Yes, the top side (ie furthest away from CPU) of R252 has

Infinity between it and TX pad
4920 ohm between it and RX pad
230 ohm between it and GND pad
just above 0 ohm between it and 3.3v pad

All with board powered off and all external cables to USB/TTL disconnected

O.K, managed to get in. Some documentation says initial boot sequence in u-boot is at 9600 changing to 115200 once the kernel starts to load and to enter tpl while in 9600 to stop the boot sequence

It it isn't at 9600  (at least not on the WR941ND v3.8) the whole sequence is at 115200, I cannot see anything at 9600 at any point in the boot sequence

So next problem is although I can tftp the openwrt-ar71xx-tl-wr941nd-v3-initramfs-uImage.bin file and get to the root@OpenWrt:/# prompt, and can ftp the stock firmware over, I can't write to any partitions (because there aren't any!), see below

root@OpenWrt:/# cd tmp
root@OpenWrt:/tmp#
root@OpenWrt:/tmp# wget ftp://192.168.1.169:21/wr941nv3_en_3_13_9_up.bin ftp://192.168.1.169:21/wr941nv3_en_3_13_9_up.bin
Connecting to 192.168.1.169:21 (192.168.1.169:21)

wr941nv3_en_3_13_9_u   0% |                               |     0  --:--:-- ETA
wr941nv3_en_3_13_9_u 100% |*******************************|  3840k --:--:-- ETA
root@OpenWrt:/tmp#
root@OpenWrt:/tmp# mtd write wr941nv3_en_3_13_9_up.bin firmware
Could not open mtd device: firmware
Can't open device for writing!
root@OpenWrt:/tmp#
root@OpenWrt:/tmp# cat /proc/mtd
dev:    size   erasesize  name
root@OpenWrt:/tmp#

Once again any help gratefully received

well that documentation of 9600 baud i think was for really old board revisions or maybe even V1.X ...

i have not understood what was not working with your serial setup!

i think the flash is not detected, post full dmesg!

also, you usually write images to flash from uboot prompt, not from a running initramfs image!

BTW, if you want mail me maybe we can do some tests...

(Last edited by nebbia88 on 26 Aug 2013, 22:56)

Serial set up was with one of my USB/TTL convertors the voltage on the cable connecting the TX from Router to RX on USB/TTL convertor was 1.3v (or 1v with the router switched off), the pull-up resistor would bring it up to 3.3v, but made no difference. The voltage the other way (i.e TX on USB/TTL to RX on Router) was 3.3v

Using the other USB/TTL convertor the voltage was 3.3v both ways. This one worked. So something weird with the first USB/TTL convertor.

So no need for the pull-up resistor

Will post dmesg shortly

Thanks for the email offer, but lets keep it in the thread. I think it very useful for others in the future to be able to search for WR941ND v3.8 and see what problems and resolutions people have had. I've certainly found it very useful to learn from others

(Last edited by larcy on 27 Aug 2013, 06:20)

ok, that was trying to speed up the resolution process, obviously when we find that everything useful will be posted...

