Any advice on a USB to RS232 connector

shepper said:
Browsing OpenWRT, I believe your device uses the U-boot bootloader. With
sysutils/screen and your serial connection you should be able to see boot messages in screen, stop booting during the initial stages of boot and pass commands once boot is stopped:
https://openwrt.org/docs/guide-user/installation/generic.flashing.tftp.easy-ubuntu

The commands in the guide are not specific to Ubuntu although when I've used them it is with Debian/Devuan.
Click to expand...
Thanks.

Thankfully, I've just set up a tftp server.

I'm not clear which files I need to put on the tftp server
 
If you can access the bootloader and stop the boot, a help command will reveal the available options. If you have the options, generally you put an initramfs image on your tftp server, may have to rename it, upload the image and boot it, The "tftp" command from screen will upload your image. I recall the command to boot an uploaded image is "bootm". Then, access the image at 192.168.1.1 and use Luci to install a factory image.

Here is an example help output from the OpenWRT forum and an example tftp/bootm flash of an initramfs image.
 
shepper said:
If you can access the bootloader and stop the boot, a help command will reveal the available options. If you have the options, generally you put an initramfs image on your tftp server, may have to rename it, upload the image and boot it, The "tftp" command from screen will upload your image. I recall the command to boot an uploaded image is "bootm". Then, access the image at 192.168.1.1 and use Luci to install a factory image.

Here is an example help output from the OpenWRT forum and an example tftp/bootm flash of an initramfs image.
Click to expand...
I must be missing something.

Are you saying I just need to put an initramfs file on the server and it will be picked up automatically?

Which one specifically and is anything else required on the server?
 
I saw your posts in the OpenWRT forum in a thread regarding 2 versions of your router. I do not know which version you have but to recover, you need the initramfs image for your version. There is an initial, short period of time where you can "hit any key to stop autoboot". Once stopped, the "tftp" command will send the initramfs file over serial to the router. The screenshots at the bottom of this link show a successful upload.

Some, but not all routers, have tftpboot enabled. In that case, an appropriately named file, in your tftp server, will be automatically be booted by the router. If tftpboot is not enabled you have to manually enter tftp in screen to send the initramfs from you server to the router. Then a second command, "bootm", to boot with the uploaded image.

Generally OpenWRT has 3 images for each router. An initramfs image that just loads into RAM, A factory image that is used to flash over factory and a sysupgrade image that will upgrade an OpenWRT Image.
Atheros generic images
The initramfs image is typically used for recovery or testing new builds.

All this will be for naught if you are unable to establish a serial interface. You can test while not uploading anything - just use screen to watch the boot messages. The important message is the one telling you to "hit any key" to stop u-boot. Some routers have that disabled in the u-boot environment.
 
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To be honest I have no real idea what I did to get this router working again since I tried so many things, but I set up a laptop with a static IP address of 192.168.1.2 and pointed my browser at 192.168.1.1 and got a login prompt from the router but it was running genuine OpenWrt 24.10.4!!! to my amazement.

I never did work out how to connect via the USB-RS232 connector which I bought specifically to try to revive the router.

However as a result of 'bricking' my router I have learnt how to turn one of my existing systems into a router with the aid of my phone, and in addition I have better Internet access :)
 
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