In /usr/src type ls -l and the file with the symlink is your current kernel.. To upgrade your kernel you want to redirect the symlink to the new kernel sources. But first you should back up via cd'ing into that symlinked folder and typing cp .config ~/something. Now to begin, go back /usr/src them rm the file with the symlink (not the file thats it pointing to), then type eselect kernel list, then eselect kernel set Kernel# (that will symlink to the new kernel sources)... Then copy the old kernel's .config file into that symlinked folder in /usr/src. Then type make olddefconfig (this will compile the new kernel sources against the old config file; this in the non-interactive option that will do exaclty whats in that config file. If you wanted to make changes type make oldconfig instead; there's other ways of doing this, see Gentoo wiki if interested). Then type make -j9 (makes a compressed image of the kernel; use -j3 if you use a duel core Then type make modules install, which will install the modules.. Then type make install which will copy the compressed kernel image in /boot/vmlinuz.. Next step is to make sure grub can detect the new kernel, if you're running grub2 install os-prober which is a utility to detect OSs on a set of drives.. Then type grub2-mkconfig -o /boot/grub/grub.cfg which adds the compressed kernel into its database. Next reboot so that changes can take effect (or use Ksplice). Once you rebooted verify your new kernel via uname -r …

Gentoo is not a plug and play OS, e.g. when you get a new computer or even a new hardware deivce you'll going to have go into the kernel and find the right drivers then compile them in. Also whenever you get a kernel upgrade you have to recompile the kernel and drivers. Recompiling the kernels and drivers is not hard as you can just use your old config file and recompile against that, but eventually it's going to break. A general rule of thumb is that with minor kernel upgrades its ok to use rhe same config file, but with major kernel upgrades you should compile a new config file scratch, otherwise it can cause issues. When you first install Gentoo you're just given a base iso and some setup tools from which you use to develope your (but you'll also have to install/configure some other stuff to get it working)entoo is not a plug and play OS, e.g. when you get a new entoo is not a plug and play OS, e.g. when you get a new computer or even acomputer or entoo is not a plug and play OS, e.g. when you get a new computer or even aeven a …