I have tried many times with various versions, but I have not moved forward. The only finding is this indication of bad CRC blocks after the first and only successful boot.
root@OpenWrt:~# fw_printenv
Warning: Bad CRC, using default environment
bootcmd=bootp; setenv bootargs root=/dev/nfs nfsroot=${serverip}:${rootpath} ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off; bootm
bootdelay=5
baudrate=115200
Any ideas if this can be related or how to overcome this?
You already installed OpenWRT, and OpenWRT does not hold information about uboot env block. There is nothing to overcome.
I am not sure I understand. Is it normal? Or is it a problem I cannot fix? I am still struggling with the initial isntallation. Once I reboot the device ends up in a boot loop.
Whats that sire?
It still does not work for me. Same as for the person in this thread, I flash factory.bin with mtd-write and it boots into OpenWRT only once. I can do whatever I want, set everything up, etc. All until a reboot. It simply never will come up into OpenWRT more than once.
Only the initramfs flashed over tftp boots correctly every time. It is gets written persistently over tftp.
Booting into initramfs and doing sysupgrade results either with the same bppt loop, or boots into initramfs.
Recover using asus tool, initramfs is meant to be netbooted, not flashed.
Just upgraded 1800U to latest asuswrt and flashed 23.05.4 via ssh
Something similar happened to me on my tuf4200ax.
Found out that recent Asus stock firmware installs an newer bootloader and will not boot snapshot builds. Openwrt latest stable at the time seems to be fine.
Possibly, if you try a snapshot build you will get a bootloop.
Overall, just wondering, why OpenWRT cannot be flashed with Asus Emergency Flash option :D? And then, now, is the ssh version from tutorial gonna work, so it stuck even after reboot?
It is time for a openWRT update from 23.05.2 and since I had these issues when installing OpenWRT I wonder if anyone knows if it is safe to do a simple update via luci or if I need to set aside enough time for a reflash over serial?
I did the update to 23.05.5 a week ago from luci and it worked flawlessly.
What helped me after 5 days of agony and frustration trying kernel/factory/version23/version24/stock-firmware ..... was: (all commands entered in the u-boot console)
=> env default -a
=> env save
Apparently at some point the update changed the bootcmd (in my case) to:
bootcmd=bootp; setenv bootargs root=/dev/nfs nfsroot=${serverip}:${rootpath} ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off; bootm
after env default the result is:
bootcmd=mtkautoboot
Hope it helps.
Haha my dude I would have needed this 2 weeks ago when I updated via sysupgrade and then had to hookup the ftdi adapter again after the update bricked it again ^^
I will try this as soon as I find enough time to work out another brick, just in case.
Thanks for letting me know!
Hello, can anyone help me with some blocks for this device?
Mine was bricked, and nvram and others partitions are empty. For testing purpose only.
If you still need anything I might take apart my router again and try to apply the fix @io_dev mentioned tomorrow or the day after.
I just want to leave this here as an update:
It looks like my router had a hardware issue with the NAND that was deteriorating over time. Our current guess is that some FW versions simply did not hit the damaged blocks which made it possible to install certain FWs while others that should have worked did not.
After 2 month since the last (3rd time) flash via serial, yesterday I found the router in a bootloop again, even though there were no changes this time. This time even the versions that worked before were causing bootloops.
Luckily amazon decided to grant me a refund even though I had the unit for 13 months (1 month over) and I will likely go for a N100 based router now.
good choice, unless you're plan to use it for the wireless too 
Sorry for taking this thread OT but now you have me worried...
The device I am currently eying has a good NIC, space for a mini PCIe WiFi card and the aluminum case is prepped for the pigtails/antennas.
I thought that there are well supported WiFi cards for that purpose?
there are, but they'll still be outperformed by most plastic routers, in functionality and price.
x86 and wifi is a bad combo, don't do it.
you had to do it...
back to doing research
thanks