Re: Loading different kernels based on platform identification (DMI)

[David Michael]

Hi,

On Thu, Jan 29, 2015 at 2:23 PM, Rajat Jain <address@hidden> wrote:
> [+David]
>
> Hello,
>
>> DMI parsing was discussed a while back and proposed patch was posted on
>> grub-devel. It was quite a while back, so patch probably needs rebasing.
>> Somebody who cares enough should probably try to submit it for review
>> again after testing with current git.
>
> I found a couple references, and the best bet I could find is this:
>
> http://lists.gnu.org/archive/html/grub-devel/2013-04/msg00153.html
>
> Can you please confirm if this is the patch you were referring to?

You can download the latest version of the bare module file from the
following link.  It's been updated to support both EFI and traditional
BIOS systems since that e-mail.

https://github.com/dm0-/gnuxc/blob/master/patches/grub-2.02~beta2-smbios.c

That module targets the last beta from alpha.gnu.org.  Sorry for the
lack of a patch file at the moment, but it can be built by moving the
file to grub-core/commands/i386/smbios.c, appending
"./grub-core/commands/i386/smbios.c" to po/POTFILES.in, appending the
following block to grub-core/Makefile.core.def, then running
autoreconf, configure, and make normally.

module = {
  name = smbios;
  x86 = commands/i386/smbios.c;
  enable = x86;
};

If you want to test the module, it returns the requested data type at
a given byte offset in an SMBIOS table entry.  You can run "smbios
--help" for the options list.  For example, this will store the system
manufacturer string in a variable:

smbios --type 1 --get-string 4 --variable system_manufacturer
echo $system_manufacturer

> David: I'm running on Intel's latest 64 bit Haswell processor. Can you please 
> confirm if this patch should work on that (I ask because I found references 
> about different ways to deal with 32 bit and 64 bit CPUs/BIOSes).

I don't recall anything offhand that will cause a problem, but it
shouldn't hurt to test.  It seemed to work okay on every machine I've
tried.

> I'm interested and I think it would be highly useful to have this up 
> streamed. Wanted to check if David or someone else is planning to submit it, 
> or shall I try submitting it after rebasing to the latest and testing on my 
> machine?

I don't mind updating and trying to submit it to the development list
for comments, maybe over the weekend.  (I left that FSF copyright
statement on it from when I originally planned to submit it long ago,
but I haven't actually submitted copyright assignment papers.  Oops.)
Can someone tell me if this change would require copyright assignment?

Thanks.

David