using less brams for powerpc code

Hi,

I have made a simple design for a powerpc. The code is running from bram and starts at 0xFFFF_0000, because I am using interrupts (when using interrupts the code needs to be 64 kB aligned). The ppc starts always at 0xFFFF_FFFC. The simplest thing to do is defining a bram space which starts at

0xFFFF_0000 and ends at 0xFFFF_FFFF. This will take 32 brams, while my application is less the 64 kB (it could fit into 12 brams). So about 20 brams are not used by application and not available for other purposes.

To reduce the used brams I have added a second bram controller which starts at 0xFFFF_C000 and ends at 0xFFFF_FFFF. I also changed the linker script and now I am saving 8 brams. The whole design is running fine. The second bram controller is starting at 0xFFFF_C000 because the minimum required size was

16 kB. However, it should only contain the boot and the boot0 sections. So 1 bram should also more than enough.

My question is: how can I save more brams? Do I have to make my own plb device which lays from 0xFFFF_F800 to 0xFFFF_FFFF? If so, how can I make it initialized with the boot and boot0 sections (how can I get this bram automatically in the bmm file which is generated by XPS and used by ISE)?

TIA, Frank