Unfortunately I'm not looking for a flag for gcc, this is for buildroot.
The only options are the ones I listed above.
I lack experience from buildroot but where do you find that those are the only options?
I see nothing about it here: http://buildroot.uclibc.org/downloads/manual/manual.html
The flags should be the same as the gcc available on your system. So if you got an up2date gcc installed then you should be able to use "silvermont" as flag for cpu choice.
As I said, I'm not looking for gcc flags. gcc flags are passed to gcc, but I'm looking for help with which processor family available in the buildroot configuration the N2820 belongs to. Buildroot and gcc are not the same thing.
The options I listed are the only (x86) ones available, and if you look at the list then you'll see that silvermont is not one of them.
Again where in the buildroot manual can I find out about these flags who according to you is not GCC flags?
To me they sound exactly like GCC flags which the buildroot config will pass over to GCC once being compiled.