There is a new TP-Link WR740N V6 now available. Just bought one today and it says V6 on the label. It has a new longer Antenna on the outside. Still uses 5 V DC adapter. Internally it uses a new Chip QCA-9533-BL3A. The memory chip is Zentel A3S56D40GTP - 50L. I guess it is 4 MB since the original firmware image is 3.8 MB in size.

Any chance on this getting supported with Openwrt. Please tell me what more information can I provide for the developers to make this happen. Will be glad to help.

If you can check the hardware details and compare it to the EU v5, and it looks identical on the important points, I could build you a test image to see if that works (you need to be able to flash again through TFTP and the likes if stuff goes wrong).

Sometimes those new versions tend to work with nothing more than a change in the firmware header.

Thanks for your support. It will be great if you could build the test image. I could not find an older v5 PCB to compare but the components do look the same. The Antenna design is a little changed externally.

Internally, the PCB design for V6 is a little changed. RAM is still 32MB, ROM is 4MB Winbond Chip 25032FVSIG and SoC is AR 9533-BL3A. It also runs on the same 5V. There is a new Dual Color Internet Globe LED that changes color from Orange (Not connected) to Green (When Internet is connected).. Rest is the same.

I believe the AR 9533 is already supported in the WR841N model , I guess they started using the same for 740N v6 now.

What other information can I provide to you, so that you have all the information you need to build the test image.

I also discovered that I can reload the original firmware using the hidden tftp method thats present on tplink routers. So I guess I can try the image you build without any risks of bricking the router. 

Thanks a lot for your help

(Last edited by traveler on 8 Apr 2016, 17:51)

That's good to hear. I have whipped up a 15.05.1 image which you can find here. If my domain does not resolve, try with e.g. Google DNS or OpenDNS servers.

If my assumptions are right this image should boot on your device. If the WAN LED you're talking about does not function, however, you need to 'poke at the GPIOs' like I was told in #openwrt to find out what GPIO handles the new LED, which we can then add to the OpenWrt code. I haven't done that myself yet (I just tested a bit though) - you can find info on hat here.

You first need to export the GPIOs, this e.g. will try to do this for GPIOs 0 through 30. Judging from the code for the TL-WR740N, that should be enough to start with:

for I in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30; do echo $I ; echo $I > /sys/class/gpio/export ; done

This should give you new files in /sys/class/gpio, like this:

root@OpenWrt:~# ls /sys/class/gpio/
export     gpio10     gpio12     gpio13     gpio14     gpio15     gpio9      gpiochip0  unexport

Maybe someone else can help out on how to proceed further, to probe those. I guess you'd need to try the other commands from the Elinux page and watch how the LEDs (or the device) reacts to it.

(Last edited by Borromini on 12 Apr 2016, 23:02)

Thanks for the image. I tried the factory image just now, unfortunately it bricked the router. I was nevertheless able to restore the original firmware successfully and it got unbricked.

Post the flash the router reboots and then I have the power LED and the LAN Port LED number 1, 2 and 3 light up and stay solid. The WAN or the System LED (Lock Icon) do not turn on at all. I tried it twice and both times it resulted in the same result. Wireshark shows no packets either on the WAN or LAN ports, just totally silent.

However the good news is that restoring it to original firmware is a breeze so there is no risk of bricking. Would appreciate if you can help me debug this issue. Hopefully we should have a working ROM for this model soon

I'm not sure how to proceed at this point. I think a bootlog might help, but I don't have the skills myself for what might be needed - all this image had is a version bump from v5 to v6 in its header.

(Last edited by Borromini on 9 Apr 2016, 12:16)

Thanks for your help in any case. Apparently there is something different in this version that requires more than the header change. I will keep the thread alive and ask for help from the community.

Looking for some help to get the 740N V6 supported with Openwrt.  I have the device and am willing to risk it being bricked. Please advise how to get this supported. Openwrt Guru's need your help with this.

This might help: https://wiki.openwrt.org/doc/devel/add.new.device

Yes, I saw that already, thanks for pointing it out. I guess the steps listed there would be useful if the device already booted with Openwrt. I can't find GPIO information etc that is mentioned without first getting into the shell and I wont get a shell without first running Openwrt on it

Borromini, can you help me to modify the header for the TP-Link 841N v10 image. That model has the exact same SoC chip , RAM and Flash. I was discussing this on the openwrt irc channel and someone suggested that if the hardware is identical then I should try flashing the image for WR841N V10. Can you help me modify the header for that image so that it can be flashed on WR740N V6.

Here is the link for the 841N V10 image.... https://downloads.openwrt.org/chaos_cal … actory.bin

Thanks a lot for all your help.

Okay I got it working !!

Here is what I did to make it work.

