[U-Boot-Users] Support for softcore ethernet chips

Wolfgang Denk wd at denx.de
Tue Nov 15 22:12:17 CET 2005

Hello Robert,

in message <20051115183458.GX1099 at pengutronix.de> you wrote:
> I have a board which uses a softcore ethernet chip, so before for
> example U-Boot is able to do networking some binary firmware has to be
> loaded into the device. 
> What's the preferred method to do this? I didn't find other boards in
> the U-Boot code but maybe missed something. 

See for example the FPGA support code which does something similar  -
load some images into a FPGA.

> Seen from a technical point of view it would be the best solution to
> just link the firmware somewhere into the U-Boot image, but I would be

I'm not sure if this is really the best solution; it may  be  a  good
thing  to have the firmware image separated and be able to replace it
without needing to replace U-boot.

> interested how this is generally seen wrt. GPL issues. I don't think

My opinion is that linking is linking, and code is code. But I am not
a lawyer (Thank goodness!). There  are  nearly  twenty  boards  which
include  some binary firmware images (search for "fpgadata.c" files),
but  in  my  (limited(  understanding  this  is   just   a   hardware
description,  not  code.  Now  "binary  firmware"  may  be  something
different. It sounds very much like code to me.

Which license is used for this firmware?

> that this creates a derivative work, taken that it is just being
> bit-banged into the hardware by some GPL code, which is not different

Unless somebody with a better understanding of the legal aspects  ex-
plains to me that I'm wrong (and why), then I will not complain about
hardware definitions like FPGA images; but code (even for a different
CPU) should be GPLed.

Just providing a loader that  loads  the  image  from  some  external
storage is IMHO the better approach anyway.

> from what the Linux firmware interface does, but anyway. It has to be
> located somehow, and spending another flash sector just for some 40KiB
> would be uggly.  

This depends on your sector size ;-) Also, you can locate  the  image
in one of your file system images und use U-Boot to laod it - we have
support  for  FAT/VFAT,  ext2, JFFS2, cramfs, and reiser - you should
find something that matches your setup.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Imitation is the sincerest form of plagarism.

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