# /boot/local/load_kernel_modules.post
#
# This is a user-serviceable script that is executed within the
# OS InitRD (Operating System Initial RAM Disk) subsequent to loading
# the Linux Kernel modules.
#
# The purpose of this script is for users to load any particular modules
# they require to boot their system within the initial boot stages.
# However, it can be used for any other purpose as this is a bash
# shell script that is run within the 'init' process directly.
# Therefore, be careful what you put here.

# Example:
modprobe abcmodulexyz
modprobe anothermodule
modprobe andanother

# Other options here are to initialise a peripheral that's attached
# to the GPIO array.
#
# Example: Initialise an ds1307-based RTC on the GPIO pins.
# Note that on the Raspberry Pi 4, this RTC is already
# initialised by the bcm2711 Kernel Module Loader helper(*)
# within the OS InitRD, and is only repeated here as an example
# of the type of options available at this stage of the boot process.
# * http://ftp.arm.slackware.com/slackwarearm/slackwareaarch64-current/source/k/SlkOS-initrd-overlay/load_kernel_modules.scr/platform/aarch64/bcm2711

# Initialise it with the i2cdetect tool:
#i2cdetect -y 1 > /dev/null 2>&1
# If detected, provide the address to the Kernel interface so that
# the RTC driver can find it:
#[ -f /sys/class/i2c-adapter/i2c-1/new_device ] && echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device

# Define a function to run from the OS InitRD's '/init' immediately prior
# to switching into the Slackware OS proper.
# This is after any software RAID arrays et al have been initialised.
# There's no current use case for this, but it may be useful in the future.
#
# At this stage, the following paths for Slackware OS are mounted:
# /proc, /sys, /run, /dev
# The root file system ('/') is mounted under /mnt
#
#function hook_pre_switch_root() {
#  echo "Just about to switch into the Slackware OS proper, leaving the OS InitRD"
#  sleep 4
#}

# Capture the final list of modules that were loaded by the Kernel module
# loader, prior to the OS booting.
# This is a hack to help keep track of the core requirements for
# a particular Hardware Model, for when we need to put the initrd's
# on a diet.
# Note: this example is an illustration of the types of things you can do at this
# stage.
#function hook_pre_switch_root() {
#  echo "Just about to switch into the Slackware OS proper, leaving the OS InitRD"
#  echo "Detecting module sub system names"
#  mount -o remount rw /mnt
#
#cat << 'EOF' > /mnt/tmp/grab-mods
#( awk '{print $1}' /proc/modules| while read mod ; do
#   mfile=$( modinfo "${mod}" | grep -E '^filename:' | awk '{print $2}' )
#   echo ${mfile%/*}
#  done ) | sort | uniq | cut -d/ -f5- > /tmp/kernel-modules-within-initrd
#
#lsmod > /tmp/lsmod-os-initrd
#EOF
#
#   chmod 755 /mnt/tmp/grab-mods
#   chroot /mnt /tmp/grab-mods
#}