some question about access I/O memory in Pistachio

hello,everyone!!
  
     I am developing a device driver based on Pistachio. The device's memory-mapped io address is fed40f00.
     I added the following code in Sigma0.cc and got the result:
 
    code:
          vendor=*(int *)(0x06400000);
          printf("read data from 6400000 success\n");
          vendor=*(int *)(0xee025000);
          printf("read data from 0xee025000 success\n");
          vendor=*(int *)(0xfed40f00);
          printf("read data from 0xfed40f00 success\n");

     result:
            read data from 6400000 success
		    read data from 0xee025000 success
			sigma0 accessed kernel space @fed40f00,ip=00021797 -deny

     In KDB environment, I got the following debug info:
     >ptab
	 Space [current]
	 Memory area:
       ...........
      ee025000 [0e00c025] phys=0e00c000 map=ee025000 4kB r~x (R~X) user WB
      ............
      fed00000 [0ec001e3]: phys=0ec00000 map=fec00000 4MB rwx (RWX) kernel global WB      


     I think it is because Kernel has mapped the virtual address fed40f00 to a physical memory address. Is it right and what or how should I do to develop the device driver?
    
     Thank you very much

      Best regard 

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　　　　　　　　　　2007-12-04