This is an old revision of the document!
The Analog Devices kernel can be built to run on the Raspberry PI boards. Unfortunately, these changes are not in master, because they diverge too much (at this point in time) from the changes in both Xilinx & ADI kernel.
Because of this, there are special branches in the repository that should be built to run on the Raspberry PI. They contain several drivers that are not upstreamed yet. These are mostly used for internal testing, and they also contain device-tree overlays for some of these drivers.
The Raspberry PI branches are:
The initial setup is to get an SD-card image from here: https://www.raspberrypi.org/downloads/raspbian/ It does not matter which distribution is used/preferred.
Instructions on writing to SD-card are here: https://www.raspberrypi.org/documentation/installation/installing-images/README.md
At the time of this writing Raspbian's kernel version is 4.14.
git clone https://github.com/analogdevicesinc/linux git checkout rpi-4.14.y
Get a toolchain for cross-compiling.
git clone https://github.com/raspberrypi/tools
Get an ARM compiler for cross-compiling for Pi 3.
ARCH=arm make adi_bcm2709_defconfig ARCH=arm CROSS_COMPILE=<path-to-arm-toolchain> make
For Pi 4.
ARCH=arm make adi_bcm2711_defconfig ARCH=arm CROSS_COMPILE=<path-to-arm-toolchain> make
Download this script (and make it executable): https://github.com/analogdevicesinc/wiki-scripts/blob/master/linux/build_rpi_kernel_image.sh
First backup the kernel7.img file on the SD-card.
The generated arch/arm/boot/zImage file should be copied to the /boot to overwrite the kernel7.img (or kernel7l.img for Pi4+).
Any drivers built as modules must be installed onto the rootfs:
make ARM=arm CROSS_COMPILE=<toolchain> INSTALL_MOD_PATH=< path to SD card rootfs> modules_install
For Raspberry-PI, a way to add a driver (and usually in IIO), is to build it into the kernel7.img and add a device-tree overlay.
Adding drivers is done via make menuconfig, and selecting the [y] option.
Device-tree overlays are covered in these docs:
Some examples of DT overlays for drivers written for ADI parts can be found at this link: https://github.com/analogdevicesinc/linux/commits/rpi-4.14.y/arch/arm/boot/dts/overlays