[U-Boot] [PATCH v2] pico-imx7d: Increase the CONFIG_ENV_OFFSET size

[Stefan Roese]

Hi Fabio,

On 30.11.18 11:58, Fabio Estevam wrote:
> On Fri, Nov 30, 2018 at 8:29 AM Stefan Roese <sr at denx.de> wrote:
> 
>>> -#define CONFIG_ENV_OFFSET                    (8 * SZ_64K)
>>> +#define CONFIG_ENV_OFFSET                    (12 * SZ_64K)
>>
>> I find this hard to read: (12 * SZ_64K). Wouldn't (768 * SZ_1K) be
>> better?
> 
> Yes, this is a good idea, but it does not work in conjunction with
> your suggestion below.
> 
>> And I found using CONFIG_BOARD_SIZE_LIMIT quite handy, as it detects
>> such increased image growths beyond its limit upon build time. Perhaps
>> you could add this as well? This should do it for this board:
>>
>> #define CONFIG_BOARD_SIZE_LIMIT            CONFIG_ENV_OFFSET
> 
> Thanks for this suggestion.
> 
> I was not aware of CONFIG_BOARD_SIZE_LIMIT, which is very helpful!

Yes, I also only found out about this a few months ago. Always something
new to learn... ;)
  
> The only issue I see with this approach is that it does not accept
> expressions like (768 * SZ_1K):
> 
>    SYM     u-boot.sym
> /bin/sh: 1: printf: (768 * SZ_1K): expected numeric value
> u-boot-nodtb.bin exceeds file size limit:
>    limit:  0 bytes
>    actual: 482952 bytes
>    excess: 482952 bytes
> Makefile:1040: recipe for target 'u-boot-nodtb.bin' failed
> 
> So I will hardcode CONFIG_ENV_OFFSET and use CONFIG_BOARD_SIZE_LIMIT:
> 
> #define CONFIG_ENV_OFFSET 786432
> /* Detect overlap between U-Boot image and environment area in build-time */
> #define CONFIG_BOARD_SIZE_LIMIT CONFIG_ENV_OFFSET
>
> IMHO it is better to get an error in build time when U-Boot and env
> area overlaps than providing a pretty CONFIG_ENV_OFFSET format :-)

I agree. I'm using hex values like this 0x80000, which look better
to my eyes (personal taste). Perhaps the Makefile logic handling
BOARD_LIMIT_SIZE can be improved to support other expressions as well.

Thanks,
Stefan