toolchain: rename external toolchain dir

Rename the external toolchain directory.
When new backends are here, it will be easier to sort them out
if they are all prefixed the same way.

Signed-off-by: Yann E. MORIN <yann.morin.1998@anciens.enib.fr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

1 files changed, 115 insertions, 0 deletions

diff --git a/toolchain/toolchain-external/ext-tool.mk b/toolchain/toolchain-external/ext-tool.mk
new file mode 100644
index 000000000..7e4645ddb
--- /dev/null
+++ b/toolchain/toolchain-external/ext-tool.mk
@@ -0,0 +1,115 @@
+
+#
+# This file implements the support for external toolchains, i.e
+# toolchains that have not been produced by Buildroot itself and that
+# are already available on the system on which Buildroot runs. So far,
+# we have tested this with:
+#
+#  * Toolchains generated by Crosstool-NG
+#  * Toolchains generated by Buildroot
+#  * ARM, MIPS and PowerPC toolchains made available by
+#    Codesourcery. For the MIPS toolchain, the -muclibc variant isn't
+#    supported yet, only the default glibc-based variant is.
+#
+# The basic principle is the following
+#
+#  1. Perform some checks on the conformity between the toolchain
+#  configuration described in the Buildroot menuconfig system, and the
+#  real configuration of the external toolchain. This is for example
+#  important to make sure that the Buildroot configuration system
+#  knows whether the toolchain supports RPC, IPv6, locales, large
+#  files, etc. Unfortunately, these things cannot be detected
+#  automatically, since the value of these options (such as
+#  BR2_INET_RPC) are needed at configuration time because these
+#  options are used as dependencies for other options. And at
+#  configuration time, we are not able to retrieve the external
+#  toolchain configuration.
+#
+#  2. Copy the libraries needed at runtime to the target directory,
+#  $(TARGET_DIR). Obviously, things such as the C library, the dynamic
+#  loader and a few other utility libraries are needed if dynamic
+#  applications are to be executed on the target system.
+#
+#  3. Copy the libraries and headers to the staging directory. This
+#  will allow all further calls to gcc to be made using --sysroot
+#  $(STAGING_DIR), which greatly simplifies the compilation of the
+#  packages when using external toolchains. So in the end, only the
+#  cross-compiler binaries remains external, all libraries and headers
+#  are imported into the Buildroot tree.
+
+uclibc: dependencies $(STAMP_DIR)/ext-toolchain-installed
+
+LIB_EXTERNAL_LIBS=ld*.so libc.so libcrypt.so libdl.so libgcc_s.so libm.so libnsl.so libresolv.so librt.so libutil.so
+ifeq ($(BR2_TOOLCHAIN_EXTERNAL_GLIBC),y)
+LIB_EXTERNAL_LIBS+=libnss_files.so libnss_dns.so
+endif
+
+ifeq ($(BR2_INSTALL_LIBSTDCPP),y)
+USR_LIB_EXTERNAL_LIBS+=libstdc++.so
+endif
+
+ifneq ($(BR2_PTHREADS_NONE),y)
+LIB_EXTERNAL_LIBS+=libpthread.so
+ifeq ($(BR2_PACKAGE_GDB_SERVER),y)
+LIB_EXTERNAL_LIBS+=libthread_db.so
+endif # gdbserver
+endif # ! no threads
+
+# SYSROOT_DIR selection. We first try the -print-sysroot option,
+# available in gcc 4.4.x and in some Codesourcery toolchains. If this
+# option is not available, we fallback to the value of --with-sysroot
+# as visible in CROSS-gcc -v. We don't pass any option to gcc that
+# could select a multilib variant as we want the "main" sysroot, which
+# contains all variants of the C library in the case of multilib
+# toolchains.
+TARGET_CC_NO_SYSROOT=$(filter-out --sysroot=%,$(TARGET_CC))
+SYSROOT_DIR=$(shell $(TARGET_CC_NO_SYSROOT) -print-sysroot 2>/dev/null)
+ifeq ($(SYSROOT_DIR),)
+SYSROOT_DIR=$(shell readlink -f $$(LANG=C $(TARGET_CC_NO_SYSROOT) -print-file-name=libc.a) |sed -r -e 's:usr/lib/libc\.a::;')
+endif
+
+# Now, find if the toolchain specifies a sub-directory for the
+# specific architecture variant we're interested in. This is the case
+# with multilib toolchain, when the selected architecture variant is
+# not the default one. To do so, we ask the compiler by passing all
+# flags, except the --sysroot flag since we want to the compiler to
+# tell us where its original sysroot is. ARCH_SUBDIR will contain the
+# subdirectory, in the main SYSROOT_DIR, that corresponds to the
+# selected architecture variant. ARCH_SYSROOT_DIR will contain the
+# full path to this location.
+ARCH_SUBDIR=$(shell $(TARGET_CC_NO_SYSROOT) $(TARGET_CFLAGS) -print-multi-directory)
+ARCH_SYSROOT_DIR=$(SYSROOT_DIR)/$(ARCH_SUBDIR)
+
+$(STAMP_DIR)/ext-toolchain-installed:
+	@echo "Checking external toolchain settings"
+	$(Q)$(call check_cross_compiler_exists)
+ifeq ($(strip $(SYSROOT_DIR)),)
+	@echo "External toolchain doesn't support --sysroot. Cannot use."
+	exit 1
+endif
+ifeq ($(BR2_arm),y)
+	$(Q)$(call check_arm_abi)
+endif
+ifeq ($(BR2_INSTALL_LIBSTDCPP),y)
+	$(Q)$(call check_cplusplus)
+endif
+ifeq ($(BR2_TOOLCHAIN_EXTERNAL_UCLIBC),y)
+	$(Q)$(call check_uclibc,$(SYSROOT_DIR))
+else
+	$(Q)$(call check_glibc,$(SYSROOT_DIR))
+endif
+	mkdir -p $(TARGET_DIR)/lib
+	@echo "Copy external toolchain libraries to target..."
+	$(Q)for libs in $(LIB_EXTERNAL_LIBS); do \
+		$(call copy_toolchain_lib_root,$(ARCH_SYSROOT_DIR),$$libs,/lib,$(BR2_TOOLCHAIN_EXTERNAL_STRIP)); \
+	done
+	$(Q)for libs in $(USR_LIB_EXTERNAL_LIBS); do \
+		$(call copy_toolchain_lib_root,$(ARCH_SYSROOT_DIR),$$libs,/usr/lib,$(BR2_TOOLCHAIN_EXTERNAL_STRIP)); \
+	done
+	@echo "Copy external toolchain sysroot to staging..."
+	$(Q)$(call copy_toolchain_sysroot,$(SYSROOT_DIR),$(ARCH_SYSROOT_DIR),$(ARCH_SUBDIR))
+	# Create lib64 symbolic links if needed
+	$(Q)if [ -L $(ARCH_SYSROOT_DIR)/lib64 ] ; then \
+		$(call create_lib64_symlinks) ; \
+	fi
+	@touch $@