Re: [Aarch64-laptops] [PATCH v7 2/2] Add a module for retrieving SMBIOS information

[Leif Lindholm]

On Fri, Jul 05, 2019 at 01:58:59PM +0100, Dimitri John Ledkov wrote:
> On Fri, 5 Jul 2019 at 13:48, David Michael <address@hidden> wrote:
> >
> > The following are two use cases from Rajat Jain <address@hidden>:
> >
> > 1) We have a board that boots Linux and this board itself can be
> >    plugged into one of different chassis types. We need to pass
> >    different parameters to the kernel based on the "CHASSIS_TYPE"
> >    information that is passed by the bios in the DMI / SMBIOS
> >    tables.
> >
> > 2) We may have a USB stick that can go into multiple boards, and
> >    the exact kernel to be loaded depends on the machine
> >    information (PRODUCT_NAME etc) passed via the DMI.
> >
> > Signed-off-by: David Michael <address@hidden>
> 
> Another use case is aarch64 laptops effort. We have the same kernel,
> and the same image bootable and usable across 4 different laptop
> models, with the only difference between them being the DTB to load.
> I was looking at how I can distinguish between the four models and
> automatically pick the right dtb. I did see these patches and was very
> sad when I found out that they didn't get merged.

I very much don't want us to depend on aarch64-laptops-special-sauce
though, so while I want this functionality in GRUB, I do not consider
the aarch64-laptops project an argument for that.

I am working on extending the standalone DtbLoader driver to do this
selection instead, meaning we won't need to roll special installers.
https://git.linaro.org/people/leif.lindholm/edk2.git/log/?h=dtbloader

/
    Leif

> Thank you for rebasing these on top of v2.04. I will try to cherrypick
> them on top of Debian's experimental 2.04 grub and try to build an
> installer "that just boots" without requiring users to pick a
> particular dtb menuentry by hand. There are only dtbs in these images,
> and only one right one for each model.
> 
> (Post install, we have flash-kernel mechanisms to continuously flash
> and use the right dtb, this is needed for the installer's grub to be
> able to detect models and thus boot the right dtb)
> 
> Whilst these laptops might become dtb-free in the future, I expect new
> hardware to come out which would need dtb picker based on SMBIOS info
> again.
> 
> -- 
> Regards,
> 
> Dimitri.
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