First you would have to follow this guide Making a bootable micro SD Card to get the files of the kernel and file system. Once you have them you need to make sure the virtualizer support the format of those files. In case it doesn’t, you need to use the BSP to build an image with a supported file format, the instructions for the BSP are in here. Once you have mounted the image in the Virtual Machine you’ll notice that you do not have access to the peripherals of the board, this mean you cannot test applications that uses the peripherals. Another alternative is to use build a standard Galileo image with the BSP and to generate an SDK, with it you should work the same way. To generate an SDK you need to follow section 7 of the BSP guide. I hope this helps.