From 953b61004c37948dcd897265b56c1613bc73b9f9 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 9 Feb 2022 14:44:48 +0100
Subject: [PATCH] kernel-install: only generate systemd.boot_id= in kernel
 command line if used for naming the boot loader spec files/dirs

Now that we can distinguish the naming of the boot loader spec
dirs/files and the machine ID let's tweak the logic for suffixing the
kernel cmdline with systemd.boot_id=: let's only do that when we
actually need the boot ID for naming these dirs/files. If we don't,
let's not bother.

This should be beneficial for "golden" images that shall not carry any
machine IDs at all, i.e acquire their identity only once the final
userspace is actually reached.
---
 src/kernel-install/90-loaderentry.install | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/kernel-install/90-loaderentry.install b/src/kernel-install/90-loaderentry.install
index 46261a2c11..c1d69aa824 100644
--- a/src/kernel-install/90-loaderentry.install
+++ b/src/kernel-install/90-loaderentry.install
@@ -70,10 +70,15 @@ else
     BOOT_OPTIONS="$(tr -s "$IFS" '\n' </proc/cmdline | grep -ve '^BOOT_IMAGE=' -e '^initrd=' | tr '\n' ' ')"
 fi
 
-# Suffix with the machine ID we use, so that the machine ID remains stable,
-# even during factory reset, in the initrd (where the system's machine ID is
-# not directly accessible yet), and if the root file system is volatile.
-BOOT_OPTIONS="${BOOT_OPTIONS% } systemd.machine_id=$MACHINE_ID"
+BOOT_OPTIONS="${BOOT_OPTIONS% }"
+
+# If the boot entries are named after the machine ID, then suffix the kernel
+# command line with the machine ID we use, so that the machine ID remains
+# stable, even during factory reset, in the initrd (where the system's machine
+# ID is not directly accessible yet), and if the root file system is volatile.
+if [ "$ENTRY_TOKEN" = "$MACHINE_ID" ]; then
+    BOOT_OPTIONS="$BOOT_OPTIONS systemd.machine_id=$MACHINE_ID"
+fi
 
 if [ -r /etc/kernel/tries ]; then
     read -r TRIES </etc/kernel/tries
@@ -121,7 +126,10 @@ mkdir -p "${LOADER_ENTRY%/*}" || {
 {
     echo "title      $PRETTY_NAME"
     echo "version    $KERNEL_VERSION"
-    echo "machine-id $MACHINE_ID"
+    if [ "$ENTRY_TOKEN" = "$MACHINE_ID" ]; then
+        # See similar logic above for the systemd.machine_id= kernel command line option
+        echo "machine-id $MACHINE_ID"
+    fi
     echo "options    $BOOT_OPTIONS"
     echo "linux      $ENTRY_DIR/linux"