Can't find how to activate SPI

I am trying to move from raspberry 3B + SPI HAT to rock 3C + SPI HAT.
My HAT uses what is know as SPI0 on a raspberry board, on pins 19, 21 & 23.
It looks like it’s called SPI1 on a rock3 board, on the same pins.

I have spent countless hours trying to understand how to activate SPI, with no luck.

I am using the rock-3c_debian_bullseye_cli_b33 image from

I have read instructions telling to configure with /boot/uEnv.txt, which is marked obsolote.
I can find overlays in /boot/dtbo and also in /usr/lib/linux-image-4.19.193-4-rk356x (which is the path specified in /boot/extlinux/extlinux.conf).

My software is expecting to find /dev/spidev0.0. I tried to load several (spidev) overlays and never got the expected device.

Any help appreciated!

The signal output to ‘Pins 19, 21, 23, 24’ is the signal from ‘SPI3’.
The ‘SPI0 (/dev/spidev0.0)’ you want is in use for other purposes and cannot be assigned to other purposes by the user.
So you need to substitute with ‘SPI3’.

root@rock-3c:~# uname -a
Linux rock-3c 4.19.193-4-rk356x #24c58c676 SMP Mon Apr 24 03:29:51 UTC 2023 aarch64 GNU/Linux

root@rock-3c:~# ls -la /dev/spi*
crw------- 1 root root 153, 0 May 19 00:12 /dev/spidev3.0

t4_4t’s reply was a first hint: I have to activate SPI3, not SPI1.
Finding the right overlay was the next one.

Here is how I finally managed to have a usable /dev/spidev3.0

root@rock-3c:~# mv /boot/dtbo/rk3568-spi3-m1-cs0-spidev.dtbo.disabled /boot/dtbo/rk3568-spi3-m1-cs0-spidev.dtbo
root@rock-3c:~# u-boot-update
root@rock-3c:~# reboot
root@rock-3c:~# ls -l /dev/spi*
crw------- 1 root root 153, 0 May 19 16:50 /dev/spidev3.0