Take the TL-WR841N Version 10 Openwrt factory image. Edit the header to reflect 740N V6 and change the checksum to the new value. Then flash through TFTP. The 740N V6 router downlaods the image, reboots and works perfectly. I can access Luci. Wifi is working so are the LED's and the LAN ports.

This hopefully confirms that the TL-WR740N V6 has the same hardware as the 841N V10. I will request the Dev team to please add support for the TL-WR740N V6 in the proper fashion since it already is present in the 841N V10 tree.

That's great to hear! I actually just wrote up a patch... Can you check it? Basically, it builds off the TL-WR841N v10 settings, then sets your hardware ID to the 740 v6, just like you did manually.

If you're not familiar with git and the mailing list I can commit it for you if you wish (of course, with proper credits). Let me know.

Patch for 15.05.1:

From 17630cf241436474d4431a54f9c4c81944b5231c Mon Sep 17 00:00:00 2001
From: Stijn Segers <francesco.borromini@inventati.org>
Date: Sat, 9 Apr 2016 17:30:22 +0200
Subject: [PATCH] ar71xx: Add TP-Link TL-WR740N v6 support

---
 target/linux/ar71xx/image/Makefile | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/target/linux/ar71xx/image/Makefile b/target/linux/ar71xx/image/Makefile
index 80adedb..fc6fbfd 100644
--- a/target/linux/ar71xx/image/Makefile
+++ b/target/linux/ar71xx/image/Makefile
@@ -509,6 +509,13 @@ define Device/tl-wr740n-v5
     CONSOLE := ttyATH0,115200
 endef
 
+define Device/tl-wr740n-v6
+    $(Device/tplink-4mlzma)
+    BOARDNAME := TL-WR841N-v9
+    DEVICE_PROFILE := TLWR740
+    TPLINK_HWID := 0x07400006
+endef
+
 define Device/tl-wr741nd-v1
     $(Device/tplink-4m)
     BOARDNAME := TL-WR741ND
@@ -546,7 +553,7 @@ define Device/tl-wr743nd-v2
     TPLINK_HWID := 0x07430002
     CONSOLE := ttyATH0,115200
 endef
-TARGET_DEVICES += tl-wr740n-v4 tl-wr740n-v5 tl-wr741nd-v1 tl-wr741nd-v2 tl-wr741nd-v4 tl-wr741nd-v5 tl-wr743nd-v2
+TARGET_DEVICES += tl-wr740n-v4 tl-wr740n-v5 tl-wr740n-v6 tl-wr741nd-v1 tl-wr741nd-v2 tl-wr741nd-v4 tl-wr741nd-v5 tl-wr743nd-v2
 
 define Device/tl-wr841-v8
     $(Device/tplink-4mlzma)
-- 
2.1.4

(Last edited by Borromini on 11 Apr 2016, 17:24)

Thanks a lot Borromini, yes please commit the patch. I am still not signed up for the Openwrt Development and it will be quicker if you do it and thanks for offering to mention me in the credits

Hopefully it should be available soon in the Image Generator also, as I need to modify some packages before I roll out my custom image...

Thanks a lot for all your help. Do send me a link to the commit once you do it .

Okay. To be on the safe side, though, I will build an image with this patch for you to test so we can be a 100% sure it's functional. Will only be tomorrow evening at the earliest though.

If you give me your name I'll mention you in the patch (if you'd rather not then I'll just mention your nick).

Sure, that is a good idea. I will test the image once you send me the link. You can mention my nick

Thanks

(Last edited by traveler on 9 Apr 2016, 20:05)

Is there a way to add this as a Device Profile to the 15.05.1 Image Builder package. I wanted to use the Image Builder to generate a custom image for me and I wanted to do this today

I think the best way to go about this is generate the image you want off a stock TL-WR841N v10 image, then hex edit the header again, like you did.

On second thought , you can just mention my nick when you submit the patch.

Okay. I have built new 15.05.1 images with an adapted patch. Could you try this for me?

Still the same link.

Thanks for your help. The image is perfect. Flashed it through Stock Firmware Upgrade option on the TP-Link WR740N V6 and it successfully flashed and booted back into OpenWRT. All functions seem to be working fine too. I guess we have a successful port.

That's great to hear. A final check: can you tell me which SVN revision is reported on the LuCI login page? Should be 49118. Just to make sure we're not looking at your previous 15.05 install .

Your image was installed on a brand new TP-Link 740v6 after downloading the image you sent, and it was done from a different PC. You can be sure that it was the image you sent cause my images have a preset password and are customized. Whereas yours was the default Access Point and had no password.

I have already sent the routers I had for installation so we will have to wait till I get another v6. But rest assured it was 100% your image that I tested.

Sorry, just wanted to be sure

Patches:

• trunk

• 15.05.1

Thanks a lot for your help. Hopefully lot of people will benefit for this in the coming days. My V6 routers are already working in production flawlessly. Have 5 of them already doing duty out in the field.