RE: UEFI support in ARM DomUs

[Peng Fan <peng.fan@nxp.com>]

> Subject: Re: UEFI support in ARM DomUs
> 
> 
> On 6/23/20 8:31 AM, Oleksandr Andrushchenko wrote:
> >
> > On 6/23/20 4:20 AM, Stefano Stabellini wrote:
> >> On Mon, 22 Jun 2020, Julien Grall wrote:
> >>>>>> For the first part (__XEN_INTERFACE_VERSION__) I think we can
> >>>>>> provide it via
> >>>>>>
> >>>>>> CFLAGS or something. This can also be done for the location of
> >>>>>> Xen headers.
> >>>>> __XEN_INTERFACE_VERSION__ should work through the CFLAGS. An
> >>>>> alternative would be to allow the user to specify through the Kconfig.
> >>>> You mean specifying via Kconfig something like "0x00040d00"?
> >>> Possibly yes.
> >>>
> >>>> And what about the headers? How will we provide their location if
> >>>> we decide not to include those
> >>>>
> >>>> in the tree?
> >>> I would do through Kconfig as well.
> >> If we specify the external location of the Xen headers via Kconfig,
> >> it seems to me that we should be able to detect the interface version
> >> automatically from any Makefile as part of the build. No need to ask
> >> the user.
> >>
> >> However, if Oleksandr is thinking of using the Xen headers for the
> >> hypercalls definitions, then I think we might not need external
> >> headers at all because that is a stable interface, as Julien wrote.
> >> We could just define our own few headers for just what you need like Linux
> does.
> >
> > This is a good idea: I'll try to get the minimal set of headers from
> > Linux
> >
> > instead of Xen as those seem to be well prepared for such a use-case.
> > This
> >
> > way we'll have headers in U-boot tree and guarantee that we have a
> > minimal
> >
> > subset which is easier to maintain. I'll keep you updated on the
> > progress
> 
> We've managed to strip the headers and remove __XEN__ and the rest
> definitions
> 
> we were talking about. So, these are now the minimal required set of headers
> 
> that allows U-boot to build serial and block drivers. Please take a look at [1]
> 
> Pull request for comments is at [2]

The U-Boot new merge window will be open in 2020/7/1, so I'd suggest
the patchset goes to U-Boot mail list for discussion if you wanna the patches
gonna merged soon.

Regards,
Peng.

> 
> >
> >>
> >> If you can do that, I think it would be better because we decouple
> >> the UBoot build from the Xen build completely. We don't even need the
> >> Xen tree checked out to build UBoot. It would be a huge advantage
> >> because it makes it far easier to build-test changes for others in
> >> the community that don't know about Xen and also it becomes far
> >> easier to integrate into any build system.
> 
> [1]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.
> com%2Fandr2000%2Fu-boot%2Ftree%2Fpvblock_upstream_v1&data=0
> 2%7C01%7Cpeng.fan%40nxp.com%7C407d8af24a36483fbdce08d81805ed88
> %7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637285761021975
> 164&sdata=5vWfBbLScICXPZWU%2BU3b7DyONcgxT8iICsxrwUbORZY%
> 3D&reserved=0
> 
> [2]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.
> com%2Fxen-troops%2Fu-boot%2Fpull%2F2&data=02%7C01%7Cpeng.fa
> n%40nxp.com%7C407d8af24a36483fbdce08d81805ed88%7C686ea1d3bc2b4
> c6fa92cd99c5c301635%7C0%7C0%7C637285761021975164&sdata=%2
> FmXheEvKssLjjaFKsHBBbqh%2B72jH3uQnE7cpN0J3k8I%3D&reserved=0