Installing a vanilla kernel in the Gentoo distribution is very easy. Just install the vanilla kernel source from kernel.org and then unpack the sources into /usr/src/linux as shown below. I am using 2.6.39-rc6 and I have symlinked the source tree to /usr/src/linux. Then type cd linux/ and then run make menuconfig to set up a configuration for a fresh new Linux kernel.
homer@localhost ~ $ ls -hula /usr/src/ total 73M drwxr-xr-x 4 root root 4.0K May 9 22:11 . drwxr-xr-x 14 root root 4.0K May 9 21:31 .. -rw-r--r-- 1 root root 0 May 7 17:35 .keep lrwxrwxrwx 1 root root 25 May 9 22:10 linux -> /usr/src/linux-2.6.39-rc6 drwxr-xr-x 24 root root 4.0K May 7 18:11 linux-2.6.37-gentoo-r4 drwxr-xr-x 24 root root 4.0K May 10 18:44 linux-2.6.39-rc6 -rw-r--r-- 1 homer homer 73M May 9 22:10 linux-2.6.39-rc6.tar.bz2
Then copy the .config file from the kernel source folder to /etc/kernels/ named to match the kernel source you want to build. This is the filename that the genkernel script was looking for on my system.
localhost linux # ls -hula /etc/kernels/ total 196K drwxr-xr-x 2 root root 4.0K May 9 23:05 . drwxr-xr-x 67 root root 4.0K May 10 22:07 .. -rw-r--r-- 1 root root 85K May 7 18:11 kernel-config-x86_64-2.6.37-gentoo-r4 -rw-r--r-- 1 root root 98K May 12 02:14 kernel-config-x86_64-2.6.39-rc6
After that, type genkernel all to build the kernel and all the required modules, this program may be obtained by running emerge genkernel to install the program. Make sure all of the file-system drivers are built into the kernel and are not modules, especially the driver for the file-system that / is on. this will build the kernel which on a i3 system like mine does not take very long at all, and then the kernel will be installed and the boot-loader menu updated. If you change the kernel configuration to get some hardware working, then you may re-run genkernel all and it will re-build and re-install the installed kernel image and then you can re-boot to enjoy your newly working hardware. Make sure you copy the new kernel config to /etc/kernels to make sure that the configuration will actually be used. This is how I installed the kernel for my system as I was not happy with the default 2.6.37-gentoo-r4 kernel supplied by the emerge gentoo-sources command. The 2.6.39 kernel on Gentoo gives the user a very fast and responsive desktop, which is faster than Ubuntu and Mint.