diff --git a/scripts/run_archiso.sh b/scripts/run_archiso.sh
index 210246c..4a062ee 100755
--- a/scripts/run_archiso.sh
+++ b/scripts/run_archiso.sh
@@ -15,117 +15,106 @@
 set -eu
 
 print_help() {
-    cat << EOF
+    local usagetext
+    IFS='' read -r -d '' usagetext <<EOF || true
 Usage:
     run_archiso [options]
 
 Options:
-    -b              set boot type to 'bios' (default)
+    -b              set boot type to 'BIOS' (default)
     -h              print help
     -i [image]      image to boot into
-    -s              use secure boot (only relevant when using UEFI)
-    -u              set boot type to 'uefi'
+    -s              use Secure Boot (only relevant when using UEFI)
+    -u              set boot type to 'UEFI'
 
 Example:
     Run an image using UEFI:
     $ run_archiso -u -i archiso-2020.05.23-x86_64.iso
 EOF
+    printf '%s' "${usagetext}"
 }
 
 cleanup_working_dir() {
-    if [ -d "${working_dir}" ]; then
-        rm -rf "${working_dir}"
+    if [[ -d "${working_dir}" ]]; then
+        rm -rf -- "${working_dir}"
     fi
 }
 
 copy_ovmf_vars() {
-    if [ ! -f /usr/share/edk2-ovmf/x64/OVMF_VARS.fd ]; then
-        echo "ERROR: OVMF_VARS.fd not found. Install edk2-ovmf."
+    if [[ ! -f '/usr/share/edk2-ovmf/x64/OVMF_VARS.fd' ]]; then
+        printf 'ERROR: %s\n' "OVMF_VARS.fd not found. Install edk2-ovmf."
         exit 1
     fi
-    cp -av /usr/share/edk2-ovmf/x64/OVMF_VARS.fd "${working_dir}"
+    cp -av -- '/usr/share/edk2-ovmf/x64/OVMF_VARS.fd' "${working_dir}/"
 }
 
 check_image() {
-    if [ -z "$image" ]; then
-        echo "ERROR: Image name can not be empty."
+    if [[ -z "$image" ]]; then
+        printf 'ERROR: %s\n' "Image name can not be empty."
         exit 1
     fi
-    if [ ! -f "$image" ]; then
-        echo "ERROR: Image file ($image) does not exist."
+    if [[ ! -f "$image" ]]; then
+        printf 'ERROR: %s\n' "Image file (${image}) does not exist."
         exit 1
     fi
 }
 
 run_image() {
-    [ "$boot_type" == "bios" ] && run_image_using_bios
-    [ "$boot_type" == "uefi" ] && run_image_using_uefi
-}
-
-run_image_using_bios() {
-    qemu-system-x86_64 \
-        -boot order=d,menu=on,reboot-timeout=5000 \
-        -m size=3072,slots=0,maxmem=$((3072*1024*1024)) \
-        -k en \
-        -name archiso,process=archiso_0 \
-        -drive file="${image}",media=cdrom,readonly=on,if=virtio \
-        -display sdl \
-        -vga virtio \
-        -device virtio-net-pci,netdev=net0 -netdev user,id=net0 \
-        -enable-kvm \
-        -no-reboot
-}
-
-run_image_using_uefi() {
-    local ovmf_code=/usr/share/edk2-ovmf/x64/OVMF_CODE.fd
-    local secure_boot_state=off
-    copy_ovmf_vars
-    if [ "${secure_boot}" == "yes" ]; then
-        echo "Using Secure Boot"
-        ovmf_code=/usr/share/edk2-ovmf/x64/OVMF_CODE.secboot.fd
-        secure_boot_state=on
+    if [[ "$boot_type" == 'uefi' ]]; then
+        copy_ovmf_vars
+        if [[ "${secure_boot}" == 'on' ]]; then
+            printf '%s\n' 'Using Secure Boot'
+            local ovmf_code='/usr/share/edk2-ovmf/x64/OVMF_CODE.secboot.fd'
+        else
+            local ovmf_code='/usr/share/edk2-ovmf/x64/OVMF_CODE.fd'
+        fi
+        qemu_options+=(
+            '-drive' "if=pflash,format=raw,unit=0,file=${ovmf_code},readonly"
+            '-drive' "if=pflash,format=raw,unit=1,file=${working_dir}/OVMF_VARS.fd"
+            '-global' "driver=cfi.pflash01,property=secure,value=${secure_boot}"
+        )
     fi
+
     qemu-system-x86_64 \
         -boot order=d,menu=on,reboot-timeout=5000 \
-        -m size=3072,slots=0,maxmem=$((3072*1024*1024)) \
+        -m "size=3072,slots=0,maxmem=$((3072*1024*1024))" \
         -k en \
         -name archiso,process=archiso_0 \
         -drive file="${image}",media=cdrom,readonly=on,if=virtio \
-        -drive if=pflash,format=raw,unit=0,file="${ovmf_code}",readonly \
-        -drive if=pflash,format=raw,unit=1,file="${working_dir}/OVMF_VARS.fd" \
-        -machine type=q35,smm=on,accel=kvm \
-        -global driver=cfi.pflash01,property=secure,value="${secure_boot_state}" \
-        -global ICH9-LPC.disable_s3=1 \
         -display sdl \
         -vga virtio \
         -device virtio-net-pci,netdev=net0 -netdev user,id=net0 \
+        -machine type=q35,smm=on,accel=kvm \
+        -global ICH9-LPC.disable_s3=1 \
         -enable-kvm \
+        "${qemu_options[@]}" \
         -no-reboot
 }
 
 set_image() {
-    if [ -z "$image" ]; then
-        echo "ERROR: Image name can not be empty."
+    if [[ -z "$image" ]]; then
+        printf 'ERROR: %s\n' "Image name can not be empty."
         exit 1
     fi
-    if [ ! -f "$image" ]; then
-        echo "ERROR: Image ($image) does not exist."
+    if [[ ! -f "$image" ]]; then
+        printf 'ERROR: %s\n' "Image (${image}) does not exist."
         exit 1
     fi
     image="$1"
 }
 
-image=""
-boot_type="bios"
-secure_boot="no"
-working_dir="$(mktemp -d)"
+image=''
+boot_type='bios'
+secure_boot='off'
+qemu_options=()
+working_dir="$(mktemp -dt run_archiso.XXXXXXXXXX)"
 trap cleanup_working_dir EXIT
 
-if [ ${#@} -gt 0 ]; then
+if (( ${#@} > 0 )); then
     while getopts 'bhi:su' flag; do
-        case "${flag}" in
+        case "$flag" in
             b)
-                boot_type=bios
+                boot_type='bios'
                 ;;
             h)
                 print_help
@@ -135,13 +124,13 @@ if [ ${#@} -gt 0 ]; then
                 image="$OPTARG"
                 ;;
             u)
-                boot_type=uefi
+                boot_type='uefi'
                 ;;
             s)
-                secure_boot=yes
+                secure_boot='on'
                 ;;
             *)
-                echo "Error: Wrong option. Try 'run_archiso -h'."
+                printf '%s\n' "Error: Wrong option. Try 'run_archiso -h'."
                 exit 1
                 ;;
         esac