1 files changed, 301 insertions, 0 deletions
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
new file mode 100755
index 000000000..c8cf45362
--- /dev/null
+++ b/scripts/link-vmlinux.sh
@@ -0,0 +1,301 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# link vmlinux
+#
+# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
+# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.a files
+# from top-level directories in the kernel tree, others are specified in
+# arch/$(ARCH)/Makefile. Ordering when linking is important, and
+# $(KBUILD_VMLINUX_INIT) must be first. $(KBUILD_VMLINUX_LIBS) are archives
+# which are linked conditionally (not within --whole-archive), and do not
+# require symbol indexes added.
+#
+# vmlinux
+#   ^
+#   |
+#   +-< $(KBUILD_VMLINUX_INIT)
+#   |   +--< init/version.o + more
+#   |
+#   +--< $(KBUILD_VMLINUX_MAIN)
+#   |    +--< drivers/built-in.a mm/built-in.a + more
+#   |
+#   +--< $(KBUILD_VMLINUX_LIBS)
+#   |    +--< lib/lib.a + more
+#   |
+#   +-< ${kallsymso} (see description in KALLSYMS section)
+#
+# vmlinux version (uname -v) cannot be updated during normal
+# descending-into-subdirs phase since we do not yet know if we need to
+# update vmlinux.
+# Therefore this step is delayed until just before final link of vmlinux.
+#
+# System.map is generated to document addresses of all kernel symbols
+
+# Error out on error
+set -e
+
+# Nice output in kbuild format
+# Will be supressed by "make -s"
+info()
+{
+	if [ "${quiet}" != "silent_" ]; then
+		printf "  %-7s %s\n" ${1} ${2}
+	fi
+}
+
+# Thin archive build here makes a final archive with symbol table and indexes
+# from vmlinux objects INIT and MAIN, which can be used as input to linker.
+# KBUILD_VMLINUX_LIBS archives should already have symbol table and indexes
+# added.
+#
+# Traditional incremental style of link does not require this step
+#
+# built-in.a output file
+#
+archive_builtin()
+{
+	info AR built-in.a
+	rm -f built-in.a;
+	${AR} rcsTP${KBUILD_ARFLAGS} built-in.a			\
+				${KBUILD_VMLINUX_INIT}		\
+				${KBUILD_VMLINUX_MAIN}
+}
+
+# Link of vmlinux.o used for section mismatch analysis
+# ${1} output file
+modpost_link()
+{
+	local objects
+
+	objects="--whole-archive				\
+		built-in.a					\
+		--no-whole-archive				\
+		--start-group					\
+		${KBUILD_VMLINUX_LIBS}				\
+		--end-group"
+
+	${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects}
+}
+
+# Link of vmlinux
+# ${1} - optional extra .o files
+# ${2} - output file
+vmlinux_link()
+{
+	local lds="${objtree}/${KBUILD_LDS}"
+	local objects
+
+	if [ "${SRCARCH}" != "um" ]; then
+		objects="--whole-archive			\
+			built-in.a				\
+			--no-whole-archive			\
+			--start-group				\
+			${KBUILD_VMLINUX_LIBS}			\
+			--end-group				\
+			${1}"
+
+		${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} -o ${2}	\
+			-T ${lds} ${objects}
+	else
+		objects="-Wl,--whole-archive			\
+			built-in.a				\
+			-Wl,--no-whole-archive			\
+			-Wl,--start-group			\
+			${KBUILD_VMLINUX_LIBS}			\
+			-Wl,--end-group				\
+			${1}"
+
+		${CC} ${CFLAGS_vmlinux} -o ${2}			\
+			-Wl,-T,${lds}				\
+			${objects}				\
+			-lutil -lrt -lpthread
+		rm -f linux
+	fi
+}
+
+
+# Create ${2} .o file with all symbols from the ${1} object file
+kallsyms()
+{
+	info KSYM ${2}
+	local kallsymopt;
+
+	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
+		kallsymopt="${kallsymopt} --all-symbols"
+	fi
+
+	if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
+		kallsymopt="${kallsymopt} --absolute-percpu"
+	fi
+
+	if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
+		kallsymopt="${kallsymopt} --base-relative"
+	fi
+
+	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
+		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
+
+	local afile="`basename ${2} .o`.S"
+
