Path: utzoo!attcan!uunet!husc6!cmcl2!brl-adm!adm!preece%fang@xenurus.gould.com From: preece%fang@xenurus.gould.com (Scott E. Preece) Newsgroups: comp.unix.wizards Subject: phys(2) under sVr3? Message-ID: <16047@brl-adm.ARPA> Date: 6 Jun 88 04:54:51 GMT Sender: news@brl-adm.ARPA Lines: 32 From: Andrew Klossner> I need to augment sys V release 3 so as to let a user process map a > video frame buffer into its address space. Something like the version 7 > phys(2) call, or what the 4.2BSD mmap(2) call promised but didn't > deliver, is what I'm looking for. ---------- In release 2.1 of Gould's UTX/32 (4.3 + System V emulation) we have added the ability to configure a system with specific areas of physical memory defined as special, so that the kernel will not allocate them for general use We call those areas extents. It is then possible, either in the system configuration file or by using a new system call, to create regions at specified offsets from the beginning of specified extents. When a region is created, a System V shared memory object is created as its handle. Jobs may then attach to that object to get access to the appropriate area of physical memory. We have also provided a way for jobs to request attachment to specified shared memory objects at exec time, using information stuffed into the COFF (well, COFF-like) header. Finally, we also added a second class of region for which "attachment" means allocating pages from the pool covered by the region. This allows handling areas of memory that have special characteristics (Gould systems can have cache-speed memory boards mixed with regular memory) but don't need contiguous allocation. -- scott preece gould/csd - urbana uucp: ihnp4!uiucuxc!urbsdc!preece arpa: preece@Gould.com