1 files changed, 45 insertions, 7 deletions

diff --git a/meta/recipes-devtools/gcc/libgcc-initial.inc b/meta/recipes-devtools/gcc/libgcc-initial.inc
index 950ad861e7..06bf224f73 100644
--- a/meta/recipes-devtools/gcc/libgcc-initial.inc
+++ b/meta/recipes-devtools/gcc/libgcc-initial.inc
@@ -1,20 +1,58 @@
+#
+# Notes on the way the OE cross toolchain now works
+#
+# We need a libgcc to build glibc. Tranditionally we therefore built
+# a non-threaded and non-shared compiler (gcc-cross-initial), then use
+# that to build libgcc-initial which is used to build glibc which we can
+# then build gcc-cross and libgcc against.
+#
+# We were able to drop the glibc dependency from gcc-cross, with two tweaks:
+
+# a) specify the minimum glibc version to support in a configure option
+# b) create a dummy limits.h file so that later when glibc creates one,
+#    the headers structure has support for it. We can do this with a simple
+#    empty file
+#
+# Once gcc-cross is libc independent, we can use it to build both
+# libgcc-initial and then later libgcc.
+#
+# libgcc-initial is tricky as we need to imitate the non-threaded and
+# non-shared case. We can do that by hacking the threading mode back to
+# "single" even if gcc reports "posix" and disable libc presence for the
+# libgcc-intial build. We have to create the dummy limits.h to avoid
+# compiler errors from a missing header.
+#
+# glibc will fail to link with libgcc-initial due to a missing "exception
+# handler" capable libgcc (libgcc_eh.a). Since we know glibc doesn't need
+# any exception handler, we can safely symlink to libgcc.a.
+#
+
 require libgcc-common.inc
 
-DEPENDS = "virtual/${TARGET_PREFIX}gcc-initial"
+DEPENDS = "virtual/${TARGET_PREFIX}gcc"
 
 LICENSE = "GPL-3.0-with-GCC-exception"
 
-STAGINGCC = "gcc-cross-initial-${TARGET_ARCH}"
-STAGINGCC_class-nativesdk = "gcc-crosssdk-initial-${SDK_SYS}"
-PATH_prepend = "${STAGING_BINDIR_TOOLCHAIN}.${STAGINGCC}:"
-
 PACKAGES = ""
 
 EXTRA_OECONF += "--disable-shared"
 
-COMPILERINITIAL = "-initial"
-
 inherit nopackages
 
 # We really only want this built by things that need it, not any recrdeptask
 deltask do_build
+
+do_configure_prepend () {
+        install -d ${STAGING_INCDIR}
+        touch ${STAGING_INCDIR}/limits.h
+        sed -i -e 's#INHIBIT_LIBC_CFLAGS =.*#INHIBIT_LIBC_CFLAGS = -Dinhibit_libc#' ${B}/gcc/libgcc.mvars
+        sed -i -e 's#inhibit_libc = false#inhibit_libc = true#' ${B}/gcc/Makefile
+}
+
+do_configure_append () {
+        sed -i -e 's#thread_header = .*#thread_header = gthr-single.h#' ${B}/${BPN}/Makefile
+}
+
+do_install_append () {
+        ln -s libgcc.a ${D}${libdir}/${TARGET_SYS}/${BINV}/libgcc_eh.a
+}