Hi @lenzo1337,
Several guys from the FreeBSD team are working on RK356x.
We see the medium path.
- Change from u-boot to EDK2 UEFI. https://github.com/jaredmcneill/quartz64_uefi
- Modify existing drivers to support ACPI mode.
At the moment there is already UEFI for Firefly Station-M2(RK3566)/P2(RK3568), RADXA CM3.
On all boards, the system boots in multi-user mode. The dwmmc and dwc v4(eqos) drivers have been tweaked, USB works in 2.0 mode.
Most of the equipment was revived on Firefly Station-M2 (this is how NVMe works on PCie).
Here an attempt was made to add EDK2 UEFI support for RADXA Rock3a.
https://github.com/strongtz/quartz64_uefi
If you have any ideas write to me.