Using the Build->Packages dialog, add the packages “Networking”, “OpenBSD TCP/IP Stack” and “Common Ethernet Support” to your configuration. Their package names are CYGPKG_NET, CYGPKG_NET_OPENBSD_STACK and CYGPKG_NET_ETH_DRIVERS respectively.
A short-cut way to do this is by using the “net” template if it is available for your platform.
The platform-specific ethernet device driver for your platform will be added as part of the target selection (in the Build->Templates “Hardware” item), along with the PCI I/O subsystem (if relevent) and the appropriate serial device driver.
For example, the PowerPC MBX target selection adds the package PKG_NET_QUICC_ETH_DRIVERS, and the Cirrus Logic EDB7xxx target selection adds the package CYGPKG_NET_EDB7XXX_ETH_DRIVERS. After this, eCos and its tests can be built exactly as usual.
Note: By default, most of the network tests are not built. This is because some of them require manual intervention, i.e. they are to be run “by hand”, and are not suitable for automated testing. To build the full set of network tests, set the configuration option CYGPKG_NET_BUILD_TESTS “Build networking tests (demo programs)” within “Networking support build options”.