[Buildroot] connman requirement for resolver in toolchain

[Buildroot] connman requirement for resolver in toolchain

[Michael J. Hammel]

I'm looking at adding connman to my build. It appears that connman can't
be enabled unless the toolchain includes resolver support.  

How does the config check for that?  I didn't see any Buildroot config
options to specify that my external toolchain has that nor is there any
option in Crosstool-NG (my toolchain) to enable it in the C library.

I'm using Buildroot 2012-02 and Crosstool-NG 1.13.4.

-- 
Michael J. Hammel <buildroot@graphics-muse.org>

[Buildroot] connman requirement for resolver in toolchain

[Thomas Petazzoni]

Hello Michael,

Le Wed, 16 May 2012 21:01:51 -0600,
"Michael J. Hammel" <buildroot@graphics-muse.org> a ?crit :

> I'm looking at adding connman to my build. It appears that connman can't
> be enabled unless the toolchain includes resolver support.  
> 
> How does the config check for that?  I didn't see any Buildroot config
> options to specify that my external toolchain has that nor is there any
> option in Crosstool-NG (my toolchain) to enable it in the C library.
> 
> I'm using Buildroot 2012-02 and Crosstool-NG 1.13.4.

All packages in Buildroot assume that if uClibc is used, then the
uClibc configuration contains at least the options that Buildroot uses
to build uClibc when the internal backend is used. Those options are
listed in toolchain/uClibc/uClibc-0.9.xx.config.

If you are building your uClibc toolchain externally with Crosstool-NG,
then it is up to you to adjust the uClibc configuration. You can either:

 *) Choose to make it identical to the uClibc configuration that
    Buildroot uses for its internal backend, which gives you a good
    certainty that packages will build

 *) Choose to progressively adjust your uClibc configuration to match
    the particular requirements of the specific packages you're using.

But the overall answer is: if you're using an uClibc external
toolchain, Buildroot can't do anything to adjust the uClibc
configuration, so it's your job to do so :-)

Personally, for the Crosstool-NG toolchains I use for the autobuilds, I
have created samples that use the Buildroot uClibc configuration, so
that it matches what Buildroot expects.

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] connman requirement for resolver in toolchain

[Michael J. Hammel]

On Thu, 2012-05-17 at 10:26 +0200, Thomas Petazzoni wrote:
> Hello Michael,

Howdy Thomas.

> All packages in Buildroot assume that if uClibc is used, then the
> uClibc configuration contains at least the options that Buildroot uses
> to build uClibc when the internal backend is used. Those options are
> listed in toolchain/uClibc/uClibc-0.9.xx.config.

Oops. That's what I missed.  I didn't check my uClibc config.  I only
looked at Crosstool-NG's config (well, and Buildroot's).  I'll check
uClibc.

> But the overall answer is: if you're using an uClibc external
> toolchain, Buildroot can't do anything to adjust the uClibc
> configuration, so it's your job to do so :-)

Yup.  I just have to remember which ones to check.  :-)

Thanks again Thomas.

-- 
Michael J. Hammel <buildroot@graphics-muse.org>

[Buildroot] connman requirement for resolver in toolchain

[Michael J. Hammel]

On Thu, 2012-05-17 at 10:26 +0200, Thomas Petazzoni wrote:
> If you are building your uClibc toolchain externally with Crosstool-NG,
> then it is up to you to adjust the uClibc configuration. You can either:
> 
>  *) Choose to make it identical to the uClibc configuration that
>     Buildroot uses for its internal backend, which gives you a good
>     certainty that packages will build
> 
>  *) Choose to progressively adjust your uClibc configuration to match
>     the particular requirements of the specific packages you're using.

I'm doing the latter.  I've diffed my uClibc config with the one for the
matching release in Buildroot and have enabled what I think is relevant
for resolver support, re: I configured uClibc with the resolver and nsl
stubs.  However, buildroot still doesn't allow me to configure connman.

I looked at connman's Config.in and it looks like this:

comment "connman needs a toolchain with resolver support"
    depends on !(BR2_UCLIBC_VERSION_SNAPSHOT ||
BR2_TOOLCHAIN_EXTERNAL_GLIBC || BR2_TOOLCHAIN_CTNG_eglibc ||
BR2_TOOLCHAIN_CTNG_eglibc

So if I'm using an external toolchain with uClibc it doesn't allow me to
configure connman, correct?  Is the uClibc resolver stub considered
unsufficient for use with connman?  Do I need to switch to glibc?

Also, it appears that BR2_TOOLCHAIN_CTNG_eglibc appears twice in that
dependency test.  Typo?

This is from the 2012.02 tarball release.  No patches.

Thanks.
-- 
Michael J. Hammel <buildroot@graphics-muse.org>

[Buildroot] connman requirement for resolver in toolchain

[Peter Korsgaard]

>>>>> "Michael" == Michael J Hammel <buildroot@graphics-muse.org> writes:

Hi,

 Michael> I'm doing the latter.  I've diffed my uClibc config with the
 Michael> one for the matching release in Buildroot and have enabled
 Michael> what I think is relevant for resolver support, re: I
 Michael> configured uClibc with the resolver and nsl stubs.  However,
 Michael> buildroot still doesn't allow me to configure connman.

 Michael> I looked at connman's Config.in and it looks like this:

 Michael> comment "connman needs a toolchain with resolver support"
 Michael>     depends on !(BR2_UCLIBC_VERSION_SNAPSHOT ||
 Michael> BR2_TOOLCHAIN_EXTERNAL_GLIBC || BR2_TOOLCHAIN_CTNG_eglibc ||
 Michael> BR2_TOOLCHAIN_CTNG_eglibc

 Michael> So if I'm using an external toolchain with uClibc it doesn't
 Michael> allow me to configure connman, correct?  Is the uClibc
 Michael> resolver stub considered unsufficient for use with connman?
 Michael> Do I need to switch to glibc?

You will need atleast uClibc 0.9.33. Connman was added before 0.9.33 was
released, so at that time you needed a snapshot version of uClibc. I've
recently updated this check in the next branch (and moved to connman
1.0) so you can actually select it with uClibc 0.9.33 / ctng toolchains:

http://git.buildroot.net/buildroot/commit/?h=next&id=96b109ad2a4ea0a4575526f0d0353d916b5122dd

Either cherrypick this commit, use the next branch or wait until I merge
next into the main branch in ~1 weeks time (E.G. right after I release
2012.05).

-- 
Bye, Peter Korsgaard