Background: I successfully compiled kernel versions 5.4.y and 5.6.y from source. It turns out I have some keyboard problems with v5.6.y on my RPI4, so I used tried v5.4.y and it works fine. However, I experience some problems with power governors, I think, on my RPI3 (it always runs at half speed - 600MHz).
In short, 5.4.y works for my RPI4 and 5.6.y works for my RPI3.
Is there a way to use both kernel versions? In other words, can I boot from
kernel7.img when my SD card is in my RPI3, and boot from
kernel7l.img when the SD card is inside RPI4?
Clarification: Currently my RPI3 boots from
kernel7l.img instead of
kernel7.img - so it is not acting as it should by default!