Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!lavaca.uh.edu!menudo.uh.edu!sugar!peter From: peter@sugar.hackercorp.com (Peter da Silva) Newsgroups: comp.sys.amiga.tech Subject: POSIX AmigaOS (Re: AmigaOS/UNIX - A Suggestion) Message-ID: <6874@sugar.hackercorp.com> Date: 23 Oct 90 12:27:51 GMT References: <606@macuni.mqcc.mq.oz> <1410053@hpcvca.CV.HP.COM> Reply-To: peter@sugar.hackercorp.com (Peter da Silva) Organization: Sugar Land Unix - Houston Lines: 20 In article <1410053@hpcvca.CV.HP.COM> abrown@hpcvca.CV.HP.COM (Allen Brown) writes: > My guess: memory protection. If Unix was a process under AmigaDOS > wouldn't any AmigaDOS process be able to write into any Unix memory? I don't see why. You can set the MMU up so the UNIX tasks are read-only, and have read-only access to the rest of the system. More of a problem is that GURUs are scary for UNIX folks. More interesting would be to consider how hard it would be for Commodore to make AmigaOS POSIX compliant. The only hard part is the fork, and if you restrict POSIX compliant programs to a set of calls to a resource-tracking shared library then that would be solvable. In fact posix.library could be written so that it runs tasks in a protected mode when available so that forks would be cheap (otherwise you'd want to defer the forking task until the child exits or execs... with some reasonably long timeout: forks on a 68000 without MMU are ugly... look at how MINIX does it). -- Peter da Silva. `-_-' .