On 28 Mar, 05:24, "Paul E. Bennett" <p...@amleth.demon.co.uk> wrote:> Baron Samedi wrote: > > I am trying to come up with an overview of a common software > > architecture, which I would like to keep reasonably generic. That > > being said, it is intended for embedded systems, specifically mobile > > (cell) 'phones. > > When you do you should write a book about it. There has, to date, been very > little agreement on what such a common architecture might be. There are > many models and overviews of a variety of architectures and each seems to > come to prominence with the whim of "the latest fashion".Agreed. People disagree. But surely tehre are some central things which we can all agree on, like memory management & tracing? Thsi is not an academic exercise and I don't want *the* solution, just smethign good enough for the real world, whcih will make our lives as develoeprs and testers easier.> > A book I am reading at present, "System Safety: HAZOP and Software HAZOP" by > Felix Redmill, Morris Chudleigh and James Catmur, has a nice chapter on > system representation which leads into a natural style for proper system > architectural decomposition. > > book-ref: > <http://www.amazon.co.uk/s/ref=nb_ss_w_h_/202-0790886-2346224?url=sear...> > > -- > ******************************************************************** > Paul E. Bennett ....................<email:/...@amleth.demon.co.uk> > Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/> > Mob: +44 (0)7811-639972 > Tel: +44 (0)1235-811095 > Going Forth Safely ..... EBA.www.electric-boat-association.org.uk.. > ********************************************************************
Common software architecture for embedded systems
Started by ●March 27, 2007
Reply by ●March 30, 20072007-03-30
Reply by ●March 30, 20072007-03-30
Op Fri, 30 Mar 2007 07:31:26 +0200 schreef Baron Samedi <Papa.Legba.666@gmail.com>:> On 27 Mar, 16:08, "Boudewijn Dijkstra" <boudew...@indes.com> wrote: >> Op Tue, 27 Mar 2007 07:32:44 +0200 schreef Baron Samedi >> <Papa.Legba....@gmail.com>: >> >> > I am trying to come up with an overview of a common software >> > architecture, which I would like to keep reasonably generic. That >> > being said, it is intended for embedded systems, specifically mobile >> > (cell) 'phones. >> >> Specifically which part(s) of a mobile phone? > > Protocol stack, from Layer 1 to Layer 3. Also teh upper layers - > internally, the MMI sends 27.007 AT commands to tthe protocol stack. > And why not cater for the devicde drivers too, for BlueTooth, etc?So you need something like a driver framework? A protocol stack can be seen as a software-only driver.>> > Irrespective of the actual software project, there are certain common >> > functionalities which should be present in most systems. The operating >> > system (currently VxWorks, but that could change) should take care of >> > things like message passing, process scheduling, timers, etc. However, >> > before beginning a project, it might be nice to have a skeleton which >> > sits above that, as a sort of scaffolding upon which to build >> > development. >> >> If your mobile phone is successful enough, the cost of 'scaffolding' >> overhead is probably more than the cost of porting to a different OS. > > Well, I am working for a small Asian company who just finished a > disastrous first project, which I do not want to see repeated. I just > want something generic, since we are customer driven and they may ask > for Synmbia, VxWorks, their own o/s ..You want common things to have a little more abstraction, so that similar things don't have to be created from scratch. Regardless of whether this should be called 'scaffolding', this is usually Good™ programming practise.> What I really trying to do is to herd cats. We have lots of reasonably > good programmers who don't really know how to work on a team. I am > hoping that a framework will save development time and effort, while > constraining them somewhat. But I am in danger of starting a new > thread here ... my main goal will be to introduce proper software > development Processes (design/review/test/etc), but let's just stick > with the framework for this discussion... > > >> > I am thinking, for instance, of a decent memory management system, >> > with defragmentation, checking for leaks, double-free and the like, >> > some debug trace logging and so on. >> >> Here you are assuming a heap-based memory allocation algorithm. I >> wouldn't call this "reasonably generic". >> > Then what do you suggest? I think that we need memory pools which > allocate dynamically at compile time, then manage that at run-time.I was mainly referring to defragmentation. * Fragmentation is impossible in proper pool-based allocation. * Leaks can be identified by use of an 'owner' field per allocation. * Double-free can be solved with a little indirection. -- Gemaakt met Opera's revolutionaire e-mailprogramma: http://www.opera.com/mail/
