Thank you both for your response.
I tried a couple of different bootfiles and i found one that works.
However i would like to understand the difference between bootfiles such as undionly.kpxe , ipxe.pxe , ipxe.efi
I tried with these 3 files and it only boots with ipxe.pxe .
Can someone explain to me the differences between these 3 and why does it works now ?
Thanks a lot ,
Laurent