On Tue, 5 Jul 2011 17:27:32 +0300, Binyamin Dissen wrote: > >:>So what is the name for the 2G to 4G range of storage? Ok, you guys >:>can go ahead and fight it out. Me? I'm just going to call it "above >:>the mini bar". > I vote for "within the bar".
>There would be the need for special page tables to execute code in that area. > Not very special. The 2 GiB thickness of the bar is a product of the fertile imagination of z/OS. Other OSes routinely permit use of storage within that range, and routinely support execution above 2GiB and above 4 GiB. >Is there now support for unlocked code above the bar? Though that Z spews if >the interrupted PSW is there. > Again, not the hardware, but a construct of z/OS which scrunches the PSW to 64 bits, discarding the upper 32 bits of the program address. It was explained here lately that if that address was 4GiB or above, the z/OS interrupt handler (not the hardware; not every OS) sets the low order bit to 1, causing a specification exception on return from the interrupt. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
