#!/bin/sh
#
# link vmlinux
#
# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
# $(KBUILD_VMLINUX_MAIN). Most are built-in.o files from top-level directories
# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
# Ordering when linking is important, and $(KBUILD_VMLINUX_INIT) must be first.
#
# vmlinux
# ^
# |
# +-< $(KBUILD_VMLINUX_INIT)
# | +--< init/version.o + more
# |
# +--< $(KBUILD_VMLINUX_MAIN)
# | +--< drivers/built-in.o mm/built-in.o + 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
}

# Link of vmlinux.o used for section mismatch analysis
# ${1} output file
modpost_link()
{
${LD} ${LDFLAGS} -r -o ${1} ${KBUILD_VMLINUX_INIT} \
--start-group ${KBUILD_VMLINUX_MAIN} --end-group
}

# Link of vmlinux
# ${1} - optional extra .o files
# ${2} - output file
vmlinux_link()
{
local lds="${objtree}/${KBUILD_LDS}"

if [ "${SRCARCH}" != "um" ]; then
${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
-T ${lds} ${KBUILD_VMLINUX_INIT} \
--start-group ${KBUILD_VMLINUX_MAIN} --end-group ${1}
else
${CC} ${CFLAGS_vmlinux} -o ${2} \
-Wl,-T,${lds} ${KBUILD_VMLINUX_INIT} \
-Wl,--start-group \
${KBUILD_VMLINUX_MAIN} \
-Wl,--end-group \
-lutil ${1}
rm -f linux
fi
}


# Create ${2} .o file with all symbols from the ${1} object file
kallsyms()
{
info KSYM ${2}
local kallsymopt;

if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
kallsymopt="${kallsymopt} --symbol-prefix=_"
fi

if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
kallsymopt="${kallsymopt} --all-symbols"
fi

if [ -n "${CONFIG_ARM}" ] && [ -n "${CONFIG_PAGE_OFFSET}" ]; then
kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET"
fi

local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"

${NM} -n ${1} | \
scripts/kallsyms ${kallsymopt} | \
${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
}

# 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
trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR
cleanup()
{
rm -f .old_version
rm -f .tmp_System.map
rm -f .tmp_kallsyms*
rm -f .tmp_version
rm -f .tmp_vmlinux*
rm -f System.map
rm -f vmlinux
rm -f vmlinux.o
}

#
#
# 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

#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

# Update version
info GEN .version
if [ ! -r .version ]; then
rm -f .version;
echo 1 >.version;
else
mv .version .old_version;
expr 0$(cat .old_version) + 1 >.version;
fi;

# final build of init/
${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init

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
# 2a) We may use an extra pass as this has been necessary to
# woraround some alignment related bugs.
# KALLSYMS_EXTRA_PASS=1 is used to trigger this.
# 3) 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 2a
if [ -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
cleanup
exit 1
fi
fi

# We made a new kernel - delete old version file
rm -f .old_version