Rock64 no HDMI (must be unplugged)


HDMI must be unplugged during boot in order for video to work.

Resolved with Kernel 5.8.y

Disabling HDMI in u-boot it supposed to be a workaround.




Lane Jennison
September 5, 2020, 1:45 AM

I just tested my rock64 with 5.8.6-current and it worked on 2 displays!. Woohoo

Piotr Szczepanik
August 20, 2020, 6:49 AM

Seems like a handshake issue.

When I tested it some time ago I also notices one more odd thing… With our downloadable images (like v20.05.4 current focal) it works fine without replug but when I built my own image it did require a replug. I then discovered that in pre-built images for rock64 we have /etc/modprobe.d/blacklist-rock64.conf with lima module blacklisted. I do not know where it comes from as we do not have “BLACKLIST_MODULE*” variables set in board config for rock64 and when I built my own images the file wasn’t there.

If I blacklisted lima in self-made images it also worked without replug at the time of those tests.

Now I only tested the dev target (without blacklisting lima) after moving to mainline u-boot so maybe the original issue was fixed in 5.8.y.

Lane Jennison
August 20, 2020, 3:51 AM

Hi i built the PR "current" as target and had the same issue. Ill try dev tomorrow.

I did notice something. The issue has more to do with the display being powered on. If i hot plugged to cable into a display looking for a signal it didnt work. If i plugged in hdmi will display was off, then powered on display (at kernel boot stage) display worked.

I was able to repeat this as well with hdmi cable staying plugged. As long as displayed was powered off durring startup, video would work after powering on display.

Same behavior on 2 displays

Piotr Szczepanik
August 19, 2020, 9:03 PM

Could you check if building an image with this PR’s branch fixes the issue for you? It switches Rock64 to mainline u-boot.

I checked dev target and it boots to desktop without the need to replug HDMI.

Lane Jennison
July 19, 2020, 11:01 PM

If i power on with hdmi plugged. No console display, no desktop.

If i plug in shortly after power up, get consile and desktop



Piotr Szczepanik


Lane Jennison