Building for ARM systems

[Dan Nicholson]

On Mar 14, 2017 3:08 AM, "Alexander Larsson" <alexl at redhat.com> wrote:

On Mon, 2017-03-13 at 22:31 -0500, Dan Nicholson wrote:
> On Mar 13, 2017 9:19 PM, "Aleix Pol" <aleixpol at kde.org> wrote:
>
> $ flatpak build sdk bash
> execvp bash: No such file or directory
> $ cat /proc/sys/fs/binfmt_misc/status
> enabled
> $ ls -l /proc/sys/fs/binfmt_misc/qemu-arm
> -rw-r--r-- 1 root root 0 mar 13 14:19 /proc/sys/fs/binfmt_misc/qemu-
> arm
>
> Can you show the contents of that qemu-arm file?

Yeah, it seems like it is dynamically linked and is not finding the
loader.


Nah, I just went through this debugging with someone at Endless yesterday.
The kernel unfortunately returns ENOENT when it can't handle the binary
format. Or possibly the ENOENT is because it can't find the interpreter for
the binfmt. Either way, I'm pretty sure it's not a dynamic linking problem
unless Aleix just installed the wrong package.

What I suspect is actually the problem is that Debian's qemu-user-static
package is setting a restrictive mask in the binfmt configuration that
doesn't have the new F flag needed so that the interpreter is opened
immediately at registration and kept open. I noticed yesterday that the
setup on xenial is that the flags are set to OC. I'm guessing this hasn't
been updated and can't really since it would make the configurations in the
package dependent on a pretty new kernel. I believe the kernel throws
EINVAL when an unrecognized option is in the mask.

What Fedora does (I'm pretty sure), and what I think Debian should do, is
leave the mask blank so the kernel defaults are used. Then you pick up the
new F flag automatically when the kernel supports it.

So, I'd like to see the actual registered configuration. If it contains OC
like I suspect, then it needs to be updated to include F or just have the
mask stripped off and use the kernel defaults.

--
Dan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/flatpak/attachments/20170314/a714aead/attachment.html>