Here I have successfully completed booting uboot,loading kernel and dtb .. through uart console..
But I need to run it without console..directly by inserting sd card it should boot and load kernel login ..for that bootscript is needed .. please give me some guidance about this ..most thankful in advance
As you mentioned, UART console is just a debug console through which you can get the boot logs for your device. You can boot the device without the console as well just you will not get the access to it. You don't need any script to make this happen.
Here I am attaching the Linux User Guide for your reference :