@paradadf thanks for the answer.
How can I close the topic? I can't find the way to proceed. I'm on mobile.
Sorry about that.

PS I find it in your signature

@paradadf Real good idea, would be better if someone could share the /usr/lib/libretro/pcsx_rearmed_libretro.so I can wright a little proc to add a core to the pcsx and how to use it for games that need a multitap on psx.
I didn't fint this info on the forum

Hello,
I try to upgrade the library pcsx_rearmed_libretro.so to play with more than two players at Playstation.
I download the last version of the library at http://buildbot.libretro.com/nightly/linux/armhf/latest/pcsx_rearmed_libretro.so.zip

But when I replace the old library, the emulation is slow.

I'm wrong somewhere, perhaps I have to compile the library?
Could you help me to resolve this issue?