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 > > 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.
