Does someone have link to a manual where not just disassembly presented, but also process of patching, packing everything back and uploading back to hardware?
I had a printer Kodak Hero 4.2. It has ink level warnings which I can not get around without new cartridge and new ink chips.
I found a way to get firmware and how to upload firmware manually. I also disassembled it and found few spots where I could change ARM asm code to jump around ink level checks. But I could not figure out how to put it all back together so printer would use this firmware instead. My naive approach did not work well and I bricked it (not a big deal).
I would love to read more about process people used to, for example, build DD-WRT, which I believe is modification of stock firmware.
I haven't seen anyone actually hack printer firmware in that way, outside of some shops in China that claim they can do that. Any chance you could do a writeup on it?
There is probably a checksum (or even worse, digital signature) on the firmware image, or some other checks like that, but as for getting the firmware back on the device, I'd probably use a hardware flash programmer.
I had a printer Kodak Hero 4.2. It has ink level warnings which I can not get around without new cartridge and new ink chips.
I found a way to get firmware and how to upload firmware manually. I also disassembled it and found few spots where I could change ARM asm code to jump around ink level checks. But I could not figure out how to put it all back together so printer would use this firmware instead. My naive approach did not work well and I bricked it (not a big deal).
I would love to read more about process people used to, for example, build DD-WRT, which I believe is modification of stock firmware.