+	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
+	${CC} ${aflags} -c -o ${2} ${afile}
+}
+
+# Create map file with all symbols from ${1}
+# See mksymap for additional details
+mksysmap()
+{
+	${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
+}
+
+sortextable()
+{
+	${objtree}/scripts/sortextable ${1}
+}
+
+# Delete output files in case of error
+cleanup()
+{
+	rm -f .tmp_System.map
+	rm -f .tmp_kallsyms*
+	rm -f .tmp_vmlinux*
+	rm -f built-in.a
+	rm -f System.map
+	rm -f vmlinux
+	rm -f vmlinux.o
+}
+
+on_exit()
+{
+	if [ $? -ne 0 ]; then
+		cleanup
+	fi
+}
+trap on_exit EXIT
+
+on_signals()
+{
+	exit 1
+}
+trap on_signals HUP INT QUIT TERM
+
+#
+#
+# Use "make V=1" to debug this script
+case "${KBUILD_VERBOSE}" in
+*1*)
+	set -x
+	;;
+esac
+
+if [ "$1" = "clean" ]; then
+	cleanup
+	exit 0
+fi
+
+# We need access to CONFIG_ symbols
+case "${KCONFIG_CONFIG}" in
+*/*)
+	. "${KCONFIG_CONFIG}"
+	;;
+*)
+	# Force using a file from the current directory
+	. "./${KCONFIG_CONFIG}"
+esac
+
+# Update version
+info GEN .version
+if [ -r .version ]; then
+	VERSION=$(expr 0$(cat .version) + 1)
+	echo $VERSION > .version
+else
+	rm -f .version
+	echo 1 > .version
+fi;
+
+# final build of init/
+${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
+
+archive_builtin
+
+#link vmlinux.o
+info LD vmlinux.o
+modpost_link vmlinux.o
+
+# modpost vmlinux.o to check for section mismatches
+${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
+
+kallsymso=""
+kallsyms_vmlinux=""
+if [ -n "${CONFIG_KALLSYMS}" ]; then
+
+	# kallsyms support
+	# Generate section listing all symbols and add it into vmlinux
+	# It's a three step process:
+	# 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
+	#     but __kallsyms is empty.
+	#     Running kallsyms on that gives us .tmp_kallsyms1.o with
+	#     the right size
+	# 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
+	#     the right size, but due to the added section, some
+	#     addresses have shifted.
+	#     From here, we generate a correct .tmp_kallsyms2.o
+	# 3)  That link may have expanded the kernel image enough that
+	#     more linker branch stubs / trampolines had to be added, which
+	#     introduces new names, which further expands kallsyms. Do another
+	#     pass if that is the case. In theory it's possible this results
+	#     in even more stubs, but unlikely.
+	#     KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
+	#     other bugs.
+	# 4)  The correct ${kallsymso} is linked into the final vmlinux.
+	#
+	# a)  Verify that the System.map from vmlinux matches the map from
+	#     ${kallsymso}.
+
+	kallsymso=.tmp_kallsyms2.o
+	kallsyms_vmlinux=.tmp_vmlinux2
+
+	# step 1
+	vmlinux_link "" .tmp_vmlinux1
+	kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
+
+	# step 2
+	vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
+	kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
+
+	# step 3
+	size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms1.o)
+	size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms2.o)
+
+	if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
+		kallsymso=.tmp_kallsyms3.o
+		kallsyms_vmlinux=.tmp_vmlinux3
+
+		vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
+
+		kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
+	fi
+fi
+
+info LD vmlinux
+vmlinux_link "${kallsymso}" vmlinux
+
+if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
+	info SORTEX vmlinux
+	sortextable vmlinux
+fi
+
+info SYSMAP System.map
+mksysmap vmlinux System.map
+
+# step a (see comment above)
+if [ -n "${CONFIG_KALLSYMS}" ]; then
+	mksysmap ${kallsyms_vmlinux} .tmp_System.map
+
+	if ! cmp -s System.map .tmp_System.map; then
+		echo >&2 Inconsistent kallsyms data
+		echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
+		exit 1
+	fi
+fi