It is a payload.bin to be used with TegraRCMGUI, as launcher, that will jump to boot the payload.bin already existing in your microsd:/payload.bin
Just copy payload.bin in any folder of your computer to be injected using TegraRCMGUI for example. You will use always this payload even the RetroReloaded payload will be updated. It always call to the new payload updated. So it will be easy. You will forget to copy payload anymore.