[PATCH 14/15] board: ti: Add j721e_beagleboneai64_* config fragments and env file

[Romain Naour]

Hello Andrew, All,

Le 03/11/2023 à 20:20, Andrew Davis a écrit :
> On 11/3/23 2:06 PM, Nishanth Menon wrote:
>> On 13:51-20231103, Andrew Davis wrote:
>>> On 11/2/23 7:38 PM, Nishanth Menon wrote:
>>>> Add defconfig fragments for J721E based BeagleBone AI-64 and
>>>> corresponding customized environment.
>>>>
>>>> Signed-off-by: Nishanth Menon <nm at ti.com>
>>>> ---
>>>>    board/ti/j721e/beagleboneai64.env        | 19 ++++++++
>>>>    board/ti/j721e/beagleboneai64_a72.config | 55 ++++++++++++++++++++++++
>>>>    board/ti/j721e/beagleboneai64_r5.config  | 19 ++++++++
>>>
>>> Beagle boards are not TI boards, add the board support to board/beagle/
>>
>> Huh, why bring in commercials and organization changes here? am335x
>> and am62 are under the TI umbrella.
>>
> 
> The SoCs used are yes, the boards are not, we only make our EVM/SK
> line of boards in house.
> 
> We did AM335x wrong, in board/ti/am335x/board.c we tried to support
> like 11 different boards in one file. And while it might have made adding
> our own extra EVMs easier, it only made things less clear for folks trying
> to add their own AM335x based boards[0].
> 
> We don't integrate support for any other board partner like this. Our
> friends over at Toradex or Phytec are currently upstreaming boards based
> on K3 SoCs and in doing so have shown us some areas we can improve.
> 
> We focus on these little short-cuts to make adding our EVMs (or boards
> that look like our EVMs) easy. But that only leads to extra work and
> code duplication for external boards.
> 
> If something is actually common to the SoC then lets move it to
> arch/arm/mach-k3/j721e. Tricks like board-variants.c only hide the
> issue and doesn't help folks wanting to add their boards based on our
> SoCs to their board/<vendor>/ directory.

I'm starting a new custom board bring-up based on a j721e SoC (without any SOM)
and adding a now board variant from the u-boot provided in the TI SDK (based on
2023.04) is far from easy for the reasons mentioned above (extra work and code
duplication for external boards).

Also the build break for j7200/j721e SoC as soon as CONFIG_TARGET_J721E_A72_EVM
and CONFIG_TARGET_J7200_A72_EVM are undefined:

https://source.denx.de/u-boot/u-boot/-/blob/v2023.10/arch/arm/mach-k3/arm64-mmu.c?ref_type=tags#L71

I always wonder if I should work on top of EVMs board or create a new
board/<vendor>/ directory for customer boards.

Best regards,
Romain

> 
> Andrew
> 
> [0] See "Software Design" https://jaycarlson.net/embedded-linux/#am335x
> 
>> $ git grep beagle board/|cut -d ':' -f1|sort -u
>> board/ti/am335x/board.c
>> board/ti/am335x/board.h
>> board/ti/am57xx/board.c
>> board/ti/am62x/beagleplay_a53.config
>> board/ti/am62x/beagleplay_r5.config
>> board/ti/am62x/MAINTAINERS
>> board/ti/beagle/beagle.c
>> board/ti/beagle/Kconfig
>> board/ti/beagle/led.c
>> board/ti/beagle/MAINTAINERS
>> board/ti/beagle/Makefile
>> board/ti/j721e/beagleboneai64_a72.config
>> board/ti/j721e/beagleboneai64_r5.config
>> board/ti/j721e/MAINTAINERS
>> board/timll/devkit8000/README
>>