I'm not sure about everyone else, but I had a lot of trouble figuring out how to setup the Cisco ASA in GNS3, even with all of the forums I found here. So this youtube video shows you how to do it. Hopefully, this saves you some hours of searching and a headache. If you create the FLASH file in a folder other than the video make sure to point the qemu binary to the proper folder.
Here's the link,
https://www.youtube.com/watch?v=PSLxcAan5Q0&feature=youtu.be