I don't think I have altered the art partition, but I could be wrong. From what I recall, I have only tried to write to mtd7 and 8. When I flash via tftp the stock firmware, I don't rewrite this partition?
I have noticed that cat /proc/mtd
output a different structure depending if I am on the stock firmware, ar71, ath79...
I haven't changed anything to the hardware.
Here is the output of dmesg on 18.06
root@OpenWrt:~# dmesg
[ 0.000000] Linux version 4.9.198 (buildbot@b87496cfc8a9) (gcc version 7.3.0 (OpenWrt GCC 7.3.0 r7897-9d401013fc) ) #0 Tue Nov 5 14:12:18 2019
[ 0.000000] bootconsole [early0] enabled
[ 0.000000] CPU0 revision is: 00019750 (MIPS 74Kc)
[ 0.000000] SoC: Qualcomm Atheros QCA9558 ver 1 rev 0
[ 0.000000] Determined physical RAM map:
[ 0.000000] memory: 10000000 @ 00000000 (usable)
[ 0.000000] User-defined physical RAM map:
[ 0.000000] memory: 10000000 @ 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 0x0000000000000000-0x000000000fffffff]
[ 0.000000] Movable zone start for each node
[ 0.000000] Early memory node ranges
[ 0.000000] node 0: [mem 0x0000000000000000-0x000000000fffffff]
[ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000000fffffff]
[ 0.000000] On node 0 totalpages: 65536
[ 0.000000] free_area_init_node: node 0, pgdat 80494a34, node_mem_map 81000020
[ 0.000000] Normal zone: 512 pages used for memmap
[ 0.000000] Normal zone: 0 pages reserved
[ 0.000000] Normal zone: 65536 pages, LIFO batch:15
[ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[ 0.000000] pcpu-alloc: [0] 0
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 65024
[ 0.000000] Kernel command line: board=NBG6716 console=ttyS0,115200 mtdparts=spi0.0:256k(u-boot)ro,64k(env)ro,64k(RFdata)ro,-(nbu);ar934x-nfc:2048k(zyxel_rfsd),2048k(romd),1024k(header),2048k(kernel),-(ubi) mem=256M ethaddr=B8:EC:A3:32:C5:04 rootfstype=squashfs noinitrd
[ 0.000000] PID hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
[ 0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
[ 0.000000] Writing ErrCtl register=00000000
[ 0.000000] Readback ErrCtl register=00000000
[ 0.000000] Memory: 254696K/262144K available (3684K kernel code, 167K rwdata, 460K rodata, 224K init, 209K bss, 7448K 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:720.000MHz, DDR:600.000MHz, AHB:200.000MHz, Ref:40.000MHz
[ 0.000000] clocksource: MIPS: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 5309056796 ns
[ 0.000008] sched_clock: 32 bits at 360MHz, resolution 2ns, wraps every 5965232126ns
[ 0.008300] Calibrating delay loop... 358.80 BogoMIPS (lpj=1794048)
[ 0.071187] pid_max: default: 32768 minimum: 301
[ 0.076187] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.083230] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.092961] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[ 0.103462] futex hash table entries: 256 (order: -1, 3072 bytes)
[ 0.110924] NET: Registered protocol family 16
[ 0.116866] MIPS: machine is Zyxel NBG6716
[ 0.166013] ar724x-pci ar724x-pci.0: PCIe link is down
[ 0.171480] registering PCI controller with io_map_base unset
[ 0.177702] registering PCI controller with io_map_base unset
[ 0.666095] PCI host bridge to bus 0000:00
[ 0.670501] pci_bus 0000:00: root bus resource [mem 0x10000000-0x11ffffff]
[ 0.677814] pci_bus 0000:00: root bus resource [io 0x0000]
[ 0.683744] pci_bus 0000:00: root bus resource [??? 0x00000000 flags 0x0]
[ 0.690961] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
[ 0.699405] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 00
[ 0.699518] PCI host bridge to bus 0000:01
