I m using s32k144 series EVB. I want to know what are the steps needed to start the boot loader on this EVB.Can we get exiting UART based boot loader to understands the working of boot loader.
I recommend you look at the document AN12218 - S32K1xx Bootloader.
The software is available and was created for the S32K148EVB.
Please refer to below links.
I believe it helps you.
If you have any question let me know.