NIC driver skeleton for study. (GXemul/PSIM)

Ian Caddy ianc at
Fri Jan 20 01:14:48 UTC 2006

Hi Karel,

When we originally did our NIC driver, we referenced the RTEMS Network 
Supplement written by Eric Norum, which was quite informative.  It 
references the network driver in the Gen68360 BSP 
(c/src/lib/libbsp/m68k/Gen68360/network/network.c) which is based on the 
Motorola 68360 processor with onboard MAC.

There are other drivers around, but that one is fairly straight forward. 
  There are PC type ones in c/src/libchip/network such as cs8900.c which 
look fairly straight forward as well.

Basically the stack will create the full ethernet frame before it drops 
down to the driver level which is only for sending and receiving frames. 
  The thing to watch out for is that they are not necessarily contained 
in one buffer, it will probably be a linked list of buffers containing 
all the data required.

I hope this helps.


Ian Caddy

Karel Gardas wrote:
> Hello,
> I'm thinking about writting as simple as possible NIC driver for RTEMS 
> for simple emulated NIC. Something for ether-like device from GXemul:
> -- 
> scroll down and look for `ether'.
> The NIC will be connected to TUN/TAP device, hence I need to get proper 
> Ethernet's frames somewhere. Does TCPIP stack produce them 
> automatically? If so, then such work should be relatively easy, but I'd 
> like to study some as simple as possible NIC driver to get an idea what 
> to do and where to start.
> Thanks!
> Karel
> -- 
> Karel Gardas                  kgardas at
> ObjectSecurity Ltd. 

Ian Caddy
Goanna Technologies Pty Ltd
+61 8 9221 1860

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