Hi, apparently I did a revert back to OpenWrt MR3020(UN) in failsafe mode,
I ran these commands:
mount_root ## this remounts your partitions from read-only to read/write mode
firstboot ## This will reset your router after reboot
reboot -f ## And force reboot

How can I restore to a healthy PirateBox installation???

After this steps, you can simply copy over a fresh install folder to the USB stick. After powering the device the automatic installation will do the rest.

It's not working for me, the usb doesn't have any files except the auto_flash folder with the stable.openwrt.piratebox.de
and the PirateBox install folder. Any ideas as to how can I restore or install a healthy functioning Pirate Box ?

mh, strange.
Can you post the output of the commands listed here ,please?
Thank you,
best regards Matthias

root@(none):/# mount
rootfs on / type rootfs (rw)
/dev/root on / type squashfs (ro,relatime)
proc on /proc type proc (rw,noatime)
sysfs on /sys type sysfs (rw,noatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noatime,size=14592k)
tmpfs on /dev type tmpfs (rw,noatime,size=512k,mode=755)
devpts on /dev/pts type devpts (rw,noatime,mode=600)
root@(none):/# ls -la /mnt/
drwxr-xr-x 2 root root 3 Feb 1 2016 .
drwxr-xr-x 16 root root 223 Nov 8 2017 ..
root@(none):/# ls -la /mnt/usb
ls: /mnt/usb: No such file or directory
root@(none):/# ls -la /mnt/usb/PirateBox
ls: /mnt/usb/PirateBox: No such file or directory
root@(none):/# ls -la /mnt/usb/install
ls: /mnt/usb/install: No such file or directory
root@(none):/# ls -la /opt/piratebox
ls: /opt/piratebox: No such file or directory
root@(none):/# ls -la /opt/piratebox/www
ls: /opt/piratebox/www: No such file or directory
root@(none):/# cat /etc/pbx_custom_image
PBX_Image_2.0.1
root@(none):/# cat /etc/openwrt_release
DISTRIB_ID="OpenWrt_backports"
DISTRIB_RELEASE="12.09.2"
DISTRIB_REVISION="r42647"
DISTRIB_CODENAME="attitude_adjustment"
DISTRIB_TARGET="ar71xx/generic"
DISTRIB_DESCRIPTION="OpenWrt_backports Attitude Adjustment 12.09.2"
DISTRIB_BACKPORT="V0.3-MaStr"
root@(none):/# cat /opt/piratebox/version
cat: can't open '/opt/piratebox/version': No such file or directory
root@(none):/# cat /opt/piratebox/tmp/error.log
cat: can't open '/opt/piratebox/tmp/error.log': No such file or directory
root@(none):/# cat /opt/piratebox/tmp/break.log
cat: can't open '/opt/piratebox/tmp/break.log': No such file or directory
root@(none):/# cat /etc/config/network
cat: can't open '/etc/config/network': No such file or directory
root@(none):/# cat /etc/config/wireless
cat: can't open '/etc/config/wireless': No such file or directory
root@(none):/# dmesg | tail -n 20
[ 0.540000] mtd: partition "rootfs" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only
[ 0.550000] mtd: partition "rootfs" set to be root filesystem
[ 0.560000] mtd: partition "rootfs_data" created automatically, ofs=310000, len=E0000
[ 0.560000] 0x000000310000-0x0000003f0000 : "rootfs_data"
[ 0.570000] 0x0000003f0000-0x000000400000 : "art"
[ 0.580000] 0x000000020000-0x0000003f0000 : "firmware"
[ 0.600000] ag71xx_mdio: probed
[ 0.600000] eth0: Atheros AG71xx at 0xb9000000, irq 4
[ 1.160000] ag71xx ag71xx.0: eth0: connected to PHY at ag71xx-mdio.1:04 [uid=004dd041, driver=Generic PHY]
[ 1.170000] TCP cubic registered
[ 1.170000] NET: Registered protocol family 17
[ 1.170000] Bridge firewalling registered
[ 1.180000] 8021q: 802.1Q VLAN Support v1.8
[ 1.190000] VFS: Mounted root (squashfs filesystem) readonly on device 31:2.
[ 1.190000] Freeing unused kernel memory: 216k freed
[ 3.570000] Registered led device: tp-link:green:3g
[ 3.570000] Registered led device: tp-link:green:wlan
[ 3.570000] Registered led device: tp-link:green:lan
[ 3.570000] Registered led device: tp-link:green:wps
[ 148.240000] eth0: link up (100Mbps/Full duplex)
root@(none):/# dmesg | grep sda
root@(none):/# ls /dev/sd*
ls: /dev/sd*: No such file or directory
root@(none):/# ps
PID USER VSZ STAT COMMAND
1 root 1640 S {preinit} /bin/sh /etc/preinit
2 root 0 SW [kthreadd]
3 root 0 SW [ksoftirqd/0]
4 root 0 SW [kworker/0:0]
5 root 0 SW [kworker/u:0]
6 root 0 SW< [khelper]
7 root 0 SW [kworker/u:1]
63 root 0 SW [sync_supers]
65 root 0 SW [bdi-default]
67 root 0 SW< [kblockd]
96 root 0 SW [kswapd0]
144 root 0 SW [fsnotify_mark]
173 root 0 SW< [ath79-spi]
184 root 0 SW [mtdblock0]
189 root 0 SW [mtdblock1]
194 root 0 SW [mtdblock2]
199 root 0 SW [mtdblock3]
204 root 0 SW [mtdblock4]
209 root 0 SW [mtdblock5]
250 root 0 SW [kworker/0:1]
365 root 804 S /sbin/hotplug2 --set-worker /lib/hotplug2/worker_for
432 root 1496 S telnetd -l /bin/login.sh
438 root 1488 S lock /tmp/.failsafe
439 root 1500 S ash --login
447 root 1500 S /bin/ash --login
476 root 1496 R ps
root@(none):/# tail -n 200 /mnt/usb/install.log
tail: can't open '/mnt/usb/install.log': No such file or directory
tail: no files



Best regards, thank you !

It seems your USB stick is not recognized during boot.
Is your device powered sufficiently ? If the auto flash feature does not work, you can still follow this path [piratebox.cc]

best regards Matthias