From owner-freebsd-hackers Fri Oct 3 19:07:01 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id TAA26792 for hackers-outgoing; Fri, 3 Oct 1997 19:07:01 -0700 (PDT) Received: from proxy3.ba.best.com (root@proxy3.ba.best.com [206.184.139.14]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id TAA26787 for ; Fri, 3 Oct 1997 19:06:58 -0700 (PDT) Received: from shellx.best.com (shellx.best.com [206.86.0.11]) by proxy3.ba.best.com (8.8.7/8.8.BEST) with ESMTP id TAA23860 for ; Fri, 3 Oct 1997 19:05:57 -0700 (PDT) Received: from localhost (mdean@localhost) by shellx.best.com (8.8.6/8.8.3) with SMTP id TAA28428 for ; Fri, 3 Oct 1997 19:05:57 -0700 (PDT) Date: Fri, 3 Oct 1997 19:05:57 -0700 (PDT) From: mdean Reply-To: mdean To: freebsd-hackers@freebsd.org Subject: lkms versus hard linked drivers Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk My question is very simple: What can't be a lkm? For instance if I have some intel 8255As that I am going to use to produce a 500hz pulse train for stepper motor control. These chips aren't stateless and need to be intialized and mostly need to be kernel code to access change of state interrupts and the high frequency clock (obviously). Can I do all this from an lkm? Will everything except the boot device driver and microkernel eventually be an lkm? Is it undesirable or something, because the only module that I am using on my system is for the screensaver? What about this: I am pretty sure I cannot do this inside the kernel. What if I want my device driver for the stepper motor to socket(2) since it is really not going to have any ioctls. This way controlling motor position can be done from any machine on the network. Can I use any system call in a) device driver in the kernel tree b) lkm?