The list of partition types is long, and world wide there are probably at least a few which override each other. I'm continously trying to compile a pretty complete list of file system identifiers. The code in the MBR sector has a very limited amount of resources available. It only has a maximum of 446 bytes to get the job done. What it has to do, is locate the partition which is marked active, load the first sector from that partition into linear memory at 00007C00h, and transfer execution to that code.
Linear address is the same.
Should be initialized. SP is also unknown. DL contain number of the drive from which the code was loaded from. The state of the other registers like AX, BX, CX, DH, SI, DI, BP, DS, ES, FS and GS are unknown. Compatibility Advice When adding new partitions to a disk, it is adviced that the partition is aligned at sector 1.