Network, Computer and Programming Resources
Boot Sector and BPB Structure[Fat32]-> BPB_RootClus [Offset=44, Size=4]Boot Sector and BPB Structure[Fat32]-> BS_BootSig [Offset=66, Size=1]Boot Sector and BPB Structure[Fat32]-> BS_DrvNum [Offset=64, Size=1]Boot Sector and BPB Structure[Fat32]-> BS_FilSysType [Offset=82, Size=8]Boot Sector and BPB Structure[Fat32]-> BS_Reserved1 [Offset=65, Size=1]Boot Sector and BPB Structure[Fat32]-> BS_VolID [Offset=67, Size=4]Boot Sector and BPB Structure[Fat32]-> BS_VolLab [Offset=71, Size=11]Boot Sector and BPB Structure-> BPB_BytsPerSec [Offset=11, Size=2]Boot Sector and BPB Structure-> BPB_FATSz16 [Offset=22, Size=2]Boot Sector and BPB Structure-> BPB_HiddSec [Offset=28, Size=4]Boot Sector and BPB Structure-> BPB_Media [Offset=21, Size=1]Boot Sector and BPB Structure-> BPB_NumFATs [Offset=16, Size=1]
Fat32 - Boot Sector and BPB Structure-> BPB_Media [Offset=21, Size=1]
0xF8 is the standard value for “fixed” (non-removable) media. For removable media, 0xF0 is frequently used. The legal values for this field are 0xF0, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, and 0xFF. The only other important point is that whatever value is put in here must also be put in the low byte of the FAT[0] entry. This dates back to the old MS-DOS 1.x media determination noted earlier and is no longer usually used for anything.