Install using Chroot - nutthawit/alpine-dotfile GitHub Wiki

On LiveCD

Define variables for use throughout this document.

DISK_DRIVE=/dev/nvme0n1
ESP_PART="${DISK_DRIVE}p1"
ROOT_PART="${DISK_DRIVE}p2"
CHROOT_DIR=/alpine
SYSLINUX_PART=${CHROOT_DIR}/EFI/syslinux
TIMEZONE=Asia/Bangkok

Install alpine-chroot-install

dnf install -y make
mkdir ~/alpine-build && cd ~/alpine-build
git clone https://github.com/alpinelinux/alpine-chroot-install.git
make install

Create Btrfs partition

alias p="parted -sa optimal ${DISK_DRIVE}"
p mklabel gpt
p mkpart p 0G 1G
p mkpart p 1G 100%
p set 1 esp
mkfs.vfat -F32 ${ESP_PART}
mkfs.btrfs -L ALPINE -n 32k ${ROOT_PART}

NOTE: The Btrfs default nodesize for metadata is 16 KiB, while the default sectorsize for data is equal to page size and autodetected. To use a larger nodesize for metadata (must be a multiple of sectorsize, up to 64 KiB is allowed), specify a value for the nodesize via the -n switch.

NOTE: According to mkfs.btrfs(8) § OPTIONS, "a smaller node size increases fragmentation but leads to taller b-trees which in turn leads to lower locking contention. Higher node sizes give better packing and less fragmentation at the cost of more expensive memory operations while updating the metadata blocks".

Create subvolumes

mkdir ${CHROOT_DIR}
mount ${ROOT_PART} ${CHROOT_DIR}
btrfs subvolume create ${CHROOT_DIR}/@
btrfs subvolume create ${CHROOT_DIR}/home
btrfs subvolume create ${CHROOT_DIR}/var
umount ${CHROOT_DIR}

Mount

mount -o compress=zstd,subvol=@ ${ROOT_PART} ${CHROOT_DIR}
mkdir -p ${CHROOT_DIR}/home
mkdir -p ${CHROOT_DIR}/var
mkdir -p ${CHROOT_DIR}/boot
mount -o compress=zstd,subvol=home ${ROOT_PART} ${CHROOT_DIR}/home
mount -o compress=zstd,subvol=var ${ROOT_PART} ${CHROOT_DIR}/var
mkdir -p ${CHROOT_DIR}/boot/EFI/syslinux
mount ${ESP_PART} ${CHROOT_DIR}/boot/EFI

Install alpine base-system to chroot dir

sudo alpine-chroot-install

Enter chroot

${CHROOT_DIR}/enter-chroot

On chroot environment

Re-define variables

DISK_DRIVE=/dev/nvme0n1
ESP_PART="${DISK_DRIVE}p1"
ROOT_PART="${DISK_DRIVE}p2"
CHROOT_DIR=/alpine
TIMEZONE=Asia/Bangkok
SYSLINUX_PART=${CHROOT_DIR}/EFI/syslinux

Preparing init services reference

apk add openrc

rc-update add devfs sysinit
rc-update add dmesg sysinit
rc-update add mdev sysinit

rc-update add hwclock boot
rc-update add modules boot
rc-update add sysctl boot
rc-update add hostname boot
rc-update add bootmisc boot
rc-update add syslog boot

rc-update add mount-ro shutdown
rc-update add killprocs shutdown
rc-update add savecache shutdown

NOTE: If btrfs is used for root filesystem, ensure that the initramfs is generated with the btrfs module, otherwise the system may fail to boot.

Edit the /etc/mkinitfs/mkinitfs.conf and ensure that "btrfs" is in the list of features

features="ata base cdrom ext4 keymap kms mmc nvme raid scsi usb virtio btrfs"

Regenerate the initramfs

mkinitfs

Load the btrfs kernel module

modprobe btrfs
echo btrfs >> /etc/modules
rc-update add btrfs-scan boot

Install bootloader (Using EFI with syslinux)

Reference: https://wiki.alpinelinux.org/wiki/Bootloaders#Syslinux

  1. Install the GPT MBR onto the drive that you want to install the bootloader on

Reference: https://wiki.archlinux.org/title/Syslinux#GUID_partition_table

apk add syslinux
dd bs=440 count=1 conv=notrunc if=/usr/share/syslinux/gptmbr.bin of=$DISK_DRIVE
  1. Install required Syslinux binaries
extlinux --install $SYSLINUX_PART
  1. Update content of /mnt/EFI/syslinux/syslinux.cfg 
# Contents of /mnt/EFI/syslinux/syslinux.cfg

...
DEFAULT menu.c32
PROMPT 0
MENU TITLE Alpine/Linux Boot Menu
MENU HIDDEN
MENU AUTOBOOT Alpine will be booted automatically in # seconds
TIMEOUT 10
LABEL lts
  MENU DEFAULT
  MENU LABEL Linux lts
  LINUX /boot/vmlinuz-lts
  INITRD /boot/initrd-lts
  APPEND root=/dev/nvme0n1p2 modules=sd-load,usb-storage,btrfs quiet
  1. Add syslinux to the EFI boot menu
apk add efibootmgr
efibootmgr -c -d $DISK_DRIVE -p 1 -l /EFI/syslinux/syslinux.efi -L "ALPINE-SYSLINUX" --unicode
  1. Set root password
passwd
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