Now that we process incoming data from the main loop - and use 'buf' both for incoming and outgoing data we should of course make sure that we never trash the incoming data with outgoing data.
The C test program may serve as copy & paste templates so it should make clear that ip65_process() is supposed to be called pretty regularly. Additionally it isn't supposed to be called recursively meaning that recv callbacks need to return quickly and defer longer processing.
The IP5 usage of ld65 segments and zeropage variables was made compatible with cc65 C programs already a while ago. This commit is the next logical step which is to introduce the actual C interface to IP65.
IP65 for C programs shares the the ip65.lib / ip65_tcp.lib with IP65 for assembler programs. However the various libraries from the 'drivers' are not reused. Instead there's exactly one library for every target named ip65_<target>.lib. Those libraries contain only functions used by ip65.lib / ip65_tcp.lib.
TODOs:
- Introduce c64_timer.s and atr_timer.s.
- Add a C interface to the rest of the IP65 functionality (especially TCP).
