Automatically answer defaults when doing 'make oldconfig' on a kernel tree

Solution 1:

make olddefconfig

is what you want. From the help (make help in the kernel source dir)

olddefconfig - Same as silentoldconfig but sets new symbols to their default value

Solution 2:

Use the command :

yes "" | make oldconfig

The 'yes' command repeatedly output a line with all specified string, or 'y' by default.

So, you can use it to simply "press enter", which will result in using the defaults value for the 'make oldconfig' command.