Did you use the Erase or Format functions in the Routerboot? (DON'T)
I also have this issue on 1 of my few devices which suffers from a bad erase block in NAND.
afaik, it's not possible to recover from it as the bad PEB data on the NAND is probably lost, meaning the system has no clue which blocks on the physical flash is working properly.
Another identical device:
RouterBOOT booter 3.24
RouterBoard 2011UiAS-2HnD
CPU frequency: 600 MHz
Memory speed: 200 MHz
Memory size: 128 MiB
NAND size: 128 MiB
Press any key within 2 seconds to enter setup..
loading kernel from nand... OK
setting up elf image... OK
jumping to kernel code
OpenWrt kernel loader for AR7XXX/AR9XXX
Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
Decompressing kernel... done!
Starting kernel at 80060000...
[ 0.000000] Linux version 4.9.120 (buildbot@builds-03.infra.lede-project.org) (gcc version 7.3.0 (OpenWrt GCC 7.3.0 r7101-a63e38b) ) #0 Wed Aug 15 20:42:39 2018
[ 0.000000] bootconsole [early0] enabled
[ 0.000000] CPU0 revision is: 0001974c (MIPS 74Kc)
[ 0.000000] SoC: Atheros AR9344 rev 3
[ 0.000000] Determined physical RAM map:
[ 0.000000] memory: 08000000 @ 00000000 (usable)
[ 0.000000] User-defined physical RAM map:
[ 0.000000] memory: 08000000 @ 00000000 (usable)
[ 0.000000] Initrd not found or empty - disabling initrd
[ 0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
[ 0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
[ 0.000000] Zone ranges:
[ 0.000000] Normal [mem 0x0000000000000000-0x0000000007ffffff]
[ 0.000000] Movable zone start for each node
[ 0.000000] Early memory node ranges
[ 0.000000] node 0: [mem 0x0000000000000000-0x0000000007ffffff]
[ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000007ffffff]
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 32512
[ 0.000000] Kernel command line: lcd_ctrl=84 parts=1 boot_part_size=4194304 gpio=249387 HZ=300000000 mem=128M kmac=E4:8D:8C:02:EE:7C board=2011r5 ver=3.24 hw_opt=00718004 boot=1 mlc=9 console=ttyS0,11d
[ 0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)
[ 0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
[ 0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
[ 0.000000] Writing ErrCtl register=00000000
[ 0.000000] Readback ErrCtl register=00000000
[ 0.000000] Memory: 124868K/131072K available (3578K kernel code, 153K rwdata, 452K rodata, 224K init, 217K bss, 6204K reserved, 0K cma-reserved)
[ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[ 0.000000] NR_IRQS:51
[ 0.000000] Clocks: CPU:600.000MHz, DDR:400.000MHz, AHB:400.000MHz, Ref:25.000MHz
[ 0.000000] clocksource: MIPS: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 6370868154 ns
[ 0.000009] sched_clock: 32 bits at 300MHz, resolution 3ns, wraps every 7158278654ns
[ 0.008867] Calibrating delay loop... 299.82 BogoMIPS (lpj=1499136)
[ 0.081948] pid_max: default: 32768 minimum: 301
[ 0.087298] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.094812] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.105739] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[ 0.116940] futex hash table entries: 256 (order: -1, 3072 bytes)
[ 0.125091] NET: Registered protocol family 16
[ 0.134953] MIPS: machine is Mikrotik RouterBOARD 2011UiAS-2HnD
[ 0.627475] Can't analyze schedule() prologue at 803dae54
[ 0.646724] clocksource: Switched to clocksource MIPS
[ 0.653535] NET: Registered protocol family 2
[ 0.659480] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.667448] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.674672] TCP: Hash tables configured (established 1024 bind 1024)
[ 0.681980] UDP hash table entries: 256 (order: 0, 4096 bytes)
[ 0.688648] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[ 0.696019] NET: Registered protocol family 1
[ 0.704805] Crashlog allocated RAM at address 0x3f00000
[ 0.711843] workingset: timestamp_bits=30 max_order=15 bucket_order=0
[ 0.726417] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[ 0.733078] jffs2: version 2.2 (NAND) (SUMMARY) (LZMA) (RTIME) (CMODE_PRIORITY) (c) 2001-2006 Red Hat, Inc.
