Easy bash script to install ArchLinuxARM for RPi3 on an SD Card

prepare_sdcard.sh

#!/bin/bash
#
# Pre-requisite: move this script next to the .tar.gz image file
# you can download at http://os.archlinuxarm.org/os/ArchLinuxARM-rpi-3-latest.tar.gz
#
# Usage: ./prepare_sdcard.sh /dev/sdb
#
#####################################
DRIVE_PATH=$1

DRIVE_BOOT=`${DRIVE_PATH}1`
DRIVE_ROOT=`${DRIVE_PATH}2`

echo ">> Clearing SDCard from previous state..."
wipefs -a $DRIVE_PATH &>/dev/null

# to create the partitions programatically (rather than manually)
# we're going to simulate the manual input to fdisk
# The sed script strips off all the comments so that we can
# document what we're doing in-line with the actual commands
# Note that a blank line (commented as "default" will send a empty
# line terminated with a newline to take the fdisk default.
echo ">> Preparing partitions..."
sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | fdisk $DRIVE_PATH &>/dev/null
  o # clear the in memory partition table
  n # new partition
  p # primary partition
  1 # partition number 1
    # default - start at beginning of disk
  +100M # 100 MB boot parttion
  t # change type
  c # to FAT
  n # new partition
  p # primary partition
  2 # partion number 2
    # default, start immediately after preceding partition
    # default, extend partition to end of disk
  w # write the partition table
  q # and we're done
EOF

# Format FAT partition
echo ">> Formatting 100MB partition to vfat..."
mkfs.vfat -F $DRIVE_BOOT &>/dev/null

# Format EXT4 partition
echo ">> Formatting the remaining partition to ext4..."
mkfs.ext4 -F $DRIVE_ROOT &>/dev/null

# Prepare required folders
echo ">> Preparing mount folders..."
mkdir -p sd-boot
mkdir -p sd-root

# Mount partitions
echo ">> Mounting partitions..."
mount $DRIVE_BOOT sd-boot &>/dev/null
mount $DRIVE_ROOT sd-root &>/dev/null

# Cleaning
echo ">> Removing previous files inside partitions..."
rm -Rf sd-boot/*
rm -Rf sd-root/*

# Extract files
echo ">> Extracting root filesystem to your SDCard..."
bsdtar -xpf ArchLinuxARM-rpi-3-latest.tar.gz -C sd-root &>/dev/null

# Flush
echo ">> Flushing..."
sync

# Move boot files to the relative partition
echo ">> Moving boot files to the relative boot partition..."
mv sd-root/boot/* sd-boot

# Unmount partitions
echo ">> Unmounting partitions..."
umount sd-boot sd-root &>/dev/null

# Cleaning
echo ">> Cleaning..."
rm -R sd-boot sd-root

# Done!
echo ">> Done!"