[dpdk-dev] [PATCH v2 2/2] doc: add a guide doc for cross compiling from x86

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

This is guild for cross compiling for ARM64 from X86 hosts.

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>
Reviewed-by: Marko Kovacevic <marko.kovacevic@intel.com>
Reviewed-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Reviewed-by: Thomas Monjalon <thomas@monjalon.net>
Reviewed-by: Bruce Richardson <bruce.richardson@intel.com>
---
 doc/guides/howto/index.rst                         |  1 +
 .../linux_gsg/cross_build_dpdk_for_arm64.rst       | 70 ++++++++++++++++++++++
 doc/guides/linux_gsg/index.rst                     |  1 +
 3 files changed, 72 insertions(+)
 create mode 100644 doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst

diff --git a/doc/guides/howto/index.rst b/doc/guides/howto/index.rst
index e13a090..35ac151 100644
--- a/doc/guides/howto/index.rst
+++ b/doc/guides/howto/index.rst
@@ -8,6 +8,7 @@ HowTo Guides
     :maxdepth: 2
     :numbered:
 
+	cross_compile_sdk_for_arm64
     lm_bond_virtio_sriov
     lm_virtio_vhost_user
     flow_bifurcation
diff --git a/doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst b/doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst
new file mode 100644
index 0000000..2abf2e8
--- /dev/null
+++ b/doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst
@@ -0,0 +1,70 @@
+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=$PATH:<install dir>/gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu/bin
+Note: For the host requirements and other info, refer to the release note section:
+https://releases.linaro.org/components/toolchain/binaries/latest/
+
+3. Getting the prerequisite library
+-----------------------------------
+-- NUMA (Note: Required by most modern machines, not needed for non-NUMA ones)
+--Prerequisite: for compiling NUMA, make sure the installed libtool version >= 2.2
+(run libtool --version to check), otherwise the compilation will fail with errors.
+$ 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 prefix=<numa install dir>
+$ make install
+You will get numa*.h files under <numa install dir>/include and libnuma.a under <numa install dor>/lib.
+
+4. Augument the cross gcc toolchain with the NUMA header and lib
+----------------------------------------------------------------
+Note: This way is optional, the alternative way is to use extra CFLAGS and LDFLAGS, depicted in Step 6)*
+Copy the NUMA header files to the cross compiler's include directory:
+$ cp <numa install dir>/include/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 <numa install dir>/lib/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 one of the target configurations,like
+arm64-dpaa2-linuxapp-gcc and arm64-thunderx-linuxapp-gcc for optimized build specific to target.
+
+$ 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-
+
+Note:
+1. If the target machine is non-NUMA, add the following to the command:
+CONFIG_RTE_LIBRTE_VHOST_NUMA=n CONFIG_RTE_EAL_NUMA_AWARE_HUGEPAGES=n
+2. If Step 4 is skipped and the toolchain was not augumented with the NUMA headers and library.
+Add EXTRA CFLAGS and LDFLAGS for the NUMA header and library. RTE_DEVEL_BUILD has to be disabled, otherwise
+the numa.h file will get a lot of Werror=cast-qual, Werror=strict-prototypes and Werror=old-style-definition
+compiling errors.
+EXTRA_CFLAGS="-I/opt/cccc/include" EXTRA_LDFLAGS="-L<numa install dir>/lib -lnuma" RTE_DEVEL_BUILD=n
diff --git a/doc/guides/linux_gsg/index.rst b/doc/guides/linux_gsg/index.rst
index 2a7bdfe..c5b1695 100644
--- a/doc/guides/linux_gsg/index.rst
+++ b/doc/guides/linux_gsg/index.rst
@@ -13,6 +13,7 @@ Getting Started Guide for Linux
     intro
     sys_reqs
     build_dpdk
+	cross_build_dpdk_for_arm64
     linux_drivers
     build_sample_apps
     enable_func
-- 
2.1.4