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:
network.h at the top level
defines various extensions, for example the API
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
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.