A few questions about using sd card

[megavolt85]

1) yes, execute from app File Manager
2) most games don't work from IP.BIN
3) yes, same problem with HDD
4) CDI is not the best choice for SD, even if the game starts it runs much slower than reading ISO or GDI-Opt

your code is call to function gd_dmaread_stream, R5 can be contain pointer to buffer with two parametrs (LBA and sector count)
SD don't have DMA and this function not work in most games