wsl-build-zfs-kernel.sh

LINUX_VERSION=5.9-rc7
LINUX_KERNEL_VERSION=mainline-${LINUX_VERSION}
ZFS_VERSION=0.8.6

# Find ROOT_DIR
ROOT_DIR=/c

if [ ! -z "$(ls -A /mnt/c)" ]; then
   ROOT_DIR=/mnt/c
fi

if [ -z "$(ls -A ${ROOT_DIR})" ]; then
  echo "ROOT_DIR ${ROOT_DIR} is empty, exiting."
  exit;
fi

echo "Found ${ROOT_DIR}"

NEW_KERNEL_VERSION=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1)
echo "Building ... kernel-fs-gpu-zfs.${NEW_KERNEL_VERSION}"

BUILD_DIR=${HOME}/build

mkdir -p ${BUILD_DIR}

cd ${BUILD_DIR}

if [[ ! -f config-wsl ]]; then
  curl -O https://raw.githubusercontent.com/microsoft/WSL2-Linux-Kernel/master/Microsoft/config-wsl
fi

if [[ ! -d linux-${LINUX_KERNEL_VERSION} ]]; then
  curl -L https://github.com/linux-wsl2/linux-mainline/archive/v${LINUX_VERSION}.tar.gz | tar -xz
fi

if [[ ! -d zfs ]]; then
  git clone https://github.com/openzfs/zfs
  cd zfs
  git checkout master
  cd --
fi

# Install the build tools and the dependencies
sudo apt update
sudo apt install -yqq build-essential autoconf automake libtool gawk alien fakeroot dkms libblkid-dev uuid-dev libudev-dev libssl-dev \
zlib1g-dev libaio-dev libattr1-dev libelf-dev python3 python3-dev python3-setuptools python3-cffi libffi-dev flex bison libncurses5-dev

export CONFIG=${BUILD_DIR}/linux-${LINUX_KERNEL_VERSION}/.config

cp config-wsl ${CONFIG}

cat <<EOT >> ${CONFIG}
CONFIG_X86_INTEL_TSX_MODE_OFF=y
CONFIG_LEGACY_VSYSCALL_NONE=y
CONFIG_VIRTIO_FS=y
CONFIG_DM_INIT=y
CONFIG_VIRTIO_BLK_SCSI=y
CONFIG_NF_CONNTRACK_BRIDGE=y
CONFIG_LOCALVERSION="-microsoft-zfs-gpu.${NEW_KERNEL_VERSION}"
CONFIG_UNICODE=y
CONFIG_NET_9P_VIRTIO=y
CONFIG_ZFS=y
CONFIG_DXGKRNL=y
EOT

cd linux-${LINUX_KERNEL_VERSION}
# make prepare scripts
# make menuconfig
make olddefconfig
# make -j

# make scripts
## ZFS
cd ${BUILD_DIR}/zfs

git checkout master
git pull

sh autogen.sh

./configure --prefix=/ --libdir=/lib --includedir=/usr/include --datarootdir=/usr/share --enable-linux-builtin=yes \
  --with-linux=$BUILD_DIR/linux-${LINUX_KERNEL_VERSION} \
  --with-linux-obj=$BUILD_DIR/linux-${LINUX_KERNEL_VERSION}

./copy-builtin $BUILD_DIR/linux-${LINUX_KERNEL_VERSION}

time make -j

sudo make install

# Enter the kernel directory
cd ${BUILD_DIR}/linux-${LINUX_KERNEL_VERSION}/
# Check if a ZFS reference already exist in the config file
if ! grep -s ZFS .config; then
  # Add the ZFS reference to the end of the config file
  echo "CONFIG_ZFS=y" >> .config
fi

## MAKE IT
make -j
# Install the modules built with the Kernel
sudo make modules_install

# Create a directory on "Windows" path to store the kernel
KERNEL_DIR=${ROOT_DIR}/wslkernel5
mkdir -p ${KERNEL_DIR}
# Copy the Kernel file
echo "Copying arch/x86/boot/bzImage -> ${KERNEL_DIR}/kernel-fs-gpu-zfs.${NEW_KERNEL_VERSION}"
cp arch/x86/boot/bzImage ${KERNEL_DIR}/kernel-fs-gpu-zfs.${NEW_KERNEL_VERSION}

## Who is the default user on Windows?
LOGGED_IN_USER=$(powershell.exe \$env:UserName | sed $'s/[^[:print:]\t]//g')

echo "Found WSL2 running under: ${LOGGED_IN_USER}"
# Edit the wslconfig file and add the Kernel setting
USER_DIR=${ROOT_DIR}/Users/${LOGGED_IN_USER}
WSL_CONFIG=${USER_DIR}/.wslconfig

echo "Using ${WSL_CONFIG}"

sed -i "s/kernel-fs-gpu-zfs.\([0-9a-zA-Z]\+\)$/kernel-fs-gpu-zfs.${NEW_KERNEL_VERSION}/g" ${WSL_CONFIG}

if grep -s ${NEW_KERNEL_VERSION} ${WSL_CONFIG}; then
  echo "DONE! Run: 'wsl.exe --shutdown' in a seperate command window.";
else
  echo "Something went wrong."
fi