ref-manual: add IMAGE_NAME_SUFFIX variable

Add a variable glossary entry for IMAGE_NAME_SUFFIX, which was added way
back in krogoth.

(From yocto-docs rev: 8158dd587b9ea0085bd9a4bde04d41ef4fdd7f62)

Signed-off-by: Paul Eggleton <paul.eggleton@microsoft.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 78920a8ea5fb991606300c1fcb48aa6a7c20f8c1)
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/documentation/ref-manual/ref-variables.rst b/documentation/ref-manual/ref-variables.rst
index d0850c3c47..df685cdd4e 100644
--- a/documentation/ref-manual/ref-variables.rst
+++ b/documentation/ref-manual/ref-variables.rst
@@ -3068,6 +3068,13 @@ system and gives an overview of their function and contents.
 
          IMAGE_NAME ?= "${IMAGE_BASENAME}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
 
+   :term:`IMAGE_NAME_SUFFIX`
+      Suffix used for the image output file name - defaults to ``".rootfs"``
+      to distinguish the image file from other files created during image
+      building; however if this suffix is redundant or not desired you can
+      clear the value of this variable (set the value to ""). For example,
+      this is typically cleared in initramfs image recipes.
+
    :term:`IMAGE_OVERHEAD_FACTOR`
       Defines a multiplier that the build system applies to the initial
       image size for cases when the multiplier times the returned disk