GeneveOS XOP Definitions

MDOS makes frequent use of XOPs and offers them for user programs. An XOP (extended operation) is a special command of the TMS processor family which causes a context switch, transferring control to a location that is specified in a table.

Compared to common architecture concepts, the XOP is TI's way of implementing a system call. All system calls are XOP 0 with specific arguments:

ARGUM  DATA <number>
       ...
       XOP  @ARGUM,0
       ...

XOP argument	Category
5	Keyboard
6	Video display
7	Memory Management
8	Device Operation
9	Utility functions
10	Mathematical functions