[ 0.754200] io scheduler noop registered
[ 0.758700] io scheduler deadline registered (default)
[ 0.764949] Serial: 8250/16550 driver, 16 ports, IRQ sharing enabled
[ 0.774889] console [ttyS0] disabled
[ 0.799119] serial8250.0: ttyS0 at MMIO 0x18020000 (irq = 11, base_baud = 1562500) is a 16550A
[ 0.808919] console [ttyS0] enabled
[ 0.808919] console [ttyS0] enabled
[ 0.816467] bootconsole [early0] disabled
[ 0.816467] bootconsole [early0] disabled
[ 0.830970] m25p80 spi0.0: found w25x05, expected m25p80
[ 0.847601] m25p80 spi0.0: w25x05 (64 Kbytes)
[ 0.852559] Creating 4 MTD partitions on "spi0.0":
[ 0.857570] 0x000000000000-0x00000000c000 : "routerboot"
[ 0.864970] 0x00000000c000-0x00000000d000 : "hard_config"
[ 0.872604] 0x00000000d000-0x00000000e000 : "bios"
[ 0.879624] 0x00000000e000-0x00000000f000 : "soft_config"
[ 0.888614] nand: device found, Manufacturer ID: 0xef, Chip ID: 0xf1
[ 0.895183] nand: Winbond NAND 128MiB 3,3V 8-bit
[ 0.899991] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
[ 0.907866] Scanning device for bad blocks
[ 0.916234] random: fast init done
[ 0.968226] Creating 3 MTD partitions on "ar934x-nfc":
[ 0.973559] 0x000000000000-0x000000040000 : "booter"
[ 0.980625] 0x000000040000-0x000000400000 : "kernel"
[ 0.987944] 0x000000400000-0x000008000000 : "ubi"
[ 0.998496] libphy: Fixed MDIO Bus: probed
[ 1.015557] libphy: ag71xx_mdio: probed
[ 1.028550] switch0: Atheros AR8327 rev. 4 switch registered on ag71xx-mdio.0
[ 1.744981] libphy: ag71xx_mdio: probed
[ 2.378182] ag71xx ag71xx.0: connected to PHY at ag71xx-mdio.0:00 [uid=004dd034, driver=Atheros AR8216/AR8236/AR8316]
[ 2.389890] eth0: Atheros AG71xx at 0xb9000000, irq 4, mode:RGMII
[ 3.018492] ag71xx-mdio.1: Found an AR934X built-in switch
[ 3.070910] eth1: Atheros AG71xx at 0xba000000, irq 5, mode:GMII
[ 3.078515] NET: Registered protocol family 10
[ 3.086442] NET: Registered protocol family 17
[ 3.091155] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[ 3.104550] 8021q: 802.1Q VLAN Support v1.8
[ 3.112575] UBI: auto-attach mtd6
[ 3.116029] ubi0: attaching mtd6
[ 4.641675] ubi0: scanning is finished
[ 4.663350] ubi0: attached mtd6 (name "ubi", size 124 MiB)
[ 4.669078] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
[ 4.676178] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 512
[ 4.683108] ubi0: VID header offset: 512 (aligned 512), data offset: 2048
[ 4.690130] ubi0: good PEBs: 992, bad PEBs: 0, corrupted PEBs: 0
[ 4.696329] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128
[ 4.703797] ubi0: max/mean erase counter: 3/1, WL threshold: 4096, image sequence number: 248002651
[ 4.713149] ubi0: available PEBs: 0, total reserved PEBs: 992, PEBs reserved for bad PEB handling: 20
[ 4.722734] ubi0: background thread "ubi_bgt0d" started, PID 368
[ 4.730876] block ubiblock0_1: created from ubi0:1(rootfs)
[ 4.736551] ubiblock: device ubiblock0_1 (rootfs) set to be root filesystem
[ 4.753277] VFS: Mounted root (squashfs filesystem) readonly on device 254:0.
[ 4.761747] Freeing unused kernel memory: 224K
[ 4.766339] This architecture does not have kernel memory protection.
