Hi Anthony and thanks for your reply.
The problem was that the whole board was freewing everytime I tried using gdb on it. I figured out it was a problem of heat since the thermal deamon of the parallella shut down the epiphany chip if the heat is above 75 degrees and mine was over 75... There was also another issue, as seen in the eSDK 2015.1 update notes : i didn't use the e_reset_system function prior to use gdb and the e-server.
Now I'm able to to use it but I'm stuck with another problem : every time i use the "next" or "nexti" commands, gdb is halting and i got no response from it. the e-server however is yelling some reading errors from other cores even though I only use one core. I tried to launch the e-server with the "--check-hw-address" option and it crashes right after the first "next", due to an access to unmapped addresses...
Besides, when I step into my program, the other cores also seem to execute some instructions even though everything used by my program (data + code) can fit into only the targeted core and that I put the standard libraries into the external memory. Can someone explain this to me ? I may have missed a critical point here.
Thanks,
Thomas.
EDIT : similar issue :
viewtopic.php?f=13&t=1643&p=10229&hilit=gdb&sid=8f0f1aad2eba35beaae29c7191414025#p10126