etc/init/wallpaperservice.cfg

{
    "jobs" : [{
            "name" : "boot",
            "cmds" : [
                "start wallpaper_service"
            ]
        }
    ],
    "services" : [{
            "name" : "wallpaper_service",
            "path" : ["/system/bin/sa_main", "/system/profile/wallpaper_service.xml"],
            "uid" : "system",
            "gid" : ["system", "shell"]
        }
    ]
}