toolchain-scripts.bbclass: Export KCFLAGS to ensure sysroot is provided

When building the U-Boot the lack of a proper sysroot can trigger
following error:

,----
| arm-poky-linux-gnueabi-ld.bfd: cannot find -lgcc
| make[2]: *** [examples/standalone/hello_world] Error 1
| make[1]: *** [examples/standalone] Error 2
| make: *** [examples] Error 2
`----

Guillaume Fournier has posted a very complete analysis of the
problem[1].

1. https://lists.yoctoproject.org/pipermail/meta-freescale/2014-November/011270.html

The use of KCFLAGS makes the build of U-Boot work out of box, now that
it uses the Linux kernel build system.

Reported-by: Guillaume Fournier <gfournier@brioconcept.com>
(From OE-Core rev: 50437f9c187f1a884825a8d1ec12da47a5e58670)

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/meta/classes/toolchain-scripts.bbclass b/meta/classes/toolchain-scripts.bbclass
index 96fd93dbc8..d5b9675b7f 100644
--- a/meta/classes/toolchain-scripts.bbclass
+++ b/meta/classes/toolchain-scripts.bbclass
@@ -68,6 +68,7 @@ toolchain_shared_env_script () {
         echo 'export CXXFLAGS="${TARGET_CXXFLAGS}"' >> $script
         echo 'export LDFLAGS="${TARGET_LDFLAGS}"' >> $script
         echo 'export CPPFLAGS="${TARGET_CPPFLAGS}"' >> $script
+        echo 'export KCFLAGS="--sysroot=$SDKTARGETSYSROOT"' >> $script
         echo 'export OECORE_DISTRO_VERSION="${DISTRO_VERSION}"' >> $script
         echo 'export OECORE_SDK_VERSION="${SDK_VERSION}"' >> $script
         echo 'export ARCH=${ARCH}' >> $script