diff --git a/README.md b/README.md
index c8072e4..c45e3d3 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,7 @@ comprehensive support for macOS and Windows**.
   * Automatic SSH port forwarding to guests
   * Network port forwarding
   * Full duplex audio
-  * EFI and Legacy BIOS booting
+  * EFI (with or without SecureBoot) and Legacy BIOS boot
   * Graphical user interfaces available
 
 Quickemu is a wrapper for the excellent [QEMU](https://www.qemu.org/) that
@@ -62,6 +62,7 @@ See this (old) video where I explain some of my motivations for creating Quickem
   * [QEMU](https://www.qemu.org/) (*6.0.0 or newer*)
   * [bash](https://www.gnu.org/software/bash/) (*4.0 or newer*)
   * [Coreutils](https://www.gnu.org/software/coreutils/)
+  * [EDK II](https://github.com/tianocore/edk2)
   * [grep](https://www.gnu.org/software/grep/)
   * [jq](https://stedolan.github.io/jq/)
   * [LSB](https://wiki.linuxfoundation.org/lsb/start)
diff --git a/quickemu b/quickemu
index ab04ac8..1d3d0fa 100755
--- a/quickemu
+++ b/quickemu
@@ -175,8 +175,25 @@ function check_cpu_flag() {
   fi
 }
 
+function efi_vars() {
+  local VARS_IN=""
+  local VARS_OUT=""
+  VARS_IN="${1}"
+  VARS_OUT="${2}"
+
+  if [ ! -e "${VARS_OUT}" ]; then
+    if [ -e "${VARS_IN}" ]; then
+      cp "${VARS_IN}" "${VARS_OUT}"
+    else
+      echo "ERROR! ${VARS_IN} was not found. Please install edk2."
+      exit 1
+    fi
+  fi
+}
+
 function vm_boot() {
   local BALLOON="-device virtio-balloon"
+  local BOOT_STATUS=""
   local CPU=""
   local DISK_USED=""
   local DISPLAY_DEVICE=""
@@ -194,13 +211,15 @@ function vm_boot() {
   local KERNEL_NAME="Unknown"
   local KERNEL_NODE=""
   local KERNEL_VER="?"
-  local LSB_DESCRIPTION=""
+  local LSB_DESCRIPTION="Unknown OS"
   local MAC_BOOTLOADER=""
   local MAC_MISSING=""
   local MAC_DISK_DEV="ide-hd,bus=ahci.2"
   local MOUSE="usb-tablet"
   local NET_DEVICE="virtio-net"
   local OSK=""
+  local QEMU_VER=""
+  local SMM="off"
   local USB_HOST_PASSTHROUGH_CONTROLLER="qemu-xhci"
   local VIDEO=""
 
@@ -210,6 +229,8 @@ function vm_boot() {
 
   if command -v lsb_release &>/dev/null; then
     LSB_DESCRIPTION=$(lsb_release --description --short)
+  elif [ -e /etc/os-release ]; then
+    LSB_DESCRIPTION=$(grep PRETTY_NAME /etc/os-release | cut -d'"' -f2)
   fi
 
   echo "Quickemu ${VERSION} using ${QEMU} v${QEMU_VER_LONG}"
@@ -306,7 +327,6 @@ function vm_boot() {
   # Always Boot macOS using EFI
   if [ "${guest_os}" == "macos" ]; then
     boot="efi"
-    echo " - BOOT:     EFI (${guest_os})"
     if [ -e "${VMDIR}/OVMF_CODE.fd" ] && [ -e "${VMDIR}/OVMF_VARS-1024x768.fd" ]; then
       EFI_CODE="${VMDIR}/OVMF_CODE.fd"
       EFI_VARS="${VMDIR}/OVMF_VARS-1024x768.fd"
@@ -328,6 +348,7 @@ function vm_boot() {
       echo "       Use 'quickget' to download the required files."
       exit 1
     fi
+    BOOT_STATUS="EFI (macOS), OVMF ($(basename "${EFI_CODE}")), SecureBoot (${secureboot})."
   elif [[ "${boot}" == *"efi"* ]]; then
     EFI_VARS="${VMDIR}/OVMF_VARS.fd"
 
