By this point the chances are you’ve already had a look around the config menu and have noticed there’s an awful lot of stuff in there you don’t need. This is probably true, and a lot of people are interested in making the kernel smaller.
People building for embedded systems, where storage space and memory are scarce, naturally will want to pull as much stuff as possible out of the kernel. We’ve mentioned that there isn’t really a performance or memory hit from having so many unused drivers compiled as modules. However, there is a disk space hit, although perhaps not as large as you might think (see box, below).
Another reason for removing things is demonstrated by the Linux-libre kernel. Here, drivers that require proprietary firmware or microcode have all been removed. As has firmware and microcode itself, which if you take a
