Handbook:AMD64/Blocks/Booting

Booting the installation media
Once the installation CD is burned, it is time to boot it. Remove all external bootable media from the system (including any CD/DVD disks or USB drives), reboot the system, and enter the motherboard's firmware user interface. This is usually performed by pressing a keyboard key such as, , , or during the Power-On Self-test (POST) process. The 'trigger' key varies depending on the system and motherboard. If it is not obvious use an internet search engine and do some research using the motherboard's model name as the search keyword. Results should be easy to determine. Once inside the motherboard's firmware menu, change the boot order so that the external bootable media (CD/DVD disks or USB drives) are tried before the internal disk devices. Without this change, the system will most likely reboot to the internal disk device, ignoring the external boot media.

Now place the installation CD in the CD-ROM drive and reboot. A boot prompt should be shown. At this screen, will begin the boot process with the default boot options. To boot the installation CD with custom boot options, specify a kernel followed by boot options and then hit.

At the boot prompt, users get the option of displaying the available kernels and boot options. If no choice is made within 15 seconds (either displaying information or using a kernel) then the installation CD will fall back to booting from disk. This allows installations to reboot and try out their installed environment without the need to remove the CD from the tray (something well appreciated for remote installations).

We mentioned specifying a kernel. On the installation CD, several kernels are provided. The default one is called gentoo. Other kernels are for specific hardware needs and the -nofb variants disable framebuffer support.

The next table gives a short overview of the available kernels.

Alongside the kernel, boot options help in tuning the boot process further.

Now boot the CD, select a kernel (if the default  kernel does not suffice) and boot options. As an example, we boot the  kernel, with   as a kernel parameter:

Next the user will be greeted with a boot screen and progress bar. If the installation is done on a system with a non-US keyboard, make sure to immediately press +  to switch to verbose mode and follow the prompt. If no selection is made in 10 seconds the default (US keyboard) will be accepted and the boot process will continue. Once the boot process completes, the user is automatically logged in to the "Live" Gentoo Linux environment as the root user, the super user. A root prompt is displayed on the current console, and one can switch to other consoles by pressing +,  +  and  +. Get back to the one started on by pressing +.