[Buildroot] [PATCH] fs/initramfs: fix show-info

[Thomas De Schampheleire]

El lun., 16 mar. 2020 a las 22:55, Yann E. MORIN
(<yann.morin.1998 at free.fr>) escribió:
>
> The initramfs is not a reall filesystem, so it does not use the
> $(rootfs) infrastructure.
>
> As a consequence, the usual rootfs-related variables are not set,
> especially the name, type, and dependencies of the (non-)filesystem.
>
> Yet, it is present in the list of rootfs to build, and thus we end
> up including it in the output of show-info. But the missing variables
> yield an incorrect json:
>
>     "": {
>         "type": "",
>         "virtual": false,
>         "version": "",
>         "licenses": "",
>         "dl_dir": "",
>         "install_target": ,
>         "install_staging": ,
>         "install_images": ,
>         "downloads": [ ],
>         "dependencies": [ ],
>         "reverse_dependencies": [ ]
>     },
>
> First, the object key is empty; second, the install_target,
> install_staging, and install_images values are empty, which is not
> valid (if they were null, that be OK though). Third, this is clearly
> the layout of a 'package' entry, not that of a 'rootfs' entry.
>
> An option to fix that would be to actually make use of the rootfs
> infra. However, that would mean doing a lot of work for nothing
> (there is actually nothing to do, yet the infra would still do a lot
> of preparatory and clean up work).
>
> The alternative is pretty simple: declare and set the variables as if
> it were a real filesystem, so that show-info can filter it to the
> proper layout and can spit out appropriate content (even if fake).
>
> The third option would be to teach show-info (and its internal
> implementation, the macro json-info) to ignore specific cases, like
> no-name items, or replace empty values with null, or whatnots. This
> again would be quite a lot of work for a single occurence.
>
> So we go for the simple faked variables.
>
> We add linux as a dependency, so that the graph-depends also properly
> represent the dependency chain, which ends up with something liKe:
>
>               ALL
>                |
>                v
>         rootfs-initramfs
>          |            |
>          v            v
>        linux     rootfs-cpio
>
> which is pretty fitting in the end.
>
> Reported-by: Thomas De Schampheleire <patrickdepinguin at gmail.com>
> Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
> ---
>  fs/initramfs/initramfs.mk | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/fs/initramfs/initramfs.mk b/fs/initramfs/initramfs.mk
> index c751093214..3b3d4ed8b9 100644
> --- a/fs/initramfs/initramfs.mk
> +++ b/fs/initramfs/initramfs.mk
> @@ -29,3 +29,8 @@ rootfs-initramfs-show-depends:
>  ifeq ($(BR2_TARGET_ROOTFS_INITRAMFS),y)
>  TARGETS_ROOTFS += rootfs-initramfs
>  endif
> +
> +# Not using the rootfs infra, so fake the variables
> +ROOTFS_INITRAMFS_NAME = rootfs-initramfs
> +ROOTFS_INITRAMFS_TYPE = rootfs
> +ROOTFS_INITRAMFS_DEPENDENCIES = rootfs-cpio linux

Thanks!

Tested-by: Thomas De Schampheleire <thomas.de_schampheleire at nokia.com>