Re: XEN modules?

[Paul Goyette <paul%whooppee.com@localhost>]

> > I know there's some magic somewhere in the Makefiles that automatically 
> > builds both "normal" and XEN variants of the modules for amd64 (and, for 
> > i386, there's a PAE variant, too)!  But I can't seem to find the magic!
> >
> > Anyway, it seems to me that, when building the XEN (or PAE) variants of 
> > each module, they should be built with -DXEN (or -DPAE) options.  There is 
> > at least one source file, compiled into the compat module, which has some 
> > code conditional on XEN.  (For those who care, it is the compat_60 x86 code 
> > for updating AMD cpu_ucode.)
> >
> > Based on log files, we're currently not defining XEN or PAE for the modules 
> > builds.  As a result the XEN variant of the compat module does not contain 
> > the required code, preventing use of the 6.0 cpuctl command.
> >
> > So,
> >
> > 1. Would it be reasonable to define the XEN and PAE macros when building
> >   the module variants?
>
> Still need an answer to this question...
>
> > 2. What would it take to make it happen?
>
> Add
>
> 	CPPFLAGS+=	-DXEN (or PAE)
>
> to the appropriate *.mk files?  (See #3 below)  These files already have
>
> 	XEN=	1
>   and	PAE=	1
>
> > 3. Where's the magic?  :)
>
> OK, found the magic.  It's in
>
> 	src/sys/modules/arch/x86/amd64-xen/bsd.amd64-xen.mk
> 	src/sys/modules/arch/x86/i386-xen/bsd.i386-xen.mk
>  and	src/sys/modules/arch/x86/i386pae-xen/bsd.i386pae-xen.mk
>
>
> If the answer to Question #1 is "Yes, it's reasonable" then I can take care 
> of making the changes.


Follow-on question:  the changes identified above have the desired 
effect, and code conditioned on XEN is now being built.  Unfortunately, 
that has exposed the next problem!

The XEN-specific code has a

	#include "xen/intrptrs.h"

which for kernel builds would be found due to a sym-link in the kernel's 
object directory:

	xen -> /build/netbsd-compat/src/sys/arch/xen/include

This symlink doesn't exist in the module's object directory, so the 
#include fails.

It would appear that I might need to add some more magic to create the 
xen (and/or pae) symlink for the modules.  It looks like this is handled 
in share/mk/bsd.klinks.mk but it's not exactly clear what I should add. 
And I can't seem to find where the kernel Makefiles make this happen, so 
no examples from which to borrow.  I can't tell if I should (a) set 
XEN_BUILD to something (to what?), (2) override an existing value of 
KLINK_MACHINE, or (3) just update KLINK_FILES?  (And what is xen-ma used 
for, anyway?)

Again, any clue/help would be greatly appreciated.

(As you all can probably tell from this thread, I'm far from an expert 
when it comes to our build infrastructure...)



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| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:          |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee dot com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd dot org |
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