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dpdkninjameson-build

*** Cannot find .config in /home/cxx/dpdk-20.05/build

Similar questions to Need help on compiling DPDK hello world. However my DPDK version is v20.05, I have to use meson and ninja to build my DPDK,so the solution doesn't work for me.

I built my DPDK following the link:https://doc.dpdk.org/guides/linux_gsg/build_dpdk.html.

Before building my DPDK, I pre-set:

export RTE_SDK=/home/cxx/dpdk-20.05
export RTE_TARGET=build

My building commands:

meson build --prefix=/home/cxx/dpdk-20.05
cd build
ninja
ninja install (I don't run the"ldconfig" command)

cd /home/cxx/dpdk-20.05/examples/helloworld 
make

the error shows:

/home/cxx/dpdk-20.05/mk/internal/rte.extvars.mk:29: *** Cannot find .config in /home/cxx/dpdk-20.05/build.  Stop.

So, I run the command below to see if the .config file really doesn't exist.

cd /home/cxx/dpdk-20.05/build 
find . -name ".config"

The result shows that there is actually no ".config" file in /home/cxx/dpdk-20.05/build.

Why did I lose the .config file and how can I do to solve the problem?

Solution

  • [EDIT-1] the real issue is

    1. mix up the steps between makefile build and meson-ninja.
    2. Since you have used prefix the default PKG_CONFIG is not able to point to libdpdk.pkg

    Explanation: From DPDK version > 19.11 LTS onwards support for meson ninja is fully integrated with the removal of Makefile. Hence one needs to use meson ninja only. So the right steps to follow are

    1. Do not execute the steps
    export RTE_SDK=/home/cxx/dpdk-20.05
export RTE_TARGET=build
    1. If the intention is to built DPDK and install in default path, then execute
    untar dpdk.tar
cd dpdk-folder
meson [desired folder name]
cd [desired folder name]
ninja
ninja install
ldconfig
    1. But if the intention is to built and save the libraries and header files in different folder then
    untar dpdk.tar
cd dpdk-folder
meson [desired folder name] --prefix=[folder to hold the built dpdk libraries and headers]
cd [desired folder name]
ninja
ninja install
ls [folder to hold the built dpdk libraries and headers]

    In order to build helloworld with step-2, gcc helloworld.c $(pkg-config --libs --cflags libdpdk) is sufficient. But in order to make use of libraries and headers from the custom folder, one requires to point PKG_CONFIG_PATH to the custom folder which has libdpdk.pkg. This will allow the libdpdk.pkg to be used from the custom folder, not /usr/lib/.

    steps to follow

    export PKG_CONFIG_PATH=[dpdk master folder]/[custom folder path where libdpdk.pkg is located]
gcc helloworld.c $(pkg-config --libs --cflags libdpdk)