[dpdk-dev] [PATCH 2/2] doc: add a guide doc for cross compiling from x86

[Gavin Hu <gavin.hu@arm.com>]

Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Steve Capper <Steve.Capper@arm.com>
Reviewed-by: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
---
 doc/cross_compiling_sdk.txt | 58 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 doc/cross_compiling_sdk.txt

diff --git a/doc/cross_compiling_sdk.txt b/doc/cross_compiling_sdk.txt
new file mode 100644
index 0000000..aa08871
--- /dev/null
+++ b/doc/cross_compiling_sdk.txt
@@ -0,0 +1,58 @@
+How to cross compile DPDK for ARM64
+-----------------------------------
+
+NOTE: Whilst it is recommended to natively build DPDK on ARM64 (just
+like with x86), it is also possible to cross-build DPDK for ARM64.  An
+ARM64 cross compile GNU toolchain is used for this, which currently requires
+the NUMA libraries to be integrated. Following are the steps to follow.
+
+1. Obtain the cross tool chain
+------------------------------
+The latest cross compile tool chain can be downloaded from:
+https://releases.linaro.org/components/toolchain/binaries/latest/aarch64-linux-gnu/
+Following is the step to get the version 7.2.1, latest so far.
+$ wget https://releases.linaro.org/components/toolchain/binaries/latest/
+aarch64-linux-gnu/gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu.tar.xz
+
+2. Unzip and add into the PATH
+------------------------------
+$ tar -xvf gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu.tar.xz
+$ export PATH=$PATH:<install dir>/gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu/bin
+Note: For the host requirements and ohter info, refer to the release note section:
+https://releases.linaro.org/components/toolchain/binaries/latest/
+
+3. Getting the prerequisite library
+-----------------------------------
+-- NUMA
+--Prequisite: make sure the installed libtool version >= 2.2(run libtool --version to check),
+otherwise the compilation will fail with errors.
+$ git clone https://github.com/numactl/numactl.git
+$ cd numactl
+$ git checkout v2.0.11 -b v2.0.11
+$ ./autogen.sh
+$ autoconf -i
+$ ./configure --host=x86_64 CC=aarch64-linux-gnu-gcc
+$ make
+
+4. Install the numa header and lib
+----------------------------------
+Copy the header files to the cross compiler's include directory:
+$ cp numa*.h <install dir>/gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu/bin/../aarch64-linux-gnu/libc/usr/include/
+Copy the numa lib to the cross compiler;s lib directory:
+$ cp .libs/libnuma.a <install dir>/gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu/lib/gcc/aarch64-linux-gnu/7.2.1/
+
+5. Configuring the DPDK Build
+-----------------------------
+To configure a build, follow the build-sdk-quick.txt file to select the target
+configuration.
+$ make config T=arm64-armv8a-linuxapp-gcc
+
+6. Cross Compiling DPDK
+-----------------------
+To cross-compile DPDK for ARM64 target machine, without compiling the kernel modules, use the following
+command:
+$ make -j CROSS=aarch64-linux-gnu- CONFIG_RTE_KNI_KMOD=n CONFIG_RTE_EAL_IGB_UIO=n
+
+To cross-compile DPDK for ARM64, including the kernel modules, the kernel source tree is required.
+Set RTE_KERNEL_SRC_ROOTDIR to the kernel source tree folder and use the following command:
+$ make -j CROSS=aarch64-linux-gnu- RTE_KERNELDIR=KERNEL_SRC_ROOTDIR CROSS_COMPILE=aarch64-linux-gnu-
-- 
2.1.4