hardware self-check and initialize about application programme

Not sure if I understand your question; the spectrum digital site has many test under "Target Content" to help veiry the EVM hardware; the source code for these tests are included so I suppose you can borrow some code from there.  However, I believe this tests are probrably overkill if it is something you are looking to do on every boot; perhaps just testing the presence of DM355 and some key peripherals for your application should be enough.

If you want a pre kernel check of the hardware before starting your app you could take the code Juan referenced and integrate it into U-boot, this would give you the effect of hardware verification before trying to boot the full kernel and application.

Typically the booting of the kernel and initialization of the drivers will act as a hardware self check, in that most of the drivers will spray out error messages on the terminal if there is an issue with the hardware.