libbpf/README

This is a mirror of bpf-next linux tree
(https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next)
bpf-next/tools/lib/bpf directory plus its supporting header files.

The following files will by sync'ed with bpf-next repo:
  src/ <-> bpf-next/tools/lib/bpf/
  include/uapi/linux/bpf_common.h <-> bpf-next/tools/include/uapi/linux/bpf_common.h
  include/uapi/linux/bpf.h <-> bpf-next/tools/include/uapi/linux/bpf.h
  include/uapi/linux/btf.h <-> bpf-next/tools/include/uapi/linux/btf.h
  include/uapi/linux/if_link.h <-> bpf-next/tools/include/uapi/linux/if_link.h
  include/uapi/linux/if_xdp.h <-> bpf-next/tools/include/uapi/linux/if_xdp.h
  include/uapi/linux/netlink.h <-> bpf-next/tools/include/uapi/linux/netlink.h
  include/tools/libc_compat.h <-> bpf-next/tools/include/tools/libc_compat.h

Other header files at this repo (include/linux/*.h) are reduced versions of
their counterpart files at bpf-next/tools/include/linux/*.h to make compilation
successful.

Build
=====
libelf is an internal dependency of libbpf and thus it is required to link
against and must be installed on the system for applications to work.
pkg-config is used by default to find libelf, and the program called can be
overridden with PKG_CONFIG.
If using pkg-config at build time is not desired, it can be disabled by setting
NO_PKG_CONFIG=1 when calling make.

To build both static libbpf.a and shared libbpf.so:
  cd src
  make

To build only static libbpf.a library in directory
build/ and install them together with libbpf headers in a staging directory
root/:
  cd src
  mkdir build root
  BUILD_STATIC_ONLY=y OBJDIR=build DESTDIR=root make install

To build both static libbpf.a and shared libbpf.so against a custom libelf
dependency installed in /build/root/ and install them together with libbpf
headers in a build directory /build/root/:

  cd src
  PKG_CONFIG_PATH=/build/root/lib64/pkgconfig DESTDIR=/build/root make install