参考ug1144 Adding an Existing Recipe into RootFS
petalinux-config -c rootfs
ethtool在RootFS menuconfig中，路径如下：
iperf不在RootFS menuconfig中
首先找一下iperf的包在哪儿，有没有
ug1144：
The location of the recipe is /opt/pkg/petalinux/components/yocto/source/
aarch64/layers/meta-openembedded/meta-oe/recipes-benchmark/iperf3/
iperf3_3.2.bb.
实际petalinux2019.2中
/home/zhangyi/opt/pkg/petalinux/2019.2/components/yocto/source/aarch64/layers/meta-openembedded/meta-oe/recipes-benchmark/iperf3/iperf3_3.6.bb
然后就是往menuconfig中加：
ug1144：
Add the following line in <plnx-proj-root>/project-spec/conf/userrootfsconfig.
CONFIG_iperf3
实际petalinux2019.2中
/home/zhangyi/work/xxxx_linux/<plnx-proj-root>/project-spec/meta-user/conf/user-rootfsconfig
CONFIG_iperf3
CONFIG_memtester
然后Run petalinux-config -c rootfs.
Select user packages → iperf3. Enable it, save and exit.
Run petalinux-build.