Hello, I am using armbian on banana pi m2 zero
 

uname -a

Linux bananapim2zero 5.16.11-sunxi #22.02.1 SMP Sun Feb 27 09:17:03 UTC 2022 armv7l armv7l armv7l GNU/Linux

 

I want to rebuild kernel, but i cannot find kernel source. Where I can find it?

This code from https://wvthoog.nl/nanopi-ov5640-camera/#OV5640_sensor doesn`t work

 

sudo apt update
sudo apt upgrade

sudo apt install build-essential
uname -r # check your current kernel version
sudo apt install linux-source-<your current kernel version>
 
In my case: 
sudo apt install linux-source-5.8.6-current-sunxi

cd /usr/src
sudo tar xf linux-source-5.8.6-sunxi.tar.xz

I would suggest you to use this tool for rebuilding a kernel. Otherwise, if you really want to build on the board, we currently have a small problem with stable repository and you need to proceed this way if you are in a hurry.