Early boot logo on Raspberry Pi after encryption - broken

I am not 100% sure if this issue should be posted on Raspberry Pi forum or here. The reason I am posting here for help is that the environment works perfectly on Raspberry Pi4 without SD Card encryption using Zymkey 4i.

I have been using Zymkey 4i with Raspberry Pi 4B and has been very happy with product and function.

The issue I am seeking help with is using this environment:
Raspberry Pi 4B / 8GB and 2GB versions / Zymkey 4i / OS: raspios_lite_arm64/bullseye
Uses Plymouth for early boot screen and SD Card encryption using Zymbit scripts.

The product installs Openbox / X11 libraries to run the product in Kiosk mode using chromium-browser.

The issue:
The issue is only with VC4-KMS drivers. There are no issues with Raspberry Pi legacy drivers.
After switching to KMS driver, I am unable to see the Plymouth screen when Kernel is booting up. After the root partition is mounted by Zymkey I do see a screen briefly for 3 seconds which looks like one of the Plymouth themes with the cryptrfs console message.

I tied the usual drill to re-generate initramfs with several possible sequences such as:

  1. Install Zymbit
  2. Install software packages (which includes Plymouth)
  3. Encrypt using Zymbit scripts
  4. Set new Plymouth theme and generate initramfs

OR

  1. Install Zymbit
  2. Encrypt using Zymbit scripts
  3. Install software packages (which includes Plymouth)
  4. Set new Plymouth theme and generate initramfs

OR

  1. Install Zymbit
  2. Install software packages (which includes Plymouth)
  3. Set new Plymouth theme and generate initramfs
  4. Encrypt using Zymbit scripts

Nothing works. Various sources indicates frame-buffer being overwritten but nothing I can really work with except tweaking some parameters on /boot/config.txt.

To repeat … I see no issues with Legacy drivers plus encryption or KMS drivers without Zymkey encryption.

I have been trying to resolve this for months now.

Any help is highly appreciated such as is it really worth trying to find a solution for this issue or live with what we have.

Thanks
Rajesh

Rajesh - I looked at this a little bit and I see the same thing as you. It worked for me with dtoverlay=vc4-fkms-v3d but goes away with dtoverlay=vc4-kms-v3d. I’m thinking it is most likely a Pi issue itself with bullseye64, kms, and encryption, not the Zymkey per se. I’ll have to do a little more research.