6.6-create-essentials.sh

#!/bin/bash
set -e

# create essential files and symlinks
ln -sv /tools/bin/{bash,cat,dd,echo,ln,pwd,rm,stty} /bin
ln -sv /tools/bin/{install,perl} /usr/bin
ln -sv /tools/lib/libgcc_s.so{,.1} /usr/lib
ln -sv /tools/lib/libstdc++.{a,so{,.6}} /usr/lib
sed 's/tools/usr/' /tools/lib/libstdc++.la > /usr/lib/libstdc++.la
for lib in blkid lzma mount uuid
do
  ln -sv /tools/lib/lib$lib.{a,so*} /usr/lib
  sed 's/tools/usr/' /tools/lib/lib${lib}.la > /usr/lib/lib${lib}.la
done
ln -sv bash /bin/sh

# create symlink for list of the mounted file systems
ln -sv /proc/self/mounts /etc/mtab

# configure root
cat > /etc/passwd <<"EOF"
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/dev/null:/bin/false
daemon:x:6:6:Daemon User:/dev/null:/bin/false
messagebus:x:18:18:D-Bus Message Daemon User:/var/run/dbus:/bin/false
systemd-bus-proxy:x:72:72:systemd Bus Proxy:/:/bin/false
systemd-journal-gateway:x:73:73:systemd Journal Gateway:/:/bin/false
systemd-journal-remote:x:74:74:systemd Journal Remote:/:/bin/false
systemd-journal-upload:x:75:75:systemd Journal Upload:/:/bin/false
systemd-network:x:76:76:systemd Network Management:/:/bin/false
systemd-resolve:x:77:77:systemd Resolver:/:/bin/false
systemd-timesync:x:78:78:systemd Time Synchronization:/:/bin/false
systemd-coredump:x:79:79:systemd Core Dumper:/:/bin/false
nobody:x:99:99:Unprivileged User:/dev/null:/bin/false
EOF

cat > /etc/group <<"EOF"
root:x:0:
bin:x:1:daemon
sys:x:2:
kmem:x:3:
tape:x:4:
tty:x:5:
daemon:x:6:
floppy:x:7:
disk:x:8:
lp:x:9:
dialout:x:10:
audio:x:11:
video:x:12:
utmp:x:13:
usb:x:14:
cdrom:x:15:
adm:x:16:
messagebus:x:18:
systemd-journal:x:23:
input:x:24:
mail:x:34:
systemd-bus-proxy:x:72:
systemd-journal-gateway:x:73:
systemd-journal-remote:x:74:
systemd-journal-upload:x:75:
systemd-network:x:76:
systemd-resolve:x:77:
systemd-timesync:x:78:
systemd-coredump:x:79:
nogroup:x:99:
users:x:999:
EOF

# initialize the log files and give them proper permissions
touch /var/log/{btmp,lastlog,faillog,wtmp}
chgrp -v utmp /var/log/lastlog
chmod -v 664 /var/log/lastlog
chmod -v 600 /var/log/btmp