bfdracut

#!/bin/sh

# Copyright (c) 2018, Mellanox Technologies
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# The views and conclusions contained in the software and documentation are those
# of the authors and should not be interpreted as representing official policies,
# either expressed or implied, of the FreeBSD Project.

set -e

#
# This script relies on dracut, a low-level tool, for generating an initramfs
# for the running kernel. This script generates the configuration file for
# dracut, installs the necessary Mellanox modules and creates a script file
# that enables IPoIB and that supports NFS mounting rootfs while PXE booting
# in IB mode.
#

PROGNAME=$(basename "$0")
# Check arguments. For now, only output initramfs image is expected.
# if the output image argument is ommitted, then the default location
# /boot/initramfs-<kernel version>-nfs-ib.img is used.
if [ $# -gt 1 ]; then
    echo "Usage: $PROGNAME <initramfs>"
	exit 1
elif [ $# -eq 1 ]; then
	INITRAMFS=$1
else
    INITRAMFS=/boot/initramfs-$(uname -r)-nfs-ib.img
fi

# Don't continue if we don't have dracut support
if [ ! -x "/usr/bin/dracut" ] || [ ! -d "/usr/lib/dracut" ] \
        || [ ! -f "/etc/dracut.conf" ]; then
    echo "$PROGNAME: *** nothing to do: dracut is not installed! ***"
    exit 1
fi


# Create temporary directories to save the configuration file and the
# script file.
TMP_DIR=/usr/lib/dracut/tmp
if [ ! -d $TMP_DIR ]; then
	mkdir -p ${TMP_DIR}/conf
	mkdir -p ${TMP_DIR}/sh
fi

# Dracut configuration file. This configuration is loaded during the
# initialisation phase of dracut.
CONF_FILE=01-mlxib-nfs.conf

# Script file to add to dracut hooks. This script is hooked to pre-udev
# and is executed at system boot (init) phase.
SH_IPOIB=90-ipoib-start.sh

# Set temporary path files
TMP_CONF=$TMP_DIR/conf/$CONF_FILE
TMP_SH=$TMP_DIR/sh/$SH_IPOIB


# In order to PXE boot in IB mode and mount an NFS-rootfs, the Mellanox
# network drivers must be loaded. Hence, set the dracut option to add the
# needed IB and network drivers.
MOD_IB=
LIB_IB=/lib/modules/$(uname -r)/updates/drivers/infiniband
MOD_LIST=$(find "$LIB_IB" -name "*.ko")
for m in $MOD_LIST; do
	modname=$(basename "$m" ".ko")
	MOD_IB="$MOD_IB $modname"
done
MOD_NET="ipv6 mlx5_core mlx_compat $MOD_IB"

# Write dracut configuration file
cat <<EOF > $TMP_CONF
dracutmodules+="network kernel-network-modules nfs udev-rules base"
add_drivers+="$MOD_NET"
EOF

# In order to expose and setup the IB network interfaces to the system
# at the boot (init) stage, the IPoIB support must be enabled and the
# driver loaded. The following script is installed into the initramfs
# and is called prior to the interface configuration. Dracut init scripts
# configure the IB interfaces, i.e., ifup and dhcp, prior to nfsroot setup.
# This requires that the TFTP, DHCP and NFS servers are set properly.

LIB_NET_MLX=/lib/modules/$(uname -r)/updates/drivers/net/ethernet/mellanox
# Write script to enable IPoIB support
cat <<EOF > $TMP_SH
#! /bin/sh
# Start the mellanox network driver.
[ ! -f $LIB_NET_MLX/mlx5/core/mlx5_core.ko ] && exit 1
modprobe mlx5_core 2>/dev/null
# Start IPoIB support, i.e. load the kernel module
[ -f $LIB_IB/ulp/ipoib/ib_ipoib.ko ] && modprobe ib_ipoib 2>/dev/null
EOF

# It is recommended that a given dracut configuration is put in separate
# files in /etc/dracut.conf.d named "<name>.conf". If the directory does
# not exist then edit /etc/dracut.conf.
if [ -d "/etc/dracut.conf.d" ]; then
	CONF=/etc/dracut.conf.d/$CONF_FILE
	# Cleanup existing configuration
	[ -e "$CONF" ] && rm -f $CONF
else
	CONF=/etc/dracut.conf
fi
cp $TMP_CONF $CONF

# Run dracut to create the initramfs image
dracut -f -i $TMP_DIR/sh /lib/dracut/hooks/pre-udev/ "$INITRAMFS"

# These temporary files are removed at the end; in case of failure
# that would be helpful for debugging and unit testing.
rm -f $TMP_SH $TMP_CONF
[ -d $TMP_DIR ] && rm -fr $TMP_DIR