
So I used PSX2PSP, a little program to create PSP eboots from ps1 isos. You have to create a homebrew using NTSC settings, then pick any USA or Japanese game ID, and select some level of compression. ISO file was generated with mkpsxiso.
The only thing that failed, was a look_at function I copied from psn00bSDK. I might try a psn00bSDK demo.