spec: own /etc/sysconfig/kernel

`grubby` reads the `/etc/sysconfig/kernel` file which isn't owned by the
package, nor created by it. This leads to all image build tooling having
to take special care to write this file [1] [2] so produced deliverables
automatically update their kernels.

This commit moves the creation of this file to the `grubby` package so
things work 'out of the box' instead of needing to do out-of-package
configuration by third parties.

[1]: https://pagure.io/fedora-kiwi-descriptions/blob/f43/f/root/etc/sysconfig
[2]: a8fafe8d9b/data/distrodefs/fedora/imagetypes.yaml (L1027-L1028)

Signed-off-by: Simon de Vlieger <supakeen@redhat.com>

10-devicetree.install

@@ -2,7 +2,7 @@
 
 # set -x
 
-if [[ "$(uname -m)" == arm* || "$(uname -m)" == aarch64 ]]
+if [[ "$(uname -m)" == arm* || "$(uname -m)" == aarch64 || "$(uname -m)" == riscv64 ]]
 then
 COMMAND="$1"
 KERNEL_VERSION="$2"

grubby-bls

@@ -356,22 +356,26 @@ get_custom_bls_filename() {
     prefix="${bls_target%%${arch}}"
     prefix="${prefix%.*}"
 
-    last=($(for bls in ${prefix}.*~custom*.conf ; do
-        if ! [[ -e "${bls}" ]] ; then
-            continue
-        fi
-        bls="${bls##${prefix}.}"
-        bls="${bls%%~custom*}"
-        echo "${bls}"
-    done | tail -n1)) || :
+    first_gap=$(
+        first=0
+        for bls_entry in $(ls "${prefix}".*~custom*.conf 2>/dev/null | sort -V); do
+            if [[ -e ${bls_entry} ]]; then
+                bls_entry="${bls_entry##"${prefix}".}"
+                bls_entry="${bls_entry%%~custom*}"
+                if [[ "${bls_entry}" = "${first}" ]]; then
+                    first=$((first+1))
+                else
+                    break
+                fi
+            fi
+        done
+        echo "${first}") || :
 
-    if [[ -z $last ]]; then
-        last="0"
-    else
-        last=$((last+1))
+    if [[ -z "$first_gap" ]]; then
+        first_gap="0"
     fi
 
-    echo "${bls_target}" | sed -e "s!${prefix}!${prefix}.${last}~custom!"
+    echo "${bls_target}" | sed -e "s!${prefix}!${prefix}.${first_gap}~custom!"
 }
 
 add_bls_fragment() {
@@ -500,7 +504,7 @@ update_bls_fragment() {
             if [[ -n $old_args ]]; then
                 opts="$(update_args "${old_args}" "${remove_args}" "${add_args}")"
                 opts="$(echo "$opts" | sed -e 's/\//\\\//g')"
-                sed -i -e "s/^GRUB_CMDLINE_LINUX.*/GRUB_CMDLINE_LINUX=\\\"${opts}\\\"/" "${grub_etc_default}"
+                sed -i -e "s/^GRUB_CMDLINE_LINUX=.*/GRUB_CMDLINE_LINUX=\\\"${opts}\\\"/" "${grub_etc_default}"
             fi
         fi
 
@@ -563,7 +567,7 @@ set_default_bls() {
             echo "default=${default}" >> "${zipl_config}"
         fi
     fi
-
+    update_grubcfg
     print_info "The default is ${bls_file[$index]} with index $index and kernel $(get_prefix)${bls_linux[$index]}"
 }
 
