I am looking for a ARM processor version of Android BSP to port it for one of my experimental boards. Where can I download this?
BSP is Board Support Package. This contain the code specific for board - i.e. MCU core + MCU Periherals + specific design (board) peripherals.
Android based on Linux kernel for ARM, so there is Android for ARM. But, for sure, you want to port it for specific MCU and peripherals. If you can base your design on board that already has Android port or at least MCU that Android already ported to, you will save a lot of time.
If not, you need to install Android Build System and write:
You didn't write what MCU you are using, and what board/peripherals you have. So I can just give you starting point for the mission: