From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32114 invoked by alias); 31 May 2006 08:37:52 -0000 Received: (qmail 32103 invoked by uid 22791); 31 May 2006 08:37:52 -0000 X-Spam-Check-By: sourceware.org Received: from londo.lunn.ch (HELO londo.lunn.ch) (80.238.139.98) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 31 May 2006 08:37:48 +0000 Received: from lunn by londo.lunn.ch with local (Exim 3.36 #1 (Debian)) id 1FlMD1-0007Bd-00; Wed, 31 May 2006 10:37:43 +0200 Date: Wed, 31 May 2006 08:37:00 -0000 To: Anthony Tonizzo Cc: ecos-discuss@ecos.sourceware.org Message-ID: <20060531083743.GD2478@lunn.ch> Mail-Followup-To: Anthony Tonizzo , ecos-discuss@ecos.sourceware.org References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11+cvs20060403 From: Andrew Lunn X-IsSubscribed: yes Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Subject: Re: [ECOS] Re: Any shell available? X-SW-Source: 2006-05/txt/msg00267.txt.bz2 On Tue, May 30, 2006 at 06:02:28PM -0700, Anthony Tonizzo wrote: > Andrew: > > >Now eCos has no concept of loading a program from secondary storage > >and executing it. It has no concept of a program. It has no concept of > >a process. > > I am not sure I agree 100% with this statement. > > eCos has both the concept of file system (and hence we can extrapolate > the concept of secondary storage) as well as the concept of process, given > that a process can be loaded by the objloader package and executed. I did wounder if anybody would bring up the objloader packege. Yes, we have a filesystem. However we don't have processes. We have threads, but not processes. To me there is a big difference. For one, a process has resource management associated to it. If a process dies, or is killed, all the resources associated to it are released. Memory is put back into the pool, file handles are closed etc. Also, a process contains one or more threads. Killing a process kills all the threads in the process. Without having processes, from a pratical standpoint, you cannot have programs which run to completion and exit. Thus you cannot have a shell. > I do not see anything wrong with an application (call it shell) that > is capable of both accessing a file system as well as loading from > that file system a file and running it. To me, that is more like a boot loader and less like a shell, although what you describe is somewhere between the two. To be a shell, what has been loaded must be able to exist and be unloaded, and you must be able to load something else which can exist and be unloaded, add-infinitum. For this you need processes, not threads. Andrew -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss