IO peripheral Address region in my platform is 0xfffb0000 - 0xfffeffff

 I want to add device driver in L4linux.

 in L4linux device driver

 ...

 *(volatile unsigned char *)0xfffb0000 = 'c';

 ...

 following case made error

result error e0
l4lx    | Invalid source for request: 2f.3f
result error e0
l4lx    | Invalid source for request: 2f.3f
result error e0
l4lx    | Invalid source for request: 2f.3f
result error e0
l4lx    | Invalid source for request: 2f.3f
result error e0
l4lx    | Invalid source for request: 2f.3f
0000003600000037
failed CLI: 0000000c.00000004

 How can I access IO Address?