Hello again, just after sending the last message I continued testing, and went have a look at the various CONFIG options I used, especially their help text...
The problem was PEBKAC, I RTFM'ed myself with: CONFIG_SYS_MMC_ENV_PART: MMC hardware partition device number on the platform where the environment is stored. Note that this is not related to any software defined partition table but instead if we are in the user area, which is partition 0 or the first boot partition, which is 1 or some other defined partition. I had it set to "3" instead of "0". I now works. BTW, I though recent Rasmus series [1] was related, but it also works without, so I dunno if I actually tested it or not. Thanks for the hints [1] https://patchwork.ozlabs.org/project/uboot/list/?series=423625 -- Vincent Legoll