I have started a project and I will update it as much as possible and that is to find out what most of the possibly useful modules do in the flash0 folder i am doing this by changing each of their names and finding out what it stops working these are the ones which I have been shown by theme psp:
Opening_plugin.rco => Contains the boot sound.
topmenu_plugin.rco => Contains Menu Names.
system_plugin_bg.rco => The wavy background.
These are the ones I have done so far:
game_install_plugin + game_plugin => When I disabled these you couldn't enter the game submenu where homebrew is kept.
I have not much so far but I will try and find another interesting one tomorrow if you know what some do please post so. Please do not flame me saying this is a useless project. My aim in the end is to have an "encyclopedia" of what certain flash0 files do and how we can change them for our own purposes. I am currently trying to find the PSP lettering that appears over the top of gameboot.pmf during game booting.