Re: [PATCH bpf-next 11/11] samples: bpf: makefile: add sysroot support

[Ivan Khoronzhuk]

On Fri, Sep 13, 2019 at 09:45:31PM +0000, Yonghong Song wrote:
> On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote:
> > Basically it only enables that was added by previous couple fixes.
> > For sure, just make tools/include to be included after sysroot
> > headers.
> >
> > export ARCH=arm
> > export CROSS_COMPILE=arm-linux-gnueabihf-
> > make samples/bpf/ SYSROOT="path/to/sysroot"
> >
> > Sysroot contains correct libs installed and its headers ofc.
> > Useful when working with NFC or virtual machine.
> >
> > Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> > ---
> >   samples/bpf/Makefile   |  5 +++++
> >   samples/bpf/README.rst | 10 ++++++++++
> >   2 files changed, 15 insertions(+)
> >
> > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > index 4edc5232cfc1..68ba78d1dbbe 100644
> > --- a/samples/bpf/Makefile
> > +++ b/samples/bpf/Makefile
> > @@ -177,6 +177,11 @@ ifeq ($(ARCH), arm)
> >   CLANG_EXTRA_CFLAGS := $(D_OPTIONS)
> >   endif
> >
> > +ifdef SYSROOT
> > +ccflags-y += --sysroot=${SYSROOT}
> > +PROGS_LDFLAGS := -L${SYSROOT}/usr/lib
> > +endif
> > +
> >   ccflags-y += -I$(objtree)/usr/include
> >   ccflags-y += -I$(srctree)/tools/lib/bpf/
> >   ccflags-y += -I$(srctree)/tools/testing/selftests/bpf/
> > diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
> > index 5f27e4faca50..786d0ab98e8a 100644
> > --- a/samples/bpf/README.rst
> > +++ b/samples/bpf/README.rst
> > @@ -74,3 +74,13 @@ samples for the cross target.
> >   export ARCH=arm64
> >   export CROSS_COMPILE="aarch64-linux-gnu-"
> >   make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > +
> > +If need to use environment of target board (headers and libs), the SYSROOT
> > +also can be set, pointing on FS of target board:
> > +
> > +export ARCH=arm64
> > +export CROSS_COMPILE="aarch64-linux-gnu-"
> > +make samples/bpf/ SYSROOT=~/some_sdk/linux-devkit/sysroots/aarch64-linux-gnu
> > +
> > +Setting LLC and CLANG is not necessarily if it's installed on HOST and have
> > +in its targets appropriate arch triple (usually it has several arches).
>
> You have very good description about how to build and test in cover
> letter. Could you include those instructions here as well? This will
> help keep a record so later people can try/test if needed.

I will try.
Thanks!!!

--
Regards,
Ivan Khoronzhuk