[ 0.703874] pci_bus 0000:01: root bus resource [mem 0x12000000-0x13ffffff]
[ 0.711206] pci_bus 0000:01: root bus resource [io 0x0001]
[ 0.717126] pci_bus 0000:01: root bus resource [??? 0x00000000 flags 0x0]
[ 0.724349] pci_bus 0000:01: No busn resource found for root bus, will use [bus 01-ff]
[ 0.732797] pci 0000:01:00.0: [168c:003c] type 00 class 0x028000
[ 0.732835] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x001fffff 64bit]
[ 0.732887] pci 0000:01:00.0: reg 0x30: [mem 0x00000000-0x0000ffff pref]
[ 0.732954] pci 0000:01:00.0: supports D1
[ 0.732962] pci 0000:01:00.0: PME# supported from D0 D1 D3hot
[ 0.733135] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 01
[ 0.733155] pci 0000:01:00.0: BAR 0: assigned [mem 0x12000000-0x121fffff 64bit]
[ 0.740972] pci 0000:01:00.0: BAR 6: assigned [mem 0x12200000-0x1220ffff pref]
[ 0.748660] pci 0000:01:00.0: using irq 41 for pin 1
[ 0.756530] clocksource: Switched to clocksource MIPS
[ 0.762758] NET: Registered protocol family 2
[ 0.768178] TCP established hash table entries: 2048 (order: 1, 8192 bytes)
[ 0.775611] TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
[ 0.782432] TCP: Hash tables configured (established 2048 bind 2048)
[ 0.789270] UDP hash table entries: 256 (order: 0, 4096 bytes)
[ 0.795490] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[ 0.802384] NET: Registered protocol family 1
[ 0.807076] PCI: CLS 0 bytes, default 32
[ 0.809303] Crashlog allocated RAM at address 0x3f00000
[ 0.815731] workingset: timestamp_bits=30 max_order=16 bucket_order=0
[ 0.828341] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[ 0.834546] jffs2: version 2.2 (NAND) (SUMMARY) (LZMA) (RTIME) (CMODE_PRIORITY) (c) 2001-2006 Red Hat, Inc.
[ 0.852538] io scheduler noop registered
[ 0.856742] io scheduler deadline registered (default)
[ 0.862551] Serial: 8250/16550 driver, 16 ports, IRQ sharing enabled
[ 0.871519] console [ttyS0] disabled
[ 0.895396] serial8250.0: ttyS0 at MMIO 0x18020000 (irq = 11, base_baud = 2500000) is a 16550A
[ 0.904578] console [ttyS0] enabled
[ 0.911995] bootconsole [early0] disabled
[ 0.924964] m25p80 spi0.0: found mx25l3205d, expected m25p80
[ 0.931153] m25p80 spi0.0: mx25l3205d (4096 Kbytes)
[ 0.936127] 4 cmdlinepart partitions found on MTD device spi0.0
[ 0.942158] Creating 4 MTD partitions on "spi0.0":
[ 0.947029] 0x000000000000-0x000000040000 : "u-boot"
[ 0.953609] 0x000000040000-0x000000050000 : "env"
[ 0.960021] 0x000000050000-0x000000060000 : "RFdata"
[ 0.966702] 0x000000060000-0x000000400000 : "nbu"
[ 0.973875] nand: device found, Manufacturer ID: 0xad, Chip ID: 0xf1
[ 0.980352] nand: Hynix NAND 128MiB 3,3V 8-bit
[ 0.984862] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
[ 0.992578] Scanning device for bad blocks
[ 0.997027] Bad eraseblock 2 at 0x000000040000
[ 1.004458] random: fast init done
[ 1.088051] 5 cmdlinepart partitions found on MTD device ar934x-nfc
[ 1.094402] Creating 5 MTD partitions on "ar934x-nfc":
[ 1.099633] 0x000000000000-0x000000200000 : "zyxel_rfsd"
[ 1.106497] 0x000000200000-0x000000400000 : "romd"
[ 1.113015] 0x000000400000-0x000000500000 : "header"
[ 1.119695] 0x000000500000-0x000000700000 : "kernel"
[ 1.126355] 0x000000700000-0x000008000000 : "ubi"
[ 1.133770] libphy: Fixed MDIO Bus: probed
[ 1.144937] switch0: Atheros AR8337 rev. 2 switch registered on ag71xx-mdio.0
[ 1.834795] libphy: ag71xx_mdio: probed
[ 2.467923] ag71xx ag71xx.0: connected to PHY at ag71xx-mdio.0:00 [uid=004dd036, driver=Atheros AR8216/AR8236/AR8316]
[ 2.479275] eth0: Atheros AG71xx at 0xb9000000, irq 4, mode:RGMII
[ 3.108153] eth1: Atheros AG71xx at 0xba000000, irq 5, mode:SGMII
