regardless. I get some 
> > > nonsensical message about being unable to find 'lvm/loop0p1' although I 
> > > am not using lvm in the image. The image only has a single MBR partition.
> > > 
> > > This seems like it should be a simple thing to do and if it is I 
> > > apologize, but I really hate it when software tries to be clever in an 
> > > effort to 'help' and makes assumptions that turn a simple matter into a 
> > > nightmare.
> > > 
> > > _______________________________________________
> > > Help-grub mailing list
> > > address@hidden
> > > https://lists.gnu.org/mailman/listinfo/help-grub
>