diff --git a/src/kernel-install/50-depmod.install b/src/kernel-install/50-depmod.install
index fd00c436322..61afdd4e9cd 100644
--- a/src/kernel-install/50-depmod.install
+++ b/src/kernel-install/50-depmod.install
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
 # ex: ts=8 sw=4 sts=4 et filetype=sh
 # SPDX-License-Identifier: LGPL-2.1-or-later
@@ -20,23 +20,27 @@
 
 COMMAND="$1"
 KERNEL_VERSION="$2"
-ENTRY_DIR_ABS="$3"
-KERNEL_IMAGE="$4"
-INITRD_OPTIONS_START="5"
-
-[[ $KERNEL_VERSION ]] || exit 1
 
 case "$COMMAND" in
     add)
-        [[ -d "/lib/modules/${KERNEL_VERSION}/kernel" ]] || exit 0
-        [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && \
-            echo "Running depmod -a ${KERNEL_VERSION}"
-        exec depmod -a "${KERNEL_VERSION}"
+        [ -d "/lib/modules/$KERNEL_VERSION/kernel" ] || exit 0
+        [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && echo "+depmod -a $KERNEL_VERSION"
+        exec depmod -a "$KERNEL_VERSION"
         ;;
     remove)
         [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && \
             echo "Removing /lib/modules/${KERNEL_VERSION}/modules.dep and associated files"
-        exec rm -f /lib/modules/"${KERNEL_VERSION}"/modules.{alias{,.bin},builtin{,.alias}.bin,dep{,.bin},devname,softdep,symbols{,.bin}}
+        exec rm -f \
+            "/lib/modules/$KERNEL_VERSION/modules.alias" \
+            "/lib/modules/$KERNEL_VERSION/modules.alias.bin" \
+            "/lib/modules/$KERNEL_VERSION/modules.builtin.bin" \
+            "/lib/modules/$KERNEL_VERSION/modules.builtin.alias.bin" \
+            "/lib/modules/$KERNEL_VERSION/modules.dep" \
+            "/lib/modules/$KERNEL_VERSION/modules.dep.bin" \
+            "/lib/modules/$KERNEL_VERSION/modules.devname" \
+            "/lib/modules/$KERNEL_VERSION/modules.softdep" \
+            "/lib/modules/$KERNEL_VERSION/modules.symbols" \
+            "/lib/modules/$KERNEL_VERSION/modules.symbols.bin"
         ;;
     *)
         exit 0
diff --git a/src/kernel-install/90-loaderentry.install b/src/kernel-install/90-loaderentry.install
index 044eced3f01..e588e72bf9c 100644
--- a/src/kernel-install/90-loaderentry.install
+++ b/src/kernel-install/90-loaderentry.install
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
 # ex: ts=8 sw=4 sts=4 et filetype=sh
 # SPDX-License-Identifier: LGPL-2.1-or-later
@@ -22,68 +22,53 @@ COMMAND="$1"
 KERNEL_VERSION="$2"
 ENTRY_DIR_ABS="$3"
 KERNEL_IMAGE="$4"
-INITRD_OPTIONS_START="5"
+INITRD_OPTIONS_SHIFT=4
 
-if ! [[ $KERNEL_INSTALL_MACHINE_ID ]]; then
-    exit 0
-fi
-
-if [ "$KERNEL_INSTALL_LAYOUT" != "bls" ]; then
-    exit 0
-fi
+[ "$KERNEL_INSTALL_LAYOUT" = "bls" ] || exit 0
 
 MACHINE_ID="$KERNEL_INSTALL_MACHINE_ID"
 BOOT_ROOT="$KERNEL_INSTALL_BOOT_ROOT"
 
 BOOT_MNT="$(stat -c %m "$BOOT_ROOT")"
-if [[ "$BOOT_MNT" == '/' ]]; then
+if [ "$BOOT_MNT" = '/' ]; then
     ENTRY_DIR="$ENTRY_DIR_ABS"
 else
     ENTRY_DIR="${ENTRY_DIR_ABS#$BOOT_MNT}"
 fi
 
