Hackers accept Sony’s 3.56 version of custom PS3 firmware. Firmwares accepted by Sony in less than 24 hours after the update’s release. Sony’s been attempting to abolish any fresh versions of custom 3.55 firmware via DMCA notices from Github. You can still get a authority of the most recent custom firmware (failOverFlow) done up by KaKaRoToKS over at Gitorious. The advantage abaft custom firmwares is that they acquiesce you to install your own amalgamation files like the ones from Sony’s PSN.
Source: https://thehackernews.com/2011/01/new-playstation-3-firmware-hacked.html