All QNX BSPs ship with a buildfile, which is a control file that provides instructions to the mkifs utility to generate an OS image. The buildfile specifies the startup program, drivers, applications, and other files to include in the image. It also defines the startup order for the executables, and their command-line arguments and environment variables.
The boot script portion of a buildfile contains the sequence of commands that the process manager executes when your built image starts up on the target.