[U-Boot] [PATCH v2 11/11] riscv: Add SiFive FU540 board support

[Alexander Graf]

On 24.01.19 11:43, Anup Patel wrote:
> 
> 
>> -----Original Message-----
>> From: Andreas Schwab [mailto:schwab at suse.de]
>> Sent: Thursday, January 24, 2019 3:24 PM
>> To: Atish Patra <Atish.Patra at wdc.com>
>> Cc: Anup Patel <anup at brainfault.org>; Anup Patel <Anup.Patel at wdc.com>;
>> Joe Hershberger <joe.hershberger at ni.com>; U-Boot Mailing List <u-
>> boot at lists.denx.de>; Palmer Dabbelt <palmer at sifive.com>; Alexander Graf
>> <agraf at suse.de>; Christoph Hellwig <hch at infradead.org>; Paul Walmsley
>> <paul.walmsley at sifive.com>
>> Subject: Re: [U-Boot] [PATCH v2 11/11] riscv: Add SiFive FU540 board support
>>
>> On Jan 23 2019, Atish Patra <atish.patra at wdc.com> wrote:
>>
>>> or you can try to edit the DT directly and update the FSBL if you are
>>> comfortable with it.
>>
>> I think it would make sense to add the node in the board init function.
>> That way it would work whether or not the FSBL is updated.
> 
> Best way is to either fix in DTS itself or BBL/OpenSBI.
> 
> For BBL it is difficult due to lack of matured FDT manipulation APIs.
> My bad for previous misinformation about BBL. I thought Atish had
> hacked this in BBL but he had hacked U-Boot.
> 
> We already have taken care of this in OpenSBI using LibFDT so with
> OpenSBI no hacks would be required.
> 
> We are just few days away from OpenSBI being made public so no point
> of adding work-around for "stdout-path" in U-Boot as well.

I disagree. We want people to easily use this code, and not use it as a
means to push for the OpenSBI vs BBL discussion.

So IMHO a quirk that adds the stdout-path property in an early board
init function is the best way to move forward here. That way the "good"
case keeps behaving the same, but we stay compatible to current,
existing previous stage firmware.

Please, don't *ever* consider DT something that you "just modify". If
anything worked with a DT before, you are required to keep it that way.
Otherwise you break the compatibility contract between your firmware layers.


Alex