Since URI caller was just released I was looking at the psvita dev wiki list of URI calls for the list of apps. Come to find out after searching google for NPXS10028, the first thing it listed is a thread from wololo titled "Dealing with the PspEmu directly". And in that thread I came across something interesting, comment number 371551 mentioning that mr.gas has actually found the custom args in order to boot or start pspemu, now mind you he was only able to get it running on firmware 3.01 but still that's a hell of find. Link to the thread and the comment: http://wololo.net/talk/viewtopic.php?p=371551#p371551 Edit: I don't know if mr. gas has a gbatemp account, but if he does I would like to get a word in to see if this can be done on 3.60. Or if some one close to him on a social media websites can ask him if he knows anything about this (I don't use social media).