there were a couple people working on this before they gave up because... well because the scene was **** back then.
They were Snowydew, KDSBest, Sandungas, Juan Nadie, naehrwert and myself.
So far we've managed to decrypt the ISO.BIN.EDATs and MINIS.EDATs (along with a special MINIS2.EDAT from Sandungas, published on the wiki).
You'll need several things:
RIF/RAP (for decryption, if raps exist, you only need that)
and last, but not least, the klicensee (good luck trying to find the ps2 klicensee on ps2_netemu.self)
i suggest Rebug REX 3.55.3 for this, along with PSoN DEX, which still works, and change the idps to the one on EID5 / or REX 4.21.1. (REX allows you to keep your act.dat indefinitely and your other purchased content aswell).
What i'm missing at this moment is only the klicensee for ps2. i already have the klicensee for psp (available on wiki) and the klicensee for psx (available on KDSBest's code)
"Whoever has ears, let them hear."