samples/bpf: Add sysroot support

Basically it only enables that was added by previous couple fixes.
Sysroot contains correct libs installed and its headers. Useful when
working with NFC or virtual machine.

Usage example:

clean (on demand)
    make ARCH=arm -C samples/bpf clean
    make ARCH=arm -C tools clean
    make ARCH=arm clean

configure and install headers:

    make ARCH=arm defconfig
    make ARCH=arm headers_install

build samples/bpf:
    make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- samples/bpf/ \
    SYSROOT="path/to/sysroot"

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191011002808.28206-15-ivan.khoronzhuk@linaro.org
This commit is contained in:
Ivan Khoronzhuk 2019-10-11 03:28:07 +03:00 committed by Alexei Starovoitov
parent d8ceae91e9
commit b2327c107d

View File

@ -187,6 +187,11 @@ TPROGS_CFLAGS += -I$(srctree)/tools/lib/
TPROGS_CFLAGS += -I$(srctree)/tools/include
TPROGS_CFLAGS += -I$(srctree)/tools/perf
ifdef SYSROOT
TPROGS_CFLAGS += --sysroot=$(SYSROOT)
TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
endif
TPROGCFLAGS_bpf_load.o += -Wno-unused-variable
TPROGS_LDLIBS += $(LIBBPF) -lelf