Hello, There are a number of ways to do that, mostly dependent upon just how "embedded" your system is to be. The following sequence is (overly) simplified, but may give you a generic reference point. I'm assuming a simple case in which there is no initrd, etc. After the kernel boots, (mounting only the root fs), it by default executes a program /sbin/init (I said the root fs needs mounted). That executable typically provides for tty's, initial runlevel, and some other necessary/useful features. Of interest here, it then runs a system initialization and startup script (although this could be an executable). This script is usually specified in the /etc/inittab file. This script in turn can run any other script, etc to start necessary daemons, and finish system bootup and initialization. On some larger embedded systems, and most server/desktop systems, there is a standard mechanism for starting and stopping services (daemons). In smaller embedded systems, everything could get started via the initial startup script (run by init). So... Depending on the complexity of your system, there are a number of points at which you could startup your application(s). On a very deeply embedded system running only a single app, you could start that in place of the (usual) init. On a somewhat more complex system, you could have init start the app instaed of the "usual" startup script, or have the startup script start the application. On an even more complex system, you could utilize the usual service startup/shutdown mechanisms. There are any number of variations of these methods as well as some other methods. For certain situations, you could even compile your application into the kernel or make it a loadable module! It is really your call. I think that this is one of the beauties of *nix and linux especially - the manifold of choices provided.
With regard to your other issues, note that linux is looking for a real filesystem - although that is frequently ram-based. The application is simply contained in the file system - quite possibly in /sbin or /bin. If you are serious about embedded linux, I would suggest that you install a standard (non-embedded) distribution on a desktop computer and study that, with emphasis on the bootup sequence and file system. you should also visit the linux documentation website for a wealth of high-quality linux documentation. There are also any number of printed books on just about any aspect of linux you want. Hope that helps, George satya kumar wrote: > > Hi All, > First of all let me state that I am a newcomer to embedded field so my queston may >sound silly, so sorry for that. > What I want to know is how to link a particular application with our OS image on a >particular hardware in such a manner so that after the embedded sytems boots up the >application starts on its own.So how this bundling od the application along with the >OS is done in linux. > How do we specify the particular addresses of the various tasks. > Any kind of help would do.Thanks in advance. > Satya > -CUT- -- ------------------------------ George Fouse, President Quantum Technology Associates System and Network Services ------------------------------ -- To unsubscribe from this list, send a message to [EMAIL PROTECTED] with the command "unsubscribe linux-embedded" in the message body. For more information, see <http://waste.org/mail/linux-embedded>.
