Add support for a saving build objects in a separate directory.
Modifications are based on the linux kernel approach and
support two use cases:

  1) Add O= to the make command line
  'make O=/tmp/build all'

  2) Set environement variable BUILD_DIR to point to the desired location
  'export BUILD_DIR=/tmp/build'
  'make'

The second approach can also be used with a MAKEALL script
'export BUILD_DIR=/tmp/build'
'./MAKEALL'

Command line 'O=' setting overrides BUILD_DIR environent variable.

When none of the above methods is used the local build is performed and
the object files are placed in the source directory.
diff --git a/tools/updater/Makefile b/tools/updater/Makefile
index 3fa1912..e9684cb 100644
--- a/tools/updater/Makefile
+++ b/tools/updater/Makefile
@@ -1,5 +1,5 @@
 #
-# (C) Copyright 2000
+# (C) Copyright 2000-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # See file CREDITS for list of people who contributed to this
@@ -25,62 +25,81 @@
 
 include $(TOPDIR)/config.mk
 
-PROG    = updater
-IMAGE   = updater.image
-SRC     = update.c flash.c flash_hw.c utils.c cmd_flash.c string.c ctype.c dummy.c
-ASRC    = ppcstring.S
-OBJS	= $(SRC:.c=.o) $(ASRC:.S=.o)
+PROG		= $(obj)updater
+IMAGE		= $(obj)updater.image
 
-LIB	= $(TOPDIR)/examples/libstubs.a
-LIBAOBJS=
-LIBCOBJS= $(TOPDIR)/examples/stubs.o
-LIBOBJS	= $(LIBAOBJS) $(LIBCOBJS)
+COBJS		= update.o flash.o flash_hw.o utils.o cmd_flash.o string.o ctype.o dummy.o
+COBJS_LINKS	= stubs.o
+AOBJS		= ppcstring.o
+AOBJS_LINKS	= memio.o
+
+OBJS	:= $(addprefix $(obj),$(COBJS) $(COBJS_LINKS) $(AOBJS) $(AOBJS_LINKS))
+SRCS	:= $(COBJS:.o=.c) $(AOBJS:.o=.S) $(addprefix $(obj), $(COBJS_LINKS:.o:.c) $(AOBJS_LINKS:.o:.S))
 
 CPPFLAGS += -I$(TOPDIR) -I$(TOPDIR)/board/MAI/AmigaOneG3SE
 CFLAGS   += -I$(TOPDIR)/board/MAI/AmigaOneG3SE
+AFLAGS   += -I$(TOPDIR)/board/MAI/AmigaOneG3SE
 
-all:	.depend $(LIB) $(PROG)
+DEPS = $(OBJTREE)/u-boot.bin $(OBJTREE)/tools/mkimage
+ifneq ($(DEPS),$(wildcard $(DEPS)))
+$(error "updater: Missing required objects, please run regular build first")
+endif
+
+all:	$(obj).depend $(PROG) $(IMAGE)
 
 #########################################################################
-$(LIB): .depend $(LIBOBJS)
-	$(AR) crv $@ $(LIBOBJS)
 
-%.srec:	%.o $(LIB)
+$(obj)%.srec:	%.o $(LIB)
 	$(LD) -g -Ttext $(LOAD_ADDR) -o $(<:.o=) -e $(<:.o=) $< $(LIB)
 	$(OBJCOPY) -O srec $(<:.o=) $@
 
-%.o: %.c
-	$(CC) $(CPPFLAGS) -c $<
+$(obj)%.o: %.c
+	$(CC) $(CFLAGS) -c -o $@ $<
 
-%.o: %.S
-	$(CC) $(CPPFLAGS) -c $<
+$(obj)%.o: %.S
+	$(CC) $(AFLAGS) -c -o $@ $<
+
+$(obj)memio.o: $(obj)memio.S
+	$(CC) $(AFLAGS) -c -o $@ $<
+
+$(obj)memio.S:
+	rm -f $(obj)memio.c
+	ln -s $(SRCTREE)/board/MAI/AmigaOneG3SE/memio.S $(obj)memio.S
+
+$(obj)stubs.o: $(obj)stubs.c
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+$(obj)stubs.c:
+	rm -f $(obj)stubs.c
+	ln -s $(SRCTREE)/examples/stubs.c $(obj)stubs.c
 
 #########################################################################
 
-updater: $(OBJS) $(LIB) $(TOPDIR)/board/MAI/AmigaOneG3SE/memio.o
-	$(LD) -g -Ttext $(LOAD_ADDR) -o updater -e _main $(OBJS) $(LIB)  \
-	$(TOPDIR)/board/MAI/AmigaOneG3SE/memio.o
-	$(OBJCOPY) -O binary updater updater.bin
+$(obj)updater: $(OBJS)
+	$(LD) -g -Ttext $(LOAD_ADDR) -o $(obj)updater -e _main $(OBJS)
+	$(OBJCOPY) -O binary $(obj)updater $(obj)updater.bin
 
-updater.image: updater $(TOPDIR)/u-boot.bin
-	cat >/tmp/tempimage updater.bin junk $(TOPDIR)/u-boot.bin
-	$(TOPDIR)/tools/mkimage -A ppc -O u-boot -T standalone -C none -a $(LOAD_ADDR) \
-	-e `ppc-elf32-nm updater | grep _main | cut --bytes=0-8` \
-	-n "Firmware Updater" -d /tmp/tempimage updater.image
+$(obj)updater.image: $(obj)updater $(OBJTREE)/u-boot.bin
+	cat >/tmp/tempimage $(obj)updater.bin junk $(OBJTREE)/u-boot.bin
+	$(OBJTREE)/tools/mkimage -A ppc -O u-boot -T standalone -C none -a $(LOAD_ADDR) \
+	-e `$(NM) $(obj)updater | grep _main | cut --bytes=0-8` \
+	-n "Firmware Updater" -d /tmp/tempimage $(obj)updater.image
 	rm /tmp/tempimage
-	cp updater.image /tftpboot
+	cp $(obj)updater.image /tftpboot
 
-updater.image2: updater $(TOPDIR)/u-boot.bin
-	cat >/tmp/tempimage updater.bin junk ../../create_image/image
-	$(TOPDIR)/tools/mkimage -A ppc -O u-boot -T standalone -C none -a $(LOAD_ADDR) \
-	-e `ppc-elf32-nm updater | grep _main | cut --bytes=0-8` \
-	-n "Firmware Updater" -d /tmp/tempimage updater.image
+(obj)updater.image2: $(obj)updater $(OBJTREE)/u-boot.bin
+	cat >/tmp/tempimage $(obj)updater.bin junk ../../create_image/image
+	$(OBJTREE)/tools/mkimage -A ppc -O u-boot -T standalone -C none -a $(LOAD_ADDR) \
+	-e `$(NM) $(obj)updater | grep _main | cut --bytes=0-8` \
+	-n "Firmware Updater" -d /tmp/tempimage $(obj)updater.image
 	rm /tmp/tempimage
-	cp updater.image /tftpboot
+	cp $(obj)updater.image /tftpboot
 
-.depend:	Makefile $(SRC) $(ASRC) $(LIBCOBJS:.o=.c) $(LIBAOBJS:.o=.S)
-		$(CC) -M $(CFLAGS) $(SRC) $(ASRC) $(LIBCOBJS:.o=.c) $(LIBAOBJS:.o=.S) > $@
+#########################################################################
 
-sinclude .depend
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
 
 #########################################################################