need help installing OpenWrt for the first time on an asus RT-ACRH17 REV 1.60 router that still has the factory firmware installed. This hardware is listed as supported and the same hardware as the RT-AC42U model router. I tried to install using the stock firmware upgrade method from the webGUI but the openwrt file was rejected as a bad firmware file (I suspect it's signature may not have matched or somesuch. ) I moved on from there and have now most likely voided the asus factory warranty by removing the 4 screws from the bottom, destroying the tamper tag on one screwhead, carefully removing the top cover, and connecting to those so nicely labeled pins on the circuit board labeled GND, RXD, & TXD with a FTDI 3v3 USB to TTL serial cable.
I now have serial console access! How can I install a working OpenWrt Firmware on this device... possibly even booting from a usb thumb drive or maybe TFTP into ram first then flash.
The serial bootlog follows and appears to give some options.... but please, the implimentation is in the details and i need help with those details as to what to do from here:
the boot commandline interface (option 4) has a few interesting options like boot from USB that could be useful, but how would i sertup the usb stick for this option.
the other options for TFTP look useful but how do i use this and TFTP to load firmware.
do I need to setup a TFTP server or client to host the firmware
how is the TFTP process done
finally there appears to be a serial option. how would I install over serial.
when successful here, I'd like to setup a support page for these units to help others.
Your specific device is not supportedby OpenWrt, as you probably already know.
Is it actually an identical device (with different model designation for whatever reason)? Just having the same hardware doesn't actually mean it is the same design. Before you go much further, you should verify that is truly the same down to the circut design level. If it's not, there is a chance that you could brick your device.
EDIT: nevermind what I said... I missed the comment on the device page that says they are equivalent devices.
Could you explain a bit further. Do I need to setup a tftp server or use a tftp client on another computer. how exactly do I serve the file to the router
Use the asus recovery tool. Hold reset for a few seconds while you plug in power. Most probably fast blinking lights or similar will indicate it’s in recovery mode. Then press send (or equivalent) in the restoration app. (Dont neet to set static ip)
I don’t know if OpenWrt and OEM differ regarding UBI partitions like the Lyra, but if it does then you need serial and tftp for unbricking. (Also I don’t know if uses HIVESPOT.trx for the tftp filename, but you can always save the first MTD and poke around it and update the OpenWrt TOH page if you find out.
well, the recovery tool just became a non-option.... probably works well for windows users but i am unable to try it as i have an older mac running osx 10.13.6 high sierra (linux via raspberry pi is likely also available). OSX comes with a TFTP server however, so on to that method via serial console.
I have the same model router. I also have the recovery tool on windows that I used yesterday to flash freshtomato on another asus model. Do I just put the acrh17 into recovery mode and upload the 2 image.itb then sysugrade and I should be good?
I just successfully flashed one of these to OpenWrt 23.05.2 stable.
I couldn't get the "recovery mode" method to work (the image uploaded but apparently didn't flash, and it just rebooted to OEM without any errors or explanation). I also don't have a serial adapter to attempt the "TFTP" method (living dangerously, hopefully I don't brick this unit while configuring it).
But the "Lyra" method mentioned above worked like a charm (with one minor hiccup, see 8 & 9):
Reset to factory defaults in OEM firmware, then do minimum setup required to get into the UI and enable SSH (it seems to force you to change the default password and click through a few more things). The SSH setting is in the Administration section.
Get the "kernel" and "sysupgrade" images for the "RT-AC42U" (same device, just named different for USA and EU) from the firmware selector (or build your own, I guess). The "kernel" image is minimal by definition and only used as a stepping stone, so don't try adding extra packages. You can add packages to the "sysupgrade" image though (remembering that this router has 128 MB of flash).
Copy the "kernel" image to the router with scp in "legacy" mode (-O) since the modern default use of sftp under the hood won't work here: