Hi,

On Thu, May 11, 2017 at 06:14:21PM +0200, Clemens Gruber wrote:
> On Mon, May 08, 2017 at 10:02:10AM +0200, Michael Olbrich wrote:
> > mkfs.ext4 in the current version can add content to the filesystem. So that
> > is the way to go. I started a patch for genimage to use it, but so far I'm
> > lacking the time to finish this.
> > The main problem is, that mkfs.ext4 checks /etc/mke2fs.conf by default and
> > looks up some stuff in /proc when deciding what to do. So it's a bit tricky
> > to make sure that the build host does not influence the creation of the
> > image.
> 
> Ok, so considering these problems of host influences when using
> mkfs.ext4, even though -d is now a supported option, shouldn't we then
> give make_ext4fs a try?

No, I want the generated filesystem to be as close as possible to something
created on the target.

> If mkfs.ext4 reads from /proc, we would have to patch this out or work
> with upstream e2fsprogs adding a flag to skip these host system lookups?

I don't think patching is necessary. What I've seen was just defaults for
some options. So this just needs review and some options.

> If you still prefer mkfs.ext4, please send the current state of your
> patch.

I've attached my genimage patch. I think the lazy_* stuff was related to
the /proc issue. I'm not sure I like the tool selection, but I don't want
to break old setups either.

> While we're at it, I thought we could also add support for f2fs image
> creation. The problem there however is, that neither the mkfs.f2fs tool
> nor any other 3rd party tool I know of can create a f2fs filesystem with
> a pre-defined root directory. But maybe I missed something.

I never used f2fs, so I have no idea.

> And loop-mounting to copy stuff to it, is probably not an option.

That requires root access and is not easily integrated.

> By the way:
> In my platformconfig, I currently use IMAGE_ROOT_EXT from section image2
> and not IMAGE_EXT2 from section image, so in my case, genext2fs is
> called from rules/post/image_ext2.make and not via genimage from
> rules/image-root-ext.make.

That makes no sense. rules/image-root-ext.make is used by IMAGE_EXT2.

> What is the purpose of there being two image sections image and image2
> and is one of them deprecated or discouraged?

Only use the new image stuff. It's a rewrite of the other rules using
genimage and other internal changes. It should also be easier to use.

I just didn't want to remove the old rules until we had all the existing
features. I should probably remove the rules that have a matching in the
new image section.

Regards,
Michael

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