30. Building Your Own Application

30.1. Compiling a Sample Application in the Development Kit Directory

When compiling a sample application (for example, hello world), the following variables must be exported: RTE_SDK and RTE_TARGET.

~/DPDK$ cd examples/helloworld/
~/DPDK/examples/helloworld$ export RTE_SDK=/home/user/DPDK
~/DPDK/examples/helloworld$ export RTE_TARGET=x86_64-native-linuxapp-gcc
~/DPDK/examples/helloworld$ make
    CC main.o
    LD helloworld
    INSTALL-APP helloworld
    INSTALL-MAP helloworld.map

The binary is generated in the build directory by default:

~/DPDK/examples/helloworld$ ls build/app
helloworld helloworld.map

30.2. Build Your Own Application Outside the Development Kit

The sample application (Hello World) can be duplicated in a new directory as a starting point for your development:

~$ cp -r DPDK/examples/helloworld my_rte_app
~$ cd my_rte_app/
~/my_rte_app$ export RTE_SDK=/home/user/DPDK
~/my_rte_app$ export RTE_TARGET=x86_64-native-linuxapp-gcc
~/my_rte_app$ make
    CC main.o
    LD helloworld
    INSTALL-APP helloworld
    INSTALL-MAP helloworld.map

30.3. Customizing Makefiles

30.3.1. Application Makefile

The default makefile provided with the Hello World sample application is a good starting point. It includes:

  • $(RTE_SDK)/mk/rte.vars.mk at the beginning
  • $(RTE_SDK)/mk/rte.extapp.mk at the end

The user must define several variables:

  • APP: Contains the name of the application.
  • SRCS-y: List of source files (*.c, *.S).

30.3.2. Library Makefile

It is also possible to build a library in the same way:

  • Include $(RTE_SDK)/mk/rte.vars.mk at the beginning.
  • Include $(RTE_SDK)/mk/rte.extlib.mk at the end.

The only difference is that APP should be replaced by LIB, which contains the name of the library. For example, libfoo.a.

30.3.3. Customize Makefile Actions

Some variables can be defined to customize Makefile actions. The most common are listed below. Refer to Makefile Description section in Development Kit Build System

chapter for details.

  • VPATH: The path list where the build system will search for sources. By default, RTE_SRCDIR will be included in VPATH.
  • CFLAGS_my_file.o: The specific flags to add for C compilation of my_file.c.
  • CFLAGS: The flags to use for C compilation.
  • LDFLAGS: The flags to use for linking.
  • CPPFLAGS: The flags to use to provide flags to the C preprocessor (only useful when assembling .S files)
  • LDLIBS: A list of libraries to link with (for example, -L /path/to/libfoo - lfoo)