I had difficult times with flashing a Xiaomi 4A Gigabit of mine with the OpenWRT firmware
At the end I managed to make the OpenWRT get flashed on the router.
Recently I realised that I have destroyed maybe the factory layout of the device, since the maximum transmit power for 5Ghz radios is hardcoded with wrong value which translated to 3dm.
I tried with Luci and uci to change this value and in fact it did not change the actual transmit power.
This issue is very annoying since getting more than 3 meters far from the router either the router or the connected device will drop the link and get disconnected from the router because of weak signal.
That saif I tried to bring the device back to the stock firmware and revive the maxium tx power for 5 GHz radio, the stock 5Ghz radio looked right to me and worked fine but after re-flashing the OpenWRT over that device the same issue came back to the life.
In fact the reflashed OpenWRT still had the same issue with the tranmission power.
Please tell me if there is an easy way to fix this issue without opening the device case?
If there is no other choice than opening the router's case I have a CH341A usb flash/programmer at my deposit and I would like to know, how can I fix the contents of the router's memory in order to bring back the maximum power to the 5GHz radio.
Which memory addresses with their contents values should get tweaked?
Shall I reflash any layout and how can I obtain the correct OpenWRT layout that I could use for reprograming the router?
Is there any need to change the MAC addresses after layout reflashing? If so how can I do that?
Thanks
Thanks
@LilRedDog
I have checked the issue and it is correct, all connected devices get disconnected when I am about 3 to 4 meters away from the router.
That said I have checked with a couple of WiFi analyzer on smartphone such as WiFi analyzer and even another OpenWRT router tuned into Channel Analysis Report
Not only the 5GHz hardcoded power table is destroys the 2.4GHz is also affected too, but for the 2.4GHz the maximum tx power is modified to 100mw which is a way less than the intended design for whatever country regulation the device is intended for.
The firmware is international.
Given that reply I presume you have not set the Country code for where you are.
When you re-flashed did you use the same download or did you download it again.
Where on the side did you get the firmware? Was is from from the firmware selector and if it was did you select Customize installed packages and/or first boot script?
I reflashed with different versions of OpenWRT, I soft bricked the router a couple of times but I managed to bring it back , from kernel to sysupgrade/snapshot and release I have tried many images, nothing has solved my issue.
For example OpenWRT snapshot 23.x.y 22.z.y ,....
I used image selector from the official openwrt webpage.
Exactly I tried your mentioned website, tried different images and nothing did work.
Even changing the country with the uci-default did not fix any issue.
As I said I am pretty sure that I have to modify some hardcoded memory locations (blocks) and I guess it is only possible with external programmer or flashing equipment such as CH341A.