Unofficial TRENDnet AC2600 (TEW-827DRU v1.0R) release v18.06.5


Device Support Status

This device is end-user ready. Wired and wireless works, LEDs work, buttons work, and factory image installation works. Testing has shown the system to be stable under load.

This document applies to the 1.0R version of hardware. Later hardware revisions are not compatible or supported here.

LEDE Project leaders previously rejected all of my patches and I didn't see any situation where it was possible to get them merged so I gave up trying. If someone else wants to take my work and move on with it, you are welcome to do so.


Currently Known Issues

There are no significant issues for this device.

We can't install OpenWRT/LEDE via the OEM web interface yet because the install will revert after next reboot due to the Safe Upgrade/redundant partition system. However, there is a recovery loader in u-boot which is easier to use anyway, so we can and should install our image that way instead.

The "LED on/off" button can't be made to work because we currently can't shut off the ethernet switch port LEDs. This may be fixed in the future if I am able to support it. The button currently does nothing, but it is configured in the DTS so you can write a script to use it if you want to. This button doesn't work under the OEM image either, so nothing lost.


Downloads/builds

The latest builds are based off the OpenWRT v18.06.5 release. The patch set for this build is v14.

Minimal image files are here:

https://jmomo.net/files/lede/TRENDnet_TEW-827DRU_20191111151852_OpenWRT_v18.06.5_minimal/bin/

Minimal+luci image files are here:

https://jmomo.net/files/lede/TRENDnet_TEW-827DRU_20191111155837_OpenWRT_v18.06.5_luci/bin/

You can download older builds and patches here:

https://jmomo.net/files/lede/

The minimal builds have a basic bare-bone package set. You have roughly 45MB of free space on the overlay to work with. No LuCi web interface or anything else. Install the packages you want with opkg.

Luci builds are like the minimal builds, but with luci-ssl added to provide a web interface.


Recovery and Installation Instructions

Installing OpenWRT/LEDE on this device is very safe, relatively speaking, and it's easy to restore the OEM image if you want to go back.

This device offers three methods for installing images: The uboot http Recovery Loader, the OEM http upgrade tool, and console uboot tftp.

Most users should use the uboot http Recovery Loader because it's easy and safe to use.

DO NOT use the OEM web/http upgrade page at this time. While the OEM upgrade tool will accept and install the OpenWRT/LEDE image, we don't yet support TRENDnet's "Fail Safe"/safeupgrade dual boot system, which means that the device will revert to the old OEM image on the next reboot.

Finally, you can install images via serial console uboot and tftp.

Be sure to download a copy of the OEM installation images in case you want to go back. See my post below for more details.

uboot http Recovery Loader

Connect an ethernet cable from your PC/switch/whatever to any one of the ethernet jacks on the router.

Manually configure your computer with an IP on the 192.168.0.0/24 network. The router does not offer DHCP services in this mode.

Press and HOLD down the RESET button on power-up for four seconds. Then release the reset button. NOTE: My testing shows the recovery system will not load if one of the ethernet ports doesn't go active/up. Make sure you have a cable plugged into an active port on other side before starting the reboot process.

The recovery page is at http://192.168.0.1/

The page should say "TRENDnet Recovery Mode" in blue text at the top and there is a "Choose File" button and "Upload" button.

If installing OpenWRT/LEDE, then upload the factory image file.

If you want to go back to the OEM image, use an OEM firmware file, such as "TEW827DRU_FW100B11.bin".

While the file is uploading, the Internet LED will blink. You can watch progress on the serial console too. Beware the progress/percent animation on the https loader page is fake/placebo.

That's it. OpenWRT/LEDE should be up and running within 30 seconds of uploading the file. The OEM image takes about two minutes and boots very slowly.

OEM http upgrade tool

DO NOT use the OEM http upgrade tool at this time. While our factory image file conforms to the OEM requirements to be accepted and installed, we don't yet support TRENDnet's "Fail Safe"/safeupgrade redundant partition boot loader scheme. The result is that the device will successfully boot into OpenWRT/LEDE after the first reboot, but upon the second reboot it will revert to the old OEM system.

I plan to work on supporting the OEM http upgrade tool and the redundant partition system in the future, but I have not gotten around to it yet.

Console uboot tftp

The serial console on this device is fairly easy to access. A 3.3v/TTL serial port can be found in the corner next to the USB ports. You will need to soldier in header pins. Disassembling the chassis is not difficult.

JP1 = Rx
JP2 = Tx
JP3 = Ground
baud = 115200

uboot gives a 2-second "Hit any key to stop autoboot" prompt, so that's easy to break. No special key combo required.

This device uses a FIT archive file, which includes an installer script, a bootconfig image, and the UBI (kernel+rootfs). All we really need to do is tftp the factory image into memory and execute the script embedded within it.

setenv ipaddr 192.168.0.1
setenv serverip 192.168.0.2
setenv netmask 255.255.255.0
tftpboot 0x42000000 openwrt-ipq806x-trendnet_tew827dru-squashfs-factory.bin
setenv imgaddr 0x42000000
source 0x42000000:script
reset

Future Plans

JTAG recovery is something I want to do some day. It may be possible to recover from JTAG by booting from RAM or programming the NAND flash on this device. I've already experimented with this but I've not yet figured everything out.

Expand the NAND partitions, or otherwise fully use the NAND flash space. The default "rootfs" partition is 64MB in size, but there is 108MB of completely-unused space on the NAND flash, outside of smem/mtd partitions. There is also an additional 64MB of space used by the redundant rootfs_1 partition. It may eventually be possible to have a rootfs file-system of 228MB in size.

Custom u-boot. This depends upon being able to safely recover. We would need either TRENDnet's broken "Fail Safe" system to be fixed, or JTAG recovery. Otherwise the risk of permanently breaking the device is too great.

Boot from USB. This is not possible right now because the OEM u-boot wasn't built with the right modules, but it is possible. This depends upon building a custom u-boot.


Old Development Forum Thread

In May of 2018 the old OpenWRT forum died due to negligent administration. Previously, this is where I had kept a running log of changes and updates for this device, but I am no longer able to update anything on the old forum thread.

This new thread replaces and supersedes any information on the old forum, but you can still read the old thread for background information for how I ported the device, previous issues, and additional technical information.

The old forum thread can be read here:
https://forum.archive.openwrt.org/viewtopic.php?id=65956

The original (now potentially invalid) URL to the old forum was:
https://forum.openwrt.org/viewtopic.php?id=65956

In 2019 the powers that be decided that it was a good idea to prevent the editing of forum posts after a short period of time, to combat some spam mechanics. Thus I intend to start a new thread for each new release since I can no longer edit my posts.

Previous releases can be found here:


2 Likes

I have not tested these particular builds, so if this works for you please be sure to let us know.

Also I have a working 19.07.0-rc1 build being tested. I am not going to publish these until official comes out, but you can build yourself with patch set v15 if you want to -- I've uploaded the patches.

1 Like

Thank you!