I bought a chinese router for openwrt development which has the following major components-
1. Mediatek MT7620A - router MCU
2. Winbond W971GG6KB-25 - 128MB RAM
3. Winbond 25Q128FVSG - 16 MB serial flash

Looking at the PCB, I found striking similarity with many other chinese routers except the RAM and flash chip. Even some popular names, such as- baidu router, xiaomi mini router probably followed the same schematic design.

However, I am confused about the wlan radio and driver. In the configuration of the router, it was mentioned that the wlan radio is RT2860 which I expected to be a hardware. But there is no wlan IC on board. What is the wlan radio for MT7620A? Which driver should I use to compile openwrt for this router? Since I can see the general configuration for MT7620A in the menuconfig, will that work for this router?

Mediatek MT7620A is a Wi-Fi System-On-Chips (WiSOC). It integrated mips processor, wifi radio & switch on same chip. See more:
https://wikidevi.com/wiki/MediaTek_MT7620
http://www.anz.ru/files/mediatek/MT7620_Datasheet.pdf

Thanks, I got confused with the product description where it was mentioned the radio was RT2860. I applied a patch for another router https://github.com/Akagi201/hiwifi-hc5661 with similar configuration and successfully compiled openwrt for my router. Although I can see the product booting successfully and recognizing both LAN and alan, it's not assigning any IP to them , nor it's activating dhcp server. But I guess I will post another topic to ask for help about it.

Have you tried this yet ? http://downloads.openwrt.org.cn/PandoraBox/MT7620A-EVB/

It's interesting that I cannot find MT7620A in the target list (at /target/linux/ramips folder) in their source code at svn://svn.openwrt.org.cn/dreambox/trunk. So, I didn't dare flashing the firmware without looking at the source code (and learning the specification of the board) first. However, since chinese router companies mostly use this repository, I will like to try compiling it for my router to solve issues with my router. Do you know where MT7620A target is in this repository?

(Last edited by mmrasheed on 24 Aug 2014, 02:26)

I just loaded the MT7620A-EVB firmware in the router's RAM without writing in the flash. It seems that both LAN and WLAN are working, but USB is not working. I guess I need to include the USB libraries to make USB working. However, I cannot find the source code tree or configuration files for this specific board. It is not listed in the chinese openwrt trunk-

Where can I find the repository (or the configuration files or patches) for this specific board?

@mmrasheed

mt7620 is a SoC chip, with  a 2x2 2.4G wifi module inside.

rt2860 is a very old product of ralink. since then, ralink keeps using this name in its wifi driver, even the chip has evolved to mt76xx already. ( prefix changed from rt to mt because mtk aquired ralink).

all the products you have mentioned, like xiaomi mini, baidu, are all using ralink's wifi driver actually. MTK did some tricks to make their driver work under openwrt framework.

as for pandorabox or dreambox, they are Chinese clone of openwrt project. They did some customization and localization.

Actually since last year, MTK has started officially support for openwrt in MT76xx series chips. They provide RD support to their customers, as well as to the community.