Read the remainder of chapter 7 and 12, focussing on creating user-level address spaces.
Assignment: Draw the prototype segmentation registers and explain their contents after the call to estabur() on line 3152 has completed. Also, explain the values that sureg() stores in the hardware segmentation register. Finally, draw a picture of a user address space, and how the kernel maps it into physical memory. You may assume the kernel is running on the PDP11/40. The figures in chapter 7 and the explanation of exec in Chapter 12 may be helpful.