dmesg
Linux version 2.6.32.27 (bencoh@procyon) (gcc version 4.3.3 (GCC) ) #3 Sun Mar 4 17:37:54 CET 2012
prom: fw_arg0=00000007, fw_arg1=a1f87fb0, fw_arg2=a1f88450, fw_arg3=00000004
MyLoader: sysp=5487bbd2, boardp=ef7fb42c, parts=392bb77a
bootconsole [early0] enabled
CPU revision is: 00019374 (MIPS 24Kc)
Atheros AR9132 rev 2, CPU:400.000 MHz, AHB:100.000 MHz, DDR:400.000 MHz
Determined physical RAM map:
memory: 02000000 @ 00000000 (usable)
Initrd not found or empty - disabling initrd
Zone PFN ranges:
  Normal   0x00000000 -> 0x00002000
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
    0: 0x00000000 -> 0x00002000
On node 0 totalpages: 8192
free_area_init_node: node 0, pgdat 802c80c0, node_mem_map 81000000
  Normal zone: 64 pages used for memmap
  Normal zone: 0 pages reserved
  Normal zone: 8128 pages, LIFO batch:0
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 8128
Kernel command line: rootfstype=squashfs,yaffs,jffs2 noinitrd console=ttyS0,115200 board=TL-WR941ND
PID hash table entries: 128 (order: -3, 512 bytes)
Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
Writing ErrCtl register=00000000
Readback ErrCtl register=00000000
Memory: 27964k/32768k available (2062k kernel code, 4804k reserved, 404k data, 1552k init, 0k highmem)
SLUB: Genslabs=7, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Hierarchical RCU implementation.
NR_IRQS:56
Calibrating delay loop... 266.24 BogoMIPS (lpj=1331200)
Mount-cache hash table entries: 512
NET: Registered protocol family 16
MIPS: machine is TP-LINK TL-WR941ND
bio: create slab <bio-0> at 0
Switching to clocksource MIPS
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 1024 (order: 1, 8192 bytes)
TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
TCP: Hash tables configured (established 1024 bind 1024)
TCP reno registered
NET: Registered protocol family 1
squashfs: version 4.0 (2009/01/31) Phillip Lougher
Registering mini_fo version $Id$
JFFS2 version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
yaffs Mar  4 2012 02:46:30 Installing.
msgmni has been set to 54
io scheduler noop registered
io scheduler deadline registered (default)
Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0x18020000 (irq = 11) is a 16550A
console [ttyS0] enabled, bootconsole disabled
Atheros AR71xx SPI Controller driver version 0.2.4
m25p80 spi0.0: unrecognized JEDEC id 1c3016
ag71xx_mdio: probed
eth0: Atheros AG71xx at 0xb9000000, irq 4
eth0: using fixed link parameters
Atheros AR71xx hardware watchdog driver version 0.1.0
ar71xx-wdt: timeout=15 secs (max=42)
TCP westwood registered
NET: Registered protocol family 17
Distributed Switch Architecture driver version 0.1
ar7240_dsa: unsupported chip, ctrl=ffffffff
eth0[0]: detected a Marvell 88E6060 switch
dsa slave smi: probed
802.1Q VLAN Support v1.8 Ben Greear <greearb@candelatech.com>
All bugs added by David S. Miller <davem@redhat.com>
Freeing unused kernel memory: 1552k freed
input: gpio-buttons as /devices/platform/gpio-buttons/input/input0
Button Hotplug driver version 0.3.1
ar71xx: pll_reg 0xb8050014: 0x13000a44
eth0: link up (100Mbps/Full duplex)
Registered led device: tl-wr941nd:green:system
Registered led device: tl-wr941nd:red:qss
Registered led device: tl-wr941nd:green:qss
Registered led device: tl-wr941nd:green:wlan
eth0: link down
ar71xx: pll_reg 0xb8050014: 0x13000a44
eth0: link up (100Mbps/Full duplex)
device lan1 entered promiscuous mode
device eth0 entered promiscuous mode
lan1: link up, 100 Mb/s, full duplex, flow control disabled
br-lan: port 1(lan1) entering forwarding state
device lan2 entered promiscuous mode
device lan3 entered promiscuous mode
device lan4 entered promiscuous mode
Compat-wireless backport release: compat-wireless-2011-11-29
Backport based on wireless-testing.git master-2011-12-01
cfg80211: Calling CRDA to update world regulatory domain
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
cfg80211: World regulatory domain updated:
cfg80211:     (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
cfg80211:     (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:     (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211:     (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211:     (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:     (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
ath: EEPROM regdomain: 0x0
ath: EEPROM indicates default country code should be used
ath: doing EEPROM country->regdmn map search
ath: country maps to regdmn code: 0x3a
ath: Country alpha2 being used: US
ath: Regpair used: 0x3a
ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
ieee80211 phy0: Atheros AR9100 MAC/BB Rev:7 AR2133 RF Rev:a2 mem=0xb80c0000, irq=2
cfg80211: Calling CRDA for country: US
PPP generic driver version 2.4.2
ip_tables: (C) 2000-2006 Netfilter Core Team
cfg80211: Regulatory domain changed to country: US
cfg80211:     (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
cfg80211:     (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2700 mBm)
cfg80211:     (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 1700 mBm)
cfg80211:     (5250000 KHz - 5330000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:     (5490000 KHz - 5600000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:     (5650000 KHz - 5710000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211:     (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 3000 mBm)
NET: Registered protocol family 24
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
nf_conntrack version 0.5.0 (461 buckets, 1844 max)
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ar71xx-wdt: enabling watchdog timer
root@OpenWrt:/tmp#

unrecognized flash chip.. as I suspected..

same here during initial support:

https://forum.openwrt.org/viewtopic.php … 56#p179356

what i DO NOT GET is why a flash chip is supported in a model and unsupported in another!

looking at the "mach-xxx" files under target/linux/ar71xx/files/arch/mips/ath79 i cannot see differences in m25p80-related instructions

maybe what makes difference is the m25p80 "version", i mean at some time the support for newer flash has been added...

where did you find that image? kernel 2.6.32.27 it's really old!

try to flash AA final:

http://downloads.openwrt.org/attitude_a … actory.bin

(Last edited by nebbia88 on 27 Aug 2013, 08:36)

Well at least we've learnt then that there is a difference between v3.8 and v3.6 (and I suspect it's worse, the reason I got here in the first place was trying to put the same gargoyle image that happily runs on a v3.6 board on the v3.8 board)

How should I flash AA final, via TFTP? using similar instructions to below, and if so what size and what from address?

ar7100> setenv serverip 192.168.1.254; setenv ipaddr 192.168.1.1
ar7100> tftp 0x80800000 openwrt-ar71xx-tl-wr941ndv2-squashfs.sysupgrade.bin
ar7100> erase.b 0xbf020000 +0x3c0000
ar7100> cp.b 0x80800000 0xbf020000 0x3c0000
ar7100> reset

Actually don't worry, just did a quick check that those values seemed o.k myself and went for it, seems to have worked o.k and am now in openwrt webgui. Will play a bit and report back

What was the issue with the flash chip?, I mean why did it work that way, but not the way I was trying, old image that didn't support that chip for some reason?

yes, support for that flash chip was added later than when your image has been build... BTW where did you get it from?

also, you were talking about gargoyle initially, if you flash 1.5.10 it should work correctly since it's based on AA final, the same revision you installed now

BTW, why did you use wr941ndv2 instead of v3??

I added this version on wiki, seems ok to you?

http://wiki.openwrt.org/toh/tp-link/tl- … d.versions

(Last edited by nebbia88 on 27 Aug 2013, 10:04)

Gargoyle 1.5.10  is now on that router, but not working correctly (no SID being broadcast). 1.4.7 works correctly. But that a gargoyle issue

I didn't use ndv2, that was just the example instructions from the wiki I copied and pasted, used nd-v3

The image was one I used to recover another router a while back, I still had it in a directory with instructions, can't remember where I got it from, it would be been from the open-wrt wiki or forum somewhere.