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

From: Stephen Boyd
Date: Fri Aug 12 2011 - 15:00:14 EST

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

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@xxxxxxxxxxxxxx>
Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
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)

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

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/