Dbus setup query

[Marc Murphy]

Hello,
I am new to the list but not new to writing applications to use dbus.

I am currently having a play getting an embedded system up from scratch using buildroot and have written some applications that will communicate over dbus.

My main issues are:
a) I have never set up a dbus system from scratch and there aren't many tutorials online about this.
b) I need to configure the system so that the dbus system is started automatically and all applications can talk on the system or session busses.

I mainly require 1 system bus and 1 session bus (maybe more session busses if I ssh through).

Using the default init script from buildroot I seem to get a system daemon running.  When I launch any apps they complain that there is no bus:
error: couldn't get bus: Could not connect: No such file or directory

I accept that, as there is no session bus running.

I would like to know how to start the session bus from a script but to make the DBUS_SESSION_BUS_ADDRESS global so that all sessions will use it  ?

The only way I have currently managed to do it is manually but using dbus-launch in the main bash session and then exporting the DBUS_SESSION_BUS_ADDRESS in each subsequent ssh session.  That is fine for testing but when I want to launch each application/process from their relevant scripts they won't have visibility of the DBUS_SESSION_BUS_ADDRESS that would have been started in the dbus init.d script.

Any help is greatly appreciated and may help others out there.

Kind Regards
Marc.