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

[Marek Vasut]

On Tuesday, November 24, 2015 at 04:17:34 AM, Chin Liang See wrote:
> On Mon, 2015-11-23 at 17:25 -0600, Dinh Nguyen wrote:
> > On 11/23/2015 05:20 PM, Marek Vasut wrote:
> > > 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.
> > 
> > I hope Chin Liang can chime here, I know that we have support for
> > NAND,
> > but I haven't been part of that task, so I don't know how it's being
> > done.
> 
> Finally my email is back online :)
> 
> We do have NAND support but not with UBI and UBIFS.

I just hope you're not using raw NAND and just hoping it will work.

> For this support, user can use U-Boot to load arbitrarily-sized U-Boot
> that run on SDRAM.
> 
> One of the nice thing of U-Boot over SPL is the console support and
> ability to troubleshoot.
> This is possible with Arria 10 SoC as we have larger OCRAM (256kB vs CV
> SoC 64kB).

OK, that's not really the point here -- the point is, if you compile enough
features into U-Boot, it will be bigger than those 256k. What will you do
then ?

Best regards,
Marek Vasut