This page shows the basic steps you need to perform, if you for any reason want to switch bootloaders or apply some manual configuration.
Syslinux is the default light-weight bootloader used in Alpine, rEFInd is an easy to use boot menu that allows booting different operating systems, and Grub is a standard linux boot loader.
For (U)EFI systems, the
refind package can provide a nice EFI boot menu that allows booting different operating system from the available partitions.
refind is not yet available in the used alpine release, it may be installed in another dual/multi-booted linux distribution.
For example, with a Debian based distribution, it can be done like this:
apt install refind refind-install cp /usr/share/refind/refind/drivers_x64/ext4_x64.efi /boot/efi/EFI/refind/drivers_x64/
(Also enables the ext4 driver, to allow finding and booting Linux installations from ext4 partitions.)
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.
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
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
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
You can also place additional menu entries in the
/etc/update-extlinux.d/ directory, e.g. for dual booting.
/mnt is a FAT32 partition of type EF00 and
/boot belongs to the rootfs created after running
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).
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
For EFI, install Grub's EFI package instead. Note that
/boot has to be an EFI compatible filesystem like FAT32.
apk add grub-efi
Next install the MBR and GRUB binaries to disk for BIOS mode:
For EFI mode:
grub-install --target=x86_64-efi --efi-directory=/boot
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
See  for a list of available options.