Re: [yocto] [meta-rockchip][PATCH] Add machine definitions for NanoPi-M4 boards

From: "Yann Dirson" <yann.dirson@blade-group.com>
To: Joshua Watt <jpewhacker@gmail.com>
Cc: Trevor Woerner <twoerner@gmail.com>,
	Yocto discussion list <yocto@yoctoproject.org>,
	 Yann Dirson <yann@blade-group.com>
Subject: Re: [yocto] [meta-rockchip][PATCH] Add machine definitions for NanoPi-M4 boards
Date: Mon, 22 Mar 2021 20:30:04 +0100	[thread overview]
Message-ID: <CA+4=imbHctrn=PtnJ9fBQVtmLpMNoDuvJLbFzuLmoyGSkSFJWg@mail.gmail.com> (raw)
In-Reply-To: <55dc5940-fb02-4db0-75bb-835f70ff908b@gmail.com>

Hi Joshua,

Le lun. 22 mars 2021 à 19:24, Joshua Watt <jpewhacker@gmail.com> a écrit :
>
>
> On 3/22/21 9:59 AM, Yann Dirson wrote:
>
> Hi Trevor,
>
> Le lun. 22 mars 2021 à 15:47, Trevor Woerner <twoerner@gmail.com> a écrit :
>
> On Mon 2021-03-22 @ 02:42:12 PM, yann.dirson@blade-group.com wrote:
>
> This supports both the 2GB and 4GB versions of the board.  This is not
> done with 2 different machine definitions since only u-boot has to
> change between those two configurations, but with a NANOPIM4_HW variable
> to set in local.conf.
>
> Traditionally in meta-rockchip this is done using two separate machine files
> with all the common things factored into a common include file. See
> tinker-board and tinker-board-s as well as all the rock-pi-4* definitions for
> examples.
>
> I would prefer if the same thing was done here.
>
> Damned that was how I did my first patch, I just felt it was much
> better this way :(
>
> Digging up that original commit re rerolling.
>
>
> Wouldn't it be useful to have a standard way to specify such hardware
> variants, that
> would be recognized as such by the layer index ?
>
> FWIW, I'd rather u-boot could automatcially detect what variant of the board it's running on and do the right thing (usually, just selecting the proper DTB from the FIT image). The only reason I did not do this on the rock-pi-4 is because there doesn't appear to be a way for u-boot to detect which variant it's on :/

Wait, it's only the dtb used by u-boot which is different in this
case, the kernel uses a single dtb for both variants.
Those probably get embedded inside the bootloader, in any case they
are not those embedded in the fitImage.

 #include "rk3399-nanopi4-u-boot.dtsi"
-#include "rk3399-sdram-ddr3-1866.dtsi"
+#include "rk3399-sdram-lpddr3-samsung-4GB-1866.dtsi"

I have no clue how easily the two boards could be told one from the
other (let alone if that can be done safely),
and I feel that would rather be uboot-side work, rather than something
to be solved on the yocto side.

>
>
>
>
> 
>

-- 
Yann Dirson <yann@blade-group.com>
Blade / Shadow -- http://shadow.tech