[OE-core] [PATCH 0/3] Introduces kernel-initramfs recipe to resolve a implicit dependency issue

[Ming Liu]

On 01/19/2016 10:37 PM, Ming Liu wrote:
>
>
> On 01/19/2016 08:34 PM, Bruce Ashfield wrote:
>> On 16-01-05 08:12 AM, Ming Liu wrote:
>>> In current initramfs bundled kernel packaging policy, there are several
>>> dependency chains co-existing:
>>>
>>> | "core-image-minimal.do_build" -> 
>>> "core-image-minimal.do_bundle_initramfs"
>>> | "core-image-minimal.do_bundle_initramfs" -> 
>>> "virtual/kernel.do_bundle_initramfs"
>>> | "core-image-minimal.do_bundle_initramfs" -> 
>>> "core-image-minimal.do_rootfs"
>>
>> In current master, the above dependency should now be
>> do_image_complete, correct ?
> Yes, now it has been changed to do_image_complete.
>
>>
>>> | "core-image-minimal.do_rootfs" -> 
>>> "virtual/kernel.do_package_write_${IMAGE_PKGTYPE}"
>>
>> And for the one above here, I'm not seeing this dependency. Are you
>> saying that it comes via the do_image_complete dependency ?
> It comes from the "recrdeptask" flag in image bbclass, for instance, 
> meta/classes/rootfs_rpm.bbclass, it has:
> do_rootfs[recrdeptask] += "do_package_write_rpm"
>
> this makes sure that do_rootfs task of a certain image would run after 
> do_package_write_rpm of all its DEPENDS and RDEPENDS, recursively.
>
>>
>>> | "virtual/kernel.do_package_write_${IMAGE_PKGTYPE}" -> 
>>> "virtual/kernel.do_package"
>>> | "virtual/kernel.do_package" -> "virtual/kernel.do_install"
>>> |
>>> | "virtual/kernel.do_deploy" -> "virtual/kernel.do_bundle_initramfs"
>>> | "virtual/kernel.do_bundle_initramfs" -> "virtual/kernel.do_install"
>>
>> I'm somehow missing the above dependency as well. I suppose I could dump
>> out the dot file, but I'd like to hear it explained here as well. Since
>> if I can't get the dependency from the text of the commits, it will
>> become hard to maintain.
> They are intertask dependencies, I still take RPM as a example:
> meta/classes/package_rpm.bbclass:addtask package_write_rpm after 
> do_packagedata do_package
> meta/classes/kernel.bbclass:addtask bundle_initramfs after do_install 
> before do_deploy
>
>>
>>>
>>> We could see, virtual/kernel.do_package is not explicitly depending on
>>> virtual/kernel.do_bundle_initramfs so far, therefore, there is not a
>>> workable way to add initramfs bundled kernel image into rootfs, because
>>> kernel's do_bundle_initramfs could run parallelly with its do_package,
>>> which means we will get a implicit kernel-image package that 
>>> sometimes it
>>> contains the initramfs bundled kernel or sometimes it doesn't.
>>
>> I do see what you are describing above. If we've defined
>> INITRAMFS_IMAGE, the anonymous python in kernel.bbclass does make
>> the kernel's do_bundle_initramfs depend on the initramfs image's
>> do_image_complete.
>>
>> Why not just add a task dependency ?
> Do you mean adding a task dependency between package and 
> bundle_initramfs in kernel recipe? But that would introduce a circular 
> dependency issue as described in commit log of 
> 609d5a9ab9e58bb1c2bcc2145399fbc8b701b85a, under following conditions:
> 1 Some kernel modules have been added into INITRAMFS_IMAGE.
> 2 INITRAMFS_IMAGE has been bundled into kernel image
> 3 kernel-image package has been added into IMAGE_INSTALL.
Here, I mean the IMAGE_INSTALL of a normal image like core-image-minimal.

//Ming Liu
>
>>
>>>
>>> To fix this problem, the idea is to let the initramfs bundled kernel
>>> packaging depend on do_bundle_initramfs, meanwhile, to avoid the 
>>> circular
>>> dependency issue that commit: 609d5a9ab9e58bb1c2bcc2145399fbc8b701b85a
>>> [ kernel.bbclass, image.bbclass: Implement kernel INITRAMFS 
>>> dependency and bundling ]
>>
>> But here's my issue. We know that the INITRAMFS image cannot contain,
>> or depend on a kernel itself. So the dependency won't be circular.
>> It is true that we don't enforce that, but that has always been stated
>> in the commits that created the bundling.
>>
>> Is it that condition you are trying to enforce with the split ?
> I know that the users are not allowed to add kernel itself into a 
> INITRAMFS_IMAGE meanwhile bundle it into kernel, which will certainly 
> create a circular dependency. The split was not trying to resolve that 
> condition, but to fix a implicit kernel-image package without 
> introducing any circular dependencies.
>
> //Ming Liu
>>
>> Bruce
>>
>>>
>>> was trying to address, this dependency has to be splitted from kernel
>>> recipe(at least, I could not figure out another way to achieve it), 
>>> so a
>>> new kernel-initramfs is introduced, in which a dependency chain is 
>>> created:
>>>
>>> | "kernel-initramfs.do_install" -> "virtual/kernel.do_deploy"
>>> | "virtual/kernel.do_deploy" -> "virtual/kernel.do_bundle_initramfs"
>>>
>>> Then the users can add initramfs bundled kernel image into rootfs by:
>>>
>>> IMAGE_INSTALL_append = " kernel-initramfs"
>>>
>>> without introducing any circular dependencies.
>>>
>>> Ming Liu (3):
>>>    kernel.bbclass: do not install initramfs bundled kernel image
>>>    image.bbclass: removes bundle_initramfs related code
>>>    kernel-initramfs: new recipe, creates initramfs bundled kernel
>>>      packaging
>>>
>>>   meta/classes/image.bbclass                    | 11 -----
>>>   meta/classes/kernel.bbclass                   |  4 --
>>>   meta/recipes-kernel/linux/kernel-initramfs.bb | 69 
>>> +++++++++++++++++++++++++++
>>>   3 files changed, 69 insertions(+), 15 deletions(-)
>>>   create mode 100644 meta/recipes-kernel/linux/kernel-initramfs.bb
>>>
>>
>