[PATCH v4 2/3] Add example initramfs module recipe

[Harald Seiler <hws@denx.de>]

Add the initramfs-example recipe/package which demonstrates how to write
initramfs modules.  It demonstrates how to add hook scripts, boot scripts,
and conf-hooks.

Signed-off-by: Harald Seiler <hws@denx.de>
---

Notes:
    Changes in v3:
    - None
    
    Changes in v4:
    - None

 .../initramfs-example/files/example.conf-hook |  7 ++++
 .../initramfs-example/files/example.hook      | 19 +++++++++
 .../initramfs-example/files/example.script    | 21 ++++++++++
 .../initramfs-example/initramfs-example.bb    | 40 +++++++++++++++++++
 4 files changed, 87 insertions(+)
 create mode 100644 meta-isar/recipes-initramfs/initramfs-example/files/example.conf-hook
 create mode 100644 meta-isar/recipes-initramfs/initramfs-example/files/example.hook
 create mode 100644 meta-isar/recipes-initramfs/initramfs-example/files/example.script
 create mode 100644 meta-isar/recipes-initramfs/initramfs-example/initramfs-example.bb

diff --git a/meta-isar/recipes-initramfs/initramfs-example/files/example.conf-hook b/meta-isar/recipes-initramfs/initramfs-example/files/example.conf-hook
new file mode 100644
index 000000000000..2a3cf7a84040
--- /dev/null
+++ b/meta-isar/recipes-initramfs/initramfs-example/files/example.conf-hook
@@ -0,0 +1,7 @@
+# Example conf-hook.
+#
+# See "CONFIGURATION HOOK SCRIPTS" in initramfs-tools(7) for details.
+
+# Example: Use busybox instead of klibc-utils.  The package must also add
+# `busybox` as a dependency when this is set.
+BUSYBOX=y
diff --git a/meta-isar/recipes-initramfs/initramfs-example/files/example.hook b/meta-isar/recipes-initramfs/initramfs-example/files/example.hook
new file mode 100644
index 000000000000..0d84e7a97efd
--- /dev/null
+++ b/meta-isar/recipes-initramfs/initramfs-example/files/example.hook
@@ -0,0 +1,19 @@
+#!/bin/sh
+# Example hook script.
+#
+# See "HOOK SCRIPTS" in initramfs-tools(7) for details.
+
+PREREQ=""
+prereqs()
+{
+    echo "$PREREQ"
+}
+case $1 in
+prereqs)
+    prereqs
+    exit 0
+    ;;
+esac
+
+. /usr/share/initramfs-tools/hook-functions
+# Begin real processing below this line
diff --git a/meta-isar/recipes-initramfs/initramfs-example/files/example.script b/meta-isar/recipes-initramfs/initramfs-example/files/example.script
new file mode 100644
index 000000000000..784fad9c99bb
--- /dev/null
+++ b/meta-isar/recipes-initramfs/initramfs-example/files/example.script
@@ -0,0 +1,21 @@
+#!/bin/sh
+# Example boot script.
+#
+# See "BOOT SCRIPTS" in initramfs-tools(7) for details.
+
+PREREQ=""
+prereqs()
+{
+    echo "$PREREQ"
+}
+case $1 in
+prereqs)
+    prereqs
+    exit 0
+    ;;
+esac
+
+. /scripts/functions
+# Begin real processing below this line
+
+log_success_msg "Hello from ISAR!"
diff --git a/meta-isar/recipes-initramfs/initramfs-example/initramfs-example.bb b/meta-isar/recipes-initramfs/initramfs-example/initramfs-example.bb
new file mode 100644
index 000000000000..c336dda92b5d
--- /dev/null
+++ b/meta-isar/recipes-initramfs/initramfs-example/initramfs-example.bb
@@ -0,0 +1,40 @@
+# Example of a recipe containing an initramfs module.  Packages like this can be
+# used with initramfs.bbclass or installed directly into a rootfs, depending on
+# the usecase.
+#
+# This software is a part of ISAR.
+
+DESCRIPTION = "Sample initramfs module for ISAR"
+MAINTAINER = "Your name here <you@domain.com>"
+DEBIAN_DEPENDS = "initramfs-tools"
+
+# If the conf-hook enables BUSYBOX=y, busybox is needed:
+DEBIAN_DEPENDS .= ", busybox"
+
+SRC_URI = " \
+    file://example.conf-hook \
+    file://example.hook \
+    file://example.script \
+    "
+
+inherit dpkg-raw
+
+do_install[cleandirs] += " \
+    ${D}/usr/share/initramfs-tools/conf-hooks.d \
+    ${D}/usr/share/initramfs-tools/hooks \
+    ${D}/usr/share/initramfs-tools/scripts/local-top \
+    "
+do_install() {
+    # See "CONFIGURATION HOOK SCRIPTS" in initramfs-tools(7) for details.
+    install "${WORKDIR}/example.conf-hook" \
+        "${D}/usr/share/initramfs-tools/conf-hooks.d/isar-example"
+
+    # See "HOOK SCRIPTS" in initramfs-tools(7) for details.
+    install "${WORKDIR}/example.hook" \
+        "${D}/usr/share/initramfs-tools/hooks/isar-example"
+
+    # Note that there are other places where a boot script might be deployed to,
+    # apart from local-top.  See "BOOT SCRIPTS" in initramfs-tools(7) for details.
+    install "${WORKDIR}/example.script" \
+        "${D}/usr/share/initramfs-tools/scripts/local-top/example.script"
+}
-- 
2.29.2