@@ -338,36 +359,73 @@ function vm_boot() {
       mv "${VMDIR}/OVMF_VARS_4M.fd" "${EFI_VARS}"
     fi
 
-    if [ -e "/usr/share/OVMF/OVMF_CODE_4M.fd" ] ||
-       [ -e "/usr/share/OVMF/x64/OVMF_CODE.fd" ] ||
-       [ -e "/usr/share/OVMF/OVMF_CODE.fd" ]; then
-      echo " - BOOT:     EFI (${guest_os})"
-
-      if [ -e "/usr/share/OVMF/OVMF_CODE_4M.fd" ]; then
-        EFI_CODE="/usr/share/OVMF/OVMF_CODE_4M.fd"
-      elif [ -e "/usr/share/OVMF/x64/OVMF_CODE.fd" ]; then
-        EFI_CODE="/usr/share/OVMF/x64/OVMF_CODE.fd"
-      elif [ -e "/usr/share/OVMF/OVMF_CODE.fd" ]; then
-        EFI_CODE="/usr/share/OVMF/OVMF_CODE.fd"
-      fi
+    # OVMF_CODE_4M.fd is for booting guests in non-Secure Boot mode.
+    # While this image technically supports Secure Boot, it does so
+    # without requiring SMM support from QEMU
+
+    # OVMF_CODE.secboot.fd is like OVMF_CODE_4M.fd, but will abort if QEMU
+    # does not support SMM.
 
