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-rwxr-xr-xscripts/link-vmlinux.sh301
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
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+++ 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