Types of images you can create

The IDE lets you create the following images:

OS image (.ifs file)
An image filesystem. A bootable image filesystem holds the proncto module, your boot script, and possibly other components such as drivers and shared objects.
Flash image (.efs file)
A flash filesystem. (The e stands for embedded.) You can use your flash memory like a hard disk to store programs and data.
Combined image
An image created by joining together any combination of components (IPL, OS image, embedded filesystem image) into a single image. You might want to combine an IPL with an OS image, for example, and then download that single image to the board's memory via a ROM monitor, which you could use to burn the image into flash. A combined image's filename extension indicates the file's format (e.g. .elf, .srec, etc.).

If you plan on debugging applications on the target, you must include pdebug in /usr/bin. If the target has no other forms of storage, include it in the OS image or flash image.

Related concepts
Components of an image, in order of booting
Project layout
Workflow of image creation