Access a lot of memory in nios/uclinux

Hi, i have a system with nios and uclinux. In future the system will have 32 Gbyte of memory.

The memory will be written by some ADC. Once the data will be in memory, this have to be send with a linux application by ethernet fast as we can.

Nios data master can't see more than 2 Gbyte (if no MMU used right?), uclinux maybe can't see also more than 2 Gbyte.

I have several questions:

1)I will need to get the exclusive priority of the avalon bus to write the memory. Is it possible?

2)How can i write the memory (Perhaps with http://www.altera.com/support/examples/nios2/exm-avalon-mm.html)

3)There is a way i can access all the memory?

4)Can i remap memory to the application user space?

Thanks a lot for the support you always give me