126.96.36.199. Information on How to Configure and Use the Bridges
By default, the SSBL only brings all the bridges out of reset. It does not automatically configure or enable the bridges. You must specifically configure and enable all the bridges according to your own design. This can be accomplished by creating a “u-boot.scr” script file that is executed by the SSBL, where the SSBL modifies any registers necessary to configure the bridges. At this point the bridges are configured and enabled, and cannot be changed by the SSBL, even during any future FPGA configurations.
For more information, refer to the example located on the Creating the U-boot Script located on RocketBoards.org.