Some documentation can be found here:
http://elinux.org/RPi_Documentation#Raspberry_Pi_Processor_Broadcom_System-On-Chip:


On 2/2/15 3:37 PM, Joe Bowers wrote:
> Does anybody know where to look for documentation on the changes, or
> general documentation for the bcm2836?
>
> On Mon, Feb 2, 2015 at 1:24 PM, Bakul Shah <bakul@bitblocks.com
> <mailto:bakul@bitblocks.com>> wrote:
>
>     On Mon, 02 Feb 2015 20:54:02 GMT Skip Tavakkolian
>     <skip.tavakkolian@gmail.com <mailto:skip.tavakkolian@gmail.com>>
>     wrote:
>     >
>     > hardkernel's odroid-c1 is similar and slightly better
>     performance for the
>     > same price; any sense which port might be easier?
>
>     Odroid-c1 is Cortex-A5 while Pi2 is Cortex-A7 so Pi2 is more
>     performant (but has worse ethernet and horrible usb). Port to
>     pi2 should be easier as the periphs are the same as in Pi1;
>     only their IO maps have changed a bit.
>
>     >
>     http://www.hardkernel.com/main/products/prdt_info.php?g_code=G141578608433
>
>