Re: [Etherboot-developers] NIC file and ROM images

[<ke...@us...>]

>What if you (we) could build a bootrom that knows about ALL
>pci network chipsets.

You already can, in theory, just do what Michael Brown did with multi
driver binaries.

>It would start with a whole bunch of 512 byte PCI headers.
>Followed by the main() and other common code,  Then, the 
>unique routines that each card needs. I don't know how big
>that is, but it seems pretty small, per chipset.

Unfortunately it isn't, if you'd written a driver before you'd know
different.  Each driver can have pretty complicated code and use large
buffers. See tulip.c for an extreme example. To share the buffers would
require some kind of dynamic memory allocation. And even then there's
the memory squeeze, see below.

>I use 29ee512 chips for the Linksys and 3Com cards, 
>I'll bet we could fit support for a lot of chipsets into 64k.

The problem is not the ROM size, but the limited execution area with
which Etherboot has to work (48kB from 0x94000). Hence the interest in a
relocatable Etherboot binary which could copy itself to the top of
memory, which should leave enough room at the bottom for the loaded code
in all except very memory deficient machines. But that's a promising
direction to work towards.