Some additional info for the previous kernel_panic error:
Stop-log:
======================================================
root@cubieboard2:~# powerpoff
Stopping Session 1 of user root.
[ OK ] Stopped target Sound Card.
Stopping User Manager for UID 0...
Stopping OpenBSD Secure Shell server...
Stopping D-Bus System Message Bus...
Stopping Regular background program processing daemon...
[ OK ] Stopped System Logging Service.
[ OK ] Stopped Internet superserver.
[ OK ] Stopped Self Monitoring and Reporting Technology (SMART) Daemon.
[ OK ] Stopped D-Bus System Message Bus.
[ OK ] Stopped irqbalance daemon.
[ OK ] Stopped Regular background program processing daemon.
[ OK ] Stopped OpenBSD Secure Shell server.
[ OK ] Stopped Serial Getty on ttyS0.
[ OK ] Stopped Getty on tty1.
[ OK ] Stopped Session 1 of user root.
[ OK ] Stopped User Manager for UID 0.
[ OK ] Removed slice User Slice of root.
Stopping Login Service...
[ OK ] Removed slice system-getty.slice.
[ OK ] Removed slice system-serial\x2dgetty.slice.
Stopping Permit User Sessions...
[ OK ] Stopped /etc/rc.local Compatibility.
[ OK ] Stopped Login Service.
[ OK ] Stopped Permit User Sessions.
[ OK ] Stopped LSB: Start NTP daemon.
[ OK ] Stopped target Network is Online.
[ OK ] Deactivated swap /var/swap_file.
[ OK ] Stopped LSB: Autogenerate and use a swap file.
[ OK ] Stopped The Apache HTTP Server.
[ OK ] Stopped target Remote File Systems.
[ OK ] Stopped target Host and Network Name Lookups.
[ OK ] Stopped target Network.
Stopping Raise network interfaces...
[ OK ] Stopped target Basic System.
[ OK ] Stopped target Paths.
[ OK ] Stopped target Slices.
[ OK ] Removed slice User and Session Slice.
[ OK ] Stopped target Sockets.
[ OK ] Closed D-Bus System Message Bus Socket.
[ OK ] Closed Syslog Socket.
[ OK ] Stopped target System Initialization.
Stopping Update UTMP about System Boot/Shutdown...
[ OK ] Stopped target Encrypted Volumes.
[ OK ] Stopped Forward Password Requests to Wall Directory Watch.
[ OK ] Stopped Dispatch Password Requests to Console Directory Watch.
Stopping Load/Save Random Seed...
[ OK ] Stopped target Swap.
[ OK ] Stopped Load/Save Random Seed.
[ OK ] Stopped Update UTMP about System Boot/Shutdown.
[ OK ] Stopped Create Volatile Files and Directories.
[ OK ] Stopped Raise network interfaces.
[ OK ] Stopped Apply Kernel Variables.
[ OK ] Stopped target Local File Systems.
Unmounting /run/user/0...
Unmounting /boot...
[ OK ] Stopped Load Kernel Modules.
[ OK ] Unmounted /run/user/0.
Unmounting /home...
[ OK ] Unmounted /boot.
[ OK ] Stopped File System Check on
/dev/d56366-7578-4efd-ab3c-dc9fb422579f.
[ OK ] Unmounted /home.
[ OK ] Reached target Unmount All Filesystems.
[ OK ] Stopped File System Check on
/dev/d1f8a9-2935-4cb6-9305-27cecd3b43c4.
[ OK ] Stopped target Local File Systems (Pre).
[ OK ] Stopped Create Static Device Nodes in /dev.
[ OK ] Stopped Remount Root and Kernel File Systems.
[ OK ] Removed slice system-systemd\x2dfsck.slice.
[ OK ] Reached target Shutdown.
[ 192.175162] reboot: Power down
[ 194.239408] i2c i2c-0: mv64xxx: I2C bus locked, block: 1, time_left: 0
[ 194.763806] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x00000000
[ 194.763806]
[ 194.772949] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted
4.9.0-7-armmp-lpae #1 Debian 4.9.110-3+deb9u2
[ 194.782500] Hardware name: Allwinner sun7i (A20) Family
[ 194.787758] [<c0231420>] (unwind_backtrace) from [<c022b568>]
(show_stack+0x20/0x24)
[ 194.795506] [<c022b568>] (show_stack) from [<c0542afc>]
(dump_stack+0x90/0xa4)
[ 194.802729] [<c0542afc>] (dump_stack) from [<c0389ae4>]
(panic+0x100/0x28c)
[ 194.809692] [<c0389ae4>] (panic) from [<c026ee44>]
(complete_and_exit+0x0/0x2c)
[ 194.817001] [<c026ee44>] (complete_and_exit) from [<c028f094>]
(SyS_reboot+0x1c8/0x238)
[ 194.825004] [<c028f094>] (SyS_reboot) from [<c0226ce0>]
(ret_fast_syscall+0x0/0x40)
[ 194.832670] ---[ end Kernel panic - not syncing: Attempted to kill
init! exitcode=0x00000000
[ 194.832670]