-if [[ $COMMAND == remove ]]; then
-    rm -f "$BOOT_ROOT/loader/entries/$MACHINE_ID-$KERNEL_VERSION.conf"
-    rm -f "$BOOT_ROOT/loader/entries/$MACHINE_ID-$KERNEL_VERSION+"*".conf"
-    exit 0
-fi
+case "$COMMAND" in
+    remove)
+        exec rm -f \
+            "$BOOT_ROOT/loader/entries/$MACHINE_ID-$KERNEL_VERSION.conf" \
+            "$BOOT_ROOT/loader/entries/$MACHINE_ID-$KERNEL_VERSION+"*".conf"
+        ;;
+    add)
+        ;;
+    *)
+        exit 1
+        ;;
+esac
 
-if ! [[ $COMMAND == add ]]; then
-    exit 1
-fi
-
-if ! [[ $KERNEL_IMAGE ]]; then
-    exit 1
-fi
-
-if [[ -f /etc/os-release ]]; then
+if [ -r /etc/os-release ]; then
     . /etc/os-release
-elif [[ -f /usr/lib/os-release ]]; then
+elif [ -r /usr/lib/os-release ]; then
     . /usr/lib/os-release
 fi
 
-if ! [[ $PRETTY_NAME ]]; then
-    PRETTY_NAME="Linux $KERNEL_VERSION"
-fi
+[ -n "$PRETTY_NAME" ] || PRETTY_NAME="Linux $KERNEL_VERSION"
 
-if [[ -f /etc/kernel/cmdline ]]; then
-    read -r -d '' -a BOOT_OPTIONS < /etc/kernel/cmdline
-elif [[ -f /usr/lib/kernel/cmdline ]]; then
-    read -r -d '' -a BOOT_OPTIONS < /usr/lib/kernel/cmdline
+if [ -r /etc/kernel/cmdline ]; then
+    BOOT_OPTIONS="$(tr -s "$IFS" ' ' </etc/kernel/cmdline)"
+elif [ -r /usr/lib/kernel/cmdline ]; then
+    BOOT_OPTIONS="$(tr -s "$IFS" ' ' </usr/lib/kernel/cmdline)"
 else
-    declare -a BOOT_OPTIONS
-
-    read -r -d '' -a line < /proc/cmdline
-    for i in "${line[@]}"; do
-        [[ "${i#initrd=*}" != "$i" ]] && continue
-        [[ "${i#BOOT_IMAGE=*}" != "$i" ]] && continue
-        BOOT_OPTIONS+=("$i")
-    done
+    BOOT_OPTIONS="$(tr -s "$IFS" '\n' </proc/cmdline | grep -ve '^BOOT_IMAGE=' -e '^initrd=' | tr '\n' ' ')"
 fi
+BOOT_OPTIONS="${BOOT_OPTIONS% }"
 
-if [[ -f /etc/kernel/tries ]]; then
+if [ -r /etc/kernel/tries ]; then
     read -r TRIES </etc/kernel/tries
-    if ! [[ "$TRIES" =~ ^[0-9]+$ ]] ; then
+    if ! echo "$TRIES" | grep -q '^[0-9][0-9]*$'; then
         echo "/etc/kernel/tries does not contain an integer." >&2
         exit 1
     fi
@@ -106,43 +91,40 @@ install -g root -o root -m 0644 "$KERNEL_IMAGE" "$ENTRY_DIR_ABS/linux" || {
     exit 1
 }
 
-INITRD_OPTIONS=( "${@:${INITRD_OPTIONS_START}}" )
+shift "$INITRD_OPTIONS_SHIFT"
+for initrd; do
+    [ -f "$initrd" ] || {
+        echo "Initrd '$initrd' not a file." >&2
+        exit 1
+    }
 
