Hello, @yangjinzhuang
Thanks for the question.
From the BSP UM, the default target is fsl-image-auto, which is commonly used. Additionally, fsl-image-flash is the flashimage target; fsl-image-ubuntu, fsl-image-ubuntu-base and fsl-image-ubuntu-ros are the ubuntu target image, the ros one additionally includes the ROS packages, fsl-image-base is similar to the fsl-image-auto, but with few packages included.
You may not need to care about the others since they are not mentioned in the manual. For example, fsl-image-bluebox… is for bluebox, which is a special mixed board that is not similar to common reference boards like RDB2/RDB3.
For your requirments, fsl-image-auto could be correct for use.
Hope it helps.
Best Regards
Chenyin