From 40b949d5ef3402a0cdf24dda457eabc7941ca0d9 Mon Sep 17 00:00:00 2001
From: Gregory Giguashvili <ggiguash@redhat.com>
Date: Thu, 8 Jan 2026 18:11:38 +0200
Subject: [PATCH 1/2] Pin OS version when installing kernel-devel package

---
 .../group2/build-serialsim.sh.template        | 22 ++++++++++---------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template b/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template
index d659cd769d..9b6187e349 100644
--- a/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template
+++ b/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template
@@ -1,24 +1,26 @@
 #!/bin/bash
 set -euo pipefail
+set -x
 
 function get_kernel_ver() {
-    KERNEL_VER=$(rpm -q --qf "%{VERSION}-%{RELEASE}\n" kernel | sort | tail -1)
+    KERNEL_VER="$(rpm -q --qf "%{VERSION}-%{RELEASE}\n" kernel | sort | tail -1)"
     KERNEL_VER_ARCH="${KERNEL_VER}.$(uname -m)"
+
     export KERNEL_VER
     export KERNEL_VER_ARCH
 }
 
-# Upgrade the kernel only if necessary to align the procedure with both RHEL and CentOS.
-#
-# On CentOS, a kernel upgrade may be required due to its different package
-# retention policy, which can cause the kernel in the base bootc image to be
-# unavailable in the repositories.
+# Set the current kernel version and architecture variables.
 get_kernel_ver
-if ! dnf --quiet list available "kernel-devel-${KERNEL_VER}" >/dev/null 2>&1; then
-    dnf install -y kernel-devel-matched
+
+# Attempt to install the kernel-devel package for the current kernel version,
+# falling back to the kernel-devel-matched package.
+# Note: The OS release version is pinned to make sure that the potentially upgraded
+# kernel package belongs to the current OS release.
+source /etc/os-release
+if ! dnf install -y --releasever="${VERSION_ID}" "kernel-devel-${KERNEL_VER}" ; then
+    dnf install -y --releasever="${VERSION_ID}" kernel-devel-matched
     get_kernel_ver
-else
-    dnf install -y "kernel-devel-${KERNEL_VER}"
 fi
 
 # Install the necessary dependencies and clean up.

From c604a4df9f6aff97d519d3b7f3cdbd4fbf6ad69c Mon Sep 17 00:00:00 2001
From: Gregory Giguashvili <ggiguash@redhat.com>
Date: Thu, 8 Jan 2026 19:20:47 +0200
Subject: [PATCH 2/2] Enable RHEL EUS repositories for kernel-devel version
 match

---
 .../group2/build-serialsim.sh.template        | 30 ++++++++++++++-----
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template b/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template
index 9b6187e349..a38a41b2fe 100644
--- a/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template
+++ b/test/image-blueprints-bootc/layer1-base/group2/build-serialsim.sh.template
@@ -13,19 +13,35 @@ function get_kernel_ver() {
 # Set the current kernel version and architecture variables.
 get_kernel_ver
 
-# Attempt to install the kernel-devel package for the current kernel version,
-# falling back to the kernel-devel-matched package.
-# Note: The OS release version is pinned to make sure that the potentially upgraded
-# kernel package belongs to the current OS release.
+# Lock the OS release version to prevent the installation of a newer kernel package
+# belonging to a newer OS release.
 source /etc/os-release
-if ! dnf install -y --releasever="${VERSION_ID}" "kernel-devel-${KERNEL_VER}" ; then
-    dnf install -y --releasever="${VERSION_ID}" kernel-devel-matched
-    get_kernel_ver
+echo "${VERSION_ID}" > /etc/dnf/vars/releasever
+
+if [[ "${ID}" == "rhel" ]] ; then
+    # On RHEL, enable RHEL EUS repositories to allow the installation of the
+    # kernel-devel package for the current kernel version.
+    VERSION_ID_MAJOR="$(awk -F. '{print $1}' <<< "${VERSION_ID}")"
+    VERSION_ID_MINOR="$(awk -F. '{print $2}' <<< "${VERSION_ID}")"
+    if (( "${VERSION_ID_MINOR}" % 2 == 0 )) ; then
+        dnf config-manager --set-enabled \
+            "rhel-${VERSION_ID_MAJOR}-for-$(uname -m)-baseos-eus-rpms" \
+            "rhel-${VERSION_ID_MAJOR}-for-$(uname -m)-appstream-eus-rpms"
+    fi
+    dnf install -y "kernel-devel-${KERNEL_VER}"
+else
+    # On CentOS, attempt to install the kernel-devel package for the current kernel
+    # version, falling back to kernel-devel-matched if the former is not available.
+    dnf install -y "kernel-devel-${KERNEL_VER}" || dnf install -y kernel-devel-matched
 fi
 
+# Reset the current kernel version and architecture variables.
+get_kernel_ver
+
 # Install the necessary dependencies and clean up.
 dnf install -y git make python3-pyserial
 dnf clean all
+rm -f /etc/dnf/vars/releasever
 
 # Clone the serialsim repository and build the serialsim module.
 git clone https://github.com/microshift-io/serialsim.git /tmp/serialsim