Official Debian support

[moonwalkers]

No, it's not the exact output but it is that kernel version.  I have an EFI partition using systemd-bootd, which loads a loader config that has the /proc/cmdline--nothing fancy, initrd, ftd which points to the dtb on the efi partition, root, and rw mostly.  Can you share yours?  I see some examples (and the default Manjaro) shows a few video= arguments.

Do you have a /dev/fb0?  I saw a kernel regression that this doesn't get setup when using EFI.  I'm also assuming you're doing extlinux boot?  You have a /extlinux directory on your boot volume?  Can you paste the output of it?

Well, your setup is definitely much more fancy than mine. Mine is as simple as a nail - u-boot, extlinux.conf in /boot/extlinux/ generated automatically by u-boot-menu package, and that's about it. My kernel command line is no different from an x86 system - no custom video modes, nothing about console or coherent_pool, just "root=..." and "ro quiet splash". My only customizations to /etc/default/u-boot is reducing timeout from 50 to 10, adding "splash" to parameters, and removing "recovery" from alternatives. I don't have a separate copy of .dtb file in /boot, there is only fdtdir entry in extlinux.conf that's auto-generated by u-boot-menu and points to /usr/lib/linux-image-<whatever>/

I do have /dev/fd0. I didn't bother with EFI because right now the only tangible benefit I see is Secure Boot, but until I start leaving my PBP unattended none of the attack vectors that Secure Boot would mitigate are anywhere near my threat model, so I just don't see the point of all that extra complexity UEFI brings and thus prefer to keep it simple and stupid.