Can this emulator play PS1 games in the future?

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This: https://github.com/DHrpcs3/rpcs3/commit/...1dc0a58e1a

DH set up a separate thread to run ELF files based on the ARM architecture (ARM v7 from the Cortex-A9 MPCore). In the commits afterwards there were some basic interpreter and disassembler implementations and finally the integration with the ELF loader.
While this is not really useful now, I believe the purpose would be to run Vita games in a parallel thread so later we could emulate the connectivity between PS3 and Vita games.

from what I can read: he defines four types of CPU: MIPS, PPU, SPU and ARMv7. They sound more like an attempt to more genericity in the way to handle cpus. This emulator is going to do some low level emulation ?

Possibly, yes. We're still not sure about how the CPU emulation will occur inside the emulator, but it would be really interesting and a great proof of concept to implement.