GRUB always enters a rescue shell.

[Aruna Hewapathirane]

>
>
> On 22.07.2017 19:35, Aruna Hewapathirane wrote:
> [...]
> >>> sudo losetup -o $((2048*512)) /dev/loop1 hd.img
> >>
> >> should'nt it be 63*512 ?
> >>
> >
> > nope should be 2048 and this is why -->
> > https://superuser.com/questions/352572/why-does-the-
partition-start-on-sector-2048-instead-of-63
>
> it is for new hard disks,

Yes agreed it is for newer hard disks..

> here it conflicts with geometry used:
>
> >>>> fdisk -u -C100 -S63 -H16 hd.img

Actually no because if you look at the initial email hao sent carefully in
step 2:

2. Create a primary partition.
fdisk -u -C100 -S63 -H16 hd.img

Notice even though hao *has* specified the geometry, fdisk does not show
this ? Try it and see... if we go through the process and ask fidsk to
print the partition information. This is what I see :

------------------------------------------------------------
------------------------------------------------------------
------------------------------------------------------------
Command (m for help): p
Disk hd.img: 49.2 MiB, 51609600 bytes, 100800 sectors ---> geometry is
usually shown on the next line but zilch here ?
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x4c0d7fa4

Device     Boot Start    End Sectors  Size Id Type
hd.img1          2048 100799   98752 48.2M 83 Linux
------------------------------------------------------------
------------------------------------------------------------
------------------------------------------------------------

But if I do this: /sbin/fdisk -c=dos -u -C100 -S63 -H16 hd3.img

then fdisk complains saying DOS-compatible mode is deprecated, and after
going through the process once again and we ask fdisk to print the
partition we see:

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Command (m for help): p
Disk hd3.img: 49.2 MiB, 51609600 bytes, 100800 sectors
Geometry: 16 heads, 63 sectors/track, 100 cylinders <----  fdisk shows
geometry this time around ah-ha !
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x030e7198
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

I put together a small video will make it easier for you to see all the
above: https://youtu.be/kmG7CCy-F9Q

> and maybe conflicts with Bochs BIOS options or disk geometry options ?

Mmm.. I don't believe there are any conflicts. Please watch the video I
sent earlier.
It has a fix and working solution : https://youtu.be/6oqTu8utMe4

:)

Thank's - Aruna



>
> --
> Best regards,
> Kamil Konieczny
> Samsung R&D Institute Poland
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20170724/c90167a7/attachment.html