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/board/altera/dk1c20/Makefile b/board/altera/dk1c20/Makefile
index 9182a4e..26c724c 100644
--- a/board/altera/dk1c20/Makefile
+++ b/board/altera/dk1c20/Makefile
@@ -1,5 +1,5 @@
 #
-# (C) Copyright 2001-2004
+# (C) Copyright 2001-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # See file CREDITS for list of people who contributed to this
@@ -23,14 +23,17 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).a
 
-OBJS	:= $(BOARD).o flash.o misc.o
-
+COBJS	:= $(BOARD).o flash.o misc.o
 SOBJS  = vectors.o
 
-$(LIB):	$(OBJS) $(SOBJS)
-	$(AR) crv $@ $^
+SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+SOBJS	:= $(addprefix $(obj),$(SOBJS))
+
+$(LIB):	$(obj).depend $(OBJS) $(SOBJS)
+	$(AR) crv $@ $(OBJS) $(SOBJS)
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
@@ -40,9 +43,9 @@
 
 #########################################################################
 
-.depend:	Makefile $(SOBJS:.o=.S) $(OBJS:.o=.c)
-		$(CC) -M $(CPPFLAGS) $(SOBJS:.o=.S) $(OBJS:.o=.c) > $@
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
 
--include .depend
+sinclude $(obj).depend
 
 #########################################################################
diff --git a/board/altera/dk1s10/Makefile b/board/altera/dk1s10/Makefile
index 9182a4e..26c724c 100644
--- a/board/altera/dk1s10/Makefile
+++ b/board/altera/dk1s10/Makefile
@@ -1,5 +1,5 @@
 #
-# (C) Copyright 2001-2004
+# (C) Copyright 2001-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # See file CREDITS for list of people who contributed to this
@@ -23,14 +23,17 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).a
 
-OBJS	:= $(BOARD).o flash.o misc.o
-
+COBJS	:= $(BOARD).o flash.o misc.o
 SOBJS  = vectors.o
 
-$(LIB):	$(OBJS) $(SOBJS)
-	$(AR) crv $@ $^
+SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+SOBJS	:= $(addprefix $(obj),$(SOBJS))
+
+$(LIB):	$(obj).depend $(OBJS) $(SOBJS)
+	$(AR) crv $@ $(OBJS) $(SOBJS)
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
@@ -40,9 +43,9 @@
 
 #########################################################################
 
-.depend:	Makefile $(SOBJS:.o=.S) $(OBJS:.o=.c)
-		$(CC) -M $(CPPFLAGS) $(SOBJS:.o=.S) $(OBJS:.o=.c) > $@
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
 
--include .depend
+sinclude $(obj).depend
 
 #########################################################################
diff --git a/board/altera/ep1c20/Makefile b/board/altera/ep1c20/Makefile
index a92b258..26873b6 100644
--- a/board/altera/ep1c20/Makefile
+++ b/board/altera/ep1c20/Makefile
@@ -1,5 +1,5 @@
 #
-# (C) Copyright 2001-2004
+# (C) Copyright 2001-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # See file CREDITS for list of people who contributed to this
@@ -12,7 +12,7 @@
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
@@ -22,17 +22,22 @@
 #
 
 include $(TOPDIR)/config.mk
+ifneq ($(OBJTREE),$(SRCTREE))
+$(shell mkdir -p $(obj)../common)
+endif
 
-LIB	= lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).a
 
 COMOBJS := ../common/AMDLV065D.o ../common/epled.o
 
-OBJS	:= $(BOARD).o $(COMOBJS)
+COBJS	:= $(BOARD).o $(COMOBJS)
 
-SOBJS	=
+SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
-$(LIB): $(OBJS) $(SOBJS)
-	$(AR) crv $@ $^
+$(LIB):	$(obj).depend $(OBJS)
+	$(AR) crv $@ $(OBJS)
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
@@ -42,9 +47,9 @@
 
 #########################################################################
 
-.depend:	Makefile $(SOBJS:.o=.S) $(OBJS:.o=.c)
-		$(CC) -M $(CPPFLAGS) $(SOBJS:.o=.S) $(OBJS:.o=.c) > $@
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
 
--include .depend
+sinclude $(obj).depend
 
 #########################################################################
diff --git a/board/altera/ep1s10/Makefile b/board/altera/ep1s10/Makefile
index a92b258..26873b6 100644
--- a/board/altera/ep1s10/Makefile
+++ b/board/altera/ep1s10/Makefile
@@ -1,5 +1,5 @@
 #
-# (C) Copyright 2001-2004
+# (C) Copyright 2001-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # See file CREDITS for list of people who contributed to this
@@ -12,7 +12,7 @@
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
@@ -22,17 +22,22 @@
 #
 
 include $(TOPDIR)/config.mk
+ifneq ($(OBJTREE),$(SRCTREE))
+$(shell mkdir -p $(obj)../common)
+endif
 
-LIB	= lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).a
 
 COMOBJS := ../common/AMDLV065D.o ../common/epled.o
 
-OBJS	:= $(BOARD).o $(COMOBJS)
+COBJS	:= $(BOARD).o $(COMOBJS)
 
-SOBJS	=
+SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
-$(LIB): $(OBJS) $(SOBJS)
-	$(AR) crv $@ $^
+$(LIB):	$(obj).depend $(OBJS)
+	$(AR) crv $@ $(OBJS)
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
@@ -42,9 +47,9 @@
 
 #########################################################################
 
-.depend:	Makefile $(SOBJS:.o=.S) $(OBJS:.o=.c)
-		$(CC) -M $(CPPFLAGS) $(SOBJS:.o=.S) $(OBJS:.o=.c) > $@
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
 
--include .depend
+sinclude $(obj).depend
 
 #########################################################################
diff --git a/board/altera/ep1s40/Makefile b/board/altera/ep1s40/Makefile
index a92b258..26873b6 100644
--- a/board/altera/ep1s40/Makefile
+++ b/board/altera/ep1s40/Makefile
@@ -1,5 +1,5 @@
 #
-# (C) Copyright 2001-2004
+# (C) Copyright 2001-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # See file CREDITS for list of people who contributed to this
@@ -12,7 +12,7 @@
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
@@ -22,17 +22,22 @@
 #
 
 include $(TOPDIR)/config.mk
+ifneq ($(OBJTREE),$(SRCTREE))
+$(shell mkdir -p $(obj)../common)
+endif
 
-LIB	= lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).a
 
 COMOBJS := ../common/AMDLV065D.o ../common/epled.o
 
-OBJS	:= $(BOARD).o $(COMOBJS)
+COBJS	:= $(BOARD).o $(COMOBJS)
 
-SOBJS	=
+SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
-$(LIB): $(OBJS) $(SOBJS)
-	$(AR) crv $@ $^
+$(LIB):	$(obj).depend $(OBJS)
+	$(AR) crv $@ $(OBJS)
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
@@ -42,9 +47,9 @@
 
 #########################################################################
 
-.depend:	Makefile $(SOBJS:.o=.S) $(OBJS:.o=.c)
-		$(CC) -M $(CPPFLAGS) $(SOBJS:.o=.S) $(OBJS:.o=.c) > $@
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
 
--include .depend
+sinclude $(obj).depend
 
 #########################################################################