[ 5.414874] init: Console is alive
[ 5.418697] init: - watchdog -
[ 5.634778] random: crng init done
[ 6.342746] kmodloader: loading kernel modules from /etc/modules-boot.d/*
[ 6.408649] usbcore: registered new interface driver usbfs
[ 6.414406] usbcore: registered new interface driver hub
[ 6.420042] usbcore: registered new device driver usb
[ 6.430761] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 6.439123] ehci-platform: EHCI generic platform driver
[ 6.447275] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 6.454945] ohci-platform: OHCI generic platform driver
[ 6.461125] kmodloader: done loading kernel modules from /etc/modules-boot.d/*
[ 6.479066] init: - preinit -
[ 7.169208] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
Press the [f] key and hit [enter] to enter failsafe mode
Press the [1], [2], [3] or [4] key and hit [enter] to select the debug level
[ 8.178327] eth0: link up (1000Mbps/Full duplex)
[ 8.183302] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 10.410243] UBIFS (ubi0:2): default file-system created
[ 10.417116] UBIFS (ubi0:2): background thread "ubifs_bgt0_2" started, PID 436
[ 10.548467] UBIFS (ubi0:2): UBIFS: mounted UBI device 0, volume 2, name "rootfs_data"
[ 10.556569] UBIFS (ubi0:2): LEB size: 129024 bytes (126 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[ 10.566846] UBIFS (ubi0:2): FS size: 119218176 bytes (113 MiB, 924 LEBs), journal size 5935104 bytes (5 MiB, 46 LEBs)
[ 10.577810] UBIFS (ubi0:2): reserved for root: 4952683 bytes (4836 KiB)
[ 10.584650] UBIFS (ubi0:2): media format: w4/r0 (latest is w4/r0), UUID EEC5D716-1CC7-48AE-95AC-D0AFE17A9B01, small LPT model
[ 10.599244] mount_root: overlay filesystem has not been fully initialized yet
[ 10.607355] mount_root: switching to ubifs overlay
[ 10.638272] urandom-seed: Seed file not found (/etc/urandom.seed)
[ 10.743256] eth0: link down
[ 10.758327] procd: - early -
[ 10.761411] procd: - watchdog -
[ 11.482628] procd: - watchdog -
[ 11.486138] procd: - ubus -
[ 11.789793] procd: - init -
Please press Enter to activate this console.
[ 12.064223] kmodloader: loading kernel modules from /etc/modules.d/*
[ 12.075546] ip6_tables: (C) 2000-2006 Netfilter Core Team
[ 12.093812] Loading modules backported from Linux version wt-2017-11-01-0-gfe248fc2c180
[ 12.102142] Backport generated by backports.git v4.14-rc2-1-31-g86cf0e5d
[ 12.112117] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 12.126703] nf_conntrack version 0.5.0 (2048 buckets, 8192 max)
[ 12.205338] xt_time: kernel timezone is -0000
[ 12.271091] PPP generic driver version 2.4.2
[ 12.278016] NET: Registered protocol family 24
[ 12.341656] ieee80211 phy0: Atheros AR9340 Rev:3 mem=0xb8100000, irq=47
[ 12.380174] kmodloader: done loading kernel modules from /etc/modules.d/*
[ 29.131980] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 29.176970] eth0: link up (1000Mbps/Full duplex)
[ 29.184387] br-lan: port 1(eth0.1) entered blocking state
[ 29.190035] br-lan: port 1(eth0.1) entered disabled state
[ 29.196006] device eth0.1 entered promiscuous mode
[ 29.201003] device eth0 entered promiscuous mode
[ 29.234918] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 29.321727] br-lan: port 1(eth0.1) entered blocking state
[ 29.327368] br-lan: port 1(eth0.1) entered forwarding state
[ 29.333291] IPv6: ADDRCONF(NETDEV_UP): br-lan: link is not ready
[ 29.754417] IPv6: ADDRCONF(NETDEV_UP): eth1: link is not ready
[ 29.808548] br-lan: port 2(eth1.1) entered blocking state
[ 29.814143] br-lan: port 2(eth1.1) entered disabled state
[ 29.820177] device eth1.1 entered promiscuous mode
[ 29.825132] device eth1 entered promiscuous mode
[ 30.176817] IPv6: ADDRCONF(NETDEV_CHANGE): br-lan: link becomes ready