Detect USB media
We have created a custom OS, which boots form Hard Disk (as usual :) ). We now need to detect the USB and its contents.
So far we are able to read the MBR and Master Partition Table(MPT)of USB using INT13/AH=02
Can somebody help one below queries:
1) In MPT CHS value was 0,1,1 which gave the BPB. Now how to locate the FAT & Root Directory using this information. Also should we read using INT13/Ah=02 (CHS method) OR INT13/AH=42 (Using LBA)
2) We are using USB of 2GB, do we neeed to check for extension interrupts 41h & 42h to read the USB data.
3) How to setup the DAP ofr Ah=42.
It will be helpfull if a sample assembly code is provided.
Thanks & Regards,