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#!/bin/sh
# Functions library :: for Linux Live Kit scripts
# Author: Tomas M. <http://www.linux-live.org>
#
# =================================================================
# debug and output functions
# =================================================================
debug_start()
{
if grep -q debug /proc/cmdline; then
DEBUG_IS_ENABLED=1
else
DEBUG_IS_ENABLED=
fi
}
debug_log()
{
if [ "$DEBUG_IS_ENABLED" ]; then
echo "- debug: $*" >&2
log "- debug: $*"
fi
}
# header
# $1 = text to show
#
header()
{
echo """$@"""
}
# echo green star
#
echo_green_star()
{
echo -ne """* """
}
# log - store given text in /var/log/livedbg
log()
{
echo "$@" 2>/dev/null >>/var/log/livedbg
}
echolog()
{
echo "$@"
log "$@"
}
# show information about the debug shell
show_debug_banner()
{
echo
echo "====="
echo ": Debugging started. Here is the root shell for you."
echo ": Type your desired commands or hit Ctrl+D to continue booting."
echo
}
# debug_shell
# executed when debug boot parameter is present
#
debug_shell()
{
if [ "$DEBUG_IS_ENABLED" ]; then
show_debug_banner
setsid sh -c 'exec sh < /dev/tty1 >/dev/tty1 2>&1'
echo
fi
}
fatal()
{
echolog
header "Fatal error occured - $1"
echolog "Something went wrong and we can't continue. This should never happen."
echolog "Please reboot your computer with Ctrl+Alt+Delete ..."
echolog
setsid sh -c 'exec sh < /dev/tty1 >/dev/tty1 2>&1'
}
# test if the script is started by root user. If not, exit
#
allow_only_root()
{
if [ "0$UID" -ne 0 ]; then
echo "Only root can run $(basename $0)"; exit 1
fi
}
# Create bundle
# call mksquashfs with apropriate arguments
# $1 = directory which will be compressed to squashfs bundle
# $2 = output file
# $3..$9 = optional arguments like -keep-as-directory or -b 123456789
#
create_bundle()
{
debug_log "create_module" "$*"
rm -f "$2" # overwrite, never append to existing file
mksquashfs "$1" "$2" -comp xz -b 512K $3 $4 $5 $6 $7 $8 $9>/dev/null
}
# Move entire initramfs tree to tmpfs mount.
# It's a bit tricky but is necessray to enable pivot_root
# even for initramfs boot image
#
transfer_initramfs()
{
if [ ! -r /lib/initramfs_escaped ]; then
echo "switch root from initramfs to ramfs"
SWITCH=/m # one letter directory
mkdir -p $SWITCH
mount -t tmpfs -o size="100%" tmpfs $SWITCH
cp -a /??* $SWITCH 2>/dev/null # only copy two-and-more-letter directories
cd $SWITCH
echo "This file indicates that we successfully escaped initramfs" > $SWITCH/lib/initramfs_escaped
exec switch_root -c /dev/console . $0
fi
}
# mount virtual filesystems like proc etc
#
init_proc_sysfs()
{
debug_log "vfs_mount_init"
mount -n -t proc proc /proc
echo "0" >/proc/sys/kernel/printk
mount -n -t sysfs sysfs /sys
mount -n -o remount,rw rootfs /
ln -sf /proc/mounts /etc/mtab
}
# make sure some devices are there
init_devs()
{
echo /sbin/mdev > /proc/sys/kernel/hotplug
mdev -s
modprobe zram 2>/dev/null
modprobe loop 2>/dev/null
modprobe squashfs 2>/dev/null
modprobe fuse 2>/dev/null
}
# Activate zram (auto-compression of RAM)
# Compressed RAM consumes 1/2 or even 1/4 of original size
# Setup static size of 500MB
#
init_zram()
{
debug_log "init_zram"
echo_green_star
echo "Setting dynamic RAM compression using ZRAM"