-for initrd in "${INITRD_OPTIONS[@]}"; do
-    if [[ -f "${initrd}" ]]; then
-        initrd_basename="$(basename ${initrd})"
-        [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && \
-            echo "Installing $ENTRY_DIR_ABS/${initrd_basename}"
-        install -g root -o root -m 0644 "${initrd}" "$ENTRY_DIR_ABS/${initrd_basename}" || {
-            echo "Could not copy '${initrd}' to '$ENTRY_DIR_ABS/${initrd_basename}'." >&2
-            exit 1
-        }
-    fi
+    initrd_basename="${initrd##*/}"
+    [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && echo "Installing $ENTRY_DIR_ABS/$initrd_basename"
+    install -g root -o root -m 0644 "$initrd" "$ENTRY_DIR_ABS/$initrd_basename" || {
+        echo "Could not copy '$initrd' to '$ENTRY_DIR_ABS/$initrd_basename'." >&2
+        exit 1
+    }
 done
 
-# If no initrd option is supplied, fall back to "initrd" which is
-# the name used by dracut when generating it in its kernel-install hook
-[[ ${#INITRD_OPTIONS[@]} == 0 ]] && INITRD_OPTIONS=( initrd )
-
 mkdir -p "${LOADER_ENTRY%/*}" || {
     echo "Could not create loader entry directory '${LOADER_ENTRY%/*}'." >&2
     exit 1
 }
 
-[ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && \
-    echo "Creating $LOADER_ENTRY"
+[ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && echo "Creating $LOADER_ENTRY"
 {
     echo "title      $PRETTY_NAME"
     echo "version    $KERNEL_VERSION"
     echo "machine-id $MACHINE_ID"
-    echo "options    ${BOOT_OPTIONS[*]}"
+    echo "options    $BOOT_OPTIONS"
     echo "linux      $ENTRY_DIR/linux"
-    for initrd in "${INITRD_OPTIONS[@]}"; do
-        [[ -f $ENTRY_DIR_ABS/$(basename ${initrd}) ]] && \
-            echo "initrd     $ENTRY_DIR/$(basename ${initrd})"
+    for initrd; do
+        echo "initrd     $ENTRY_DIR/${initrd##*/}"
     done
+    # Try "initrd", generated by dracut in its kernel-install hook, if no initrds were supplied
+    [ $# -eq 0 ] && [ -f "$ENTRY_DIR_ABS/initrd" ] && echo "initrd     $ENTRY_DIR/initrd"
     :
-} > "$LOADER_ENTRY" || {
+} >"$LOADER_ENTRY" || {
     echo "Could not create loader entry '$LOADER_ENTRY'." >&2
     exit 1
 }
diff --git a/src/kernel-install/kernel-install b/src/kernel-install/kernel-install
index d85852532b6..e56483ef960 100755
--- a/src/kernel-install/kernel-install
+++ b/src/kernel-install/kernel-install
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
 # ex: ts=8 sw=4 sts=4 et filetype=sh
 # SPDX-License-Identifier: LGPL-2.1-or-later
@@ -18,7 +18,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with systemd; If not, see <http://www.gnu.org/licenses/>.
 
-SKIP_REMAINING=77
+skip_remaining=77
 
 usage()
 {
@@ -26,30 +26,23 @@ usage()
     echo "  $0 [OPTIONS...] add KERNEL-VERSION KERNEL-IMAGE [INITRD-FILE ...]"
     echo "  $0 [OPTIONS...] remove KERNEL-VERSION"
     echo "Options:"
-    echo "  -h,--help     Print this help"
-    echo "  -v,--verbose  Increase verbosity"
+    echo "  -h, --help     Print this help"
+    echo "  -v, --verbose  Increase verbosity"
 }
 
 dropindirs_sort()
 {
-    local suffix=$1; shift
-    local -a files
-    local f d i
+    suffix="$1"
+    shift
 
