PROCESSOR-SDK-AM335X: Uenv.txt file missing on boot SD card

Part Number: PROCESSOR-SDK-AM335X

Good Day all!

I am working on TI Board (am335x-evm).

I am trying to reduce boot time and I follows TI Wiki  (http://processors.wiki.ti.com/index.php/Sitara_Linux_Training)

However, my SDK and u-boot are newest version so that document doesnot really fit for my environment well.

In order to optimize u-boot and kernel, i have to fix uenv.txt file in sd card.

But I couldn't find that file. how should i do?  

Also, do you have any idea to optimize boot time for new SDK?

Thanks.