Re: [RFC PATCH 2/3] RISC-V: Initial DTS for Microchip ICICLE board

[Ben Dooks]

On 03/11/2020 18:40, Cyril.Jean@xxxxxxxxxxxxx wrote:
> On 11/3/20 6:28 PM, Ben Dooks wrote:
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> > On 03/11/2020 18:10, Cyril.Jean@xxxxxxxxxxxxx wrote:
> > > On 11/3/20 3:07 PM, Atish Patra wrote:
> > > > EXTERNAL EMAIL: Do not click links or open attachments unless you
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> > > >
> > > > On Fri, Oct 30, 2020 at 2:20 PM Ben Dooks
> > > > <ben.dooks@xxxxxxxxxxxxxxx> wrote:
> >
> > ,snip[
> >
> > > > > > @Cyril : Can we enable both eMMC & sdcard at the same time ?
> > > > > I would put /both/ in but only enable the one in use for the moment.
> > > > > Our boards are booting of eMMC as supplied, so this isn't going to
> > > > > work
> > > > > as well. The eMMC is 8bit wide, and thus is only delivering 11MB/sec
> > > > > instead of 22MB/sec. This performance is still not great, but losing
> > > > > half the data-rate is just not good.
> > > > I am not sure what should be enabled by default. Updating sdcard is
> > > > much
> > > > easier than eMMC card and we use that approach.
> > > >
> > > > @Cyril: Is there a way that we can enable both ?
> > > Yes, we can enable both but this requires a modification to the FPGA
> > > design. One of the guys prototyped this while I was away. We will move
> > > this along. This will require reprogramming the FPGA with a new design
> > > and HSS version.
> > >
> > > Regards,
> > >
> > > Cyril.
> >
> > I either missed or couldn't find a way of forcing the boot mode to be
> > from the SD slot. Have I missed something? At the moment we'd like to
> > have more storage available as the ~7G free on the eMMC is not enough.
> Currently, you need to program a different FPGA bitstream on  the board
> to boot from SD-card. The different bitstream configures muxes on the
> board to connect the SD slot to the FPGA and the HSS included in the bit
> stream configures the FPGA IOs correctly.
>
> Links to the programming files are found in this document:
> https://github.com/polarfire-soc/polarfire-soc-documentation/blob/master/boards/mpfs-icicle-kit-es/updating-icicle-kit/updating-icicle-kit-design-and-linux.md

Thanks, but i've no way of remotely re-writing the bitstream
of the FPGA since the tools are x86 only and we're using a Pi3
to connect the boards we have to the network.

--
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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