Asus RT-N12E C1 3-in-1 WiFi router

For Developers
#1

Hi, all, I have this Asus RT-N12E Wireless-N300 3-in-1 WiFi router, but its version is not B1 as listed supported version; rather, it is C1. I think the main difference between B1 and C1, in terms of functionality, it is that the C1 is a 3-in-1 router, means it can be operated in one of the three modes: wifi router, wifi repeater and wifi access point modes, whilst the B1 probably cannot, with native firmware, support repeater mode. Hardware wise, this C1 mode has 8MB fash and 32MB RAM; whilst the B1 is with only 4MB flash. The hardware specs of C1 mode can be found here,

My question is, which openwrt firmware should I download for this? From the hardware table I saw RT-N12E B1, RT-N12+, RT-N12 C1. They sounds similar but the CPUs are different, some modes are with mediaTech cip, whilst some other are with Broadcom chip. My exact mode, i.e., "RT-N12E C1" is not even listed in the supported hardware table. Does this version get OpenWRT support at all?

Please bear in mind again, the C1 mode is with 8MB flash, so it should be ideal to run OpenWRT.

Many thanks.

#2

Hardware specs: https://wikidevi.wi-cat.ru/ASUS_RT-N12E_C1

With only 32MB of RAM, chances are low to get this device supported, IMHO.

#3

You will need an image exactly for your device, anything else will either (hopefully) be rejected by the device or may brick it permanently (almost 100% certainty). This means porting your device to OpenWrt would be necessary, but as tmomas mentioned, there is little chance that anyone will do it for you (age, low system specs, if anyone with the necessary experience had access to the device, it would have been ported to OpenWrt years ago). The only one who might be motivated enough to do that, would probably be you yourself - or you might want to look into replacing it with better/ supported devices in the 5-20 EUR/ USD range (especially the used markets often have amazing devices in the sub 10 buck range).

#4

Thanks for your reponses. I must first express apology for wasting you developers's precious time to answer this kind of basic questions. I meant to post this question to hardware questions but I must mis-clicked my mouse and did not notice it. I actually did quite a search just now and found my post landed in "Developers" channel.

Yes, I do understand the 4/32 resource warning. The Asus link itself clearly says it has only 32MB RAM. But I am not afraid of tailor my own image if I am provided the tools. I had been a happy OpenWRT user since WhiteRussian. At that time we don't have LuCI GUI, at that time the package format and the tool was still ipkg install of opkg. This router has 8MB flash, so it would be very nice to replace the stock firmware with OpenWRT.

My key question is not yet answered, i.e., is this mode, mainly the CPU chip, supported? The B1 version is listed in ToH, but not C1. B1, and those other RT-N12 modes all have CPU chip information listed, but not this RT-N12E C1 mode, nor the ASUS link, nor the wi-cat.ru link that slh kindly provided.

#5

Sorry again. Re-reading the wi-cat.ru link that slh provided, I found it says its CPU is " MediaTek MT7628N ( 575 MHz )". This is almost identical to RT-N12E B1, which wi-cat.ru site says is with CPU " MediaTek MT7620N ( 600 MHz )".

I am wondering if it is worthy a try with the OpenWRT build for B1?

#6

See slh's answer above. There is nothing to add.

#7

I guess that I can argue about the claim of likely permanent bricking of this router. It has 8MB flash, not 4MB. The source restraint of this router is its 32MB RAM. So, if I use the ready-cooked OpenWRT image, providing I picked right one for the chip, then it might work badly, for example it may be slow, it may be unstable, it may crash often, but it should not brick the device, isn't it? I can comfortably remove LuCI and/or other run-time RAM-grabbing packages, or just disable the services, after firmware flashing, can't I? Please correct me if I am wrong.

The SoC of this router is MT7628. I see other OpenWRT images support this chip, not marked for this router though. Other than this most important chip, is there any other hardware pieces which might cause problem?

Thanks.

#8

You are mistaken, badly.

If the flash type and partitioning doesn't match 100%, your attempts to flash an otherwise 'similar' (sorry, that term doesn't exist for embedded devices, which are almost always one-off) will overwrite crucial and irrecoverable parts of the flash. If you overwrite the bootloader or damage its environment, it's game over - if you damage the wifi calibration data, it's time to say bye, bye to wireless support (forever). This kind of data is hardcoded into each firmware image, it must match, 100%. Before even thinking about details like GPIOs, network- and switch setup or sysupgrade support.

But hey, if you feel lucky, it's your device - and there's nothing but burnt money in the morning. Feel free to make your own experiences the hard way, just don't complain later that you haven't been warned explicitly.

2 Likes
#9

Your kind advice is well taken. Many thanks for you for explaining the risk in such a detailed level. I'll be very cautious. I don't have an urge to do it now, but if I decide to give it a try, I'll be mentally prepared to accept the router's destiny. :wink:

#11

If you show boot log (or serial boot log) I can try to build firmware for your router.

#12

Hello there,
I recently added the OEM Bootlog to the wiki https://openwrt.org/inbox/toh/asus/asus_rt-n12e_c1 because I try to get this device working with OpenWRT. At the moment I cannot find the original gpl sources from asus anywhere to get started with the correct configuration. Maybe someone can help.

#13

If I understand correctly FCC ID of your device is the same for routers ASUS_RT-N11P_B1, ASUS RT-N12+B1, ASUS RT-N300 B1.
Did you try precompiled firmwares for these devices?
ASUS_RT-N11P_B1

#14

I found a hint in the bootlog that the device itself assumes to be an RT-N11P_B1. Meanwhile the tarball of asuswrt for this device is also available on the website from asus. I will have a look into the sources, as soon as I find some spare time to do so.