[U-Boot] single build of uboot supporting env stored in dynamically detected boot device

[Stefan Roese <sr@denx.de>]

Hi Tim,

(added Igor to cc)

On 10.04.2015 00:58, Tim Harvey wrote:
> It seems the U-Boot's env storage is implemented by various types of
> storage from common/env_*.c, one (and only one) which is included by
> common/Makefile based off of the CONFIG_ENV_IS_IN_* config.
>
> I want to build a single uboot image which can be installed on one of
> several supported boot devices (NAND, SATA, SD for example) and have
> the env storage hooked to the device that was detected as the boot
> device. Am I correct in assuming this is not currently possible and
> that instead I would have to build 3 versions of uboot each with one
> type of storage defined?
>
> If it turns out that this is not currently possible, I'm open to
> suggestions on how to rectify it (or if you think I'm crazy for
> wanting to have a single uboot image for the above please explain your
> reasoning). I'm thinking I would start by making the env_init/saveenv
> functions (I believe those are the only ones that need to be
> implemented by an env storage subsystem) unique function names, then
> creating a wrapper for those functions that call the right one.

IIRC, Compulab has such a feature implemented in some of their U-Boot 
versions. Igor, please either correct me if I'm wrong. Or elaborate how 
you have implemented this dynamic env feature.

Thanks,
Stefan