manuals: improve initramfs details

- Create a new entry in the glossary
- Add implementation details
- Replace the mention of "init ramdisk" by "initramfs¨
  whenever possible
- Remove obsolete and duplicate information
- Fix spacing issues in the Sphinx code

(From yocto-docs rev: 952c7e6dee49532705b2c162f4728e635c38df3f)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

4 files changed, 9 insertions, 9 deletions

diff --git a/documentation/migration-guides/migration-2.4.rst b/documentation/migration-guides/migration-2.4.rst
index 964ed92937..8904495022 100644
--- a/documentation/migration-guides/migration-2.4.rst
+++ b/documentation/migration-guides/migration-2.4.rst
@@ -54,7 +54,7 @@ occurred:
       when "pam" is in :term:`DISTRO_FEATURES`.
 
    -  The ``switch_root`` program is now packaged in a separate
-      "util-linux-switch-root" package for small initramfs images that
+      "util-linux-switch-root" package for small :term:`Initramfs` images that
       do not need the whole ``util-linux`` package or the busybox
       binary, which are both much larger than ``switch_root``. The main
       ``util-linux`` package has a recommended runtime dependency (i.e.
diff --git a/documentation/migration-guides/migration-3.2.rst b/documentation/migration-guides/migration-3.2.rst
index 92b7f91f2c..cc6f05322a 100644
--- a/documentation/migration-guides/migration-3.2.rst
+++ b/documentation/migration-guides/migration-3.2.rst
@@ -265,10 +265,10 @@ using the GL options.
 
 .. _migration-3.2-initramfs-suffix:
 
-initramfs images now use a blank suffix
+Initramfs images now use a blank suffix
 ---------------------------------------
 
-The reference initramfs images (``core-image-minimal-initramfs``,
+The reference :term:`Initramfs` images (``core-image-minimal-initramfs``,
 ``core-image-tiny-initramfs`` and ``core-image-testmaster-initramfs``) now
 set an empty string for :term:`IMAGE_NAME_SUFFIX`, which otherwise defaults
 to ``".rootfs"``. These images aren't root filesystems and thus the rootfs
diff --git a/documentation/migration-guides/release-notes-3.4.rst b/documentation/migration-guides/release-notes-3.4.rst
index 323e4df7ae..4319bf119d 100644
--- a/documentation/migration-guides/release-notes-3.4.rst
+++ b/documentation/migration-guides/release-notes-3.4.rst
@@ -36,7 +36,7 @@ New Features / Enhancements in 3.4
 
 -  Kernel-related enhancements:
 
-   -  Support zstd-compressed modules and initramfs images
+   -  Support zstd-compressed modules and :term:`Initramfs` images
    -  Allow opt-out of split kernel modules
    -  linux-yocto-dev: base AUTOREV on specified version
    -  kernel-yocto: provide debug / summary information for metadata
@@ -211,7 +211,7 @@ The following corrections have been made to the LICENSE values set by recipes:
 Other license-related notes:
 
 -  When creating recipes for Python software, recipetool will now treat "BSD" as "BSD-3-Clause" for the purposes of setting LICENSE, as that is the most common understanding.
--  Please be aware that an initramfs bundled with the kernel using :term:`INITRAMFS_IMAGE_BUNDLE` should only contain GPLv2-compatible software; this is now mentioned in the documentation.
+-  Please be aware that an :term:`Initramfs` bundled with the kernel using :term:`INITRAMFS_IMAGE_BUNDLE` should only contain GPLv2-compatible software; this is now mentioned in the documentation.
 
 Security Fixes in 3.4
 ~~~~~~~~~~~~~~~~~~~~~
diff --git a/documentation/migration-guides/release-notes-4.0.rst b/documentation/migration-guides/release-notes-4.0.rst
index b675cae217..a61ccc6913 100644
--- a/documentation/migration-guides/release-notes-4.0.rst
+++ b/documentation/migration-guides/release-notes-4.0.rst
@@ -30,7 +30,7 @@ New Features / Enhancements in 4.0
 
 - New :ref:`overlayfs <ref-classes-overlayfs>` and
   :ref:`overlayfs-etc <ref-classes-overlayfs-etc>` classes and
-  ``overlayroot`` support in the initramfs framework to make it easier to
+  ``overlayroot`` support in the :term:`Initramfs` framework to make it easier to
   overlay read-only filesystems (for example) with
   `OverlayFS <https://en.wikipedia.org/wiki/OverlayFS>`__.
 
@@ -168,7 +168,7 @@ New Features / Enhancements in 4.0
 
 -  Kernel-related enhancements:
 
-   - Allow initramfs to be built from a separate multiconfig
+   - Allow :term:`Initramfs` to be built from a separate multiconfig
    - Make kernel-base recommend kernel-image, not depend (allowing images containing kernel modules without kernel image)
    - linux-yocto: split vtpm for more granular inclusion
    - linux-yocto: cfg/debug: add configs for kcsan
@@ -182,7 +182,7 @@ New Features / Enhancements in 4.0
 
 - FIT image related enhancements:
 
-   - New ``FIT_SUPPORTED_INITRAMFS_FSTYPES`` variable to allow extending initramfs image types to look for
+   - New ``FIT_SUPPORTED_INITRAMFS_FSTYPES`` variable to allow extending :term:`Initramfs` image types to look for
    - New ``FIT_CONF_PREFIX`` variable to allow overriding FIT configuration prefix
    - Use 'bbnote' for better logging
 
@@ -276,7 +276,7 @@ New Features / Enhancements in 4.0
 - volatile-binds: SELinux and overlayfs extensions in mount-copybind
 - gtk-icon-cache: Allow using gtk4
 - kmod: Add an exclude directive to depmod
-- os-release: add os-release-initrd package for use in systemd-based initramfs images
+- os-release: add os-release-initrd package for use in systemd-based :term:`Initramfs` images
 - gstreamer1.0-plugins-base: add support for graphene
 - gpg-sign: Add parameters to gpg signature function
 - package_manager: sign DEB package feeds