KernSISData

Dereferences to the linear address pointing to the global info segment.

Is about the equivalent of what DevHelp_GetDOSVar returns for index DHGETDOSV_SYSINFOSEG (where the latter returns a segment value where the segment offset 0 points to the global info seg pointer and therefore needs to be dereferenced once more).

The _KernSISData global variable is a pointer to a data structure that contains information about the OS/2 kernel's Global Information Segment (GIS). The GIS is a data structure that contains information global to the system.