Difference between revisions of "Bootloaders"

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The settings for this script can be found in <code>/etc/update-extlinux.conf</code>, including the option to disable automatic overwriting of <code>/boot/extlinux.conf</code>.
 
The settings for this script can be found in <code>/etc/update-extlinux.conf</code>, including the option to disable automatic overwriting of <code>/boot/extlinux.conf</code>.
 
You can also place additional menu entries in the <code>/etc/update-extlinux.d/</code> directory, e.g. for dual boating.
 
You can also place additional menu entries in the <code>/etc/update-extlinux.d/</code> directory, e.g. for dual boating.
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== EFI ==
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{{Todo|Work in progress. This should at least get you started.}}
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Assuming <code>/mnt</code> is a FAT32 partition of type EF00 and <code>/boot</code> belongs to the rootfs created after running <code>setup-disk</code>:
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<pre>
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mkdir -p /mnt/EFI/syslinux
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cp /usr/share/syslinux/efi64/* /mnt/EFI/syslinux/
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cp /boot/extlinux.conf /mnt/EFI/syslinux/syslinux.cfg
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cp /boot/vmlinuz* /mnt/
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cp /boot/initramfs* /mnt/
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</pre>
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You may need to modify <code>/mnt/EFI/syslinux/syslinux.cfg</code> to change the paths to absolute paths (just add a / in front of the vmlinuz/initramfs entries),
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or copy the files to <code>/mnt/EFI/syslinux</code> instead (XXX: untested).
  
  
 
= Installing GRUB =
 
= Installing GRUB =
 
{{Todo|EFI example, dual boot scenarios.}}
 
  
 
To install GRUB in BIOS mode, (optionally) remove the Syslinux package and install the required GRUB packages:
 
To install GRUB in BIOS mode, (optionally) remove the Syslinux package and install the required GRUB packages:

Revision as of 11:49, 20 July 2017

By default Alpine uses Syslinux as bootloader. This page shows the basic steps you need to perform, if you for any reason want to switch bootloaders or apply some manual configuration.


Installing Syslinux

If you want to switch from another bootloader back to Syslinux, or if you for some reason want to install Syslinux manually, the following steps are required.

Install the syslinux package:

apk add syslinux

If you're using GPT partitions, install the GPT MBR onto the drive you want to install the bootloader on (in this case /dev/sda):

dd bs=440 count=1 conv=notrunc if=/usr/share/syslinux/gptmbr.bin of=/dev/sda

Or if you're using DOS partitions, install the DOS MBR instead:

dd bs=440 count=1 conv=notrunc if=/usr/share/syslinux/mbr.bin of=/dev/sda


Next install the required Syslinux binaries. Despite being called extlinux, Syslinux supports booting from FAT12/16/32, NTFS, ext2/3/4, Btrfs, XFS, and UFS/FFS filesystems.

extlinux --install /boot

The configuration file is located in /boot/extlinux.conf. Alpine ships with a script called update-extlinux which automatically (re)generates this file, for example on updates to Syslinux. The settings for this script can be found in /etc/update-extlinux.conf, including the option to disable automatic overwriting of /boot/extlinux.conf. You can also place additional menu entries in the /etc/update-extlinux.d/ directory, e.g. for dual boating.


EFI

Underconstruction clock icon gray.svg
Todo: Work in progress. This should at least get you started.


Assuming /mnt is a FAT32 partition of type EF00 and /boot belongs to the rootfs created after running setup-disk:

mkdir -p /mnt/EFI/syslinux
cp /usr/share/syslinux/efi64/* /mnt/EFI/syslinux/
cp /boot/extlinux.conf /mnt/EFI/syslinux/syslinux.cfg
cp /boot/vmlinuz* /mnt/
cp /boot/initramfs* /mnt/

You may need to modify /mnt/EFI/syslinux/syslinux.cfg to change the paths to absolute paths (just add a / in front of the vmlinuz/initramfs entries), or copy the files to /mnt/EFI/syslinux instead (XXX: untested).


Installing GRUB

To install GRUB in BIOS mode, (optionally) remove the Syslinux package and install the required GRUB packages:

apk del syslinux
apk add grub grub-bios

Next install the MBR and GRUB binaries to disk:

grub-install /dev/vda

GRUB ships with an automatic config generator, including some automatic detection of other operating systems installed on the device:

grub-mkconfig -o /boot/grub/grub.cfg

This script can be configured via the /etc/default/grub file. See [1] for a list of available options.