[PATCH] ARM: zImage: Skip relinking if nothing changes

Stephen Boyd
2011-08-12T19:00:11Z

lib1funcs.S is reshipped even though the file hasn't changed
because the make rule is marked with FORCE. According to Sam
Ravnborg:

The FORCE prerequisite will tell make to always execute
the command.
But we only want to execute the command if:
1) $(obj)/lib1funcs.S is missing
2) or $(srctree)/arch/$(SRCARCH)/lib/lib1funcs.S is not
older then $(obj)/lib1funcs.S

So dropping FORCE should be a safe thing to do.

This fixes the shipped problem, but we still have to reassemble
lib1funcs.S because it isn't part of $targets. Add
lib1funcs.{S,o} to $targets to avoid relinking the compressed
vmlinux if nothing changes.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
---
arch/arm/boot/compressed/Makefile | 8 +++-----
1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 0c74a6f..937fd26 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -91,7 +91,7 @@ suffix_$(CONFIG_KERNEL_LZMA) = lzma

targets := vmlinux vmlinux.lds \
piggy.$(suffix_y) piggy.$(suffix_y).o \
- font.o font.c head.o misc.o $(OBJS)
+ font.o font.c head.o misc.o lib1funcs.o lib1funcs.S $(OBJS)

# Make sure files are removed during clean
extra-y += piggy.gzip piggy.lzo piggy.lzma lib1funcs.S
@@ -121,9 +121,7 @@ LDFLAGS_vmlinux += -X
LDFLAGS_vmlinux += -T

# For __aeabi_uidivmod
-lib1funcs = $(obj)/lib1funcs.o
-
-$(obj)/lib1funcs.S: $(srctree)/arch/$(SRCARCH)/lib/lib1funcs.S FORCE
+$(obj)/lib1funcs.S: $(srctree)/arch/$(SRCARCH)/lib/lib1funcs.S
$(call cmd,shipped)

# We need to prevent any GOTOFF relocs being used with references
@@ -140,7 +138,7 @@ bad_syms=$$($(CROSS_COMPILE)nm $@ | sed -n 's/^.\{8\} [bc] \(.*\)/\1/p') && \
echo "$$bad_syms" >&2; rm -f $@; false )

$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD) $(obj)/piggy.$(suffix_y).o \
- $(addprefix $(obj)/, $(OBJS)) $(lib1funcs) FORCE
+ $(addprefix $(obj)/, $(OBJS)) $(obj)/lib1funcs.o FORCE
$(call if_changed,ld)
@$(check_for_bad_syms)

--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.