Linux kernel based on the mainline 5.17.5 kernel for Banana Pi M2 Zero with WiFi. Note that the WiFi driver is missing, need to add it via Linux firmware blob(s)

1. I built this on Ubuntu 22.04 x86_64 with the Arm GNU Toolchain (arm-none-linux-gnueabihf), so download and extract it and set the bin dir to PATH:

export PATH=$PATH:/opt/gcc-arm-10.3-2021.07-x86_64-arm-none-linux-gnueabihf/bin

1.1 NOTE: Seems like that the normal arm-linux-gnueabihf- package from Ubuntu's repos is enough for compiling the kernel.

sudo apt install arm-linux-gnueabihf
prepend this to the make command: CROSS_COMPILE=arm-linux-gnueabihf-

2. Install the following tools and libs:

sudo apt-get install flex bison g++ libgmp3-dev libmpc-dev device-tree-compiler build-essential python3-setuptools python3-dev

3. Build from this project root.

make INSTALL_MOD_PATH=output ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabihf- m2z_lima_defconfig zImage modules modules_install dtbs -j$(nproc)

3.1 Normal arm-linux-gnueabi cross-compiler:

make INSTALL_MOD_PATH=output ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- m2z_lima_defconfig zImage modules modules_install dtbs -j$(nproc)

4. Copy over the output/* (lib/modules) into rootfs of memory card

sudo cp -vfr ./output/lib/* /dev/sda2/lib/
sync

5. Install into the /boot dir of the memory card:

sudo cp -fv ./arch/arm/boot/zImage /dev/sda1/zImage
sync
sudo cp -fv ./arch/arm/boot/dts/bpi-m2-zero-v4.dtb /dev/sda1/bpi-m2-zero.dtb
sync

6. Install/transfer the correct WiFi radio blob to /lib/firmware

TODO

7. Copy Buildroot/barebones OS rootfs to SDCard for fast booting. This kernel takes 3s to boot itself, with userspace taking 10s+ to a login shell. (Normal Bookworm rootfs)

TODO

• (TODO) Enable/add the USB gadget ConfigFS/FunctionFS for g_ether, etc.

• Used the m2z_lima_defconfig from https://github.com/avafinger/linux-5.6.y with some modifications to it. (This and some from here, although I'm not sure if the latter was necessary for wifi to be working)

• Added sun8iw7p1smp_bpi-m2z_defconfig and m2z_defconfig.

• Added bpi-m2-zero-v4.dts, along with the headers it requires and modified the Makefile to accomodate this.