Here we go:
My WNDR4700 was working like 10 years with 1.0.0.56 native firmware.
Yet it cause bandwidth drop from 200mbps to 12mbps in 25 days, and that is annoying to make manual restarts.
So i decided to check OpenWrt FW, downloaded an [23.05.RC2](https://
A brief moment of Joy - wait 3 minutes until it is applyed - last words from router in admin panel.
It started blinking green power LED and do nothing.
Here in the forum i discovered partial information about recovery and tryed it:
Enabled TFTP in Windows10.
Connected LAN to WAN/LAN4 ports - network unidentified.
Made manual settings for Ethernet3 ipv.4 (192.168.0.1/192.168.1.1)
And made an string for file push.
tftp -i 192.168.1.2 put H:\openwrt22035.img 192.168.1.1
Connect request failed
(where i shortened another file, thought recommended as recovery, and put it into root of an drive H:)
The kernel on recent OpenWrt builds is too big for the standard settings and a change in the uboot environment is needed to be able to make it work. See the link above for the details.
Following @konus ' advice, it is unwise to try to flash directly the latest stable, and furthermore a snapshot on such an old device. You may face partition layout change, kernel size and many other issues that have occured in the meantime since first support.
Simple advice would be to flash an early version of OpenWrt, than upgrade one step at a time. At each step you may face a new problem that requires a change.
Finally when you would have solved all issues and gain experience on how to solve them, you may flash the latest stable. It's not even sure that it runs.
I finally got back to the WNDR4700 at my parents place and updated the bootcmd over serial. 22.03.5 works fine with the new bootcmd however upgrading to 23.05.rc2 does result in a brick. So it looks like the new bootcmd is not enough to get 23.05.rc2 to work unfortunately.
Recovery with nmrp flash to netgear stock firmware and then upgrade to 22.03.5 factory image works fine. Updated bootcmd still works and survives recovery using nmrp flash.
I was going to fire up my old unused WNDR4700 which was previously flashed to Openwrt with the USB3 drivers 3 or 4 years ago.
If I installed ANY NETGEAR WNDR4700 OEM FLASH using netgear site and nrmp flash command. AND, then flash with the Openwrt factory flash v 23.05 and then sysupgrade, will it work?
Even though I do it for my tasmota flash, I always feel lazy doing serial cable!!!
Do you think, as described above, go back to netgear OEM flash (which btw is bootleg openwrt too!!) and then flash to openwrt-22.05 factory and then sysupgrade-22.05 can I bypass the serial cable? And still update DTS and partition layout?
I've updated the boot command over serial and that works with 22.05. A couple days ago I've updated to 23.05.2 and that works fine. So the issue I had before with 23.05.0 not booting seems to be fixed.
I'm pretty sure the boot command needs to be updated for any of the recent openwrt releases to work due to the larger kernel size. In theory this can be done from a running openwrt install but requires the correct fw_env.config to define the uboot environment parameters location. I've tried some random combinations in the past but never found the correct settings. So I think serial will be required to upgrade to the latest version.
However I'm no hardware expert so you could always give it a try and if it doesn't work use nrmp flash to revert back.
root@OpenWrt:~# fw_printenv
read failed about /sys/bus/nvmem/devices/mtd10/of_node/compatible
Cannot parse config file '/etc/fw_env.config': No such file or directory
Failed to find NVMEM device
root@OpenWrt:~#
When I try to list the uboot environment variables from 23.05.2 I get the error above so I think the correct settings have not been found / included in the latest release. So I'm pretty sure a serial connection will be required.
It is just something that happens with older devices. The manufacturer uses a kernel and partition layout that worked fine at the time they introduced the product but does not take into account any future upgrades. It is easier / more profitable to release a next generation product with better hardware and features etc. OpenWrt uses the mainline kernel which grows with every new version so at some point the kernel / firmware grows too large and does not fit with the original layout. Adjusting the boot command will allow this device to continue to run the latest OpenWrt firmware but there will be a point sometime in the future that is not possible any more and support will stop. The wndr4700 was introduced around 10 years ago so OpenWrt has given it an extended life compared to the average consumer electronics.
I've got a Linksys MR8300 and this also needed a boot command adjustment but it is easier on that device since it can be done over ssh.
Hi Koen:
There is no doubt that OpenWRT has supported the device for much longer than anyone else would have thought. This is also playing a great role for ecology by prolonging the life of the product and with much richer functionality than what the OEM had intended. I ask questions like this to understand as I also have other openwrt devices which serve fast roaming dumb devices and have been put together using OEM "abandoned" devices.
The WNDR4700 is my favorite as it has a sata device and works like a fabulous NAS. I dislike that it does not have 802.11AC but love the fact that its life can be extended.
One day, I will use serial and fix and then pat myself on the back!!
