Re: out of range pointer with ext2 filesystem

[Marco Gerards <metgerards@student.han.nl>]

"richard juckes" <richardjuckes@fastmail.cn> writes:

> Hi, this is the problem I'm having with Grub2-cvs and ext2 filesystems.
> I get a successful boot from a kernel on floppy with a fat filesystem,
> but no luck when the same floppy is formatted with ext2.

[...]

> --> make
> --> ./grub-mkimage -v -d . -o core.img _chain boot cat cmp ext2 fat
> fshelp halt help linux ls normal pc reboot terminal
> --> su mkdosfs /dev/fd0
> --> dd if=boot.img of=/devfd0 bs=512 count=1
> --> dd if=core.img of=/devfd0 bs=512 seek=1

First you create a filesystem and after that you overwrite it.  I
doubt that it will work.

> reboot
>
> GNU GRUB version 1.90
>
> grub> ls
> (fd0) (hd0) (hd0,0) (hd0,4) ..... (hd0,11)
> grub> ls -l
> Disk: fd0
> Disk: hd0
> unaligned pointer 0xfaa4

In this example you use mkdosfs, or did you mean mkfe2fs?

> make another kernel floppy
>
> --# mke2fs /dev/fd0
> mke2fs 1.36 (05-Feb-2005)
> Filesystem label=
> OS type: Linux
> Block size=1024 (log=0)
> Fragment size=1024 (log=0)
> 184 inodes, 1440 blocks
> 72 blocks (5.00%) reserved for the super user
> First data block=1
> 1 block group
> 8192 blocks per group, 8192 fragments per group
> 184 inodes per group
>
> Writing inode tables: done
> Writing superblocks and filesystem accounting information: done
>
> This filesystem will be automatically checked every 31 mounts or
> 180 days, whichever comes first.  Use tune2fs -c or -i to override.
>
> reboot

You don't put GRUB on it?

> grub> linux (fd0)/bzImage root=/dev/hda6
> out of range pointer 0x7fca0

This is weird and should not happen.  A broken filesystem should never
cause a crash.  I will have a look at next weekend.

Thanks,
Marco