Changing U-Boot Env variable with a complete chip dump

Hello, so I read about this:

I can't find my USB-to-serial and I do not want to compile a custom image just to get uboot-envtools working properly... So was thinking, since I can (and did multiple times, as backup and anti-brick insurance) get an full chip image (Raspberry PI + flashrom) of my Router flash (I've a TD-W8970 v1), is there a way (possibly with a tool, even hex editing is ok but I'll need a small guide at least) to directly modify the flash dump to change the various uboot variables?

It's probably possible, but there likely isn't a guide.

Also, you run a high risk of corrupting the image by hex editing.

If you can find the variables, you edit them, simple (that's also where you risk corrupting the image). :worried:

I highly advise you just locate or replace your TTL serial adapter.

O wait can I use my raspberry pi as serial adapter?

Yes, if it's compatible with the router's serial port.