v2025.10 env Kconfig rename (fb5235239aad) removed backward compatibility

[Quentin Schulz]

On 11/24/25 1:32 PM, Quentin Schulz wrote:
> Hi Ozan,
> 
> On 11/22/25 2:18 PM, Ozan Durgut wrote:
>> [You don't often get email from ozandurgut.2001 at hotmail.com. Learn why 
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>>
>> Dear U-Boot maintainers,
>>
>> I hope you're doing well.
>>
>> I would like to raise a backward compatibility concern regarding commit
>> fb5235239aad ("env: Rename DEFAULT_ENV_FILE to
>> ENV_DEFAULT_ENV_TEXT_FILE"), which landed in the v2025.10 release.
>>
> 
> I don't think we ever advertised backward compatibility for Kconfig 
> symbols/defconfig.
> 
>> Previously used Kconfig symbols CONFIG_USE_DEFAULT_ENV_FILE and
>> CONFIG_DEFAULT_ENV_FILE have been replaced with
>> CONFIG_ENV_USE_DEFAULT_ENV_TEXT_FILE and
>> CONFIG_ENV_DEFAULT_ENV_TEXT_FILE. However, the old symbols were removed
>> outright, without a compatibility shim or deprecation period.
>>
>> This change causes breakage when integrating U-Boot with Buildroot, as
>> Buildroot currently lacks a mechanism to handle such changes
>> conditionally based on U-Boot's version. As a result, downstream users
>> are forced to choose between breaking support for older or newer U-Boot
>> versions.
>>
> 
> Currently yes, but that's an issue in Buildroot you can fix. This was 
> already asked on #u-boot and I already answered "just enable the new 
> option as well?" (https://libera.catirclogs.org/u- 
> boot/2025-11-20#39059950;). I've sent a patch to the Buildroot ML with a 
> tentative patch (though it doesn't seem to appear on the ML archive just 
> yet for some reason):

https://lore.kernel.org/all/20251124-uboot-env-rename-v1-1-7ac5a21da6e2@cherry.de/

Cheers,
Quentin