-      if [ ! -e "${EFI_VARS}" ]; then
-        if [ -e "/usr/share/OVMF/OVMF_VARS_4M.fd" ]; then
-          cp "/usr/share/OVMF/OVMF_VARS_4M.fd" "${EFI_VARS}"
-        elif [ -e "/usr/share/OVMF/x64/OVMF_VARS.fd" ]; then
-          cp "/usr/share/OVMF/x64/OVMF_VARS.fd" "${EFI_VARS}"
-        elif [ -e "/usr/share/OVMF/OVMF_VARS.fd" ]; then
-          cp "/usr/share/OVMF/OVMF_VARS.fd" "${EFI_VARS}"
+    # https://bugzilla.redhat.com/show_bug.cgi?id=1929357#c5
+    case ${secureboot} in
+      on)
+        if [ -e "/usr/share/OVMF/OVMF_CODE_4M.secboot.fd" ]; then
+          EFI_CODE="/usr/share/OVMF/OVMF_CODE_4M.secboot.fd"
+          efi_vars "/usr/share/OVMF/OVMF_VARS_4M.fd" "${EFI_VARS}"
+        elif [ -e "/usr/share/edk2/ovmf/OVMF_CODE.secboot.fd" ]; then
+          EFI_CODE="/usr/share/edk2/ovmf/OVMF_CODE.secboot.fd"
+          efi_vars "/usr/share/edk2/ovmf/OVMF_VARS.fd" "${EFI_VARS}"
+        elif [ -e "/usr/share/OVMF/x64/OVMF_CODE.secboot.fd" ]; then
+          EFI_CODE="/usr/share/OVMF/x64/OVMF_CODE.secboot.fd"
+          efi_vars "/usr/share/OVMF/x64/OVMF_VARS.fd" "${EFI_VARS}"
+        else
+          echo "ERROR! SecureBoot was requested but no SecureBoot capable firmware was found."
+          echo "       Please install OVMF firmware."
+          exit 1
         fi
-      fi
-    else
-      boot="legacy"
-      echo " - BOOT:     Legacy BIOS (${guest_os}) - EFI requested but no EFI firmware found."
+        ;;
+      *)
+        if [ -e "/usr/share/OVMF/OVMF_CODE_4M.fd" ]; then
+          EFI_CODE="/usr/share/OVMF/OVMF_CODE_4M.fd"
+          efi_vars "/usr/share/OVMF/OVMF_VARS_4M.fd" "${EFI_VARS}"
+        elif [ -e "/usr/share/edk2/ovmf/OVMF_CODE.fd" ]; then
+          EFI_CODE="/usr/share/edk2/ovmf/OVMF_CODE.fd"
+          efi_vars "/usr/share/edk2/ovmf/OVMF_VARS.fd" "${EFI_VARS}"
+        elif [ -e "/usr/share/OVMF/x64/OVMF_CODE.fd" ]; then
+          EFI_CODE="/usr/share/OVMF/x64/OVMF_CODE.fd"
+          efi_vars "/usr/share/OVMF/x64/OVMF_VARS.fd" "${EFI_VARS}"
+        else
+          echo "ERROR! EFI boot requested but no EFI firmware found."
+          echo "       Please install OVMF firmware."
+          exit 1
+        fi
+        ;;
+    esac
+
+    # Make sure EFI_VARS references an actual, writeable, file
+    if [ ! -f "${EFI_VARS}" ] || [ ! -w "${EFI_VARS}" ]; then
+      echo " - EFI:      ERROR! ${EFI_VARS} is not a regular file or not writeable."
+      echo "             Deleting ${EFI_VARS}. Please re-run quickemu."
+      rm -f "${EFI_VARS}"
+      exit 1
+    fi
+
+    # If EFI_CODE references a symlink, resolve it to the real file.
+    if [ -L "${EFI_CODE}" ]; then
+      echo " - EFI:      WARNING! ${EFI_CODE} is a symlink."
+      echo -n "             Resolving to... "
+      EFI_CODE=$(realpath "${EFI_CODE}")
+      echo "${EFI_CODE}"
     fi
+    BOOT_STATUS="EFI (${guest_os^}), OVMF (${EFI_CODE}), SecureBoot (${secureboot})."
   else
-    echo " - BOOT:     Legacy BIOS (${guest_os})"
+    BOOT_STATUS="Legacy BIOS (${guest_os^})"
+    boot="legacy"
+    secureboot="off"
   fi
 
+  echo " - BOOT:     ${BOOT_STATUS}"
+
   # Make any OS specific adjustments
   case ${guest_os} in
     freebsd|linux|openbsd)
@@ -443,6 +501,7 @@ function vm_boot() {
       if [ -z "${disk_size}" ]; then
         disk_size="64G"
       fi
+      SMM="on"
       ;;
     *)
       CPU="-cpu host,kvm=on"
@@ -454,6 +513,11 @@ function vm_boot() {
       ;;
   esac
 
+  # Disable suspend to RAM if SecureBoot/SMM is enabled
+  if [ "${secureboot}" == "on" ] || [ "${SMM}" == "on" ]; then
+    GUEST_TWEAKS="${GUEST_TWEAKS} -global ICH9-LPC.disable_s3=1"
+  fi
+
   echo " - Disk:     ${disk_img} (${disk_size})"
   if [ ! -f "${disk_img}" ]; then
       # If there is no disk image, create a new image.
@@ -531,20 +595,6 @@ function vm_boot() {
     echo " - CD-ROM:   ${fixed_iso}"
   fi
 
