Re: NetBSD 9.0_RC1 - installation on GPT (with BIOS boot) not bootable

[Matthias Petermann <mp%petermann-it.de@localhost>]

Hi, replying to myself here... will try this[1] on my X220 this morning:

"Add an option to gpart(8) to location the fake GPT (0xee) entry in the 
pMBR in a non-default location
Writing the 0xee entry to the 2nd partition slot, instead of the first, 
allows afflicted Lenovo's (x220, t420, t520) to boot GPT in BIOS mode"

Kind regards
Matthias


[1] https://reviews.freebsd.org/D3065

On 12/13/19 7:22 AM, Matthias Petermann wrote:
> ...
> What came to mind: many years ago I installed freebsd on the same 
> device. That would have been around FreeBSD 9 or 10. Back then, 
> bsdinstall gave me a warning that there was a BIOS bug for this model 
> and asked if I wanted to use a fix for it. I did google this and found a 
> discussion in FreeBSD forum[1], as well a mailing list post[2] which 
> appears to summarize the needed change. They are talking about setting 
> an "active bit" in addition to the "active flag".
>
> I don't understand the context in detail yet, but i will take a look at 
> the source of gpart in FreeBSD to find out what this "lenovofix" does. 
> At the moment it looks to me like a problem specific to this machine, 
> not in general. At least with regards to NetBSD 9.0 RC1, I did not test 
> with current so far.
>
> In addition to this, do you see some indication of a problem in the 
> provided information above (gpt show)? I am happy to provide more 
> details if I know exactly what you need.
>
> Kind regards
> Matthias
>
> [1] https://forums.freebsd.org/threads/thinkpad-x220-boot-problem.70865/
> [2] 
> https://lists.freebsd.org/pipermail/freebsd-current/2015-July/056574.html