looking for eprom info re 3c905b

Donald Becker becker@cesdis1.gsfc.nasa.gov
Mon Aug 17 18:48:38 1998


On Mon, 17 Aug 1998, Andru Luvisi wrote:

> I work for a university library, and after evaluating 6 proprietary
> network computer type offerings, we decided we could do better on our own.
> our current plan is to use netboot (http://www.han.de/~gero/netboot.html)
> to boot linux with a read-only nfs root partition.  we have it almost
> fully implimented (fully implimented if we use an NE2000 or 3c509 ethernet
> card), but we can't figure out how to get a boot prom to run in the 3c905
> (which is what we'd greatly prefer to use in case our campus goes over to
> 100BaseT within the next several years). 3c90xcfg shows the eprom as
> mapped into a region near the top of the current ram, rather than anywhere
> in 0xc0000-0xef800.  it's not that the eprom doesn't work... it's never
> executed!  3com tech support has been anything but helpful, and I'm
> begining to run out of ideas to try.  I would be greatful for *any*
> pointers to technical information on booting from an eprom using 3c90x
> cards, or *any* advice anyone can offer. 

Boot ROMs are special on PCI: the PCI definition explicitly handles them
with a specific mapping register.  The BIOS is responsible for mapping them,
and then copying the code into RAM before execution.  Since the hardware is
simple, most of what can go wrong is in the BIOS.

BTW, where did you get a 3c905 boot-ROM image?  Are you certain that it's
not for the 3c509?

Donald Becker					  becker@cesdis.gsfc.nasa.gov
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html