diff --git a/diskimage_builder/elements/bootloader/README.rst b/diskimage_builder/elements/bootloader/README.rst
index ce2147bca..56e170768 100644
--- a/diskimage_builder/elements/bootloader/README.rst
+++ b/diskimage_builder/elements/bootloader/README.rst
@@ -13,6 +13,6 @@ Arguments
* ``DIB_GRUB_TIMEOUT`` sets the ``grub`` menu timeout. It defaults to
5 seconds. Set this to 0 (no timeout) for fast boot times.
-* ``DIB_BOOTLOADER_DEFAULT_CMDLINE`` sets the CMDLINE parameters that
- are appended to the grub.cfg configuration. It defaults to
- 'nofb nomodeset vga=normal'
+* ``DIB_BOOTLOADER_DEFAULT_CMDLINE`` sets parameters that are appended
+ to the ``GRUB_CMDLINE_LINUX_DEFAULT`` values in ``grub.cfg``
+ configuration. It defaults to ``nofb nomodeset vga=normal``.
diff --git a/diskimage_builder/elements/bootloader/finalise.d/50-bootloader b/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
index 0a6b0db6b..75dfd78c3 100755
--- a/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
+++ b/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
@@ -185,9 +185,8 @@ function install_grub2 {
GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=${SERIAL_CONSOLE} no_timer_check"
- echo "GRUB_CMDLINE_LINUX_DEFAULT=\"${GRUB_CMDLINE_LINUX_DEFAULT}\"" >>/etc/default/grub
+ echo "GRUB_CMDLINE_LINUX_DEFAULT=\"${GRUB_CMDLINE_LINUX_DEFAULT} ${DIB_BOOTLOADER_DEFAULT_CMDLINE}\"" >>/etc/default/grub
echo 'GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"' >>/etc/default/grub
- sed -i -e "s/\(^GRUB_CMDLINE_LINUX.*\)\"$/\1 ${DIB_BOOTLOADER_DEFAULT_CMDLINE}\"/" /etc/default/grub
if type grub2-mkconfig >/dev/null; then
GRUB_MKCONFIG="grub2-mkconfig -o $GRUB_CFG"
diff --git a/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml b/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml
new file mode 100644
index 000000000..643d22b9a
--- /dev/null
+++ b/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml
@@ -0,0 +1,7 @@
+---
+other:
+ - It has been clarified that the ``DIB_BOOTLOADER_DEFAULT_CMDLINE``
+ variable appends its values to grubs
+ ``GRUB_CMDLINE_LINUX_DEFAULT``, which is used during all normal
+ boots but not rescue boots; as opposed to applying to
+ ``GRUB_CMDLINE_LINUX``