I've now modified my config.txt according previous pacman instructions.
$this->bbcode_second_pass_code('', '
/boot/kodi.config.txt :
dtoverlay=vc4-kms-v3d,cma-512
dtoverlay=rpivid-v4l2
disable_overscan=1
disable_fw_kms_setup=1
/boot/config.txt:
initramfs initramfs-linux.img followkernel
[all]
include kodi.config.txt
#gpu_mem=320
#hdmi_enable_4kp60=1
#hdmi_edid_file=1
#hdmi_drive=2
#hdmi_group=2
#hdmi_mode=87
#hdmi_cvt 1920 1080 60 3 0 0 1
#max_framebuffer_width=1920
#max_framebuffer_height=1080
#dtoverlay=vc4-fkms-v3d
#dtparam=audio=on
#dtparam=spi=on
')
Before kodi starts it's spewing out the vc4-hdmi lines as described in the https://archlinuxarm.org/forum/viewtopic.php?f=15&t=15162#p65979 thread.
No sound!
Kodi > Settings > System > Audio > Audio input device is greyed out and empty.
So I tried uncommenting dtparam=audio=on.
$this->bbcode_second_pass_code('', '
/boot/config.txt:
initramfs initramfs-linux.img followkernel
[all]
include kodi.config.txt
#gpu_mem=320
#hdmi_enable_4kp60=1
#hdmi_edid_file=1
#hdmi_drive=2
#hdmi_group=2
#hdmi_mode=87
#hdmi_cvt 1920 1080 60 3 0 0 1
#max_framebuffer_width=1920
#max_framebuffer_height=1080
#dtoverlay=vc4-fkms-v3d
dtparam=audio=on
#dtparam=spi=on
')
Now I have on kodi Settings > System > Audio > Audio output device:
bcm2835 Headphones (default)
But hdmi output is missing!
I also tried uncommenting hdmi_drive=2 but same result.
So next I removed my /home/user/.kodi folder and created a new (empty) .kodi folder and rebooted.
Now kodi starts with a completely fresh profile, no addons, no media, nothing as expected.
But there is still only headphones, no hdmi output selectable!
So I'm out of options, there seems to be no hdmi output on kodi 19 when you follow the pacman instructions after updating from previous kodi 18.9. I hope graysky can shine a light on this.