Re: Lenovo BIOS boot fix

On 2015-07-12 01:49, Allan Jude wrote:
> I have spent my weekend researching why my Lenovo X220s refuse to boot
> from GPT partitioned disks.
> 
> Based on this mailing list post:
> https://lists.freebsd.org/pipermail/freebsd-i386/2013-March/010437.html
> 
> I have written a patch for gpart to change the way the PMBR is created.
> 
> Instead of writing the 0xee partition in the first slot (offset 0), it
> writes it to the 2nd slot (offset 1).
> 
> This resolves the issue on my Lenovo X220s, and the installed image
> boots fine on my T530, and various other non-lenovo amd64 machines at my
> house.
> 
> If others could please test this image (it is a pre-installed system, so
> just dd it to a memory stick, and see if it boots. Can be safely done
> without touching your disks), that would be most helpful.
> 
> compressed (193 MiB):
> http://www.allanjude.com/bsd/lenovofix_20150704-r285132.img.xz
> 
> uncompressed (1 GiB):
> http://www.allanjude.com/bsd/lenovofix_20150704-r285132.img
> 
> 

I forgot to include the link to the patch as well:

http://www.allanjude.com/bsd/lenovofix_gpart.patch

I will most likely make this patch optional, behind a flag to the 'gpart
create -s gpt' command, to avoid potentially breaking existing working
systems, but if using offset 1 works on all other hardware, having it as
the default would be nice.

Another option would be to make a separate standalone program to modify
the pMBR for Lenovo machines, rather than modifying gpart.

Thoughts?

-- 
Allan Jude