[ 3.116226] NET: Registered protocol family 10
[ 3.124477] NET: Registered protocol family 17
[ 3.129072] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[ 3.142308] 8021q: 802.1Q VLAN Support v1.8
[ 3.149789] UBI: auto-attach mtd8
[ 3.153171] ubi0: attaching mtd8
[ 3.192152] UBI: EOF marker found, PEBs from 25 will be erased
[ 3.198879] ubi0: scanning is finished
[ 3.238587] ubi0: volume 1 ("rootfs_data") re-sized from 9 to 921 LEBs
[ 3.245983] ubi0: attached mtd8 (name "ubi", size 121 MiB)
[ 3.251587] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes
[ 3.258570] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048
[ 3.265452] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096
[ 3.272518] ubi0: good PEBs: 968, bad PEBs: 0, corrupted PEBs: 0
[ 3.278615] ubi0: user volume: 2, internal volumes: 1, max. volumes count: 128
[ 3.285940] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 145950960
[ 3.295116] ubi0: available PEBs: 0, total reserved PEBs: 968, PEBs reserved for bad PEB handling: 20
[ 3.304505] ubi0: background thread "ubi_bgt0d" started, PID 351
[ 3.312995] block ubiblock0_0: created from ubi0:0(rootfs)
[ 3.318603] ubiblock: device ubiblock0_0 (rootfs) set to be root filesystem
[ 3.325664] hctosys: unable to open rtc device (rtc0)
[ 3.344503] VFS: Mounted root (squashfs filesystem) readonly on device 254:0.
[ 3.352564] Freeing unused kernel memory: 224K
[ 3.357100] This architecture does not have kernel memory protection.
[ 3.961601] init: Console is alive
[ 3.965229] init: - watchdog -
[ 4.796696] kmodloader: loading kernel modules from /etc/modules-boot.d/*
[ 4.844676] kmodloader: done loading kernel modules from /etc/modules-boot.d/*
[ 4.862540] init: - preinit -
[ 5.823102] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 5.864999] random: procd: uninitialized urandom read (4 bytes read)
[ 6.847961] eth0: link up (1000Mbps/Full duplex)
[ 6.852784] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 9.122632] UBIFS (ubi0:1): default file-system created
[ 9.129583] UBIFS (ubi0:1): background thread "ubifs_bgt0_1" started, PID 407
[ 9.368997] UBIFS (ubi0:1): UBIFS: mounted UBI device 0, volume 1, name "rootfs_data"
[ 9.376988] UBIFS (ubi0:1): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[ 9.387055] UBIFS (ubi0:1): FS size: 115548160 bytes (110 MiB, 910 LEBs), journal size 5840896 bytes (5 MiB, 46 LEBs)
[ 9.397819] UBIFS (ubi0:1): reserved for root: 4952683 bytes (4836 KiB)
[ 9.404530] UBIFS (ubi0:1): media format: w4/r0 (latest is w4/r0), UUID 1FFA07CE-2321-423A-9754-FBBF417FA518, small LPT model
[ 9.418800] mount_root: overlay filesystem has not been fully initialized yet
[ 9.426607] mount_root: switching to ubifs overlay
[ 9.450934] urandom-seed: Seed file not found (/etc/urandom.seed)
[ 9.548068] eth0: link down
[ 9.560653] procd: - early -
[ 9.563653] procd: - watchdog -
[ 10.176393] procd: - watchdog -
[ 10.179814] procd: - ubus -
[ 10.255715] random: ubusd: uninitialized urandom read (4 bytes read)
[ 10.284714] random: ubusd: uninitialized urandom read (4 bytes read)
[ 10.291592] random: ubusd: uninitialized urandom read (4 bytes read)
[ 10.298835] procd: - init -
[ 10.623850] kmodloader: loading kernel modules from /etc/modules.d/*
[ 10.655290] ip6_tables: (C) 2000-2006 Netfilter Core Team
[ 10.668224] i2c /dev entries driver
[ 10.674785] Loading modules backported from Linux version wt-2017-11-01-0-gfe248fc2c180
[ 10.682948] Backport generated by backports.git v4.14-rc2-1-31-g86cf0e5d
[ 10.692053] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 10.704229] nf_conntrack version 0.5.0 (4096 buckets, 16384 max)
