TCP/IP Networking for eCos now provides a complete TCP/IP networking stack, which is derived from a stable release of OpenBSD. The networking support is fully featured and well tested within the eCos environment. Since this networking package is based on BSD code, it is very complete and robust. The eCos implementation includes support for the following protocols: IPv4 UDP TCP ICMP raw packet interface Along with support for the above mentioned protocols, the OpenBSD stack also supports ethernet bridging. The following additional features are also present in the package, but are not supported: Berkeley Packet Filter Multi-cast and uni-cast support, including multi-cast routing IPv6 This document describes how to get started with the OpenBSD TCP/IP network stack. A number of ethernet devices may be supported. The default configuration supports two instances of the interface by default, and you will need to write your own driver instantiation code, and supplemental startup and initialization code, if you should add additional ones. The target for your board will normally be supplied with an ethernet driver, in which case including the network stack and generic ethernet driver package to your build will automatically enable usage of the ethernet device driver. If your target is not supplied with an ethernet driver, you will need to use loopback (see ). 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. 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”. The OpenBSD stack does not by default result in the inclusion of the bridge code. To include bridging functionality the CDL option CYGPKG_NET_BRIDGE must be enable . It is also possible to enable more than one concurrent bridge. The number of bridges active in a device is configured by the CDL option CYGNUM_NET_BRIDGES, which has a default value of 1. The default behavior of a bridge is to operate without the spanning tree protocol. When devices are operated in this default mode it must be ensured the network topology is loop-free. Any loops will cause broadcast storms and general mayhem on the network. Including spanning tree code during the build process will allow the bridge to communicate with other bridges. They can then detect such loops and by disabling selected interfaces break the loop. To enable spanning tree enable the CDL option CYGPKG_NET_BRIDGE_STP_CODE. The APIs for the standard networking calls such as socket(), recv() and so on, are in header files relative to the top-level include directory, within the standard subdirectories as conventionally found in /usr/include. For example: install/include/arpa/tftp.h install/include/netinet/tcpip.h install/include/sys/socket.h install/include/sys/socketvar.h install/include/sys/sockio.h network.h at the top level defines various extensions, for example the API init_all_network_interfaces(void) described above. We advise including network.h whether you use these features or not. In general, using the networking code may require definition of two symbols: _KERNEL and __ECOS. _KERNEL is not normally required; __ECOS is normally required. So add this to your compile lines for files which use the network stack: -D__ECOS To expand a little, it’s like this because this is a port of a standard distribution external to Red Hat. One goal is to perturb the sources as little as possible, so that upgrading and maintenance from the external distribution is simplified. The __ECOS symbol marks out Red Hat’s additions in making the port. The _KERNEL symbol is traditional UNIX practice: it distinguishes a compilation which is to be linked into the kernel from one which is part of an application. eCos applications are fully linked, so this distinction does not apply. _KERNEL can however be used to control the visibility of the internals of the stack, so depending on what features your application uses, it may or may not be necessary. The include file network.h undefines _KERNEL unconditionally, to provide an application-like compilation environment. If you were writing code which, for example, enumerates the stack’s internal structures, that is a kernel-like compilation environment, so you would need to define _KERNEL (in addition to __ECOS) and avoid including network.h. The network stack supports an extension to the standard select semantics which allows all threads that are waiting to be restarted even if the select conditions are not satisfied. The standard select() API: int select(int nfd, fd_set *in, fd_set *out, fd_set *ex, struct timeval *tv); does not support the restart. The additional API: int cyg_select_with_abort(int nfd, fd_set *in, fd_set *out, fd_set *ex, struct timeval *tv) behaves exactly as select() with the additional feature that a call to void cyg_select_abort(void) will cause all threads waiting in any cyg_select_with_abort() call to cease waiting and continue execution. &net-tcpip-openbsd-manpages-netintro-sgml &net-tcpip-openbsd-manpages-bridge-sgml &net-tcpip-openbsd-manpages-stp-sgml