-  # Enable TPM
-  if [ "${tpm}" == "on" ]; then
-    if command -v swtpm &>/dev/null; then
-      swtpm socket \
-        --ctrl type=unixio,path="${VMDIR}/${VMNAME}.swtpm-sock" \
-        --terminate \
-        --tpmstate dir="${VMDIR}" \
-        --tpm2 &
-      echo " - TPM:      ${VMDIR}/${VMNAME}.swtpm-sock (${!})"
-    else
-      echo " - TPM:      swtpm is not installed, TPM not available!"
-    fi
-  fi
-
   # Determine a sane resolution for Linux guests.
   if [ "${guest_os}" == "linux" ]; then
     local X_RES=1152
@@ -716,12 +766,29 @@ function vm_boot() {
 
   enable_usb_passthrough
 
+  echo "#!/usr/bin/env bash" > "${VMDIR}/${VMNAME}.sh"
+
+  # Start TPM
+  if [ "${tpm}" == "on" ]; then
+    local tpm_args=()
+    # shellcheck disable=SC2054
+    tpm_args+=(socket
+            --ctrl type=unixio,path="${VMDIR}/${VMNAME}.swtpm-sock"
+            --terminate
+            --tpmstate dir="${VMDIR}"
+            --tpm2)
+    echo "${SWTPM} ${tpm_args[@]} &" >> "${VMDIR}/${VMNAME}.sh"
+    ${SWTPM} "${tpm_args[@]}" >> "${VMDIR}/${VMNAME}.log" &
+    echo " - TPM:      ${VMDIR}/${VMNAME}.swtpm-sock (${!})"
+    sleep 1
+  fi
+
   # Boot the VM
   local args=()
 
   # shellcheck disable=SC2054,SC2206,SC2140
   args+=(-name ${VMNAME},process=${VMNAME} -pidfile "${VMDIR}/${VMNAME}.pid"
-         -enable-kvm -machine q35,vmport=off ${GUEST_TWEAKS}
+         -enable-kvm -machine q35,smm=${SMM},vmport=off ${GUEST_TWEAKS}
          ${CPU} ${SMP}
          -m ${RAM_VM} ${BALLOON}
          -smbios type=2,manufacturer="Wimpys World",product="Quickemu",version="${VERSION}",serial="jvzclfjbeyq.pbz",location="wimpysworld.com",asset="${VMNAME}"
@@ -754,8 +821,9 @@ function vm_boot() {
   # - https://turlucode.com/qemu-disk-io-performance-comparison-native-or-threads-windows-10-version/
   if [[ "${boot}" == *"efi"* ]]; then
     # shellcheck disable=SC2054
-    args+=(-drive if=pflash,format=raw,file="${EFI_CODE}",readonly=on
-           -drive if=pflash,format=raw,file="${EFI_VARS}")
+    args+=(-global driver=cfi.pflash01,property=secure,value=on
+           -drive if=pflash,format=raw,unit=0,file="${EFI_CODE}",readonly=on
+           -drive if=pflash,format=raw,unit=1,file="${EFI_VARS}")
   fi
 
   if [ -n "${floppy}" ]; then
@@ -841,9 +909,7 @@ function vm_boot() {
   SHELL_ARGS="${SHELL_ARGS//)/\\)}"
   SHELL_ARGS="${SHELL_ARGS//Wimpys World/\"Wimpys World\"}"
 
-  echo "#!/usr/bin/env bash" > "${VMDIR}/${VMNAME}.sh"
   echo "${QEMU}" "${SHELL_ARGS}" >> "${VMDIR}/${VMNAME}.sh"
-
   ${QEMU} "${args[@]}" > "${VMDIR}/${VMNAME}.log" &
 
   # If output is 'none' then SPICE was requested.
@@ -909,6 +975,7 @@ macos_release=""
 port_forwards=()
 preallocation="off"
 ram=""
+secureboot="off"
 tpm="off"
 usb_devices=()
 
@@ -1054,6 +1121,14 @@ if [ -n "${VM}" ] && [ -e "${VM}" ]; then
   if [ -n "${disk}" ]; then
     disk_size="${disk}"
   fi
+
+  if [ "${tpm}" == "on" ]; then
+    SWTPM=$(command -v swtpm)
+    if [ ! -e "${SWTPM}" ]; then
+      echo "ERROR! TPM is enabled, but swtpm was not found."
+      exit 1
+    fi
+  fi
 else
   echo "ERROR! Virtual machine configuration not found."
   usage