Re: [Etherboot-developers] Question on supporting nVidia .o driver

[Michael B. <mb...@fe...>]

On Wed, 21 Aug 2002, Andy Green wrote:
> Over at the xbox linux project there is some discussion today about
> supporting the nVidia inside the xbox (and used on nForce motherboards)
> Ethernet controller with an etherboot driver.
> The issue is that nVidia supply a .o file containing all the goodies; it
>   is believed to be quite possible to fake up something using the kernel
> network API to use this and make it believe it was a kernel driver.
> The main question is, what's the prevailing opinion about using a .o in
> this way GPL-wise.  It has been suggested that we'll be okay if we do
> not distribute the .o but make our GPL project consist of everything
> but.  (Because we are running on the xbox only, portability is not a
> concern).
> In addition, has anyone made such a fake kernel API shell before?  Has
> anyone looked at supporting nForce motherboards?

Aside from the legal / copyright issues, a few technical points spring
to mind:

1. The nVidia .o file is 20kB in size - around 4-5 times the size of most
   of the Etherboot drivers.  This might be enough to prevent it working
   in 5.0.x (AFAICT, the memory-map changes in the 5.1.x branch will fix
   this anyway).

2. Is it possible to use the .o file to create a polling driver?
   Etherboot doesn't use interrupts.

3. As others have said, don't bother faking a kernel network API - just
   take the skeleton Etherboot driver in skel.c and fill out the gaps
   between that and the nVidia .o file.

Michael Brown
http://www.fensystems.co.uk