[U-Boot-Users] Some RFCs about U-Boot's the generic FPGA support

[Matthias Fuchs]

Bruce,

On Monday 20 August 2007 20:46, Bruce_Leonard at selinc.com wrote:
> > 1) Make the 'size' parameter obsolete for the 'fpga loadb' command.
> > The actual bitstream size is taken from the bitstream.
> 
> Agreed, plus you can remove the check against the size parameter passed in 
> from the command line that doesn't make any sense.
Yes, I thought about that, too. But I wanted to take care about people using the
useless size parameter:-)
> 
> > 
> > 2) Do not bit-swap the bytes in the xilinx bitstream. When using the
> > slave serial code the bits may not be swapped. I can imagine that this 
> > swapping requirement comes from a special board layout. So is should
> > be done in board specific code. When removing the swapping code, we
> > can get rid of the complete malloc/free stuff in fpga_loadbitstream().
> 
> I would make this optional/configurable as I mentioned in my last post. 
> Doing the bit swapping makes sense for a little endian processor but 
> doesn't make sense for the big endian machines like the PPC.
Why? AFAIK, the _bit_order has nothing to do with die CPU endianess.
We are talking about mirrowing the 8 bits in a byte. 

BTW, you can tell Xilinx promgen tool to use the other bitorder, so there is
no need to do correct it in U-Boot.
> 
> > 
> > 4) Make post() and pre() callback optional in relocation. So do
> > not relocate NULL-pointers. This has been discussed a short time ago
> > on the list.
> 
> Agreed
> 
> > 
> > 6) Add some more devices.
> > 
> 
> More devices are always good.  That way folks in the future have a 
> starting place.
> 
> > 
> > BTW: Are there any boards that use the FPGA stuff and that are not 
> > made public ?:-)
> >
> 
> Our board is totally custom and will never be used by anyone but us, but 
> as Wolfgang pointed out that's not the lists problem that's our problem. 
> Folks using u-boot need to be aware that things change and they need to be 
> careful when doing pulls from the repository.
Even totally custom boards should be in the U-Boot repository. Many boards
that are supported by U-Boot are custom boards. For examples esd 
build more than 25 boards that are using U-Boot as bootloader. Less than 50%
of these boards are COTS product. The others are totally customized boards.

Matthias