Source code for previous PSP MAME4ALL v4.7 & 4.6 Hires releases can be downloaded from:
after psptoolchain with sdl correctly installed, unzip prefered archive and execute:
$ make -f Makefile.psp
after that a EBOOT.PBP will be created. On your memory stick make a mame4all folder and into it create “hi”, “cfg” and “roms” folder, and copy on latest one your legally owner roms.