Adding OpenWrt support for Linksys E5600

ct25 · November 6, 2020, 6:24am

So last week I got this new Linksys Router : Linksys E5600 ( https://www.linksys.com/sg/p/P-E5600/ )

Its a very decent router with, from what I could gather information about, a mediatek MT7621A* version with dual core 880Mhz cpu. it does have gigabit. It is missing a usb port but comes with lot of ram and flash. I believe the hardware is very similar to edgerouter X except with wifi and still maintains a cheap 50$ price. The default firmware is really new and very limiting for basic home use (the firmware was an update over initial but shipped with it so im guessing it is the first firmware anyway). But I think with OpenWRT this can be a very good value. Can someone direct me to how to start tinkering and possibly building for this target. The problem is I don't know how to look inside of this without destroying the case. How to access bootlogs on something like this ?

n007 · November 6, 2020, 6:27am

Unfortunately there's no other way but to get down and dirty with the device, including being prepared for a possibility of bricking it. But to get started, you will have to dismantle the router and look for a pack of either pins or pcb pads, these may be marked or unmarked depending on what you have. These are UART pins that'll allow you look "inside" the router firmware. There you will be able to see boot parameters, boot partitions etc.
This will be a good place to start:

https://openwrt.org/docs/techref/hardware/port.serial
https://openwrt.org/docs/guide-quick-start/factory_installation

Followed by:
https://openwrt.org/docs/guide-quick-start/start

tmomas · November 6, 2020, 6:26am

This post is perfectly fine in the developers section.

ct25 · November 6, 2020, 6:53am

Excellent ... thank you ...

aashishkul · February 7, 2021, 3:18pm

I have a Linksys E5600 but couldn't find any documentation about support for this device. I tried to open the router but couldn't even get it dissembled. It seems they didn't even want people to open the device. Any lead in this direction will be appreciated.
I do have experience in porting OpenWRT. I can volunteer to add support for this device. But at least if someone has been successful in opening the router to access it's PCB, it will be really helpful.

ct25 · February 9, 2021, 3:37pm

the bottom has screws under the sticker. once you remote them you need a pry tool to remove the plastic surrounding the ethernet ports with a pry tool again and the board should slide out but be careful cause you could break it. Hardware seems standard (website says 880MHz dual core processor which at this price point is likely mt7621 according to wikidevi at least). If you get a working build i can do testing and building using a dtsi but i don't have any hardware right now for serial connection.

aashishkul · February 9, 2021, 4:15pm

Thanks. I was able to remove the sticker on the bottom and remove 4 screws and detach blue part. There were 2 more screws which was holding PCB holder (i think) which I removed too. I tried hard to remove the plastic around the ethernet port but couldn't. Have you been successful in removing the PCB?

ct25 · February 10, 2021, 3:42am

after removing the plastic i can get to the pins which i'm hoping is enough so no need to go any further to remove the pcb from the housing. once you remove the bottom screws you've voided your warranty so as long as you want an intact case you may not remove the pcb but otherwise breaking the case is probably the only way i see right now to completely remove the pcb which is very weird but i think serial is already soldered from which i can see from the outside.

aashishkul · February 10, 2021, 6:43am

Yes. Linksys has made this 'use and throw' with no scope to remove and repair. Unless there are any special tools for the purpose.
Yes. I can see that serial port header is already soldered into place.
I will wait until this week to see if anyone has better way to get the PCB out of the casing. If not, I believe, there must be screws on the other side i.e. the side on which LEDs are placed.

ct25 · February 12, 2021, 4:47am

With a better firmware it would be great value. With OpenWRT it would be a steal. But its stock firmware has buggy DNS. At least in PPPoE the DNS setting doesn't work.

aashishkul · February 12, 2021, 9:54pm

A good news is that I was able to boot openwrt on this router and it works very smooth. However, there are many hurdles to cross before we can release a version. As of now, only initram kernel is being loaded into memory using TFTP.
Things working fine as of now-

Full basic router functionality
Luci web interface
2.4 GHz wifi
LEDs

aashishkul · February 12, 2021, 9:57pm

The important point pending right now is:
The router uses W29N01HVSINF 1Gb NAND-Flash. I have not found any router which uses this chip. Also, I am not sure how to configure dtsi for the partition layout section. Can someone please guide on this point. If I get solution to above points, I can roll out device support in a couple of days.

aashishkul · February 12, 2021, 10:30pm

Another good news- 5GHz wifi also works. So now I just need to figure out how to save firmware on the flash.

aashishkul · February 16, 2021, 11:46am

A pull request is created. This is verified on a real device and works fine. Try at your own risk as I uploaded the firmware using TFTP method.

PreachingPython · February 17, 2021, 9:10pm

I actually just bought this router and by sheer coincidence you started doing this in the last week. I'm a little out of my depth using Git, although I've gotten as far as getting GitHub Desktop to download your pull request along with the openwrt master. Regrettably I'm on a windows machine, so I'm hitting a wall with the actual image creation. Any chance you could upload a firmware image for the Linksys E5600? Either way, thanks for your work on this!

aashishkul · February 18, 2021, 12:09pm

Yes. I will upload the factory upload image. At present, upgrade from OEM web UI is not working because it has some validations. Only options is to open the router and use TTL converter on UART. The firmware otherwise works superbly. Just give me some time to add header to meet the validation from OEM UI firmware update.

PreachingPython · February 18, 2021, 3:02pm

Ok sounds good, thanks again!

ct25 · February 19, 2021, 10:30am

incredible. however your pull request has some changes suggested. I'm guessing that you are working on them but take your time. based on your experience i am guessing this is a great candidate for a cheap openwrt device. wonder how the wifi stability / performance is because the archer a6 with similar chips is having issues.

aashishkul · February 19, 2021, 10:43am

Yes, it is incredible device for the price. I am working on the changes and hopefully we can have a working build ready by early next week. At present, I have installed it using tftp but I hope to release a version which can be as easy as upload a new version directly using router GUI. That's all you need to do.

ct25 · February 26, 2021, 10:26am

Any update on this ? Also with a dts file is it possible for me to select the target and build an image ? Usually I only need luci luci-app-sqm and stubby which gets me a basic router more than enough for home use. So I can build such an image from the current git to see how it would work ...