[ 10.752458] xt_time: kernel timezone is -0000
[ 10.921721] PPP generic driver version 2.4.2
[ 10.928053] NET: Registered protocol family 24
[ 10.950459] PCI: Enabling device 0000:01:00.0 (0000 -> 0002)
[ 10.956360] ath10k_pci 0000:01:00.0: pci irq legacy oper_irq_mode 1 irq_mode 0 reset_mode 0
[ 11.229830] ath10k_pci 0000:01:00.0: Direct firmware load for ath10k/pre-cal-pci-0000:01:00.0.bin failed with error -2
[ 11.240713] ath10k_pci 0000:01:00.0: Falling back to user helper
[ 11.411009] firmware ath10k!pre-cal-pci-0000:01:00.0.bin: firmware_loading_store: map pages failed
[ 11.420352] ath10k_pci 0000:01:00.0: Direct firmware load for ath10k/cal-pci-0000:01:00.0.bin failed with error -2
[ 11.430878] ath10k_pci 0000:01:00.0: Falling back to user helper
[ 11.636389] ath10k_pci 0000:01:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/firmware-6.bin failed with error -2
[ 11.647281] ath10k_pci 0000:01:00.0: Falling back to user helper
[ 11.739705] firmware ath10k!QCA988X!hw2.0!firmware-6.bin: firmware_loading_store: map pages failed
[ 11.753107] ath10k_pci 0000:01:00.0: qca988x hw2.0 target 0x4100016c chip_id 0x043202ff sub 0000:0000
[ 11.762504] ath10k_pci 0000:01:00.0: kconfig debug 0 debugfs 1 tracing 0 dfs 1 testmode 1
[ 11.775546] ath10k_pci 0000:01:00.0: firmware ver 10.2.4-1.0-00037 api 5 features no-p2p,raw-mode,mfp,allows-mesh-bcast crc32 a4a52adb
[ 11.871826] ath10k_pci 0000:01:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/board-2.bin failed with error -2
[ 11.882461] ath10k_pci 0000:01:00.0: Falling back to user helper
[ 11.955231] firmware ath10k!QCA988X!hw2.0!board-2.bin: firmware_loading_store: map pages failed
[ 11.985853] ath10k_pci 0000:01:00.0: board_file api 1 bmi_id N/A crc32 bebc7c08
[ 13.097932] ath10k_pci 0000:01:00.0: htt-ver 2.1 wmi-op 5 htt-op 2 cal file max-sta 128 raw 0 hwcrypto 1
[ 13.237761] ath: EEPROM regdomain: 0x0
[ 13.237767] ath: EEPROM indicates default country code should be used
[ 13.237770] ath: doing EEPROM country->regdmn map search
[ 13.237782] ath: country maps to regdmn code: 0x3a
[ 13.237786] ath: Country alpha2 being used: US
[ 13.237789] ath: Regpair used: 0x3a
[ 13.291417] ath: EEPROM regdomain: 0x0
[ 13.291424] ath: EEPROM indicates default country code should be used
[ 13.291427] ath: doing EEPROM country->regdmn map search
[ 13.291439] ath: country maps to regdmn code: 0x3a
[ 13.291443] ath: Country alpha2 being used: US
[ 13.291446] ath: Regpair used: 0x3a
[ 13.307422] ieee80211 phy1: Selected rate control algorithm 'minstrel_ht'
[ 13.310537] ieee80211 phy1: Atheros AR9550 Rev:0 mem=0xb8100000, irq=47
[ 13.389159] kmodloader: done loading kernel modules from /etc/modules.d/*
[ 14.672810] urandom_read: 5 callbacks suppressed
[ 14.672817] random: jshn: uninitialized urandom read (4 bytes read)
[ 15.989655] random: crng init done
[ 27.517661] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 27.525139] eth0: link up (1000Mbps/Full duplex)
[ 27.556598] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 27.568998] br-lan: port 1(eth0.1) entered blocking state
[ 27.574485] br-lan: port 1(eth0.1) entered disabled state
[ 27.580332] device eth0.1 entered promiscuous mode
[ 27.585191] device eth0 entered promiscuous mode
[ 27.682764] br-lan: port 1(eth0.1) entered blocking state
[ 27.688287] br-lan: port 1(eth0.1) entered forwarding state
[ 27.694063] IPv6: ADDRCONF(NETDEV_UP): br-lan: link is not ready
[ 27.799286] eth1: link up (1000Mbps/Full duplex)
[ 28.526701] IPv6: ADDRCONF(NETDEV_CHANGE): br-lan: link becomes ready