Reply by ●March 30, 20072007-03-30
Baron Samedi wrote:>... snip ...> > All sofwtare, including HAl - and above - needs memory management,^^> debug trace log,e tc, and taht is what I woudl liek to discuss...^^^^ ^^ ^^ ^^ Do you never read what you type :-) -- Chuck F (cbfalconer at maineline dot net) Available for consulting/temporary embedded and systems. <http://cbfalconer.home.att.net> -- Posted via a free Usenet account from http://www.teranews.com
Reply by ●March 30, 20072007-03-30
Baron Samedi wrote:> On 27 Mar, 16:08, "Boudewijn Dijkstra" <boudew...@indes.com> wrote: >> Op Tue, 27 Mar 2007 07:32:44 +0200 schreef Baron Samedi >> <Papa.Legba....@gmail.com>: >> >>> I am trying to come up with an overview of a common software >>> architecture, which I would like to keep reasonably generic. That >>> being said, it is intended for embedded systems, specifically mobile >>> (cell) 'phones. >> Specifically which part(s) of a mobile phone? > > Protocol stack, from Layer 1 to Layer 3. Also teh upper layers - > internally, the MMI sends 27.007 AT commands to tthe protocol stack. > And why not cater for the devicde drivers too, for BlueTooth, etc?I have worked with Protocol Stack software for mobile phones, though not in the last years. It will be a lot of work for your "herd of cats", to do it again from scratch, but it will be interesting and hopefully fun. In the protocol stacks, the threads are well-defined, the interaction will be message-driven and the architecture can be derived more or less from the specs. For Layer 2-3, I suggest thread functions that take a message as an argument and process it, keeping some state, of course. This will allow you to test them in simple PC applications, and the code is OS-independent with respect to message-passing and thread control. I have never seen or used this in real code, but I wish the code had been that way. It would have worked well. Layer 1 is very timer-related code, and also quite hardware dependend, probably mostly located in the interrupt handlers. It is difficult to get right and needs a large part of the CPU time. GPRS and 3G will need good handling of the data streams; I have not much experience with this, but have a good eye on it while designing. For memory management and logging, I suggest you define your own interface similar to malloc/free and printf (or new/delete and cout<<, if you decide to use C++). In the beginning, it can be a very thin layer, and get more sophisticated later (heap debugging, log filtering / compression). In the stack, responsibilites for memory should be clear enough, and timing is important. Properly debugged memory pool or heap operation seems better to me than gargabe collection. For logging, I found the interface of the mozilla project "log4cxx" (log4net, log4c, log4j etc) quite useful; the actual code was too heavyweight for our application, so we reimplemented the interface in a reduced, lightweight version. Good luck, Tobias
Reply by ●April 2, 20072007-04-02
On 26 Mar 2007 22:32:44 -0700, "Baron Samedi" <Papa.Legba.666@gmail.com> wrote:>I am trying to come up with an overview of a common software >architecture, which I would like to keep reasonably generic. That >being said, it is intended for embedded systems, specifically mobile >(cell) 'phones. >[ text deleted ]>of? > >Thanks very much in advance >If you are referring to architectures then there theses references to Product Line Architectures, which is widely used in mobile phones. http://sureshkrishna.wordpress.com/2006/12/09/product-line-architecture-in-automobile-industry/ www-nrc.nokia.com/Vivian/Public/Misc/artMyllVR.pdf +====================================+ I hate junk email. Please direct any genuine email to: kenlee at hotpop.com
