[U-Boot] [PATCH] ARM: tegra: add Colibri T30 board support

[Stephen Warren <swarren@wwwdotorg.org>]

On 08/02/2014 08:09 AM, Stefan Agner wrote:
> Am 2014-07-31 20:21, schrieb Stephen Warren:
>> On 07/31/2014 11:36 AM, Stefan Agner wrote:
>>> This adds board support for the Toradex Colibri T30 module.
>>>
>>> Working functions:
>>> - SD card boot
>>> - eMMC environment and boot
>>> - USB host/USB client (on the dual role port)
>>> - Network (via ASIX USB)

>>> +#define BOARD_EXTRA_ENV_SETTINGS \
>>> +	"board_name=colibri-eval-v3\0" \
>>> +	"fdtfile=tegra30-colibri-eval-v3.dtb\0"
>>
>> It'd be nice to name the board the same in U-Boot as the kernel DT
>> filename. Then you wouldn't need to manually override the default
>> values here.
>
> This is a somewhat complicated topic in our case. Our products are
> named:
>
> "Colibri T20"
> "Colibri T30"
> "Apalis T30"
>
> Since quite a long time, we use those names, except replacing the space
> by an underline character and preferable use small caps. Hence e.g. the
> U-Boot configurations in the downstream tree:
>
> colibri_t20_config
> colibri_t30_config
> apalis_t30_config
>
> However, in the kernel world, since device tree was introduced there is
> this reverse notation, SoC-board.dts... e.g. tegra30-colibri_t30.dts. We
> descided to drop that t30, since its somewhat duplicated. Not sure this
> was the right description, but its in the kernel that way right now.
>
> Additionally, this whole carrier board (Evaluation Board v3)/module
> (Colibri T30) relation is also taken into account at kernel side, hence
> the full name today
> tegra30-colibri-eval-v3.dts
...
> Also we use the same boot
> loader configuration for our three own Carrier Boards.

OK, it mostly makes sense to have U-Boot configuration names that only 
mention the CPU module and not the carrier board in that case.

However, if the U-Boot default environment defines the full kernel DTB 
name, then that isn't possible. A U-Boot board will be tied to a 
particular carrier-board configuration that way.

Perhaps remove the DT filename from the default environment, and require 
the user or flashing process to set the correct value?

Alternatively, perhaps add the core U-Boot support under one (primary 
configuration and board directory) name, and add additional entry to 
boards.cfg/Kconfig to override that one fdtfile value in the 
environment? I see quite a few other boards do so something similar, 
albeit likely for larger variations than just one environment variable:-)