I have the required CP2101 USB UART Board and I have soldered a 4 pin header block to the serial communication "ports" on the router's main board. I have been able to connect this all together and setup the baud rate in minicom to 115200 so I see text on the minicom serial communication interface but so far I have not been successful at breaking into the boot sequence of the router. The directions say to press "4" to break into the bootloader and I do see the choice on the menu that is presented for "Enter boot command line interface". I have tried this over and over again but so far it ALWAYS does the default boot where it "Boot system code via flash"
Has anyone been able to successfully break into the boot loader sequence on one of these Asus AX4200 wifi routers?
I did think I might be able to use some sort of web flash thing but whatever version of the default Asus firmware is on this thing that I bought, it does not seem to have any of the web setup pages I have seen on various other "help" guides for this. So that is why I fell back to this serial option.
Just curious, why is it important to upgrade to 24 or 25?
I am currently running 23.05.5.241021 Because that was what was linked from the howto doc on that github link I gave previously
BTW, I figured out the problem with not being able to access the normal Asus firmware admin menus. It turns out if you don't do a minimal setup of the router you don't get access to those normal menus. Once I did that I got to the normal menus and was able to flsh the trx file and the bin files. So my AX4200 is now running OpenWRT as I wanted.
You should only use the openwrt wiki or this forum for official instructions, not some random link you found.
My advice is only from initial flash using remittor's TRX file. If you already have openwrt installed, you can syupgrade to 25.12 but do not keep settings.