i’m having trouble confirming the effect of device tree overlays. as an example, consider the hifiberry-dac overlay. if i go into /boot/hw_initfc.conf, and uncomment initfc:dtoverlay=hifiberry-dac, there are 3 things i would expect to notice after rebooting:
- there should be a new “pcm5102a-codec” device in the device tree
- there should be a new “sound-ext-card” device in the device tree
- i2s1 (aka i2s@ff890000) should now have status=“okay”
what i find this that (1) is not true, (2) is true, but the status=“disabled”, and (3) is not true.
i’ve also noticed that some very simple (change one device property) DT overlays that i’ve tried adding to /boot, have not been taking effect.
how can i debug the application of device tree overlays during the boot process?