7.10 Setting the Segmentation Registers

Prototypes for the user segmentation registers are set up by “estabur” which is called when a program is first launched into execution, and again whenever a significant change in memory allocation requires it. The prototypes are stored in the arrays “u.u_uisa”, “u.u_uisd”.

Whenever process #i is about to be reactivated, the procedure “sureg” is called to copy the the prototypes into the appropriate registers. The description registers are copied directly, but the address registers must be adjusted to reflect the actual location in physical memory of the area used.