Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!husc6!rice!sun-spots-request From: legato!!mojo@uunet.uu.net (Joseph Moran) Newsgroups: comp.sys.sun Subject: Re: Help needed: clearing the 68020 cache. Keywords: SunOS Message-ID: <602@brazos.Rice.edu> Date: 27 Jul 89 02:52:44 GMT Sender: root@rice.edu Organization: Sun-Spots Lines: 32 Approved: Sun-Spots@rice.edu X-Sun-Spots-Digest: Volume 8, Issue 88, message 3 of 16 In article <83@brazos.Rice.edu> agesen@daimi.dk (Ole Agesen) writes: >Can anyone tell me how to clear the cache? > Can I get supervisor privileges for a user process? I hope not. :-) > Is there a kernel operation clearing the cache? In SunOS, you can execute a "trap #2". This undocumented interface was used by the old pixrect code that used to build and execute subroutines on the stack. On an 020, doing a trap #2 will execute: movl #9,d0 # clear and renable instruction cache movc d0,cacr rte On an 030, doing a trap #2 will execute: movl #3919,d0 # clear and renable instruction and data caches movc d0,cacr rte This is exactly what you need. Joseph Moran Legato Systems, Inc. 260 Sheridan Avenue Palo Alto, CA 94306 (415) 329-7886 mojo@Legato.COM or {sun,uunet}!legato!mojo