U-Boot HDMI console on rk3399

[Peter Robinson]

On Sun, 29 Mar 2026 at 13:59, Tamás Szabó <szabo_tamas at windowslive.com> wrote:
>
> Hello,
>
>
> I read there is possible to use HDMI as console output on rk3399, but I
> do not find any documentation about this, only Google AI give some
> hints, but mostly mix up rockchip and sunxi stuff.
>
> I have a Giada DN74 which is based on rk3399 but I am not able to enable
> HDMI output in u-boot.
>
> I check in which defconfig is use necessary configs (|example:
> CONFIG_VIDEO_ROCKCHIP|) and which one is similar to my board, I choose
> nanopi-m4-rk3399_defconfig and build u-boot but no output.
>
>
> Is the HDMI output in some rk3399  board enabled by default?

It works on a number of devices I have tested it on, eg rockpro64 and Rock960.

> There is documentation about HDMI output in u-boot?

Not particularly I am aware of.

> If not documentation, someone could please write a sort advise how to
> enable HDMI output.

Check what other devices are using, rockpro64, rock960 and likely a
bunch of others.