echo 536870912 > /sys/block/zram0/disksize # 512MB
mkswap /dev/zram0 >/dev/null
swapon /dev/zram0 -p 32767
echo 100 > /proc/sys/vm/swappiness
}
# load the AUFS kernel module if needed
#
init_aufs()
{
debug_log "init_aufs"
# TODO maybe check here if aufs support is working at all
# and procude useful error message if user has no aufs
modprobe aufs 2>/dev/null
}
# Setup empty union
# $1 = changes directory (ramfs or persistent changes)
# $2 = union directory where to mount the union
#
init_union()
{
debug_log "init_union"
echo_green_star
echo "Setting up union using AUFS 3"
mkdir -p "$1"
mkdir -p "$2"
mount -t aufs -o xino="/.xino",br="$1" aufs "$2"
}
# Return device mounted for given directory
# $1 = directory
#
mounted_device()
{
debug_log "mounted_device"
local MNT TARGET
MNT="$1"
while [ "$MNT" != "/" -a "$MNT" != "." -a "$MNT" != "" ]; do
TARGET="$(grep -F " $MNT " /proc/mounts | cut -d " " -f 1)"
if [ "$TARGET" != "" ]; then
echo "$TARGET:$MNT"
return
fi
MNT="$(dirname $MNT)"
done
}
# Make sure to mount FAT12/16/32 using vfat
# in order to support long filenames
# $1 = device
#
device_bestfs()
{
debug_log "device_bestfs"
local FS
FS="$(blkid "$1" | sed -r "s/.*TYPE=//" | tr -d '"' | tr [A-Z] [a-z])"
if [ "$FS" = "msdos" -o "$FS" = "fat" -o "$FS" = "vfat" ]; then
FS="vfat"
elif [ "$FS" = "ntfs" ]; then
FS="ntfs-3g"
fi
echo "-t $FS"
}
# Filesystem options for mount
# $1 = filesystem or '-t filesystem'
#
fs_options()
{
if [ "$1" = "-t" ]; then
shift
fi
if [ "$1" = "vfat" ]; then
echo "-o check=s,shortname=mixed,iocharset=utf8"
fi
if [ "$1" = "ntfs-3g" ]; then
echo "-- -o attr_timeout=300,entry_timeout=300,negative_timeout=300,kernel_cache,allow_other"
fi
}
# Find LIVEKIT data by mounting all devices
# If found, keep mounted, else unmount
# $1 = data directory target (mount here)
#
find_data_try()
{
debug_log "find_data_try"
local DEVICE FS MNT OPTIONS
mkdir -p "$1"
blkid | sort | cut -d: -f 1 | grep -E -v "/loop|/ram|/zram" | while read DEVICE; do
FS="$(device_bestfs "$DEVICE")"
OPTIONS="$(fs_options $FS)"
mount -r "$DEVICE" "$1" $FS $OPTIONS 2>/dev/null
if [ -d "$1/$LIVEKITNAME" ]; then
mount -o remount,rw "$DEVICE" "$1" 2>/dev/null
echo "$1/$LIVEKITNAME"
return
fi
umount "$1" 2>/dev/null
done
}
# Retry finding LIVEKIT data several times,
# until timeouted or until data is found
# $1 = timeout
# $2 = data directory target (mount here)
#
find_data()
{
debug_log "find_data"
local DATA
echo_green_star >&2
echo -n "Looking for $LIVEKITNAME data .." >&2
for timeout in $(seq 1 $1); do
echo -n "." >&2
DATA="$(find_data_try "$2")"
if [ "$DATA" != "" ]; then
echo "" >&2
echo "* Found in $(mounted_device "$DATA" | cut -d : -f 1)" >&2
echo "$DATA"
return
fi
sleep 1
done
echo "" >&2
if [ "$DATA" = "" ]; then
fatal "$LIVEKITNAME data not found"
fi
}
# Activate persistent changes
# $1 = data directory
# $2 = target changes directory
#
persistent_changes()
{
local CHANGES T1 T2
CHANGES="$1/$(basename "$2")"
T1="$CHANGES/.empty"
T2="$T1"2
# Setup the directory anyway, it will be used in all cases
mkdir -p "$2"
# If persistent changes are not requested, end here
if grep -vq perch /proc/cmdline; then
return
fi
# check if changes directory exists and is writable
touch "$T1" 2>/dev/null && rm -f "$T1" 2>/dev/null
