This is a Linux 5.4.12 kernel source for Banana Pi R2 (BPI-R2) which includes Atheros CSI tool.

• Debian Image (Jan 09, 2020, 5.4.2 Kernel)
  This image is a result of dd of 8GB sdcard and only kernel is installed. ID: root \ PWD: bananapi. I recommend you to install the Build Output below after install this image on your SD card.
• Debian Appready Image (Jan 11, 2020, 5.4.2 Kernel)
  This is also an image of 8GB sdcard, and all prerequisites are installed. ID: momo \ PWD: momo.
  Default shell is fish shell, you can change it to bash by typing chsh momo /bin/bash.
  There is CSI-Collector app on home directory. To use them, git pull on that directory and read this readme.
  I recommend you to install the Build Output below after install this image on your SD card.
• Build Output (Jan 17, 2020, 5.4.12 Kernel)
  This is a latest csitool-runability-checked output of "pack" option at method B.

If you installed image file, after installation, you can extend your partition to the end of the sdcard using below commands in root shell:

apt-get install cloud-guest-utils
growpart /dev/mmcblk0 2
resize2fs /dev/mmcblk0p2

Check the installation with dmesg | grep debug_csi.

On a x86/x64-host you need cross compile tools for the armhf architecture (bison and flex package are needed for kernels >=4.16):

sudo apt install ccache gcc-arm-linux-gnueabihf libc6-armhf-cross u-boot-tools bc make gcc libc6-dev libncurses5-dev libssl-dev bison flex

If you build it directly on the BananaPi-R2 you do not need the crosscompile-packages gcc-arm-linux-gnueabihf and libc6-armhf-cross

Then build using with default configuration:

./build.sh

The option "pack" creates a tar.gz-file which contains folders BPI-BOOT (content of boot-partition aka /boot) and BPI-ROOT (content for rootfs aka /).

Simply backup your existing /boot/bananapi/bpi-r2/linux/uImage and unpack the content of these 2 folders to your system.

You can also install direct to sd-card which makes a backup of kernelfile, here you have to change your uEnv.txt if you use a new filename (by default it's containing kernelversion.)

Finally, check the installation with dmesg | grep debug_csi.

Look here.

• Base Linux Kernel: Linux Kernel Contributors, GPL-2.0, optimized and extended for BPI-R2 by frank-w.

• ath9k CSITool Driver: Yaxiong Xie (Project Homepage).