HOw do i add .CSO files onto psp gen D2 (full)?

Anyone know how to do so?

yes sir! place your iso/cso files in the ISO folder. should be on the root of your Memory stick. for me, its drive letter F path F/ISO just like that.

make sure your umd mode is on either M33 or the sony N9XXX

[crait]

I use the No UMD mode but I'm not sure if that function is available on Gen D2.

its not plain old no umd on any firmware, i dont think. I use the sony N9 one no matter what i do. still no umd.