From Gentoo Wiki
Jump to:navigation Jump to:search

Booting the installation CD

Once the installation CD is burned, it is time to boot it. Remove all CDs from the CD drives, and insert the Gentoo installation CD. Reboot the system and wait for the EFI firmware to load on the console. The exact option to select will differ depending on the hardware.

Most implementations usually present an option directly on the first menu (the EFI Boot Manager). The exact wording would differ but would usually be something like "CD Boot", "Removable Media Boot" or "Internal Bootable DVD". Select this option.

If the EFI implementation does not present such an option, boot the CD using the EFI Shell. All implementations will present an option to enter the shell on the Boot Manager menu. Select this option. The EFI Shell will display a list of usable block devices (blkn:) and also a list of filesystems the EFI Shell can actually access (fsn:).

In most cases the option will be the fs0: choice; regardless, (provided the CD drive recognizes the CD), one fsn entry for the CD drive (the CD drive's EFI device path will contain CD-ROM in the wording) will be displayed. Enter fsn:, replacing n as required and including the colon, followed by the Enter key. Next just type elilo followed by the Enter key.

The ELILO boot message is up next, and asks the user to enter a kernel to boot as well as any additional options to pass to the kernel command line. In most cases just hit the Enter key or wait five seconds. Only one kernel is supplied on the IA64 installation CD, the gentoo kernel.

Several kernel aliases are provided which add extra options to the kernel command line, which may need to be used instead of the default gentoo option depending on the hardware:

  • The gentoo-serial option forces a serial console on the first serial port (ttyS0) at 9600bps. This may be required on some older EFI implementations where the kernel can't detect what console to use. Try this option if booting the default gentoo kernel produces no output and if a serial console is used. If the serial console is not connected to the the first serial port then manually select the console by typing gentoo console=ttyS#,9600 where # is the number of the serial port.
  • The gentoo-ilo option forces a serial console on the ttyS3 serial port at 9600bps. This should be used when installing using the HP iLO remote console feature.
  • The gentoo-sgi option forces a serial console on the ttySG0 serial port at 115200bps. This should only be needed on SGI hardware; if the console is properly selected in the default EFI settings, or when using a video console, then this option should not be required.

It is also possible to provide additional kernel options. They represent optional settings to (de)activate at will.

Hardware options
acpi=on This loads support for ACPI and also causes the acpid daemon to be started by the CD on boot. This is only needed if the system requires ACPI to function properly. This is not required for Hyperthreading support.
acpi=off Completely disables ACPI. This is useful on some older systems and is also a requirement for using APM. This will disable any Hyperthreading support of your processor.
console=X This sets up serial console access for the CD. The first option is the device, usually ttyS0 on x86, followed by any connection options, which are comma separated. The default options are 9600,8,n,1.
dmraid=X This allows for passing options to the device-mapper RAID subsystem. Options should be encapsulated in quotes.
doapm This loads APM driver support. This also requires that acpi=off.
dopcmcia This loads support for PCMCIA and Cardbus hardware and also causes the pcmcia cardmgr to be started by the CD on boot. This is only required when booting from PCMCIA/Cardbus devices.
doscsi This loads support for most SCSI controllers. This is also a requirement for booting most USB devices, as they use the SCSI subsystem of the kernel.
sda=stroke This allows the user to partition the whole hard disk even when the BIOS is unable to handle large disks. This option is only used on machines with an older BIOS. Replace sda with the device that requires this option.
ide=nodma This forces the disabling of DMA in the kernel and is required by some IDE chipsets and also by some CD-ROM drives. If the system is having trouble reading from the IDE CD-ROM, try this option. This also disables the default hdparm settings from being executed.
noapic This disables the Advanced Programmable Interrupt Controller that is present on newer motherboards. It has been known to cause some problems on older hardware.
nodetect This disables all of the autodetection done by the CD, including device autodetection and DHCP probing. This is useful for doing debugging of a failing CD or driver.
nodhcp This disables DHCP probing on detected network cards. This is useful on networks with only static addresses.
nodmraid Disables support for device-mapper RAID, such as that used for on-board IDE/SATA RAID controllers.
nofirewire This disables the loading of Firewire modules. This should only be necessary if your Firewire hardware is causing a problem with booting the CD.
nogpm This disables gpm console mouse support.
nohotplug This disables the loading of the hotplug and coldplug init scripts at boot. This is useful for doing debugging of a failing CD or driver.
nokeymap This disables the keymap selection used to select non-US keyboard layouts.
nolapic This disables the local APIC on Uniprocessor kernels.
nosata This disables the loading of Serial ATA modules. This is used if the system is having problems with the SATA subsystem.
nosmp This disables SMP, or Symmetric Multiprocessing, on SMP-enabled kernels. This is useful for debugging SMP-related issues with certain drivers and motherboards.
nosound This disables sound support and volume setting. This is useful for systems where sound support causes problems.
nousb This disables the autoloading of USB modules. This is useful for debugging USB issues.
slowusb This adds some extra pauses into the boot process for slow USB CD-ROMs, like in the IBM BladeCenter.
Logical volume/device management
dolvm This enables support for Linux's Logical Volume Management.
Other options
debug Enables debugging code. This might get messy, as it displays a lot of data to the screen.
docache This caches the entire runtime portion of the CD into RAM, which allows the user to umount /mnt/cdrom and mount another CD-ROM. This option requires that there is at least twice as much available RAM as the size of the CD.
doload=X This causes the initial ramdisk to load any module listed, as well as dependencies. Replace X with the module name. Multiple modules can be specified by a comma-separated list.
dosshd Starts sshd on boot, which is useful for unattended installs.
passwd=foo Sets whatever follows the equal sign as the root password, which is required for dosshd since the root password is by default scrambled.
noload=X This causes the initial ramdisk to skip the loading of a specific module that may be causing a problem. Syntax matches that of doload.
nonfs Disables the starting of portmap/nfsmount on boot.
nox This causes an X-enabled LiveCD to not automatically start X, but rather, to drop to the command line instead.
scandelay This causes the CD to pause for 10 seconds during certain portions the boot process to allow for devices that are slow to initialize to be ready for use.
scandelay=N This allows the user to specify a given delay, in seconds, to be added to certain portions of the boot process to allow for devices that are slow to initialize to be ready for use. Replace X with the number of seconds to pause.
The CD will check for no* options before do* options, so that options can be overridden in the exact order specified.

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 Alt+F1 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 Alt+F2, Alt+F3, Alt+F4 ... Get back to the one started on by pressing Alt+F1.