Merge branch 'baserock/richardmaw/S11159/initramfs-support'

Reviewed-by: Sam Thursfield and Richard Ipsum

5 files changed, 74 insertions, 0 deletions

diff --git a/morphlib/exts/initramfs.write b/morphlib/exts/initramfs.write
new file mode 100755
index 00000000..815772f2
--- /dev/null
+++ b/morphlib/exts/initramfs.write
@@ -0,0 +1,27 @@
+#!/bin/sh
+# Copyright (C) 2014  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# =*= License: GPL-2 =*=
+
+set -e
+
+ROOTDIR="$1"
+INITRAMFS_PATH="$2"
+
+(cd "$ROOTDIR" &&
+    find . -print0 |
+    cpio -0 -H newc -o |
+    gzip -c) >"$INITRAMFS_PATH"
diff --git a/morphlib/exts/initramfs.write.help b/morphlib/exts/initramfs.write.help
new file mode 100644
index 00000000..29a9d266
--- /dev/null
+++ b/morphlib/exts/initramfs.write.help
@@ -0,0 +1,35 @@
+help: |
+    Create an initramfs for a system by taking an existing system and
+    converting it to the appropriate format.
+
+    The system must have a `/init` executable as the userland entry-point.
+    This can have a different path, if `rdinit=$path` is added to
+    the kernel command line. This can be added to the `rawdisk`,
+    `virtualbox-ssh` and `kvm` write extensions with the `KERNEL_CMDLINE`
+    option.
+
+    It is possible to use a ramfs as the final rootfs without a `/init`
+    executable, by setting `root=/dev/mem`, or `rdinit=/sbin/init`,
+    but this is beyond the scope for the `initramfs.write` extension.
+
+    The intended use of initramfs.write is to be part of a nested
+    deployment, so the parent system has an initramfs stored as
+    `/boot/initramfs.gz`. See the following example:
+
+        name: initramfs-test
+        kind: cluster
+        systems:
+        - morph: minimal-system-x86_64-generic
+          deploy:
+            system:
+              type: rawdisk
+              location: initramfs-system-x86_64.img
+              DISK_SIZE: 1G
+              HOSTNAME: initramfs-system
+              INITRAMFS_PATH: boot/initramfs.gz
+          subsystems:
+          - morph: initramfs-x86_64
+            deploy:
+              initramfs:
+                type: initramfs
+                location: boot/initramfs.gz
diff --git a/morphlib/exts/kvm.write.help b/morphlib/exts/kvm.write.help
new file mode 100644
index 00000000..8b5053a5
--- /dev/null
+++ b/morphlib/exts/kvm.write.help
@@ -0,0 +1,4 @@
+help: |
+    The INITRAMFS_PATH option can be used to specify the location of an
+    initramfs for syslinux to tell Linux to use, rather than booting
+    the rootfs directly.
diff --git a/morphlib/exts/rawdisk.write.help b/morphlib/exts/rawdisk.write.help
index a514a4e8..298d441c 100644
--- a/morphlib/exts/rawdisk.write.help
+++ b/morphlib/exts/rawdisk.write.help
@@ -5,3 +5,7 @@ help: |
 
     The `location` argument is a pathname to the image to be
     created or upgraded.
+
+    The INITRAMFS_PATH option can be used to specify the location of an
+    initramfs for syslinux to tell Linux to use, rather than booting
+    the rootfs directly.
diff --git a/morphlib/exts/virtualbox-ssh.write.help b/morphlib/exts/virtualbox-ssh.write.help
new file mode 100644
index 00000000..8b5053a5
--- /dev/null
+++ b/morphlib/exts/virtualbox-ssh.write.help
@@ -0,0 +1,4 @@
+help: |
+    The INITRAMFS_PATH option can be used to specify the location of an
+    initramfs for syslinux to tell Linux to use, rather than booting
+    the rootfs directly.