I'm going to compile a new Linux distribution for my old DVR, but I'm having trouble understanding uBoot!

I own an old DVR (Digital Video Recorder). My initial goal was to use it with its default Linux system, but I don’t know the root password and there doesn’t seem to be any vulnerability. I technically have the password hash, but it is protected with md5crypt. I tried common wordlists, but none of them were successful. Maybe I’ll try again later. So I thought, why not build a new Linux for it? I have no prior experience with this, but first I need to back up the existing firmware so I can restore it in case something goes wrong. I also need the DTB (Device Tree Blob), as far as I understand. Because of this, I want to dump everything using U-Boot. However, this U-Boot version is very old, and I haven’t been able to locate the DTB so far. I’ve read the documentation, but if there are any mistakes or misunderstandings in my explanation, I would appreciate it if you could point them out. In short, I need help with the U-Boot part. I need to dump the kernel, firmware, or DTB. Thank you. Note: My native language is not English; this translation was done using AI.I am also connecting to the device via UART. submitted by /u/TurkLine [link] [comments]

from hacking: security in practice https://ift.tt/ZxmVN1c