[U-Boot] is it mandatory for SPL to support DM

[Marek Vasut]

On 5/25/20 5:48 PM, Simon Glass wrote:
> Hi Marek,
> 
> On Mon, 25 May 2020 at 09:43, Marek Vasut <marex at denx.de> wrote:
>>
>> On 5/25/20 5:36 PM, Simon Glass wrote:
>>> Hi,
>>>
>>> On Mon, 25 May 2020 at 04:35, Marek Vasut <marex at denx.de> wrote:
>>>>
>>>> On 5/25/20 10:44 AM, Jagan Teki wrote:
>>>>> SPL has a foot-print constraint, so fully switching a particular
>>>>> subsystem like SPI or SPI Flash to DM would increase the size of it.
>>>>>
>>>>> Possible areas to look at are (assume SPL_DM supported)
>>>>> 1) platdata
>>>>> 2) implement board or platform specific spl device driver which
>>>>> bypassed the actual framework ex: spl_spi_sunxi.c
>>>>>
>>>>> Do we have any other solutions? or any arguments on above step 2?
>>>>
>>>> SPL does not need to support DM until the size problem is solved.
>>>
>>> I don't think the problem will ever be 'solved'. It is an ongoing battle.
>>>
>>> But as it happens I've just sent a proposal for tiny-dm that I think will help.
>>>
>>> Jagan, which board are you trying to convert? If you are trying to
>>> convert SPI flash, I think we need to remove the legacy code first.
>>
>> If you want a board which boots from SPI NOR and has some 14k or so
>> limit on SPL, any of the R-Car Gen2 boards fit the bill.
> 
> Thanks...do you have a link to one?

https://elinux.org/R-Car/Boards/U-Boot-Gen2

> Also was there a 64-bit board that had to run 64-bit SPL? I think I
> remember you mentioning it.

You can build SPL for R-Car Gen3 boards.