Deleteable files

By cleanup do you mean check in (i.e. the minimal set of files you need). Just remember if you start deleting db folder files and have incremental compilation turned on you'll have to do a full compilation next time.

Typically when I go to store off a minimal set I keep these around:

ptf

qsf

qpf

bdf (top level)

component folders

software folders (without /debug or /release)

sof (so that if I come back I don't have to regenerated and compile again)

You can check and maybe update:

http://nioswiki.jot.com/versioncontrol (http://nioswiki.jot.com/versioncontrol)

if you placed components into the project other than the Nios, you should keep the HDL source and its symbol if used

The reconstruction sequence may have other steps if complex configurable components are used like the DDR, which requires the generation of timing scripts.

IzI