AlpineLinux pre-build disk images

# building images

# docker based building
# flavor=virt format=qcow2
make images/virt/alpine.qcow2
# flavor=lts format=raw
make images/lts/alpine.raw

# packer based building
cd builds/alpine
efi=1 flavor=lts format=raw make

pre-build disk image can be download from releases

Features

• Minimal build
• Raw disk image
  • default to 2G
    • [OPTIONAL] can shrink image
• Auto build - based on GitHub Actions

⚠️

Default user:password is admin:admin or root:root

Directory

• builds/
  • alpine/
    • packer based base image builder
  • sysfs.apkvol/
    • build sysfs.apkvol for later installer
• scripts/
  • alpine.pkr.hcl
    • standard alpine installation
      • version = 3.12.0
      • mirror = https://mirrors.aliyun.com/alpine
      • flavor = virt, lts
      • format = qcow2
      • size = 40G
      • accel = hvf (macOS), kvm, none
• artifacts/ - prebuild apkvol, makes install predictable, cleaner, faster
  • sysfs.apkvol.tar.gz
    • build by sysfs
    • user root:root
    • dns 114.114.114.114
    • service sshd, acpid, ntpd
    • extra service - haveged
      • highly recommanded for virt
    • setup timezone(Asia/Shanghai), keymap
  • rootfs.apkvol.tar.gz
    • minimal apkvol

How to use

# All release https://github.com/wenerme/alpine-image/releases
# latest alpine-virt-3.12.img.gz
file=alpine-virt-3.12.img.gz
download_url=$(curl -s https://api.github.com/repos/wenerme/alpine-image/releases/latest | grep $file | sed -rn 's/.*?(https[^"]+).*/\1/p')
curl -LOC- $download_url
gzip -dk $file
# start by using qemu
qemu-system-x86_64 -hda ${file%%.gz}

# write to disk or usb
# macOS use rdisk
diskutil unmountdisk rdisk2
sudo dd if=${file%%.gz} of=/dev/rdisk2 of=/dev/rdisk2 conv=sparse status=progress bs=128MB
# Linux use sdx
sudo dd if=${file%%.gz} of=/dev/sdb conv=sparse status=progress bs=128MB

# now you can boot from the external storage

Images

• alpine-$FLAVOR-$VERSION-$ARCH.img
  • FLAVOR
    • virt
      • for cloud env - aws, gce, aliyun
      • for vm - qemu, libvirt
      • linux without firmware
    • ltx - Linux 5.14
      • with firmwares
      • can run on phy machines
    • rpi
      • Raspberry PI
      • armhf - PiZero Pi 1
      • armv7 - Pi 2, Pi 3
      • aarch64 - Pi 3, Pi 4
  • ARCH
    • x86_64
    • armhf - armv6
    • aarch64 - armv8 - arm64

Troubleshoting

flash to disk under macOS

# which disk to flush to
diskutil list

DISK=disk3
diskutil umountdisk $DISK

sudo dd if=dist/alpine-lts-3.15.0-x86_64-efi.raw of=/dev/r$DISK conv=sparse status=progress bs=128MB

diskutil eject $DISK

can not boot

using qemu with kernel

qemu with knernel can boot but can not direct boot

fixing boot or mbr

Check binfmt works

docker run -v --privileged -v /dev:/dev:ro \
  -v "$PWD":/build -w /build \
  -v "$PWD/cache/apk/${ARCH:-x86_64}:/etc/apk/cache" \
  wener/base ./check-binfmt.sh

Dev

# build using privileged - loopdev
FLAVOR=virt ./docker-build.sh
# enter shell for testing
FLAVOR=virt ./test.sh

# Normal boot
# macOS -accel hvf
qemu-system-x86_64 -accel hvf -hda alpine-x86_64-virt.img
# testing boot
qemu-system-x86_64 -accel hvf -hda alpine-x86_64-virt.img \
  -kernel vmlinuz-virt -initrd initramfs-virt

# testing cmdline
ROOT_UUID=$(./get-root-uuid.sh alpine-x86_64-virt.img)
#
qemu-system-x86_64 -accel hvf -hda alpine-x86_64-virt.img \
  -kernel vmlinuz-virt -initrd initramfs-virt \
  -append "root=UUID=$ROOT_UUID modules=sd-mod,usb-storage,ext4 nomodeset quiet rootfstype=ext4"

# MBR fix
dd bs=440 conv=notrunc count=1 if=/usr/share/syslinux/mbr.bin of=/dev/loop0
# dd bs=440 conv=notrunc count=1 if=mbr.bin of=alpine-x86_64-virt.img

# Local Playground
docker run --rm -it \
  --privileged -v /dev:/dev:ro \
  -v "$PWD/cache/apk/${ARCH:-x86_64}:/etc/apk/cache" \
  -v "$PWD":/build -w /build \
  --name builder wener/alpine-image-builder

Dev Pi

curl -O https://mirrors.tuna.tsinghua.edu.cn/alpine/v3.12/releases/aarch64/alpine-rpi-3.12.0-aarch64.tar.gz
mkdir -p aarch64/rpi
tar zxf alpine-rpi-3.12.0-aarch64.tar.gz -C aarch64/rpi


ARCH=aarch64 FLAVOR=rpi ./docker-build.sh

# aarch64 RPi 3B
# Keybord and network seems not working
#
# cmdline for stdio
# console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait
# cmdline for pi
# dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
# dtbs
# bcm2710-rpi-3-b.dtb bcm2837-rpi-3-b.dtb
qemu-system-aarch64 -M raspi3 \
  -append "console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait" \
  -serial stdio \
  -dtb aarch64/rpi/bcm2837-rpi-3-b.dtb \
  -kernel aarch64/rpi/boot/vmlinuz-rpi -initrd aarch64/rpi/boot/initramfs-rpi \
  -sd alpine-aarch64-rpi.img

# armhf RPi 3B
wget -qcN https://mirrors.tuna.tsinghua.edu.cn/alpine/v3.12/releases/armhf/alpine-rpi-3.12.0-armhf.tar.gz
mkdir -p armhf/rpi
tar zxf alpine-rpi-3.12.0-armhf.tar.gz -C armhf/rpi

qemu-system-arm -M raspi2 \
  -append "console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait" \
  -serial stdio \
  -dtb armhf/rpi/bcm2710-rpi-2-b.dtb \
  -kernel armhf/rpi/boot/vmlinuz-rpi2 -initrd armhf/rpi/boot/initramfs-rpi2 \
  -sd alpine-armhf-rpi.img

Roadmap

• more arch
  • x390
• uboot booting non x86

Local builds

ARCH=armhf FLAVOR=rpi ./docker-build.sh
ARCH=aarch64 FLAVOR=rpi ./docker-build.sh
FLAVOR=virt ./docker-build.sh
FLAVOR=lts ./docker-build.sh

Seealso

• knoopx/alpine-raspberry-pi