[oe] prebuilt toolchain versus --sysroot

[Denys Dmytriyenko]

On Wed, Mar 30, 2011 at 04:00:52PM +0400, Elena Vengerova wrote:
> Hello,
>
> I'm trying to use pre-built SDK. PATH, CPPFLAGS and LDFLAGS are correct. 
> However configure of the first target package fails because compiler cannot 
> find crt1.o. I've found out that it's due --sysroot that points to 
> STAGING_DIR_TARGET.
>
> Should I copy SDK libraries and headers to STAGING_DIR_TARGET or there is 
> more correct option to resolve this issue?

Elena,

Pre-built SDKs (e.g. generated by OE from meta-toolchain) are usually meant to 
be used on their own, outside of the normal bitbake flow of OpenEmbedded. 

Previously it was possible to still use them externally by setting 
TARGET_CPPFLAGS and TARGET_LDFLAGS, like you are saying. Unfortunately, with 
the mandated use of --sysroot in latest OE, all the toolchain components have 
to be inside our sysroot, which is STAGING_DIR...

Please check external-toolchain-csl.bb and external-toolchain-angstrom.bb 
recipes in recipes/meta/ directory for specific pointers on how to copy/stage 
the necessary objects, libraries and headers. Plus, installing/staging them 
properly also solves packaging and allows proper rootfs image generation with 
deployed libc packages from external toolchain.

-- 
Denys