-    readarray -t files <<<"$(
-        for d in "$@"; do
-            for i in "$d/"*"$suffix"; do
-                if [[ -e "$i" ]]; then
-                    echo "${i##*/}"
-                fi
-            done
-        done | sort -Vu
-    )"
-
-    for f in "${files[@]}"; do
-        for d in "$@"; do
-            if [[ -e "$d/$f" ]]; then
-                echo "$d/$f"
+    for d; do
+        for i in "$d/"*"$suffix"; do
+            [ -e "$i" ] && echo "${i##*/}"
+        done
+    done | sort -Vu | while read -r f; do
+        for d; do
+            if [ -e "$d/$f" ]; then
+                [ -x "$d/$f" ] && echo "$d/$f"
                 continue 2
             fi
         done
@@ -58,38 +51,35 @@ dropindirs_sort()
 
 export LC_COLLATE=C
 
-for i in "$@"; do
-    if [ "$i" == "--help" -o "$i" == "-h" ]; then
+for i; do
+    if [ "$i" = "--help" ] || [ "$i" = "-h" ]; then
         usage
         exit 0
     fi
 done
 
-KERNEL_INSTALL_VERBOSE=0
-if [ "$1" == "--verbose" -o "$1" == "-v" ]; then
+export KERNEL_INSTALL_VERBOSE=0
+if [ "$1" = "--verbose" ] || [ "$1" = "-v" ]; then
     shift
     KERNEL_INSTALL_VERBOSE=1
 fi
-export KERNEL_INSTALL_VERBOSE
 
-if [[ "${0##*/}" == 'installkernel' ]]; then
-    COMMAND='add'
-    # make install doesn't pass any parameter wrt initrd handling
-    INITRD_OPTIONS=()
+if [ "${0##*/}" = "installkernel" ]; then
+    COMMAND=add
+    # make install doesn't pass any initrds
 else
     COMMAND="$1"
-    shift
-    INITRD_OPTIONS=( "${@:3}" )
+    [ $# -ge 1 ] && shift
 fi
 
-KERNEL_VERSION="$1"
-KERNEL_IMAGE="$2"
-
-if [[ ! $COMMAND ]] || [[ ! $KERNEL_VERSION ]]; then
+if [ $# -lt 1 ]; then
     echo "Not enough arguments" >&2
     exit 1
 fi
 
+KERNEL_VERSION="$1"
+shift
+
 if [ -r "/etc/kernel/install.conf" ]; then
     . /etc/kernel/install.conf
 elif [ -r "/usr/lib/kernel/install.conf" ]; then
@@ -99,12 +89,11 @@ fi
 # Prefer to use an existing machine ID from /etc/machine-info or /etc/machine-id. If we're using the machine
 # ID /etc/machine-id, try to persist it in /etc/machine-info. If no machine ID is found, try to generate
 # a new machine ID in /etc/machine-info. If that fails, use "Default".
-
-[ -z "$MACHINE_ID" ] && [ -f /etc/machine-info ] && source /etc/machine-info && MACHINE_ID="$KERNEL_INSTALL_MACHINE_ID"
-[ -z "$MACHINE_ID" ] && [ -f /etc/machine-id ] && read -r MACHINE_ID </etc/machine-id
-[ -n "$MACHINE_ID" ] && [ -z "$KERNEL_INSTALL_MACHINE_ID" ] && echo "KERNEL_INSTALL_MACHINE_ID=$MACHINE_ID" >>/etc/machine-info
+[ -z "$MACHINE_ID" ] && [ -r /etc/machine-info ]              && . /etc/machine-info && MACHINE_ID="$KERNEL_INSTALL_MACHINE_ID"
+[ -z "$MACHINE_ID" ] && [ -r /etc/machine-id ]                && read -r MACHINE_ID </etc/machine-id
+[ -n "$MACHINE_ID" ] && [ -z "$KERNEL_INSTALL_MACHINE_ID" ]   && echo "KERNEL_INSTALL_MACHINE_ID=$MACHINE_ID" >>/etc/machine-info
 [ -z "$MACHINE_ID" ] && NEW_MACHINE_ID="$(systemd-id128 new)" && echo "KERNEL_INSTALL_MACHINE_ID=$NEW_MACHINE_ID" >>/etc/machine-info
-[ -z "$MACHINE_ID" ] && [ -f /etc/machine-info ] && source /etc/machine-info && MACHINE_ID="$KERNEL_INSTALL_MACHINE_ID"
+[ -z "$MACHINE_ID" ] && [ -r /etc/machine-info ]              && . /etc/machine-info && MACHINE_ID="$KERNEL_INSTALL_MACHINE_ID"
 [ -z "$MACHINE_ID" ] && MACHINE_ID="Default"
 
