#!/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"
proc info
{
	if test $(quiet) != "silent_" {
		printf "  %-7s %s\n" $(1) $(2)
	}
}

# Link of vmlinux.o used for section mismatch analysis
# ${1} output file
proc 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
# ${2} - output file
proc vmlinux_link
{
	var lds = ""$(objtree)/$(KBUILD_LDS)""

	if test $(SRCARCH) != "um" {
		$(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 -lrt -lpthread $(1)
		rm -f linux
	}
}


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

	if test -n $(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX) {
		set kallsymopt = ""$(kallsymopt) --symbol-prefix=_""
	}

	if test -n $(CONFIG_KALLSYMS_ALL) {
		set kallsymopt = ""$(kallsymopt) --all-symbols""
	}

	if test -n $(CONFIG_KALLSYMS_ABSOLUTE_PERCPU) {
		set kallsymopt = ""$(kallsymopt) --absolute-percpu""
	}

	if test -n $(CONFIG_KALLSYMS_BASE_RELATIVE) {
		set kallsymopt = ""$(kallsymopt) --base-relative""
	}

	var aflags = ""$(KBUILD_AFLAGS) $(KBUILD_AFLAGS_KERNEL)               \
		      $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(KBUILD_CPPFLAGS)""

	var 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
proc mksysmap
{
	$(CONFIG_SHELL) "$(srctree)/scripts/mksysmap" $(1) $(2)
}

proc sortextable
{
	$(objtree)/scripts/sortextable $(1)
}

# Delete output files in case of error
proc 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
}

proc on_exit
{
	if test $Status -ne 0 {
		cleanup
	}
}
trap on_exit EXIT

proc on_signals
{
	exit 1
}
trap on_signals HUP INT QUIT TERM

#
#
# Use "make V=1" to debug this script
match $(KBUILD_VERBOSE) {
with *1*
	set -x
	
}

if test $1 = "clean" {
	cleanup
	exit 0
}

# We need access to CONFIG_ symbols
match $(KCONFIG_CONFIG) {
with */*
	source "${KCONFIG_CONFIG}"
	
with *
	# Force using a file from the current directory
	source "./${KCONFIG_CONFIG}"
}

#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 test ! -r .version {
	rm -f .version;
	echo 1 >.version;
} else {
	mv .version .old_version;
	expr 0$[cat .old_version] + 1 >.version;
};

# final build of init/
$(MAKE) -f "$(srctree)/scripts/Makefile.build" obj=init GCC_PLUGINS_CFLAGS="$(GCC_PLUGINS_CFLAGS)"

setglobal kallsymso = ''""
setglobal kallsyms_vmlinux = ''""
if test -n $(CONFIG_KALLSYMS) {

	# 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}.

	setglobal kallsymso = '.tmp_kallsyms2.o'
	setglobal 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 test -n $(KALLSYMS_EXTRA_PASS) {
		setglobal kallsymso = '.tmp_kallsyms3.o'
		setglobal kallsyms_vmlinux = '.tmp_vmlinux3'

		vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3

		kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
	}
}

info LD vmlinux
vmlinux_link $(kallsymso) vmlinux

if test -n $(CONFIG_BUILDTIME_EXTABLE_SORT) {
	info SORTEX vmlinux
	sortextable vmlinux
}

info SYSMAP System.map
mksysmap vmlinux System.map

# step a (see comment above)
if test -n $(CONFIG_KALLSYMS) {
	mksysmap $(kallsyms_vmlinux) .tmp_System.map

	if ! cmp -s System.map .tmp_System.map {
		echo >&2 Inconsistent kallsyms data> !2 Inconsistent kallsyms data
		echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround> !2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
		exit 1
	}
}

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