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Date:   Sat, 14 Sep 2019 01:36:43 +0300
From:   Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
To:     Yonghong Song <yhs@fb.com>
Cc:     "ast@kernel.org" <ast@kernel.org>,
        "daniel@iogearbox.net" <daniel@iogearbox.net>,
        "davem@davemloft.net" <davem@davemloft.net>,
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        "john.fastabend@gmail.com" <john.fastabend@gmail.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "bpf@vger.kernel.org" <bpf@vger.kernel.org>,
        "clang-built-linux@googlegroups.com" 
        <clang-built-linux@googlegroups.com>
Subject: Re: [PATCH bpf-next 11/11] samples: bpf: makefile: add sysroot
 support
Message-ID: <20190913223642.GG26724@khorivan>
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References: <20190910103830.20794-1-ivan.khoronzhuk@linaro.org>
 <20190910103830.20794-12-ivan.khoronzhuk@linaro.org>
 <e967744b-0286-d92f-9fc8-70f5759cc4a1@fb.com>
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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@linaro.org>
>> ---
>>   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