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-rw-r--r--arch/Kconfig6
-rw-r--r--scripts/Makefile.build23
-rwxr-xr-xscripts/link-vmlinux.sh71
3 files changed, 85 insertions, 15 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index bd8056b5b246..6842154813e5 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -461,6 +461,12 @@ config CC_STACKPROTECTOR_STRONG
endchoice
+config THIN_ARCHIVES
+ bool
+ help
+ Select this if the architecture wants to use thin archives
+ instead of ld -r to create the built-in.o files.
+
config HAVE_CONTEXT_TRACKING
bool
help
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index cd9bf22bb027..de46ab03f063 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -359,12 +359,22 @@ $(sort $(subdir-obj-y)): $(subdir-ym) ;
# Rule to compile a set of .o files into one .o file
#
ifdef builtin-target
-quiet_cmd_link_o_target = LD $@
+
+ifdef CONFIG_THIN_ARCHIVES
+ cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
+ cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
+ quiet_cmd_link_o_target = AR $@
+else
+ cmd_make_builtin = $(LD) $(ld_flags) -r -o
+ cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
+ quiet_cmd_link_o_target = LD $@
+endif
+
# If the list of objects to link is empty, just create an empty built-in.o
cmd_link_o_target = $(if $(strip $(obj-y)),\
- $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
+ $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
$(cmd_secanalysis),\
- rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
+ $(cmd_make_empty_builtin) $@)
$(builtin-target): $(obj-y) FORCE
$(call if_changed,link_o_target)
@@ -390,7 +400,12 @@ $(modorder-target): $(subdir-ym) FORCE
#
ifdef lib-target
quiet_cmd_link_l_target = AR $@
-cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
+
+ifdef CONFIG_THIN_ARCHIVES
+ cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y)
+else
+ cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
+endif
$(lib-target): $(lib-y) FORCE
$(call if_changed,link_l_target)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 4f727eb5ec43..f742c65108b9 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -37,12 +37,40 @@ info()
fi
}
+# Thin archive build here makes a final archive with
+# symbol table and indexes from vmlinux objects, which can be
+# used as input to linker.
+#
+# Traditional incremental style of link does not require this step
+#
+# built-in.o output file
+#
+archive_builtin()
+{
+ if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
+ info AR built-in.o
+ rm -f built-in.o;
+ ${AR} rcsT${KBUILD_ARFLAGS} built-in.o \
+ ${KBUILD_VMLINUX_INIT} \
+ ${KBUILD_VMLINUX_MAIN}
+ 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 ${KBUILD_VMLINUX_MAIN} --end-group
+ local objects
+
+ if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
+ objects="--whole-archive built-in.o"
+ else
+ objects="${KBUILD_VMLINUX_INIT} \
+ --start-group \
+ ${KBUILD_VMLINUX_MAIN} \
+ --end-group"
+ fi
+ ${LD} ${LDFLAGS} -r -o ${1} ${objects}
}
# Link of vmlinux
@@ -51,18 +79,36 @@ modpost_link()
vmlinux_link()
{
local lds="${objtree}/${KBUILD_LDS}"
+ local objects
if [ "${SRCARCH}" != "um" ]; then
- ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
- -T ${lds} ${KBUILD_VMLINUX_INIT} \
- --start-group ${KBUILD_VMLINUX_MAIN} --end-group ${1}
+ if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
+ objects="--whole-archive built-in.o ${1}"
+ else
+ objects="${KBUILD_VMLINUX_INIT} \
+ --start-group \
+ ${KBUILD_VMLINUX_MAIN} \
+ --end-group \
+ ${1}"
+ fi
+
+ ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
+ -T ${lds} ${objects}
else
- ${CC} ${CFLAGS_vmlinux} -o ${2} \
- -Wl,-T,${lds} ${KBUILD_VMLINUX_INIT} \
- -Wl,--start-group \
- ${KBUILD_VMLINUX_MAIN} \
- -Wl,--end-group \
- -lutil -lrt -lpthread ${1}
+ if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
+ objects="-Wl,--whole-archive built-in.o ${1}"
+ else
+ objects="${KBUILD_VMLINUX_INIT} \
+ -Wl,--start-group \
+ ${KBUILD_VMLINUX_MAIN} \
+ -Wl,--end-group \
+ ${1}"
+ fi
+
+ ${CC} ${CFLAGS_vmlinux} -o ${2} \
+ -Wl,-T,${lds} \
+ ${objects} \
+ -lutil -lrt -lpthread
rm -f linux
fi
}
@@ -119,6 +165,7 @@ cleanup()
rm -f .tmp_kallsyms*
rm -f .tmp_version
rm -f .tmp_vmlinux*
+ rm -f built-in.o
rm -f System.map
rm -f vmlinux
rm -f vmlinux.o
@@ -162,6 +209,8 @@ case "${KCONFIG_CONFIG}" in
. "./${KCONFIG_CONFIG}"
esac
+archive_builtin
+
#link vmlinux.o
info LD vmlinux.o
modpost_link vmlinux.o
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