commit 06744d69273de4945cf0ffcaa4a6abf7cec707b6
Author: Nigel Croxon <nigel.croxon@hp.com>
Date:   Fri Mar 14 13:47:39 2014 -0400

    From: Sylvain Gault <sylvain.gault@gmail.com>
    Date: Wed, 19 Feb 2014 05:18:14 +0100
    Subject: [PATCH] make install: Don't overwrite up-to-date files
    
    make install used to copy files unconditionnally to their destination.
    However, if the destination is used by another Makefile, it will always
    see modified files. "install" target now only update the files when they
    need to.
    
    Signed-off-by: Sylvain Gault <sylvain.gault@gmail.com>
    Signed-off-by: Nigel Croxon <nigel.croxon@hp.com>

diff --git a/gnuefi/Makefile b/gnuefi/Makefile
index e99adbe..85a7db8 100644
--- a/gnuefi/Makefile
+++ b/gnuefi/Makefile
@@ -49,6 +49,19 @@ OBJS	= $(FILES:%=%.o)
 
 TARGETS	= crt0-efi-$(ARCH).o libgnuefi.a
 
+INSTALLTARGETS = $(TARGETS)
+ifneq (,$(findstring FreeBSD,$(OS)))
+ ifeq ($(ARCH),x86_64)
+  INSTALLTARGETS += elf_$(ARCH)_fbsd_efi.lds
+ else
+  INSTALLTARGETS += elf_$(ARCH)_efi.lds
+ endif
+else
+  INSTALLTARGETS += elf_$(ARCH)_efi.lds
+endif
+
+LIBDIRINSTALL = $(INSTALLROOT)/$(LIBDIR)
+
 all:	$(TARGETS)
 
 libgnuefi.a: $(patsubst %,libgnuefi.a(%),$(OBJS))
@@ -56,17 +69,14 @@ libgnuefi.a: $(patsubst %,libgnuefi.a(%),$(OBJS))
 clean:
 	rm -f $(TARGETS) *~ *.o $(OBJS)
 
-install:
-	mkdir -p $(INSTALLROOT)/$(LIBDIR)
-	$(INSTALL) -m 644 $(TARGETS) $(INSTALLROOT)/$(LIBDIR)
-ifneq (,$(findstring FreeBSD,$(OS)))
- ifeq ($(ARCH),x86_64)
-	$(INSTALL) -m 644 $(SRCDIR)/elf_$(ARCH)_fbsd_efi.lds $(INSTALLROOT)/$(LIBDIR)
- else
-	$(INSTALL) -m 644 $(SRCDIR)/elf_$(ARCH)_efi.lds $(INSTALLROOT)/$(LIBDIR)
- endif
-else
-	$(INSTALL) -m 644 $(SRCDIR)/elf_$(ARCH)_efi.lds $(INSTALLROOT)/$(LIBDIR)
-endif
+$(LIBDIRINSTALL):
+	mkdir -p $@
+
+.SECONDEXPANSION:
+
+$(LIBDIRINSTALL)/%: % | $$(dir $$@)
+	$(INSTALL) -m 644 $< $(dir $@)
+
+install: $(addprefix $(LIBDIRINSTALL)/,$(INSTALLTARGETS))
 
 include $(SRCDIR)/../Make.rules
diff --git a/inc/Makefile b/inc/Makefile
index 273d303..297385b 100644
--- a/inc/Makefile
+++ b/inc/Makefile
@@ -8,20 +8,32 @@ TOPDIR = $(SRCDIR)/..
 
 CDIR=$(TOPDIR)/..
 
+INCDIRINSTALL = $(INSTALLROOT)$(PREFIX)/include/efi
+
+SRCHEADERS = $(wildcard $(SRCDIR)/*.h) \
+             $(wildcard $(SRCDIR)/protocol/*.h) \
+             $(wildcard $(SRCDIR)/$(ARCH)/*.h)
+ifeq ($(ARCH),ia64)
+ SRCHEADERS += $(wildcard $(SRCDIR)/protocol/$(ARCH)/*.h)
+endif
+
+HEADERS = $(patsubst $(SRCDIR)/%,%,$(SRCHEADERS))
+
 all:
 
 clean:
 
-install:
-	mkdir -p $(INSTALLROOT)$(PREFIX)/include/efi
-	mkdir -p $(INSTALLROOT)$(PREFIX)/include/efi/protocol
-	mkdir -p $(INSTALLROOT)$(PREFIX)/include/efi/$(ARCH)
-	$(INSTALL) -m 644 $(SRCDIR)/*.h $(INSTALLROOT)$(PREFIX)/include/efi
-	$(INSTALL) -m 644 $(SRCDIR)/protocol/*.h $(INSTALLROOT)$(PREFIX)/include/efi/protocol
-	$(INSTALL) -m 644 $(SRCDIR)/$(ARCH)/*.h $(INSTALLROOT)$(PREFIX)/include/efi/$(ARCH)
-ifeq ($(ARCH),ia64)
-	mkdir -p $(INSTALLROOT)$(PREFIX)/include/efi/protocol/ia64
-	$(INSTALL) -m 644 $(SRCDIR)/protocol/ia64/*.h $(INSTALLROOT)$(PREFIX)/include/efi/protocol/ia64
-endif
+$(INCDIRINSTALL) \
+$(INCDIRINSTALL)/protocol \
+$(INCDIRINSTALL)/$(ARCH) \
+$(INCDIRINSTALL)/protocol/$(ARCH):
+	mkdir -p $@
+
+.SECONDEXPANSION:
+
+$(INCDIRINSTALL)/%.h: %.h | $$(dir $$@)
+	$(INSTALL) -m 644 $< $(dir $@)
+
+install: $(addprefix $(INCDIRINSTALL)/,$(HEADERS))
 
 include $(SRCDIR)/../Make.rules
diff --git a/lib/Makefile b/lib/Makefile
index e9f604e..d2635ad 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -61,8 +61,11 @@ OBJS  = $(FILES:%=%.o)
 
 SUBDIRS = ia32 x86_64 ia64 runtime
 
+LIBDIRINSTALL = $(INSTALLROOT)/$(LIBDIR)
+
 all: libsubdirs libefi.a
 
+.PHONY: libsubdirs
 libsubdirs:
 	for sdir in $(SUBDIRS); do mkdir -p $$sdir; done
 
@@ -71,9 +74,13 @@ libefi.a: $(patsubst %,libefi.a(%),$(OBJS))
 clean:
 	rm -f libefi.a *~ $(OBJS) */*.o
 
-install: libefi.a
-	mkdir -p $(INSTALLROOT)/$(LIBDIR)
-	$(INSTALL) -m 644 libefi.a $(INSTALLROOT)/$(LIBDIR)
+$(LIBDIRINSTALL):
+	mkdir -p $@
+
+$(LIBDIRINSTALL)/libefi.a: libefi.a | $(LIBDIRINSTALL)
+	$(INSTALL) -m 644 $< $(dir $@)
+
+install: $(LIBDIRINSTALL)/libefi.a
 
 include $(SRCDIR)/../Make.rules