From owner-freebsd-hackers Fri Jul 13 8:37:40 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from revolt.poohsticks.org (revolt.poohsticks.org [63.227.60.74]) by hub.freebsd.org (Postfix) with ESMTP id 9BE5037B406 for ; Fri, 13 Jul 2001 08:37:38 -0700 (PDT) (envelope-from drew@revolt.poohsticks.org) Received: from revolt.poohsticks.org (localhost [127.0.0.1]) by revolt.poohsticks.org (8.11.3/8.11.3) with ESMTP id f6DFbET69664; Fri, 13 Jul 2001 09:37:14 -0600 (MDT) (envelope-from drew@revolt.poohsticks.org) Message-Id: <200107131537.f6DFbET69664@revolt.poohsticks.org> To: "Eugene L. Vorokov" Cc: Alfred Perlstein , freebsd-hackers@FreeBSD.ORG Subject: Re: Some questions about kernel programming In-reply-to: Your message of "Fri, 13 Jul 2001 19:38:55 +0400." <200107131538.f6DFctQ00744@bugz.infotecs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <69661.995038634.1@revolt.poohsticks.org> Date: Fri, 13 Jul 2001 09:37:14 -0600 From: Drew Eckhardt Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message <200107131538.f6DFctQ00744@bugz.infotecs.ru>, vel@bugz.infotecs.ru w rites: >> ch = fubyte(uaddr); > >And one more question, does this mean that I can't use things x = *uaddr >and *uaddr = x for userspace, but always have to use fubyte() and subyte () ? Right. >If so, what is the reason it was done like that ? Architectural constraints on some platforms (say you can address just 64K at a time. Obviously, the kernel's 64K and user's 64K can't be accessed using normal pointers). To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message