Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!spool.mu.edu!usenet.eel.ufl.edu!news.ultranet.com!usenet From: moncrg@ultranet.com (Gregory D. Moncreaff) Newsgroups: comp.unix.bsd.freebsd.misc Subject: need help accessing device i/o memory from device driver Date: Wed, 09 Oct 1996 01:58:40 GMT Organization: UltraNet Communications, Inc. Lines: 18 Message-ID: <325b02fd.1625642@news.ma.ultranet.com> NNTP-Posting-Host: dominus.ultranet.com X-Newsreader: Forte Agent .99e/32.227 I'm working on a device driver for a serial board under Freebsd. I did a hack and slash on a similar driver that used the same serial chips as the board I'm working with. The only difference is that the new board has a dual-port ram and the old board/driver didn't. What I don't understand is how you "wire" pages of, virtual I guess, memory to a physical location. I can see in some other device drivers calls to kvtope() which then calls pmap_kextract(), neither of which are mentioned in design & implemetaion of bsd 4.4, and neither of which seems to have an obvious effect, and seem to indicate the reverse operation of what I think should be needed. Are there any references as to how this needs to be done that I could be looking at? are there man pages for kernel functions for those working inside the kernel? Thanks, gdm