I'd do rows by hanging on to the top bunk and pulling myself up. Could also do a sort-of-chin-up like that if I kept my legs tucked in. Which would hit the biceps. I would hold the bars, and lean back, and then pull myself into them to hit more biceps, and some back, albeit not too well. Maybe just do burnout sets doing this.
Pushups of course...wide grip, close grip, neutral grip...whatever. For chest. Also, for chest, I'd stand beside the bed upright posts, and do 1-arm flyes by letting my body fall while holding the bar, then sort of "flye" my body back up.
I'd do handstand pushups for my shoulders.
I'd do up/downs for cardio (burpees).
Easy to work the abs of course.
I'd do dips off the bottom bunk to hit triceps (kick the feet out in front of me on the floor, and do the dips). Could also do close grip pushups for triceps, and do close grip pushes off the bars in the cell to burn them out.
I'd do one legged calf raises, so it's easier to burn them out.
Hamstrings I think would be hard...maybe you could link your feet under the bottom bunk and try a make-shift glute ham raise. But it might not work. You could also try to do an isometric deadlift by grabbing the bars on the cell door and trying to lift it until you burned the hammies out.
I'd also do lots of glute work to keep them tight. For prevention of the whole prison rape thing...
