Difference between revisions of "Install/BootLoader"

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m (see: https://bugs.funtoo.org/browse/FL-1856)
(Installing a Bootloader)
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}}
 
}}
  
After you have edited your <code>/etc/boot.conf</code> file, run <code>boot-update</code>. If you check your <code>/boot/grub/grub.cfg</code> now, you should see something like this:  
+
After you have edited your <code>/etc/boot.conf</code> file, run <code>boot-update</code>. You should now have a <code>/boot/grub/grub.cfg</code> file, which you can edit using the following command:
  
{{file|name=/boot/grub/grub.cfg|desc=|body=
+
<console>
set timeout=3
+
# ##i##nano /boot/grub/grub.cfg
 +
</console>
  
  insmod part_gpt
 
  insmod fat
 
  set root=(hostdisk//dev/sda,gpt1)
 
  search --no-floppy --fs-uuid --set 3CFD-6884
 
if loadfont /grub/unifont.pf2; then
 
  set gfxmode=text
 
  insmod gfxterm
 
  insmod vbe
 
  terminal_output gfxterm
 
fi
 
  
set menu_color_normal=cyan/blue
+
To get your <code>/boot/grub/grub.cfg</code> to support booting with UEFI, make the following changes. Below the existing insmod lines, add the following lines.  Both of these involve adding support for the UEFI framebuffer to GRUB.:
set menu_color_highlight=blue/cyan
 
  
menuentry "Funtoo Linux - vmlinuz-3.16.3" {
+
<pre>
  insmod part_gpt
 
  insmod fat
 
  set root=(hostdisk//dev/sda,gpt1)
 
  search --no-floppy --fs-uuid --set 3CFD-6884
 
  linux /vmlinuz-3.16.3 video=uvesafb:1920x1080-32,mtrr:3,ywrap rootfstype=ext4 root=/dev/sda2
 
  set gfxpayload=text
 
}
 
set default=0
 
}}
 
 
 
To get your <code>/boot/grub/grub.cfg</code> to support booting with UEFI, make your <code>/boot/grub/grub.cfg</code> look like this:
 
{{file|name=/boot/grub/grub.cfg|desc=|body=
 
set timeout=3
 
 
 
  insmod part_gpt
 
  insmod fat
 
 
   insmod efi_gop
 
   insmod efi_gop
 
   insmod efi_uga
 
   insmod efi_uga
  set root=(hostdisk//dev/sda,gpt1)
+
</pre>
  search --no-floppy --fs-uuid --set 3CFD-6884
 
if loadfont /grub/unifont.pf2; then
 
  set gfxmode=auto
 
  insmod gfxterm
 
  insmod vbe
 
  terminal_output gfxterm
 
fi
 
  
set menu_color_normal=cyan/blue
+
Then, change the <code>set gfxpayload</code> line to read as follows. UEFI does not support text mode, so we will keep video initialized to the current resolution.:
set menu_color_highlight=blue/cyan
 
  
menuentry "Funtoo Linux - vmlinuz-3.16.3" {
+
<pre>
  insmod part_gpt
 
  insmod fat
 
  set root=(hostdisk//dev/sda,gpt1)
 
  search --no-floppy --fs-uuid --set 3CFD-6884
 
  linux /vmlinuz-3.16.3 video=uvesafb:1920x1080-32,mtrr:3,ywrap rootfstype=ext4 root=/dev/sda2
 
 
   set gfxpayload=keep
 
   set gfxpayload=keep
}
+
</pre>
set default=0
 
}}
 
  
The lines that we have added and altered do the following:
+
You can now save your changes by pressing <code>Control-X</code> and answering <code>y</code> when asked if you want to save the modified buffer. When prompted for a filename, hit Enter to use the existing filename.
* <code>insmod efi_gop</code> and <code>insmod efi_uga</code>: Both of these involve adding support for the UEFI framebuffer to GRUB.
 
* <code>set gfxmode=auto</code>: Instead of having the GRUB boot option screen being displayed at the smallest resolution possible, changing this to auto will make it fit the resolution of your display.
 

Revision as of 16:10, December 5, 2014


   Note

This is a template that is used as part of the Installation instructions which covers: boot loader configuration. Templates are being used to allow multiple variant install guides that use most of the same re-usable parts.


Installing a Bootloader

These install instructions show you how to use GRUB to boot using BIOS (old-school) or UEFI (new-school).

Old School (BIOS)

If you're using the BIOS to boot, setting up GRUB, the bootloader, is pretty easy.

