added pre-init script that setup things before starting systemd

rootfs-overlay/usr/sbin/init

@@ -0,0 +1,61 @@
+#!/bin/sh
+# Nimux pre-systemd boot
+
+export ROOT_DEV=/dev/ram0
+export RUN_NIMUX=/run/nimux
+export ROOTFS_ORIG=$RUN_NIMUX/rootfs.orig
+export NIMUX_OVERLAY=$RUN_NIMUX/overlay
+
+# create the minimal required mount
+/bin/echo "[init] Cmdline:" "$@"
+/bin/echo "[init] perform early mounts"
+/bin/mount -t proc proc /proc
+/bin/mount -t sysfs sysfs /sys
+/bin/mount -t devtmpfs devtmpfs /dev
+/bin/mount -t tmpfs tmpfs /run
+/bin/mount -t tmpfs tmpfs /mnt
+
+# mount root on a future accesable place
+/bin/echo "[init] re-mount rootfs"
+/bin/mkdir -p $ROOTFS_ORIG
+/bin/mount -t squashfs -o ro $ROOT_DEV $ROOTFS_ORIG
+/bin/mount --make-rprivate $ROOTFS_ORIG
+
+# overlay the /var directory with a volatile tmpfs
+/bin/echo "[init] overlay /var"
+export VAR_LOWER=$ROOTFS_ORIG/var
+export VAR_UPPER=$NIMUX_OVERLAY/var/upper
+export VAR_WORK=$NIMUX_OVERLAY/var/work
+
+/bin/mkdir -p $VAR_UPPER $VAR_WORK
+/bin/mount -t overlay overlay-var -o lowerdir=$VAR_LOWER,upperdir=$VAR_UPPER,workdir=$VAR_WORK /var
+
+# ovelay /etc and patch with persistant storage 
+# we don´t overlay on persistent storage, because this will cause bootfailures
+# when the lower dir (rootfs.squashfs) is updated by a future release of Numix
+/bin/echo "[init] overlay /etc"
+export ETC_LOWER=$ROOTFS_ORIG/etc
+export ETC_UPPER=$NIMUX_OVERLAY/etc/upper
+export ETC_WORK=$NIMUX_OVERLAY/etc/work
+
+/bin/mkdir -p $ETC_UPPER $ETC_WORK
+/bin/mount -t overlay overlay-etc -o lowerdir=$ETC_LOWER,upperdir=$ETC_UPPER,workdir=$ETC_WORK /etc
+
+# import zpool (this will also mount etc & home)
+/bin/echo "[init] import zpool"
+/sbin/zpool import nimux-zfs
+
+# update etc dir with persitent data
+export ETC_PERSIST=$NIMUX_OVERLAY/etc/persist
+/bin/echo "[init] update /etc with persistant data"
+/bin/echo "[init] /etc persist dir: " $ETC_PERSIST
+/bin/cp -R $ETC_PERSIST/* /etc
+
+# hand over to systemd
+/bin/echo "[init] handover control to systemd"
+exec /usr/lib/systemd/systemd
+
+# we shouldn´t get to here
+echo "[init] ERROR: switch_root failed!" >&2
+export PS1="\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\] (init-rescue)# "
+exec sh