Re: [Qemu-devel] Sparc system patch 12

[Derek Fawcus]

On Tue, Oct 26, 2004 at 05:36:28PM +0200, Blue Swirl wrote:
> Hi,
> 
> Lance (Am79C90) is much older than PC-Net (Am79C970A).  PC-net has 128 
> registers, prom and a buffer, while Lance only has 4 registers, no proms or 
> buffers.  I don't know about in-memory structures, the code looks similar.  
> Bus is different (ISA/PCI vs. SBUS), but that has very little effect.  In 
> Linux there are different drivers for these chips for some reason 
> (sunlance.c and pcnet32.c).
> 
> If PC-net is close to 100% backwards compatible, or the compatibility is 
> easy to add (compile or run time), it may be useful to merge the two.  Your 
> code looks much more complete, with debugging for in-memory stuff etc so 
> that could be the starting point.

The PC-net in 16 bit mode is largely compatible.  As I recall the only issue
is to make sure that the media selection is programmed properly (since the
10base-T interface (and it's registers) doesn't exist on LANCE).

I have in the past written a driver (in 16bit mode) which worked with both the
PC-net and the LANCE.  This was on a PC (under an odd OS),  the LANCE was on
an ISA bus,  and the PC-net on a PCI bus.

DF