To use this recommended boot method, first emerge boot-update. This will also cause grub-2 to be merged, since it is a dependency of boot-update.

(chroot) # emerge boot-update

Then, edit /etc/boot.conf and specify "Funtoo Linux genkernel" as the default setting at the top of the file, replacing "Funtoo Linux".

/etc/boot.conf should now look like this:

boot {
	generate grub
	default "Funtoo Linux genkernel" 
	timeout 3 
}

"Funtoo Linux" {
	kernel bzImage[-v]
}

"Funtoo Linux genkernel" {
	kernel kernel[-v]
	initrd initramfs[-v]
	params += real_root=auto 
} 

"Funtoo Linux better-initramfs" {
	kernel vmlinuz[-v]
	initrd /initramfs.cpio.gz
}

Please read man boot.conf for further details.

Running grub-install and boot-update

Finally, we will need to actually install the GRUB boot loader to your disk, and also run boot-update which will generate your boot loader configuration file:

(chroot) # grub-install --no-floppy /dev/sda
(chroot) # boot-update

Now you need to update your boot loader configuration file:

(chroot) # boot-update

You only need to run grub-install when you first install Funtoo Linux, but you need to re-run boot-update every time you modify your /etc/boot.conf file, so your changes are applied on next boot.

New School (UEFI)

If you're using UEFI to boot, setting up the boot loader is a bit more complicated for now, but this process will be improving soon. Perform the following steps.

Emerging GRUB

You will still use GRUB as a boot loader, but before emerging grub, you will need to enable EFI booting. To do this, add the following line to /etc/make.conf:

GRUB_PLATFORMS="efi-64"

Then, emerge boot-update. You will notice grub and efibootmgr getting pulled in as dependencies. This is expected and good:

(chroot) # emerge boot-update
Installing GRUB

Now, for the magic of getting everything in place for booting. You should copy your kernel and initramfs (if you have one -- you will if you are following the default install) to /boot. GRUB will boot those. But how do we get UEFI to boot GRUB? Well, we need to run the following command:

(chroot) # grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id="Funtoo Linux [GRUB]" --recheck /dev/sda

This command will simply install all the stuff to /boot/EFI and /boot/grub that your system needs to boot. In particular, the /boot/EFI/grub/grubx64.efi file will be created. This is the GRUB boot image that UEFI will load and start.

A more detailed explanation of the flags used in the above command:

  • --target=x86_64-efi: Tells GRUB that we want to install it in a way that allows it to boot in UEFI
  • --efi-directory=/boot: All GRUB UEFI files will be installed in /boot
  • --bootloader-id="Funtoo Linux [GRUB]": This flag is not necessary for GRUB to boot. However, it allows you to change the text of the boot option in the UEFI BIOS. The stuff in the quotes can be set to anything that you would like.
  • --recheck: If a device map already exists on the disk or partition that GRUB is being installed on, it will be removed.
  • /dev/sda:The device that we are installing GRUB on.
Configuring GRUB

OK, now UEFI has the GRUB image it needs to boot. But we still need to configure GRUB itself so it finds and boots your kernel and initramfs. This is done by performing the following steps. Since boot-update doesn't yet support UEFI, we will use boot-update, but then edit our /boot/grub/grub.cfg to support UEFI booting.

First, you will need to edit /etc/boot.conf. Format this as you would if you were booting without UEFI. If you are not sure how this should look, below is an example of what it could look like if you are booting from an unencrypted ext4 partition:

   /etc/boot.conf
boot {
        generate grub
        default "Funtoo Linux"
        timeout 3
}

"Funtoo Linux" {
        kernel vmlinuz[-v]
        params += rootfstype=ext4 root=/dev/sda2
}

After you have edited your /etc/boot.conf file, run boot-update. You should now have a /boot/grub/grub.cfg file, which you can edit using the following command:

root # nano /boot/grub/grub.cfg


To get your /boot/grub/grub.cfg to support booting with UEFI, make the following changes. Below the existing insmod lines, add the following lines. Both of these involve adding support for the UEFI framebuffer to GRUB.:

  insmod efi_gop
  insmod efi_uga

Then, change the set gfxpayload line to read as follows. UEFI does not support text mode, so we will keep video initialized to the current resolution.:

  set gfxpayload=keep

You can now save your changes by pressing Control-X and answering y when asked if you want to save the modified buffer. When prompted for a filename, hit Enter to use the existing filename.