For example ARM TF-A for RK3566. U-Boot and Linux code is available and the development is in the open thanks to GPL, TF-A is just a blob released by rockchip (

For example ARM TF-A for RK3566. U-Boot and Linux code is available and the development is in the open thanks to GPL, TF-A is just a blob released by rockchip (TF-A is originally from ARM). My Quartz64 SBC sits unused because of non-free boot path and supervisor code.