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] > >> >> 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://github.com/andr2000/u-boot/tree/pvblock_upstream_v1 [2] https://github.com/xen-troops/u-boot/pull/2
