diff --git a/platforms/chibios/boards/GENERIC_STM32_F401XC/configs/mcuconf.h b/platforms/chibios/boards/GENERIC_STM32_F401XC/configs/mcuconf.h
index 24cec7137d6..1208563aa15 100644
--- a/platforms/chibios/boards/GENERIC_STM32_F401XC/configs/mcuconf.h
+++ b/platforms/chibios/boards/GENERIC_STM32_F401XC/configs/mcuconf.h
@@ -53,8 +53,8 @@
 #define STM32_PLLP_VALUE                    4
 #define STM32_PLLQ_VALUE                    7
 #define STM32_HPRE                          STM32_HPRE_DIV1
-#define STM32_PPRE1                         STM32_PPRE1_DIV2  
-#define STM32_PPRE2                         STM32_PPRE2_DIV1 
+#define STM32_PPRE1                         STM32_PPRE1_DIV2
+#define STM32_PPRE2                         STM32_PPRE2_DIV1
 #define STM32_RTCSEL                        STM32_RTCSEL_LSI
 #define STM32_RTCPRE_VALUE                  8
 #define STM32_MCO1SEL                       STM32_MCO1SEL_HSI
diff --git a/platforms/chibios/boards/STEMCELL/configs/mcuconf.h b/platforms/chibios/boards/STEMCELL/configs/mcuconf.h
index 621d3fcace2..db239854aa5 100644
--- a/platforms/chibios/boards/STEMCELL/configs/mcuconf.h
+++ b/platforms/chibios/boards/STEMCELL/configs/mcuconf.h
@@ -1,5 +1,18 @@
-// Copyright 2022 Mega Mind (@megamind4089)
-// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+    ChibiOS - Copyright (C) 2006..2020 Giovanni Di Sirio
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
 
 #ifndef MCUCONF_H
 #define MCUCONF_H
@@ -165,6 +178,14 @@
 #define STM32_PWM_USE_TIM10                 FALSE
 #define STM32_PWM_USE_TIM11                 FALSE
 
+/*
+ * RTC driver system settings.
+ */
+#define STM32_RTC_PRESA_VALUE               32
+#define STM32_RTC_PRESS_VALUE               1024
+#define STM32_RTC_CR_INIT                   0
+#define STM32_RTC_TAMPCR_INIT               0
+
 /*
  * SERIAL driver system settings.
  */
diff --git a/util/chibios_conf_updater.sh b/util/chibios_conf_updater.sh
index a5699ca3cb2..3c400ab63c2 100755
--- a/util/chibios_conf_updater.sh
+++ b/util/chibios_conf_updater.sh
@@ -12,11 +12,14 @@ umask 022
 #   wget -qO - https://adoptopenjdk.jfrog.io/adoptopenjdk/api/gpg/key/public | sudo apt-key add -
 #   sudo add-apt-repository --yes https://adoptopenjdk.jfrog.io/adoptopenjdk/deb/
 #   sudo apt-get update && sudo apt-get install adoptopenjdk-8-hotspot
-
+#
+# For Fedora 36-ish distros:
+#  # Prep yum repository from https://adoptium.net/installation/linux/
+#  sudo dnf install -y ant temurin-8-jdk
+#  export JAVA_HOME=/usr/lib/jvm/temurin-8-jdk
 
 sinfo() { echo "$@" >&2 ; }
 shead() { sinfo "" ; sinfo "---------------------------------" ; sinfo "-- $@" ; sinfo "---------------------------------" ; }
-havecmd()  { command command type "${1}" >/dev/null 2>&1 || return 1 ; }
 
 this_script="$(realpath "${BASH_SOURCE[0]}")"
 script_dir="$(realpath "$(dirname "$this_script")")"
@@ -31,7 +34,7 @@ build_fmpp() {
         || { mkdir "$script_dir/fmpp" && tar xf "$script_dir/fmpp.tar.gz" -C "$script_dir/fmpp" --strip-components=1 ; }
     pushd "$script_dir/fmpp" >/dev/null 2>&1
     sed -e "s#bootclasspath.path=.*#bootclasspath.path=$(find /usr/lib/jvm -name 'rt.jar' | sort | tail -n1)#g" \
-        -e "s#ant.jar.path=.*#ant.jar.path=$(find /usr/share/java -name 'ant-1*.jar' | sort | tail -n1)#g" \
+        -e "s#ant.jar.path=.*#ant.jar.path=$(find /usr/share/java -name 'ant-1*.jar' -or -name 'ant.jar' | sort | tail -n1)#g" \
         build.properties.sample > build.properties
     sed -e 's#source="1.5"#source="1.8"#g' \
         -e 's#target="1.5"#target="1.8"#g' \
@@ -98,7 +101,8 @@ upgrade_mcuconf_files() {
     popd >/dev/null 2>&1
 }
 
-havecmd fmpp || build_fmpp
+hash -r
+[[ -n "$(which fmpp 2>/dev/null)" ]] || build_fmpp
 
 upgrade_mcuconf_files
 upgrade_chconf_files