Installing Your Kernel

Once compiled, your custom kernel can be found as a file called "bsd" in the compile directory. Confirm that you have your current, well-running kernel backed up, and copy this file to /bsd. That's it! The next time you reboot, you will be running on your new kernel.

Some people do not like to copy their custom kernel to /bsd until they are absolutely certain that the kernel will boot. You can copy this custom kernel to any file in the root partition and use the alternate kernel booting process to boot your custom kernel. You can assume that your new kernel will work and install it immediately, but be prepared to fall back to a good kernel, or you can assume your new kernel will fail and test it before installing it. Because the kernel install process is so simple, once you've mastered booting alternate kernels (see Chapter 6) you really don't have much to worry about.

Identifying Your Booted Kernel

If you have been running on a custom kernel for some time, you might even forget what configuration you're actually running on. The uname(1) command will tell you the name of the kernel configuration file used to build the kernel you booted on. (This is not necessarily /bsd; remember, you can boot an alternate kernel, as discussed in Chapter 6.) While uname(1) has many flags, the "-v" flag will give you the name of your kernel configuration and the number of times you have compiled that particular kernel.

 # uname -v OPENBSDTEST#0 # 

Congratulations! You're running on your new kernel. At this point, you should have your base system functioning as desired. Let's see how to actually make it useful.