Generally, the BSP stands for Board Support Package.
The elements that are contained in the BSP are
1) Boot Loader
2) OEM Adaptation Layer (OAL)
3) Device Drivers
4) Configuration Files
--> Boot Loader downloads the OS images in to the target board
--> OAL links the kernel image and supports hardware initialization and management.
--> Device Drivers supports on board peripherals OR peripherals that are attached to the board at run time
--> Configuration Files are created to configure the BSP environment variables.
I hope, this helps you.
Srinivas G.