Tested my new r2pro and noticed that sdcard was not booted because emmc is not empty. There is a broken bootchain on userpartition which boots till spl uboot and then hang.
Booting from sdcard is only possible if pressing the maskroom button (which i guess should mean maskrom) while poweron.
Then i can erase the beginning of emmc user partition from linux. 2M was not enough so it seems the downstream bootchain is different to mainline where idbloader is at block 64 (32k).
If i erase first 10M i can boot from sdcard.
Are you using u-boot-2022 on an SD card? This is a known compatibility issue of the main u-boot and u-boot-rk-2017 (special separate partition is used to host the u-boot). For this reason, I am currently using u-boot-2017 so that any untrained user can start the system from an SD card without any problems.
Yes i know that downstream spl cannot load mainline uboot the question is: why is there anything on emmc?
it is unforunately that emmc is tried first…better will be sd first and if not available try emmc. So you can always boot system with sdcard even if emmc has bootable system. But afaik this is a soc specific limitation
Edit: btw. Even if no sdcard is inserted (emmc-only boot) system does not boot into something where i can do anything (uboot), hangs on spl too. So it is no issue with my mainline uboot on sdcard.