Hi,
in OpenSTLinux v1.1, for eMMC the enviromnent in saved in ext4 file in bootfs... (CONFIG_ENV_EXT4_FILE = "/uboot.env")
But the U-Boot ext4 suport cause issue as some EXT4 option are not supported in U-Boot to allow write.
in OpenSTLinux v2.0, the eMMC now environment is saved at the END of the U-Boot partition in RAW (CONFIG_ENV_MMC)
https://wiki.st.com/stm32mpu/wiki/U-Boot_overview#U-Boot_environment_variables
And normally CONFIG_ENV_OFFSET is not used for env/mmc.c if "u-boot,mmc-env-partition" is defined in config node of DT
but it can be used as fallback when the partition name is not present in the device tree.
in ST boards, CONFIG_ENV_OFFSET=0X2800000 is used ony for NOR
So I assumed that "u-boot,mmc-env-partition" is missing in your device tree (it is an addition between V1.1 and V2.0)
see ST boards device tree for example
arch/arm/dts/stm32mp157a-dk1-u-boot.dtsi:19:
arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi:20:
/ {
......
config {
.....
u-boot,mmc-env-partition = "ssbl"; <<<<< NEW in v2.0
.....
};
regards
Patrick