Trying to install OpenWRT in unknown Chinese router

[soldar]

I know this is a shot in the dark but here goes.

I have a Chinese router, TP-Link TL-WR2041R which I would like to install OpenWRT but I find no support in their website. It is Chinese and totally unknown. I would think it has a double for export but I cannot know.

I cannot find reliable specs but looking at the board I see

Qualcomm QCA9558-AT4A which I believe is a "router on a chip" including WiFi

M13S5121632A-5TG
8M x 16 Bit x 4 Banks
32M X 16 DDR DRAM, 0.7 ns, PDSO66
Elite Semiconductor Memory Technology, Inc.

And another small chip I can hardly read but I suppose may be the flash memory.

If I go to the http GUI everything is OK (in Chinese)

If I try to SSH the connection is rejected.

The board has 4 holes for a 4 pin serial jtag interface.

Is there a simple way to determine the size of flash memory?

Maybe there is a way with a photo of the board to find a twin?

Is there some simple "universal" OpenWRT or even just basic Linux that I could install and would allow me to peek around and determine the HW configuration?

What is the best way to "attack" this router? It's been in a box for years and I have no other use for it so I do not mind risking it.

This is translated from the menu.

Software Upgrade
By upgrading the software of this router, you will get new features.
Current software version: 3.15.34 Build 130823 Rel.57853n
Current hardware version: +WR2041N v2 00000000
Note: When upgrading, please select the software that is consistent with the current hardware version. Do not turn off the power of the router during the upgrade process, otherwise the router will be damaged and unusable. The upgrade process takes about 60 seconds. When the upgrade is completed, the router will automatically restart.


软件升级
通过升级本路由器的软件，您将获得新的功能。
文 件： 当前软件版本： 3.15.34 Build 130823 Rel.57853n
当前硬件版本：    WR2041N v2 00000000
注意：升级时请选择与当前硬件版本一致的软件。升级过程不能关闭路由器电源，否则将导致路由器损坏而无法使用。升级过程约60秒，当升级结束后，路由器将会自动重新启动。