[U-Boot] ETH RBPTR incorrect mapping for rtx volatile structure

[BUGNIOT Geoffrey]

Hi,

(my configuration is MPC8270 on a Interface Concept board plines VMEb)

I'm facing a problem relating to my ETH FCC interface (FCC2)
It appears during a TFTPBOOT command that configuration informations are not the expecting one.
Basically, I'm facing timeout in my serial terminal and several "Rx errors" with value 0xC10

My first interpretation is that RX buffer descriptor is not valid.

During my analysis, I have detected some elements.
     RXPTR and TXPTR are assigned with regular RAM values (area folling the reserved RAM for uboot usage) instead of DPRAM.
     that rtx value is volatile, appearing in the GOT table with a famous predefined value following uboot ram reserved area.
     that rtx is not constrained to be implemented in a specific DPRAM area.

My questions are:
    Is it mandatory to force FCC / RXPTR/TXPTR to use DPRAM?
    How to force RXPTR/TXPTR in DPRAM area?

NOTA: ping is working, a single sentence is appearing ( alive or not alive, no information on packets)
NOTA2: u-boot version is 2011.12

Regards