Hey this will be my first time flashing OpenWRT and would appreciate some advice before I start.
Device in Question (2.0 EU version): https://openwrt.org/toh/tp-link/tl-wr810n
I don't know if I can just flash the newest firmware: wr810n
Or I need to use an older version or compile it myself because of the 8MB flash issue.
Do you have read and understood https://openwrt.org/supported_devices/864_warning ?
Ah okay it will probably just work. IDK I previously landed on a different warning page that I think said a custom build is required. For I now barely enough is enough for me, just want to get my toes wet. If I need more space will try the builder.
What binary from here can I flash via the webui? https://downloads.openwrt.org/releases/24.10.0/targets/ath79/generic/
If you have never flashed OpenWrt on that device then
https://downloads.openwrt.org/releases/24.10.0/targets/ath79/generic/openwrt-24.10.0-ath79-generic-tplink_tl-wr810n-v1-squashfs-factory.bin
And if there is already OpenWrt flashed then https://downloads.openwrt.org/releases/24.10.0/targets/ath79/generic/openwrt-24.10.0-ath79-generic-tplink_tl-wr810n-v1-squashfs-sysupgrade.bin
(I have not checked how the 2.0 is supported I only saw that the missing usb port is the difference...., without warrenty as always. But you should now be able to find the firmware files on your own, and know the difference between factory and sysupgrade. But feel free to ask.)
Thanks! Why is an init-ram provided? In case you brick the early boot?
Judging by this thread v1 firmware does not seem to be flashable to v2 hardware, it seems like you have to modify the image a bit. (EDIT: Nevermind, this was relating to v1 (US), not sure what actually was necessary to get it running, haven't read the whole thread.)
Regardless of all of this, table of hardware spits out this: https://downloads.openwrt.org/releases/22.03.5/targets/ath79/generic/openwrt-22.03.5-ath79-generic-tplink_tl-wr810n-v2-squashfs-factory.bin
So maybe you can use 22.03.5 factory image and then sysupgrade your way to the desired version (then using v1 sysupgrade image, as then there is no more stock web UI that complains about using the wrong image version ).
Here Says US and EU are different.
Will first try to install the version mentioned in the toh
Prep fifty bucks for replacement, depending on luck with first flashing it will be useful next week or next year 
Whats printed on the label? And about mtd in oem boot log?
Sadly I don't have anything on hand to gain serial access
It refuses to upgrade because of the file name...
this is the name from the official firmware:
wr810nv2_eu_3_16_9_up_boot(160509).bin
160509 seems to be the year in YYMMDD
3_16_9 is the version number.
This is the current version on the device:
Firmware Version:
3.16.9 Build 160509 Rel.47223n
Hardware Version:
WR810N v2 00000000
Tried many combinations but can't get it to accept.
It even refuses to use the offical file name, IDK if this indicates I want to flash the wrong firmware or it just refuses to use the current version number and anything older.
Rename it to blob.bin
Upgrading OEM fw is not essential for openwrt install
does not work with the openwrt firmware. Here the full error message:
Error code: 18005
Upgrade unsuccessfully because the version of the upgraded file was incorrect. Please check the file name.
EDIT: Nevermind selected another version via. the firmware selector (renamed to blob.bin). It flashed. Will have to configure it, hopefully will be able to upgrade.
Currently on 22.03.7-ath79.
The firmware selector only shows the newer version for the V1...
My feeling reading the other threads was that the only difference with v2 is that it just needs a different factory image.
So I believe you should be fine just using sysupgrade from now on with the v1 image.
But that's just my gut feeling, either you read some more and find someone that posted that sysupgrading with v1 image was successful or you just go ahead and try it for yourself and risk bricking.
Of course, you could also look through the source code and see what was modified in 22.03.7 to build for v2. If the only changes made relate to creating a factory image the stock firmware's web UI doesn't complain about, you should be fine with just using later sysupgrade images meant for v1. But if there were other changes as well, you'd have to be more cautious/try to build your own 24.10.0/SNAPSHOT image that incorporates those changes.
Tried to force flash 24.10.0, but after loading for 10min it just failed and I landed in the webui of 22.03.07.
Will have to take a closer look.
You have to sysupgrade only since in openwrt.
This is the image you should be using:
Tried to flash it 7 times with the firmware provided here:
As far as I can the this should be the same generic sys-upgrade binary (did not check signature or hash):
https://downloads.openwrt.org/releases/24.10.0/targets/ath79/generic/openwrt-24.10.0-ath79-generic-tplink_tl-wr810n-v1-squashfs-sysupgrade.bin
But this one worked first try!
It's the same file/sha256 hash. Anyways, good that it's working now!
Can't believe is old thing is usable again.
Thanks guys!