On Tuesday 18 April 2017 03:42 PM, Sekhar Nori wrote: > Hi Jonathan, Randy, > > On Friday 14 April 2017 08:53 PM, Jonathan Cameron wrote: >> On 14/04/17 16:23, Randy Dunlap wrote: >>> On 04/14/17 07:42, Jonathan Cameron wrote: >>>> On 11/04/17 12:06, Sekhar Nori wrote: >>>>> Very often, especially when cross compiling, there is a need >>>>> to pass kernel headers different from those installed on the >>>>> build machine. >>>>> >>>>> Add support for doing this for iio utils by using the >>>>> 'INSTALL_HDR_PATH' environment variable. This is supported by >>>>> 'make headers_install' for installing kernel headers at a >>>>> user specified location. So you will do: >>>>> >>>>> $ make headers_install ARCH=arm INSTALL_HDR_PATH=<absolute-path> >>>>> $ make -C tools/iio ARCH=arm INSTALL_HDR_PATH=<absolute-path> >>>>> >>>>> Signed-off-by: Sekhar Nori <nsekhar@xxxxxx> >>>> >>>> It's a bit of an oddity as that usually refers to where to put >>>> the headers rather than where they are. >>>> >>>> Is there a more general solution? I couldn't find anything >>>> particularly consistent in tools. >>> >>> Whatever the solution is, it should be used for all tools/, not just iio. >>> >> Agreed! > > Alright, I will try to come up with something more generic and post > another version. I have been looking at this, and coming up with something generic is more complicated than I thought. The problem is the flexibility thats allowed in building many of the tools. For example, you can build the led tools using any of these three methods: $ make -C <kernelsrcdir> tools/leds $ make -C <kernelsrcdir>/tools leds $ make -C <kernelsrcdir>/tools/leds The last one is specifically complicated because it totally bypasses all top level makefiles. I think adding dependency with a top level makefile will be a step backwards at least for leds. Currently the leds makefile adds '-I../../include/uapi' to CFLAGS to access the latest kernel headers. Something similar is done for some other tools too. This makes it work for all the build cases above. I propose we do something similar for iio too. Thanks, Sekhar -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
