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

From: Ben Dooks <ben.dooks@codethink.co.uk>
To: Cyril.Jean@microchip.com, atishp@atishpatra.org
Cc: devicetree@vger.kernel.org, aou@eecs.berkeley.edu,
	Daire.McNamara@microchip.com, anup.patel@wdc.com,
	linux-kernel@vger.kernel.org, atish.patra@wdc.com,
	robh+dt@kernel.org, alistair.francis@wdc.com,
	paul.walmsley@sifive.com, palmer@dabbelt.com,
	linux-riscv@lists.infradead.org, Padmarao.Begari@microchip.com
Subject: Re: [RFC PATCH 2/3] RISC-V: Initial DTS for Microchip ICICLE board
Date: Tue, 3 Nov 2020 18:46:06 +0000	[thread overview]
Message-ID: <0eb43b3e-e5dc-4d97-895e-b872ac1fcf05@codethink.co.uk> (raw)
In-Reply-To: <21ded848-5dcb-ccbb-acd5-391bff667a53@microchip.com>

On 03/11/2020 18:40, Cyril.Jean@microchip.com wrote:
> On 11/3/20 6:28 PM, Ben Dooks wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know
>> the content is safe
>>
>> On 03/11/2020 18:10, Cyril.Jean@microchip.com wrote:
>>> On 11/3/20 3:07 PM, Atish Patra wrote:
>>>> EXTERNAL EMAIL: Do not click links or open attachments unless you
>>>> know the content is safe
>>>>
>>>> On Fri, Oct 30, 2020 at 2:20 PM Ben Dooks
>>>> <ben.dooks@codethink.co.uk> 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

https://www.codethink.co.uk/privacy.html

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv