| Message ID | 20140325161722.GA23842@ulmo (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> > There are two things that don't work too well with this. First this > causes the build to break if the build machine doesn't have the new > public header (include/uapi/linux/dma-buf.h) installed yet. So the only > way to make this work would be by building the kernel once with SAMPLES > disabled, install the headers and then build again with SAMPLES enabled. > Which really isn't very nice. > > One other option that I've tried is to modify the include path so that > the test program would get the in-tree copy of the public header file, > but that didn't build properly either because the header files aren't > properly sanitized and therefore the compiler complains about it > (include/uapi/linux/types.h). > > One other disadvantage of carrying the sample program in the tree is > that there's only infrastructure to build programs natively on the build > machine. That's somewhat unfortunate because if you want to run the test > program on a different architecture you have to either compile the > kernel natively on that architecture (which isn't very practical on many > embedded devices) or cross-compile manually. > > I think a much nicer solution would be to add infrastructure to cross- > compile these test programs, so that they end up being built for the > same architecture as the kernel image (i.e. using CROSS_COMPILE). > > Adding Michal and the linux-kbuild mailing list, perhaps this has been > discussed before, or maybe somebody has a better idea on how to solve > this. I actually looked into this some time ago. May try to dust off the patch. IIRC the kernel provided headers were used for building - not the one installed on the machine. And crosscompile were supported. Sam
On Tue, Mar 25, 2014 at 07:01:10PM +0100, Sam Ravnborg wrote: > > > > There are two things that don't work too well with this. First this > > causes the build to break if the build machine doesn't have the new > > public header (include/uapi/linux/dma-buf.h) installed yet. So the only > > way to make this work would be by building the kernel once with SAMPLES > > disabled, install the headers and then build again with SAMPLES enabled. > > Which really isn't very nice. > > > > One other option that I've tried is to modify the include path so that > > the test program would get the in-tree copy of the public header file, > > but that didn't build properly either because the header files aren't > > properly sanitized and therefore the compiler complains about it > > (include/uapi/linux/types.h). > > > > One other disadvantage of carrying the sample program in the tree is > > that there's only infrastructure to build programs natively on the build > > machine. That's somewhat unfortunate because if you want to run the test > > program on a different architecture you have to either compile the > > kernel natively on that architecture (which isn't very practical on many > > embedded devices) or cross-compile manually. > > > > I think a much nicer solution would be to add infrastructure to cross- > > compile these test programs, so that they end up being built for the > > same architecture as the kernel image (i.e. using CROSS_COMPILE). > > > > Adding Michal and the linux-kbuild mailing list, perhaps this has been > > discussed before, or maybe somebody has a better idea on how to solve > > this. > I actually looked into this some time ago. > May try to dust off the patch. > IIRC the kernel provided headers were used for building - not the one installed on the machine. > And crosscompile were supported. That sounds exactly like what I'd want for this. If you need any help, please let me know. Thanks, Thierry
On Wed, Mar 26, 2014 at 09:32:47AM +0100, Thierry Reding wrote: > On Tue, Mar 25, 2014 at 07:01:10PM +0100, Sam Ravnborg wrote: > > > > > > There are two things that don't work too well with this. First this > > > causes the build to break if the build machine doesn't have the new > > > public header (include/uapi/linux/dma-buf.h) installed yet. So the only > > > way to make this work would be by building the kernel once with SAMPLES > > > disabled, install the headers and then build again with SAMPLES enabled. > > > Which really isn't very nice. > > > > > > One other option that I've tried is to modify the include path so that > > > the test program would get the in-tree copy of the public header file, > > > but that didn't build properly either because the header files aren't > > > properly sanitized and therefore the compiler complains about it > > > (include/uapi/linux/types.h). > > > > > > One other disadvantage of carrying the sample program in the tree is > > > that there's only infrastructure to build programs natively on the build > > > machine. That's somewhat unfortunate because if you want to run the test > > > program on a different architecture you have to either compile the > > > kernel natively on that architecture (which isn't very practical on many > > > embedded devices) or cross-compile manually. > > > > > > I think a much nicer solution would be to add infrastructure to cross- > > > compile these test programs, so that they end up being built for the > > > same architecture as the kernel image (i.e. using CROSS_COMPILE). > > > > > > Adding Michal and the linux-kbuild mailing list, perhaps this has been > > > discussed before, or maybe somebody has a better idea on how to solve > > > this. > > I actually looked into this some time ago. > > May try to dust off the patch. > > IIRC the kernel provided headers were used for building - not the one installed on the machine. > > And crosscompile were supported. > > That sounds exactly like what I'd want for this. If you need any help, > please let me know. Did you have any time to look into dusting off the patch? If not I'll gladly take whatever you have and dust it off myself. Thierry
On Thu, Jul 10, 2014 at 11:55:26AM +0200, Thierry Reding wrote: > On Wed, Mar 26, 2014 at 09:32:47AM +0100, Thierry Reding wrote: > > On Tue, Mar 25, 2014 at 07:01:10PM +0100, Sam Ravnborg wrote: > > > > > > > > There are two things that don't work too well with this. First this > > > > causes the build to break if the build machine doesn't have the new > > > > public header (include/uapi/linux/dma-buf.h) installed yet. So the only > > > > way to make this work would be by building the kernel once with SAMPLES > > > > disabled, install the headers and then build again with SAMPLES enabled. > > > > Which really isn't very nice. > > > > > > > > One other option that I've tried is to modify the include path so that > > > > the test program would get the in-tree copy of the public header file, > > > > but that didn't build properly either because the header files aren't > > > > properly sanitized and therefore the compiler complains about it > > > > (include/uapi/linux/types.h). > > > > > > > > One other disadvantage of carrying the sample program in the tree is > > > > that there's only infrastructure to build programs natively on the build > > > > machine. That's somewhat unfortunate because if you want to run the test > > > > program on a different architecture you have to either compile the > > > > kernel natively on that architecture (which isn't very practical on many > > > > embedded devices) or cross-compile manually. > > > > > > > > I think a much nicer solution would be to add infrastructure to cross- > > > > compile these test programs, so that they end up being built for the > > > > same architecture as the kernel image (i.e. using CROSS_COMPILE). > > > > > > > > Adding Michal and the linux-kbuild mailing list, perhaps this has been > > > > discussed before, or maybe somebody has a better idea on how to solve > > > > this. > > > I actually looked into this some time ago. > > > May try to dust off the patch. > > > IIRC the kernel provided headers were used for building - not the one installed on the machine. > > > And crosscompile were supported. > > > > That sounds exactly like what I'd want for this. If you need any help, > > please let me know. > > Did you have any time to look into dusting off the patch? If not I'll > gladly take whatever you have and dust it off myself. Thanks for the reminder. I got it almost working after simplifying it a lot. I will be travelling for the next few days but will continue to work on this after the weekend. Sam
diff --git a/samples/dma-buf/Makefile b/samples/dma-buf/Makefile new file mode 100644 index 000000000000..bcaa117474d7 --- /dev/null +++ b/samples/dma-buf/Makefile @@ -0,0 +1,8 @@ +obj- := dummy.o + +HOSTCFLAGS_dma-buf-test.o += $(shell pkg-config --cflags libdrm) +HOSTLOADLIBES_dma-buf-test += $(shell pkg-config --libs libdrm) + +hostprogs-y := dma-buf-test + +always := $(hostprogs-y)