Not sure what you would need to look into it.
So heres a link to a tutorial on how to make a multi disc eboot
http://www.consolespot.net/forums/psp-h ... eboot.html
Also here is a link to the source code for PSX Rearmed owhich has the ability to use them
https://github.com/libretro/pcsx_rearmed
(These files appear to rellate directly to the eboots
https://github.com/libretro/pcsx_rearme ... e/cdriso.c
https://github.com/libretro/pcsx_rearme ... e/cdriso.h
)
They are really handy for saving space on memory cards