# if not, simply return back
if [ $? -ne 0 ]; then
echo "* Persistent changes not writable or not used"
return
fi
echo_green_star
echo "Testing persistent changes for posix compatibility"
touch "$T1" && ln -sf "$T1" "$T2" 2>/dev/null && \
chmod +x "$T1" 2>/dev/null && test -x "$T1" && \
chmod -x "$T1" 2>/dev/null && test ! -x "$T1" && \
rm "$T1" "$T2" 2>/dev/null
if [ $? -ne 0 ]; then
echo "* Activating dynamic sized storage for persistent changes"
rm "$T1" "$T2" 2>/dev/null
mount.dynfilefs "$CHANGES/changes.dat" 4000 "$2"
if [ "$(device_bestfs "$2/loop.fs" | tr -d " ")" = "-t" ]; then
mke2fs -F "$2/loop.fs" >/dev/null
fi
mount -o loop,sync "$2/loop.fs" "$2"
rmdir "$2/lost+found"
else
echo "* Activating native persistent changes"
mount --bind "$CHANGES" "$2"
fi
}
# Copy data to RAM if requested
# $1 = live data directory
# $2 = changes directory
#
copy_to_ram()
{
local DM RAM CHANGES
if grep -vq toram /proc/cmdline; then
echo "$1"
return
fi
CHANGES="$(basename $2)"
DM="$(mounted_device "$1" | cut -d : -f 2-)"
RAM="$DM.ram"
echo "* Copying $LIVEKITNAME data to RAM..." >&2
mkdir -p "$RAM"
cp -a "$DM/$LIVEKITNAME" "$RAM"
echo "$RAM/$LIVEKITNAME"
if grep -q perch /proc/cmdline; then
umount "$2" 2>/dev/null
umount "$DM/$LIVEKITNAME/$CHANGES" 2>/dev/null
umount "$DM/$LIVEKITNAME/$CHANGES" 2>/dev/null
mount --bind "$RAM/$LIVEKITNAME/$CHANGES" "$2"
fi
umount "$DM"
}
# Mount squashfs filesystem bundles
# and add them to union
# $1 = directory where to search for bundles
# $2 = directory where to mount bundles
# $3 = directory where union is mounted
#
union_append_bundles()
{
debug_log "union_append_bundles"
echo_green_star
echo "Adding bundles to union"
ls -1 "$1" | grep '.'$BEXT'$' | sort | while read BUNDLE; do
echo "* $BUNDLE"
mkdir -p "$2/$BUNDLE"
mount -o loop -t squashfs "$1/$BUNDLE" "$2/$BUNDLE"
mount -o remount,add:1:"$2/$BUNDLE" aufs "$3"
done
}
# Create empty fstab properly
# $1 = root directory
#
fstab_create()
{
local FSTAB
FSTAB="$1/etc/fstab"
echo aufs / aufs defaults 0 0 > $FSTAB
echo proc /proc proc defaults 0 0 >> $FSTAB
echo sysfs /sys sysfs defaults 0 0 >> $FSTAB
echo devpts /dev/pts devpts gid=5,mode=620 0 0 >> $FSTAB
echo tmpfs /dev/shm tmpfs defaults 0 0 >> $FSTAB
}
# Change root and execute init
# $1 = where to change root
#
change_root()
{
umount /proc
umount /sys
rm -Rf /lib/modules # this will no longer be needed at all
cd "$1"
# make sure important devices are in union
if [ ! -e dev/console ]; then mknod dev/console c 5 1; fi
if [ ! -e dev/null ]; then mknod dev/null c 1 3; fi
# find chroot and init
if [ -x bin/chroot ]; then CHROOT=bin/chroot; fi
if [ -x sbin/chroot ]; then CHROOT=sbin/chroot; fi
if [ -x usr/bin/chroot ]; then CHROOT=usr/bin/chroot; fi
if [ -x usr/sbin/chroot ]; then CHROOT=usr/sbin/chroot; fi
if [ "$CHROOT" = "" ]; then fatal "Can't find executable chroot command"; fi
if [ -x bin/init ]; then INIT=bin/init; fi
if [ -x sbin/init ]; then INIT=sbin/init; fi
if [ "$INIT" = "" ]; then fatal "Can't find executable init command"; fi
mkdir -p mnt/live
mount -n -o remount,ro aufs .
pivot_root . mnt/live
exec $CHROOT . $INIT < dev/console > dev/console 2>&1
}
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