@@ -595,33 +599,29 @@ remove_var_prefix() {
 
 update_grubcfg()
 {
-    # Older ppc64le OPAL firmware (petitboot version < 1.8.0) don't have BLS support
-    # so grub2-mkconfig has to be run to generate a config with menuentry commands.
-    if [ "${arch}" = "ppc64le" ] && [ -d /sys/firmware/opal ]; then
+    # Turn on RUN_MKCONFIG on different archs/scenarios
+    if [[ "${arch}" = 's390' ]] || [[ "${arch}" = 's390x' ]]; then
+        # On s390/s390x systems, run mkconfig/zipl
         RUN_MKCONFIG="true"
-        petitboot_path="/sys/firmware/devicetree/base/ibm,firmware-versions/petitboot"
-
-        if test -e ${petitboot_path}; then
-            read -r -d '' petitboot_version < ${petitboot_path}
-            petitboot_version="$(echo ${petitboot_version//v})"
-
-            if test -n ${petitboot_version}; then
-                major_version="$(echo ${petitboot_version} | cut -d . -f1)"
-                minor_version="$(echo ${petitboot_version} | cut -d . -f2)"
-
-                re='^[0-9]+$'
-                if [[ $major_version =~ $re ]] && [[ $minor_version =~ $re ]] &&
-                       ([[ ${major_version} -gt 1 ]] ||
-                            [[ ${major_version} -eq 1 &&
-                                 ${minor_version} -ge 8  ]]); then
-                    RUN_MKCONFIG="false"
-                fi
-            fi
+    elif [[ "${arch}" = "ppc64le" ]] && [[ -d /sys/firmware/opal ]]; then
+        # Older ppc64le OPAL firmware don't have BLS support so grub2-mkconfig has to be run
+        # to generate a config with menuentry commands.
+        RUN_MKCONFIG="true"
+    elif [[ -e /sys/hypervisor/type ]] && grep -q "^xen$" /sys/hypervisor/type; then
+        if [ ! -e /sys/hypervisor/guest_type ] || ! grep -q "^HVM$" /sys/hypervisor/guest_type; then
+            # PV and PVH Xen DomU guests boot with pygrub that doesn't have BLS support,
+            # also Xen Dom0 use the menuentries from 20_linux_xen and not the ones from
+            # 10_linux. So grub2-mkconfig has to run for both Xen Dom0 and DomU.
+            RUN_MKCONFIG=true
         fi
     fi
 
     if [[ $RUN_MKCONFIG = "true" ]]; then
-        grub2-mkconfig --no-grubenv-update -o "${grub_config}" >& /dev/null
+        if [[ $bootloader = "zipl" ]]; then
+            zipl
+        else
+            grub2-mkconfig --no-grubenv-update -o "${grub_config}" &> /dev/null
+        fi
     fi
 }
 
@@ -630,7 +630,7 @@ print_usage()
     cat <<EOF
 Usage: grubby [OPTION...]
       --add-kernel=kernel-path            add an entry for the specified kernel
-      --args=args                         default arguments for the new kernel or new arguments for kernel being updated)
+      --args=args                         default arguments for the new kernel or new arguments for kernel being updated
       --bad-image-okay                    don't sanity check images in boot entries (for testing only)
   -c, --config-file=path                  path to grub config file to update ("-" for stdin)
       --copy-default                      use the default boot entry as a template for the new entry being added; if the default is not a linux image, or if the kernel referenced by the default image does not exist, the

grubby.spec

@@ -3,15 +3,16 @@
 
 Name: grubby
 Version: 8.40
-Release: 72%{?dist}
+Release: 86%{?dist}
 Summary: Command line tool for updating bootloader configs
-License: GPLv2+
+License: GPL-2.0-or-later
 Source1: grubby-bls
 # Source2: rpm-sort.c
 Source3: COPYING
 Source5: 95-kernel-hooks.install
 Source6: 10-devicetree.install
 Source7: grubby.8
+Source8: kernel.sysconfig
 
