[U-Boot] [PATCH 10/10] ARM: socfpga: arria10: add support for building Arria10

[Marek Vasut]

On Tuesday, November 24, 2015 at 12:04:10 AM, Dinh Nguyen wrote:
> On 11/23/2015 05:03 PM, Marek Vasut wrote:
> > On Monday, November 23, 2015 at 11:50:15 PM, Dinh Nguyen wrote:
> >> On 11/23/2015 04:46 PM, Marek Vasut wrote:
> >>> On Monday, November 23, 2015 at 11:32:27 PM, Dinh Nguyen wrote:
> >>> [...]
> >>> 
> >>>>>>>> The main point is that we need to program the FPGA
> >>>>>>>> during U-Boot booting up with a ~>10 MB rbf file while being
> >>>>>>>> limited to the OCRAM's size. I would like to contain this
> >>>>>>>> ugliness in it's own directory.
> >>>>>>> 
> >>>>>>> What's the problem with this ? We already support loading files
> >>>>>>> from storage in SPL, so just compile the FPGA manager into SPL as
> >>>>>>> well and use it.
> >>>>>> 
> >>>>>> Ok, let me re-work it all under the c5/a5 directory. Thanks for
> >>>>>> reviewing.
> >>>>> 
> >>>>> But you didn't really answer my question -- what is the problem with
> >>>>> the FPGA loader in SPL ?
> >>>> 
> >>>> I thought you've already answered your own question. For whatever
> >>>> reason, the downstream A10 is re-doing the FPGA manager just for this
> >>>> purpose.
> >>> 
> >>> Could the reason be that the FPGA manager in it's current state expects
> >>> one big buffer with the entire FPGA bitstream ? When you're in SPL and
> >>> you still don't have DRAM running, you cannot create such buffer
> >>> anywhere. Thus, what you need to do is to have some sort of code which
> >>> loads a bit of the bitstream file at time and feeds it into the FPGA
> >>> manager, piece by piece. This should be doable pretty easily, what do
> >>> you think ?
> >> 
> >> That's exactly what is being in the mach-socfpga directory.
> > 
> > Um, am I missing it in this patchset ?
> 
> No, you're not missing it, I have not sent it up yet. That support is in
> the downstream, but also with the fpga-manager driver re-written. I need
> to clean this up before I can send it.

OK, thanks :)

> >> Yes, but should that code go into mach-socfpga or drivers?
> > 
> > The FPGA manager bits are already in drivers/fpga/ , so that's where the
> > improvements should go. If you need some special handling in the SPL,
> > that should be in mach-socfpga . In case it's too much change to the
> > current SPL, moving the spl.c to spl-gen5.c and creating new spl-gen10.c
> > might make sense ... or something like that, possibly even with some
> > spl-common.c .
> 
> Ok. BTW, Arria10 is not using SPL. It has 256K of OCRAM that U-Boot can
> use to setup the SDRAM.

So what do I do if I want to boot arria10 from NAND ? UBI and UBIFS won't
fit into 256kiB, so I think using SPL might be the sensible thing afterall,
since you would be able to use arbitrarily-sized U-Boot.

Best regards,
Marek Vasut