From: Tom Marchant <[email protected]> Date: 06/27/2013 10:46 AM
On Wed, 26 Jun 2013 22:45:50 -0700, Ed Jaffe wrote: >AFAIK, there is only one 4K range of virtual addresses guaranteed to >generate 0C4 now and forever: 7FFFF000 - 7FFFFFFF. I didn't know that. Is it documented anywhere? The 4K range from 00000000 - 00000FFF is key 0 storage and, as such, is protected from stores by unauthorized programs. -- Tom Marchant ------------------------------- Look in the z/Arch book (Principles) for LAP. It even prevents authorized programs from writing into the "PSA". [Low Address Protection ?] You have to set the LAP bit off in a CR to be able to update that area. Regards, Steve Thompson ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
