Bug#495049: why is (fd0) hard-coded into the grub image?

[Felix Zielcke]

Am Freitag, den 15.08.2008, 03:18 -0700 schrieb ian_bruce at fastmail.fm:
> I should point out that when grub drops into the rescue prompt, it
> coughs up the message "error: unknown device fd0". Perhaps this is why
> it goes into rescue mode?

Thanks for telling us.
This is a bit different then:
"GRUB doestn't load normal.mod because there is no string normal in
core.img"

> My "device.map" file, as previously listed, does not contain an entry
> for "fd0", because the machine does not in fact have a floppy
> drive. Wondering if this might help, I added the entry "(fd0) /dev/fd0",
> and reinstalled grub.

I think you understand something wrong.
The problem is that GRUB thinks fd0 is your bootdevice, even though your
device.map is right.
Of course it doestn't help if you make your harddisk to fd0.
Why should GRUB then suddenly see it as hd0 ?

> 
> Some questions suggest themselves:
> 
> -- why is there a hard-coded dependency on "fd0", when neither
> "device.map" nor "grub.cfg" mention it?
> -- is the "fd0" dependency the reason why grub drops into rescue mode?

Please stop assuming things if you don't understand how GRUB works.

> -- why does adding an "fd0" entry to "device.map" not resolve this
> error?

Why should GRUB then think your harddisk is hd0 instead of fd0 which it
currently does?

> Finally, I suggest the following patch for clarifying exactly what
> "grub-install" is doing, at least until some of these issues are
> resolved.

Please read man bash
There's an -x option which does something like that.

For example run: bash -x /usr/sbin/grub-install /dev/sda


I assume you don't know enough C to understand the whole sourcecode.
That's totally okay of course you don't need that to report a bug.
But please just state your problem.

I already wanted to make that to you clear with my "I think it's normal
that core.img doestn't contain the string normal to load normal.mod"

Please let it to Robert and me trying to find out the `why?'.

It is totally okay if you would your report just like this

for me grub goes to rescue mode with "unknown device fd0"
I only need to do
insmod normal
normal

then the menu comes up and I can boot my system
I have LVM on /


That means:
just state your problem and details of your system for example that you
use LVM

Don't tell us that probable XYZ is the problem and that it's easy to
fix, if you are not sure that it is.
And error messages like that "unknown device fd0" are shown for a reason
and so should be in your bug report _submission_. (that means not in the
3rd mail but instead already in the 1st)