 BuildRequires: gcc
 BuildRequires: glib2-devel
@@ -21,7 +22,7 @@ BuildRequires: pkgconfig
 BuildRequires: popt-devel
 BuildRequires: rpm-devel
 BuildRequires: sed
-%ifarch aarch64 x86_64 %{power64}
+%ifarch aarch64 x86_64 %{power64} riscv64
 BuildRequires: grub2-tools-minimal
 Requires: grub2-tools-minimal
 Requires: grub2-tools
@@ -59,6 +60,9 @@ install -D -m 0755 -t %{buildroot}%{_prefix}/lib/kernel/install.d/ %{SOURCE6}
 mkdir -p %{buildroot}%{_mandir}/man8
 install -m 0644 %{SOURCE7} %{buildroot}%{_mandir}/man8/
 
+mkdir -p %{buildroot}%{_sysconfdir}/sysconfig
+install -m 0644 %{SOURCE8} %{buildroot}%{_sysconfdir}/sysconfig/kernel
+
 %post
 if [ "$1" = 2 ]; then
     arch=$(uname -m)
@@ -72,8 +76,52 @@ fi
 %attr(0755,root,root) %{_prefix}/lib/kernel/install.d/10-devicetree.install
 %attr(0755,root,root) %{_prefix}/lib/kernel/install.d/95-kernel-hooks.install
 %{_mandir}/man8/grubby.8*
+%config(noreplace) %{_sysconfdir}/sysconfig/kernel
 
 %changelog
+* Wed Dec 10 2025 Simon de Vlieger <cmdr@supakeen.com> - 8.40-86
+- Own `/etc/sysconfig/kernel` which is used for `grubby` configuration
+
+* Wed Jul 30 2025 Leo Sandoval <lsandova@redhat.com> - 8.40-85
+- Update cfg when setting a default kernel
+
+* Thu Jul 24 2025 Fedora Release Engineering <releng@fedoraproject.org> - 8.40-84
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_43_Mass_Rebuild
+
+* Thu Mar 20 2025 Leo Sandoval <lsandova@redhat.com> - 8.40-83
+- grubby-bls: in s390* systems, run zipl on grub cfg update event
+  Fixes previous commit and formats better the conditions that trigger grub cfg updates
+
+* Fri Jan 17 2025 Fedora Release Engineering <releng@fedoraproject.org> - 8.40-82
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild
+
+* Mon Jan 06 2025 Nicolas Frayer <nfrayer@redhat.com> - 8.40-81
+- Fixups to custom kernel targets
+
+* Fri Dec 06 2024 Leo Sandoval <lsandova@redhat.com> - 8.40-80
+- grubby-bls: on PPC systems, remove petiboot's version checks
+
+* Fri Dec 06 2024 Leo Sandoval <lsandova@redhat.com> - 8.40-79
+- grubby-bls: in s390* systems, run zipl on grub cfg update event
+
+* Mon Dec 02 2024 David Abdurachmanov <davidlt@rivosinc.com> - 8.40-78
+- Add riscv64 support
+
+* Mon Nov 25 2024 Leo Sandoval <lsandova@redhat.com> - 8.40-77
+- On grub cfg updates, run grub2-mkconfig for Xen systems
+
+* Thu Jul 18 2024 Fedora Release Engineering <releng@fedoraproject.org> - 8.40-76
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_41_Mass_Rebuild
+
+* Wed Jan 24 2024 Fedora Release Engineering <releng@fedoraproject.org> - 8.40-75
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild
+
+* Sat Jan 20 2024 Fedora Release Engineering <releng@fedoraproject.org> - 8.40-74
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild
+
+* Wed Jan 10 2024 Marta Lewandowska <mlewando@redhat.com> - 8.40-73
+- Do not overwrite all vars that start with GRUB_CMDLINE_LINUX
+
 * Mon Sep 11 2023 Zbigniew Jedrzejewski-Szmek <zbyszek@in.waw.pl> - 8.40-72
 - Drop installkernel so that it can be provided by systemd
 

kernel.sysconfig

@@ -0,0 +1,6 @@
+# UPDATEDEFAULT specifies if kernel-install should make
+# new kernels the default
+UPDATEDEFAULT=yes
+
+# DEFAULTKERNEL specifies the default kernel package type
+DEFAULTKERNEL=kernel-core