Hello Friends and Developers of OpenWRT,
I am using a TP-Link Archer C1200 v3 as reported by my router:
There is an image of Openwrt for TP-Link Archer C1200 v2
https://openwrt.org/toh/tp-link/archer_c1200_v2
So will this image work with my router C1200 v3?
No. Every model requires a bespoke firmware image. In general, you will probably brick your router if you install firmware that has been built for another model.
But that said,I don't even see an image for the v2, despite the fact that there is an entry in the table of hardware. It appears the neither of those devices (v2 or v3) is supported.
No. Can´t see any image...
It is rather freshly released device. Lets see whats inside without opening it.
Go to log section (last item in menus, like advanced, or service, set logging level to DEBUG/Maximum and restart the device, then go to same place and view thee log and copy to text editor (eg notepad++)
Search:
"Linux version" -> near it is SoC, CPU types and memory size, note them down
mtd -> copy all lines to asses size of permanent memory (numbers are hex, convert biggest to decimal and you have it)
ubi -> new partition scheme - if anything is there, copy all lines.
Post the 2-3 sections formatted </> nicely here.
Post a link where you would download firmware upgrades.
I think it is pretty much dead end (unless you want very poorly functioning wifi)
https://www.tp-link.com/mx/support/download/archer-c1200/v3/#Firmware (might be different story in different region)
3996992 0x3CFD40 Unix path: /home/hd2/C1200/21Nov2019_C1200v3_US/boards/model_brcm_bcm470x/sdk/linux-2.6.36-router-9.10.178.50/main/components/opensource/li
I have chosen Type=ALL, Level=ALL
It even does not show anything about the hardware parts, even no Linux version.
Download for Archer C1200 | TP-Link
It seems that I have to sell it and find a more secure one. 
Can you show the label blurring out barcodes and MAC address last 3 pieces and serial number and barcodes?
OK, it is same firmware as MX
Broadcom wifi is not well supported using opensource drivers, you may have better luck ad dd-wrt (router is not supported but has some perspective over there with broadcom drivers)
If you want to tinker around and make support happen as this far first owner of this device:
https://openwrt.org/docs/guide-developer/add.new.device
Hidden boot log hopefully can be retrieved from serial port to show device hardware, or to override and boot linux with initial ram disk from the network. word "signed" in firmware may mean OEM locked out any 3rd party code.
Firmware contains
fw-type:Cloud
fwup-ptn fs-uboot base 0x01000 size 0x29cf9
fwup-ptn os-image base 0x2acf9 size 0x1d8001
fwup-ptn file-system base 0x202cfa size 0xc3c001
fwup-ptn soft-version base 0xe3ecfb size 0x00059
fwup-ptn extra-para base 0xe3ed54 size 0x0000b
fwup-ptn support-list base 0xe3ed5f size 0x0011d
fwup-ptn profile base 0xe3ee7c size 0x02790
fwup-ptn default-config base 0xe4160c size 0x07da8
fwup-ptn qos-db base 0xe493b4 size 0x32071
fwup-ptn partition-table base 0x00800 size 0x00800
partition factory-boot base 0x00000 size 0x40000
partition fs-uboot base 0x40000 size 0x40000
partition os-image base 0x80000 size 0x200000
partition file-system base 0x280000 size 0xc80000
partition default-mac base 0xf00000 size 0x00200
partition pin base 0xf00200 size 0x00100
partition device-id base 0xf00300 size 0x00100
partition certificate base 0xf00400 size 0x0fc00
partition product-info base 0xf10000 size 0x06000
partition soft-version base 0xf16000 size 0x01000
partition extra-para base 0xf17000 size 0x01000
partition support-list base 0xf18000 size 0x08000
partition profile base 0xf20000 size 0x03000
partition default-config base 0xf23000 size 0x0d000
partition user-config base 0xf30000 size 0x40000
partition qos-db base 0xf70000 size 0x40000
partition partition-table base 0xfb0000 size 0x10000
partition log base 0xfc0000 size 0x20000
partition radio_bk base 0xfe0000 size 0x10000
partition radio base 0xff0000 size 0x10000
May help to find similar device from same tplink with same layout that has recipe to bypass eventual signature check.
Does it mean that I have to open the enclosure and find out the serial com port?
Hello Friend,
I have found this very detailed information of my current router.
Is there a chance to flash it with an existing OpenWRT firmware?
As noted by another user:
Feel free to flash at your own risk.
Spec says it is broadcom wifi, which does not work well , like with limited bandwidth etc.
If you relly want to make port the maximum achievable may not be generally very usable.
Then, I will choose a new MediaTek. Thanks for your information. 
