If this is an inappropriate post here in the forums feel free to delete. I will understand.
@Strit has said that the manjaro team is sticking with mainline and will not do VC4 until mainline does. So in the mean time I am using the current manjaro arm kernel from the repo and only changed some files in /boot and added the Pi Foundation's overlays. Now I have the much needed VC4 gpu hardware decoding I need in my hobby with my pi3b/pi3b+.
Added additional note:
Because of the nature of VC4 you will see a few lines of text scroll by when it first boots and when it enters VC4 mode the text lines will cease in the terminal and you will not see any activity but it is still loading up things. The next thing you will see is when it enters graphical mode at the graphical login screen.
First off I temporally moved all uboot related files to /boot/sav. I do not like uboot and it is not needed to boot the manjaro arm kernel. I am now using the same boot format as the Pi Foundation:
I moved Image --> kernel8.img
I compiled Pi Foundation's overlays and put them in /boot/overlays:
sudo pacman -S dtc git clone -b rpi-5.1.y --single-branch --depth 1 https://github.com/raspberrypi/linux.git cd linux make -j4 DTC_FLAGS="-@" dtbs sudo mkdir /boot/overlays cp -v arch/arm/boot/dts/overlays/*.dtb /boot/overlays sudo sync
I moved the 3 broadcom .dtb's /boot/dts/broadcom to /boot
I created an cmdline.txt file and modified it to allocate 256M for cma
I modified the config.txt to use the vc4 3d overlay and pointed to the kernel, overlays and the correct .dtb for my device. Notice the gpu mem is 16 as the cma=256M above is what VC4 uses:
I fixed the no sound issue in the image
I took /etc/X11/xorg.conf.d/99-fbturbo.conf out of the picture:
sudo mv /etc/X11/xorg.conf.d/99-fbturbo.conf /etc/X11/xorg.conf.d/99-fbturbo~
Pic is clip of the Xorg.log showing VC4 loaded:
The next 2 pics show mpv tryng to play first with out VC4 and the next pic shows mpv playing with VC4: