On 13-08-20 12:41 PM, Andrea Adami wrote:
On Tue, Aug 20, 2013 at 6:28 PM, Bruce Ashfield
<bruce.ashfi...@windriver.com> wrote:
On 13-08-20 11:03 AM, Andrea Adami wrote:

On Tue, Aug 20, 2013 at 3:51 PM, Bruce Ashfield
<bruce.ashfi...@windriver.com> wrote:

On 13-08-19 03:11 PM, Jason Wessel wrote:


This patch aims to fix the following two cases for the INITRAMFS
generation.
     1) Allow an image recipe to specify a paired INITRAMFS recipe such
        as core-image-minimal-initramfs.  This allows building a base
        image which always generates the needed initramfs image in one
step
     2) Allow building a single binary which contains a kernel and
        the initramfs.

A key requirement of the initramfs is to be able to add kernel
modules.  The current implementation of the INITRAMFS_IMAGE variable
has a circular dependency when using kernel modules in the initramfs
image.bb file that is caused by kernel.bbclass trying to build the
initramfs before the kernel's do_install rule.

The solution for this problem is to have the kernel's
do_bundle_initramfs_image task depend on the do_rootfs from the
INITRAMFS_IMAGE and not some intermediate point.  The image.bbclass
will also sets up dependencies to make the initramfs creation task run
last.

The code to bundle the kernel and initramfs together has been added.
At a high level, all it is doing is invoking a second compilation of
the kernel but changing the value of CONFIG_INITRAMFS_SOURCE to point
to the generated initramfs from the image recipe.



In case it wasn't obvious with Jason cc'ing me, I've seen the patch
before, and I'm good with the change.

So definitely: Acked-by: Bruce Ashfield <bruce.ashfi...@windriver.com>

I'm adding Andrea to the cc list as well, since we've been talking
about initramfs creation for years now, and I'd want his opinion on
whether this looks good, and would work for meta-handheld.

Cheers,

Bruce



Signed-off-by: Jason Wessel <jason.wes...@windriver.com>
---
    meta/classes/image.bbclass  |   12 ++++++
    meta/classes/kernel.bbclass |   96
+++++++++++++++++++++++++++++++++++++------
    meta/conf/local.conf.sample |   20 +++++++++
    3 files changed, 116 insertions(+), 12 deletions(-)

diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 116bd22..78c25db 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -140,6 +140,10 @@ python () {
        d.setVar('MULTILIB_VENDORS', ml_vendor_list)

        check_image_features(d)
+    initramfs_image = d.getVar('INITRAMFS_IMAGE', True) or ""
+    if initramfs_image != "":
+        d.appendVarFlag('do_build', 'depends', "
%s:do_bundle_initramfs"
%  d.getVar('PN', True))
+        d.appendVarFlag('do_bundle_initramfs', 'depends', "
%s:do_rootfs"
% initramfs_image)
    }

    #
@@ -614,3 +618,11 @@ do_package_write_deb[noexec] = "1"
    do_package_write_rpm[noexec] = "1"

    addtask rootfs before do_build
+# Allow the kernel to be repacked with the initramfs and boot image
file
as a single file
+do_bundle_initramfs[depends] += "virtual/kernel:do_bundle_initramfs"
+do_bundle_initramfs[nostamp] = "1"
+do_bundle_initramfs[noexec] = "1"
+do_bundle_initramfs () {
+       :
+}
+addtask bundle_initramfs after do_rootfs
diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index e039dfc..8cf66ce 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -9,6 +9,7 @@ INHIBIT_DEFAULT_DEPS = "1"
    KERNEL_IMAGETYPE ?= "zImage"
    INITRAMFS_IMAGE ?= ""
    INITRAMFS_TASK ?= ""
+INITRAMFS_IMAGE_BUNDLE ?= ""

    python __anonymous () {
        kerneltype = d.getVar('KERNEL_IMAGETYPE', True) or ''
@@ -19,7 +20,15 @@ python __anonymous () {

        image = d.getVar('INITRAMFS_IMAGE', True)
        if image:
-        d.setVar('INITRAMFS_TASK', '${INITRAMFS_IMAGE}:do_rootfs')
+        d.appendVarFlag('do_bundle_initramfs', 'depends', '
${INITRAMFS_IMAGE}:do_rootfs')
+
+    # NOTE: setting INITRAMFS_TASK is for backward compatibility
+    #       The preferred method is to set INITRAMFS_IMAGE, because
+    #       this INITRAMFS_TASK has circular dependency problems
+    #       if the initramfs requires kernel modules
+    image_task = d.getVar('INITRAMFS_TASK', True)
+    if image_task:
+        d.appendVarFlag('do_configure', 'depends', '
${INITRAMFS_TASK}')
    }

    inherit kernel-arch deploy
@@ -72,9 +81,82 @@ KERNEL_SRC_PATH = "/usr/src/kernel"

    KERNEL_IMAGETYPE_FOR_MAKE = "${@(lambda s: s[:-3] if s[-3:] == ".gz"
else s)(d.getVar('KERNEL_IMAGETYPE', True))}"

+copy_initramfs() {
+       echo "Copying initramfs into ./usr ..."
+       # Find and use the first initramfs image archive type we find
+       rm -f ${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.cpio
+       for img in cpio.gz cpio.lzo cpio.lzma cpio.xz; do
+               if [ -e
"${DEPLOY_DIR_IMAGE}/${INITRAMFS_IMAGE}-${MACHINE}.$img" ]; then
+                       cp
${DEPLOY_DIR_IMAGE}/${INITRAMFS_IMAGE}-${MACHINE}.$img ${B}/usr/.
+                       case $img in
+                       *gz)
+                               echo "gzip decompressing image"
+                               gunzip -f
${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.$img
+                               break
+                               ;;
+                       *lzo)
+                               echo "lzo decompressing image"
+                               lzop -df
${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.$img
+                               break
+                               ;;
+                       *lzma)
+                               echo "lzma decompressing image"
+                               lzmash -df
${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.$img
+                               break
+                               ;;
+                       *xz)
+                               echo "xz decompressing image"
+                               xz -df
${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.$img
+                               break
+                               ;;
+                       esac
+               fi
+       done
+       echo "Finished copy of initramfs into ./usr"
+}
+
+INITRAMFS_BASE_NAME =
"${KERNEL_IMAGETYPE}-initramfs-${PV}-${PR}-${MACHINE}-${DATETIME}"
+INITRAMFS_BASE_NAME[vardepsexclude] = "DATETIME"
+do_bundle_initramfs () {
+       if [ ! -z "${INITRAMFS_IMAGE}" -a x"${INITRAMFS_IMAGE_BUNDLE}" =
x1 ]; then
+               echo "Creating a kernel image with a bundled
initramfs..."
+               copy_initramfs
+               if [ -e ${KERNEL_OUTPUT} ] ; then
+                       mv -f ${KERNEL_OUTPUT} ${KERNEL_OUTPUT}.bak
+               fi
+

use_alternate_initrd=CONFIG_INITRAMFS_SOURCE=${B}/usr/${INITRAMFS_IMAGE}-${MACHINE}.cpio
+               kernel_do_compile
+               mv -f ${KERNEL_OUTPUT} ${KERNEL_OUTPUT}.initramfs
+               mv -f ${KERNEL_OUTPUT}.bak ${KERNEL_OUTPUT}
+               # Update install area
+               echo "There is kernel image bundled with initramfs:
${B}/${KERNEL_OUTPUT}.initramfs"
+               install -m 0644 ${B}/${KERNEL_OUTPUT}.initramfs
${D}/boot/${KERNEL_IMAGETYPE}-initramfs-${MACHINE}.bin
+               echo "${B}/${KERNEL_OUTPUT}.initramfs"
+               cd ${B}
+               # Update deploy directory
+               if [ -e "${KERNEL_OUTPUT}.initramfs" ]; then
+                       echo "Copying deploy kernel-initramfs image and
setting up links..."
+                       initramfs_base_name=${INITRAMFS_BASE_NAME}
+
initramfs_symlink_name=${KERNEL_IMAGETYPE}-initramfs-${MACHINE}
+                       install -m 0644 ${KERNEL_OUTPUT}.initramfs
${DEPLOY_DIR_IMAGE}/${initramfs_base_name}.bin
+                       cd ${DEPLOY_DIR_IMAGE}
+                       ln -sf ${initramfs_base_name}.bin
${initramfs_symlink_name}.bin
+               fi
+       fi
+}
+do_bundle_initramfs[nostamp] = "1"
+addtask bundle_initramfs after do_compile
+
    kernel_do_compile() {
          unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS MACHINE
-       oe_runmake ${KERNEL_IMAGETYPE_FOR_MAKE} ${KERNEL_ALT_IMAGETYPE}
CC="${KERNEL_CC}" LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
+       # The $use_alternate_initrd is only set from
+       # do_bundle_initramfs() This variable is specifically for the
+       # case where we are making a second pass at the kernel
+       # compilation and we want to force the kernel build to use a
+       # different initramfs image.  The way to do that in the kernel
+       # is to specify:
+       # make ...args...
CONFIG_INITRAMFS_SOURCE=some_other_initramfs.cpio
+       oe_runmake ${KERNEL_IMAGETYPE_FOR_MAKE} ${KERNEL_ALT_IMAGETYPE}
CC="${KERNEL_CC}" LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
$use_alternate_initrd
          if test "${KERNEL_IMAGETYPE_FOR_MAKE}.gz" =
"${KERNEL_IMAGETYPE}";
then
                  gzip -9c < "${KERNEL_IMAGETYPE_FOR_MAKE}" >
"${KERNEL_OUTPUT}"
          fi
@@ -219,18 +301,8 @@ kernel_do_configure() {
                  cp "${WORKDIR}/defconfig" "${B}/.config"
          fi
          yes '' | oe_runmake oldconfig
-
-       if [ ! -z "${INITRAMFS_IMAGE}" ]; then
-               for img in cpio.gz cpio.lzo cpio.lzma cpio.xz; do
-               if [ -e
"${DEPLOY_DIR_IMAGE}/${INITRAMFS_IMAGE}-${MACHINE}.$img" ]; then
-                       cp
"${DEPLOY_DIR_IMAGE}/${INITRAMFS_IMAGE}-${MACHINE}.$img" initramfs.$img
-               fi
-               done
-       fi
    }

-do_configure[depends] += "${INITRAMFS_TASK}"
-
    do_savedefconfig() {
          oe_runmake savedefconfig
    }
diff --git a/meta/conf/local.conf.sample b/meta/conf/local.conf.sample
index 2b078d0..17733ab 100644
--- a/meta/conf/local.conf.sample
+++ b/meta/conf/local.conf.sample
@@ -146,6 +146,26 @@ EXTRA_IMAGE_FEATURES = "debug-tweaks"
    USER_CLASSES ?= "buildstats image-mklibs image-prelink"

    #
+# Kernel image features
+#
+# The INITRAMFS_IMAGE image variable will cause an additional recipe to
+# be built as a dependency to the what ever rootfs recipe you might be
+# using such as core-image-sato.  The initramfs might be needed for
+# the initial boot of of the target system such as to load kernel
+# modules prior to mounting the root file system.
+#
+# INITRAMFS_IMAGE_BUNDLE variable controls if the image recipe
+# specified by the INITRAMFS_IMAGE will be run through an extra pass
+# through the kernel compilation in order to build a single binary
+# which contains both the kernel image and the initramfs.  The
+# combined binary will be deposited into the tmp/deploy directory.
+# NOTE: You can set INITRAMFS_IMAGE in an image recipe, but
+#       INITRAMFS_IMAGE_BUNDLE can only be set in a conf file.
+#
+#INITRAMFS_IMAGE = "core-image-minimal-initramfs"
+#INITRAMFS_IMAGE_BUNDLE = "1"
+
+#
    # Runtime testing of images
    #
    # The build system can test booting virtual machine images under qemu
(an emulator)



I plan to test this as soon as possible.

Though, it seems to me a bit too special-cased: you only change
CONFIG_INITRAMFS_SOURCE=some_other_initramfs.cpio.
I mean, our necessity is to have a *different* second kernel embedding
the initramfs and in fact we have linux-yocto as standard kernel and a
linux-yocto-tiny derived special-purpose kernel+cpio.


This is exactly what I was hoping to hear as feedback, and yes,
this solution does stop short of the kexec solution or a two
kernel variant. It does allow you to have a kernel module for a
driver in your initramfs, and a unique filesystem for that
initramfs.

Your document/steps are one of the cases that I had in mind, it
would be nice to make it simpler as well .. if possible.



(in case you missed it:
http://kexecboot.org/documentation/crosscompiling/oe-yocto )

About building all in one-pass, well, we were there and we did step back.
It was preferred to build only the 'production' kernel when building
images and to build separately the special kernel+cpio.
The logic was to create a dummy recipe and let the option to build it
automatically i.e. adding it as # EXTRA_IMAGEDEPENDS += "dummy" in
your machine.conf or another conf file


Remind me on this part. When you assemble and include that second
kernel into the production kernel's initramfs, how are the build
artifacts shared ? i.e. it's just a second build with a shared
deploy directory ? (your my-installer.bb recipe) ?

Yes, exactly.
In the specific case you can manually do 'bitbake zaurus-installer' or
just uncomment the
following line in zaurus.inc (belongs to the machine config file).

# If set here, each image will also build linux-yocto-tiny-kexecboot
and the updater
# EXTRA_IMAGEDEPENDS += "zaurus-installer"

This will build all the needed parts.

cool. Thanks for the confirmation.

Bruce


Regards

Andrea


Cheers,

Bruce



I'll test soon anyway, thx.

Cheers

Andrea



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