Re: How do I find out where u-boot environment is stored?

[Rick Thomas <rbthomas@pobox.com>]

> On Mar 6, 2019, at 7:46 PM, Vagrant Cascadian <vagrant@debian.org> wrote:
> 
> On 2019-03-06, Rick Thomas wrote:
>> Anybody know how can I determine where u-boot is storing it’s environment?
>> Is there an environment variable where that info is stored?
>> (-: Any ironic self-reference in the previous question is entirely un-intentional… ;-)
> 
> At least for recent u-boot packages in Debian:
> 
>  $ zgrep ^C.*ENV_IS_IN /usr/share/doc/u-boot-*/configs/config.*
>  /usr/share/doc/u-boot-sunxi/configs/config.a64-olinuxino.gz:CONFIG_ENV_IS_IN_FAT=y
>  /usr/share/doc/u-boot-sunxi/configs/config.pine64_plus.gz:CONFIG_ENV_IS_IN_FAT=y
>  /usr/share/doc/u-boot-sunxi/configs/config.pinebook.gz:CONFIG_ENV_IS_IN_FAT=y
> 
> To get more detailed information, you may need to read the source for
> the relevent board.
> 
> 
> live well,
>  vagrant

So on my Cubox-i4Pro, for example, it says:

rbthomas@cube:~$ zgrep ^C.*ENV_IS_IN /usr/share/doc/u-boot-imx/configs/config.mx6cuboxi.gz 
CONFIG_ENV_IS_IN_MMC=y

Which confirms that the environment is stored on the mmc/SD card.
But where (at what address) on the mmc card is it stored?

Is that something I’d have to read the code for?
If so, can you point me to the relevant code file?

Thanks for your help!
Rick