From mboxrd@z Thu Jan  1 00:00:00 1970
From: Grant Edwards <grant.b.edwards@gmail.com>
Date: Fri, 26 Mar 2010 01:04:33 +0000 (UTC)
Subject: [Buildroot] external toolchain and sysroot
References: <1272730299.20100325182803@ya.ru> <hog24r$1nu$1@dough.gmane.org>
	<93399903.20100325201240@ya.ru> <44830928.20100325201616@ya.ru>
	<hog8rg$sis$1@dough.gmane.org> <20100325233452.3794166b@surf>
Message-ID: <hoh171$jf0$1@dough.gmane.org>
List-Id: <buildroot.busybox.net>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: buildroot@busybox.net

On 2010-03-25, Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote:
> On Thu, 25 Mar 2010 18:08:49 +0000 (UTC)
> Grant Edwards <grant.b.edwards@gmail.com> wrote:
>
>> Based on my sample of three packages (two had the problem), I'm
>> guessing it's a very common problem.  It looks like the buildroot
>> developers use external toolchains that don't require a --sysroot
>> option. 
>
> They do.
>
> What we do to support external toolchains is :
>
>  * We copy the full sysroot of the toolchain into $(STAGING_DIR)
>  * We copy just the C library and related libraries from the sysroot to
>    the $(TARGET_DIR)

Agreed.

>  * We pass --sysroot $(STAGING_DIR) to every gcc/ld invocation, so that
>    gcc/ld find the libraries and header files correctly.

Perhaps that's what's supposed to happen, but there appear to be a lot
of packages where it doesn't happen (at least for some of us).

> Actually, this mechanism *only* works with toolchain supporting
> --sysroot. Toolchains *not* supporting --sysroot are rejected (see
> toolchain/external-toolchain/ext-tool.mk).

True.

-- 
Grant