Support for TP-LINK Archer C7 v5 (RU)

Hi everyone,

Recently I've upgraded to a TP-LINK Archer C7 v5 router, but didn't manage to flash OpenWrt neither through web UI nor through TFTP at first.
After connecting to it's serial port I see that firmware update with TFTP method fails with the product id verify fail! error (without connecting to serial port you can see that router reboots almost immediately after downloading ArcherC7v5_tp_recovery.bin). A bit of research later I figured out that I have a RU version router which has a different special_id and it's not included neither in 18.06.1 nor in snapshot version of OpenWrt (as of today). Adding it makes TFTP flash method work as usual.

This is not a descriptive tutorial, because essentially this is a "Using the Image Builder" procedure with a small temporarily (I believe) workaround.
I assume that this workaround works only for RU version routers because of different special_id, so if you have a EU/US version this won't help you.

So what I did:

  1. Downloaded 18.06.1 OpenWrt Image Builder for ar71xx
  2. Opened staging_dir/host/bin/.tplink-safeloader.bin with a HEX editor
  3. Found one place with {product_name:Archer C7,product_ver:5.0.0,special_id:55530000} line and replaced 5553 with 5255.
  4. Proceeded with building process according to "Using the Image Builder" docs (https://openwrt.org/docs/guide-user/additional-software/imagebuilder)
  5. Renamed freshly built factory image to ArcherC7v5_tp_recovery.bin and flashed it successfully using TFTP method (didn't test other methods)

Notes after installation:

  • 802.11ac refuses to work occasionally when I tried to use 80MHz autochannel config (e.g. giving iw dev wlan0 scan responds with command failed: Resource busy (-16)). Using fixed channel 149 and 80MHz bandwith resolves my problem (country code: UA), other solutions may be avaialble.
  • LED configuration is missing, can be added manually.
  • USB works, checked with a RTL SDR dongle.
  • Quick speed tests: >900Mbps at LAN (file transfer via Ethernet), ~130Mbps at 802.11ac (one-time iperf test between PC and smartphone), >90Mbps at WAN (speedtest app on smartphone).

No other issues found, router is working perfectly fine for more than a week, so I didn't bother taking a deeper look at everything.
But I hope my post will help someone who might stuck unable to flash RU version these days. Also I hope that one of the following releases will include support for this router so usual flashing methods will work instead of doing this workaround.

Once the new release will be available, I'll check if the workaround is still needed.

6 Likes

Great investigation and analysis . Hopefully someone familiar with the archer family can suggest how to merge support for this. Sounds like it might be achievable as a different hardware “version” perhaps

Very helpful, thanks

Hi, I've got C7(US) V5. I received it with Openwrt installed from my ISP.
I wanted to reflash it as I did not want to use unknown device which I don't have access.
When tried to do I did it via UART. I tried to flash
openwrt-18.06.1-ar71xx-generic-archer-c7-v5-squashfs-factory.bin

My logs


Request for: /
Request for: /
Data will be downloaded at 0x80060000 in RAM
Upgrade type: firmware
Upload file size: 3997406 bytes
Loading: #######################################
         #######################################
         #######################################
         ###################################

Firmware Recovery file length : 3997406

Firmware process common.

Image verify OK!

Firmware file Verify ok!

product-info:product_name:Archer C7
product_ver:5.0.0
special_id:55530000

[Error]sysmgr_cfg_checkSupportList(): 1023 @ specialId 00000000 NOT Match.

Firmware supports, check OK.

Firmware Recovery check ok!

upgrade_filecheck ok
HTTP upload is done! Upgrading...
do http upgrade
Firmware Recovery file length : 3997406

Firmware process common.

Image verify OK!

Firmware file Verify ok!

product-info:product_name:Archer C7
product_ver:5.0.0
special_id:55530000

[Error]sysmgr_cfg_checkSupportList(): 1023 @ specialId 00000000 NOT Match.

when I tried to flash TP-Link original firmware(Archer C7(US)_V5_180425) I received this

Hit any key to stop autoboot:  0
Trying eth0
eth0 link down
FAIL
Trying eth0
dup 1 speed 1000
HTTP server is starting at IP: 192.168.0.1
HTTP server is ready!

Request for: /cgi-bin/luci
## Error: request file name not suport!
Request for: /cgi-bin/luci
## Error: request file name not suport!
Request for: /cgi-bin/luci
## Error: request file name not suport!
Request for: /
Data will be downloaded at 0x80060000 in RAM
Upgrade type: firmware
Upload file size: 15504354 bytes
Loading: #######################################
         #######################################
removed bunch of similar rows
         #######################################
         #######################################
         #####################################

Firmware Recovery file length : 15504354

Firmware process id 2.

handle_fw_cloud 146

Image verify OK!

Firmware file Verify ok!

product-info:product_name:Archer C7
product_ver:5.0.0
special_id:55530000

[Error]sysmgr_cfg_checkSupportList(): 1023 @ specialId 45550000 NOT Match.

Firmware supports, check OK.

Firmware Recovery check ok!

upgrade_filecheck ok
HTTP upload is done! Upgrading...
do http upgrade
Firmware Recovery file length : 15504354

Firmware process id 2.

handle_fw_cloud 146

Image verify OK!

Firmware file Verify ok!

product-info:product_name:Archer C7
product_ver:5.0.0
special_id:55530000

[Error]sysmgr_cfg_checkSupportList(): 1023 @ specialId 45550000 NOT Match.

What should I do to flash it?

  1. Maybe read the first posting of this topic? It is confirmed to be working.

  2. Wait until the patch has been implemented, and then flash a snapshot image.

Update: had a chance to install OpenWrt 19.07.2 for this router through factory web UI, everything works fine. I'm glad to inform that this workaround is not needed anymore.

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