[Makers] Linux embedded with semi obsolete hardware (eg dsl modems)

[Tere]

Hello!
Last year, while idle at work (I was working in a telecommunications
service provider provider, don't know how to say it in english) I've tried
"play" blindly with some unused DSL modems that were left in stock, my Idea
was to recycle them and maybe install some wrt solution in them (and I'm a
little of a hoarder, I find beauty in trash, specially if trash still
works).
I was able to communicate with them via ttl to usb adapter using putty
(yes, work computer had windows in it, I'm pretty new to linux) and that's
it, as pandemics recoiled, idle time was scarcer and scarcer so I left my
rudimentary experimentation.
Anyway, it was glorious when I saw a linux shell coming out of the modem.
Later, this 2021, I went from 2 subjects for quarter to 4 or 5, soI left
that full time job and after living upside down doing some freelance
translation jobs for around 4 months, 1 I took a 4 hour tech support
internship in order to get out of my place and see real people and go to
sleep and wake up more or less with the rest of my human suroundings.
This mail is getting long and I'm getting tired and not reaching the point
where I say what I want to say (maybe I'm not sure of what to say).
In the second quarter of 2021 I found out that one of the subjects is about
embedded linux. They point it to a raspberry pi that doesn't exist anymore
as during pandemic lockdown someone entered the faculty and took the
prototypes. Anyway I learned a lot more and am not as blind as I was in
2020.
We use qemu, uboot, configure and cross compile a linux kernel, then use
busybox filesystem and there's as far as I got
Have any of you done some experimentation of this sort? Do any of you want
to?
Thanks and sorry for the messy and long and self-referencial email.

tere