W5100 emulation in OpenMSX would be really great! It could be used for DenYoNet as well.
It would work directly on TCP/UDP layer, not below. Maybe this higher level is easier to implement in a portable way?
However, there is an idea to do high level emulation of networking by making a virtual device that implements the UNAPI software interface.
That's definitely the way to go: I think we can assume that what most users want is to be able to use UNAPI compatible applications, without really caring about the underlying (real or emulated) hardware. That's also the approach I followed to provide networking capabilities to NestorMSX.
I am spending a bit of time on this, trying to get Fuzix to work with gr8net, and I have found gr8net uses a Wiznet 5100 which turns out to be pretty common hardware.
There is a w5100 driver inside Fuzix I am trying to make work on the msx2 port, but... I can only debug on real hardware because there is no networking emulation support in openMSX.
But looking into this I found somebody already implemented w5100 emulation for a different machine:
https://github.com/cpswan/RC2014-Emulator/blob/master/w5100.c
Because of the way the w5100 works, the emulation is pretty much a translation layer to the socket implementation available on the host. Therefore is quite portable.
I know it would be harder to debug the Fuzix driver on the hardware only, than develop an openMSX extension for a subset of gr8net that includes only networking, and then debug using it.
Would this be an acceptable contribution to openMSX? a gr8net extension that contains only the network part?
Very unlikely for a gr8net extension as it is proprietary code and it depends also on the fpga it has, but Denyonet has open-source drivers for it and uses Wiznet 5100 too, that one is very possible if w5100 emulation is added
However, there is an idea to do high level emulation of networking by making a virtual device that implements the UNAPI software interface.
That's definitely the way to go: I think we can assume that what most users want is to be able to use UNAPI compatible applications, without really caring about the underlying (real or emulated) hardware. That's also the approach I followed to provide networking capabilities to NestorMSX.
It is a bummer that I didn't have time to do it yet, hope someone picks up this idea, simple and would work very nicely B-)
Yeah alright, w5100 emulation should work for any device that uses that chip. The differences may come from the way i/o access is mapped, but those are implementation details. The emulation is basically the same.
If as you say Denyonet is open source, it should be easy to use an existing UNAPI ROM to interface with the emulated device once is running.
As I explain above, for now I am working on the w5100 fuzix driver for msx and using a physical gr8net. Is almost ready and I am going to start testing in real hardware. Let's see what happens.