 [ -z "$BOOT_ROOT" ] && for suff in "$MACHINE_ID" "loader/entries"; do
@@ -125,11 +114,6 @@ done
 [ -z "$BOOT_ROOT" ] && BOOT_ROOT="/boot"
 
 
-ENTRY_DIR_ABS="$BOOT_ROOT/$MACHINE_ID/$KERNEL_VERSION"
-
-export KERNEL_INSTALL_MACHINE_ID="$MACHINE_ID"
-export KERNEL_INSTALL_BOOT_ROOT="$BOOT_ROOT"
-
 if [ -z "$layout" ]; then
     # Administrative decision: if not present, some scripts generate into /boot.
     if [ -d "$BOOT_ROOT/$MACHINE_ID" ]; then
@@ -152,21 +136,23 @@ MAKE_ENTRY_DIR_ABS=$?
 
 ret=0
 
-readarray -t PLUGINS <<<"$(
+PLUGINS="$(
     dropindirs_sort ".install" \
         "/etc/kernel/install.d" \
         "/usr/lib/kernel/install.d"
 )"
+IFS="
+"
 
-case $COMMAND in
+case "$COMMAND" in
     add)
-        if [[ ! "$KERNEL_IMAGE" ]]; then
-            echo "Command 'add' requires an argument" >&2
+        if [ $# -lt 1 ]; then
+            echo "Command 'add' requires a kernel image" >&2
             exit 1
         fi
 
-        if [[ ! -f "$KERNEL_IMAGE" ]]; then
-            echo "Kernel image argument ${KERNEL_IMAGE} not a file" >&2
+        if ! [ -f "$1" ]; then
+            echo "Kernel image argument $1 not a file" >&2
             exit 1
         fi
 
@@ -182,32 +168,22 @@ case $COMMAND in
             fi
         fi
 
-        for f in "${PLUGINS[@]}"; do
-            if [[ -x $f ]]; then
-                [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && \
-                    echo "+$f add $KERNEL_VERSION $ENTRY_DIR_ABS $KERNEL_IMAGE ${INITRD_OPTIONS[@]}"
-                "$f" add "$KERNEL_VERSION" "$ENTRY_DIR_ABS" "$KERNEL_IMAGE" "${INITRD_OPTIONS[@]}"
-                x=$?
-                if [[ $x == $SKIP_REMAINING ]]; then
-                    break
-                fi
-                ((ret+=$x))
-            fi
+        for f in $PLUGINS; do
+            [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && echo "+$f add $KERNEL_VERSION $ENTRY_DIR_ABS $*"
+            "$f" add "$KERNEL_VERSION" "$ENTRY_DIR_ABS" "$@"
+            err=$?
+            [ $err -eq $skip_remaining ] && break
+            ret=$(( ret + err ))
         done
         ;;
 
     remove)
-        for f in "${PLUGINS[@]}"; do
-            if [[ -x $f ]]; then
-                [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && \
-                    echo "+$f remove $KERNEL_VERSION $ENTRY_DIR_ABS"
-                "$f" remove "$KERNEL_VERSION" "$ENTRY_DIR_ABS"
-                x=$?
-                if [[ $x == $SKIP_REMAINING ]]; then
-                    break
-                fi
-                ((ret+=$x))
-            fi
+        for f in $PLUGINS; do
+            [ "$KERNEL_INSTALL_VERBOSE" -gt 0 ] && echo "+$f remove $KERNEL_VERSION $ENTRY_DIR_ABS"
+            "$f" remove "$KERNEL_VERSION" "$ENTRY_DIR_ABS"
+            err=$?
+            [ $err -eq $skip_remaining ] && break
+            ret=$(( ret + err ))
         done
 
         if [ "$MAKE_ENTRY_DIR_ABS" -eq 0 ]; then
@@ -222,4 +198,4 @@ case $COMMAND in
         ;;
 esac
 
-exit $ret
+exit "$ret"