I’ve got OP-TEE running on the Radxa ROCK 4D (RK3576, 12 GiB LPDDR5) with mainline TF-A + OP-TEE OS + U-Boot v2026.04-rc1.
Full boot chain confirmed: DDR → SPL → BL31 → OP-TEE (BL32) → U-Boot
Patches are pending upstream review:
OP-TEE OS: https://github.com/OP-TEE/optee_os/pull/7821
TF-A: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/51089
patches + build instructions: https://github.com/gahingwoo/bl32-rk3576
Known limitations: TRNG_S address unconfirmed (SW PRNG fallback), persistent HUK disabled pending TRM confirmation, U-Boot must be v2026.04-rc1.
Happy to answer questions or collaborate on next steps (TRNG, RPMB, Armbian kernel config).
