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/icecube/Makefile b/board/icecube/Makefile
index eb5ed59..8e61c79 100644
--- a/board/icecube/Makefile
+++ b/board/icecube/Makefile
@@ -1,6 +1,6 @@
 
 #
-# (C) Copyright 2003
+# (C) Copyright 2003-2006
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 # See file CREDITS for list of people who contributed to this
@@ -24,11 +24,15 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).a
 
-OBJS	:= $(BOARD).o flash.o
+COBJS	:= $(BOARD).o flash.o
 
-$(LIB):	$(OBJS) $(SOBJS)
+SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+SOBJS	:= $(addprefix $(obj),$(SOBJS))
+
+$(LIB):	$(obj).depend $(OBJS)
 	$(AR) crv $@ $(OBJS)
 
 clean:
@@ -39,9 +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/icecube/config.mk b/board/icecube/config.mk
index 07b5de1..170779d 100644
--- a/board/icecube/config.mk
+++ b/board/icecube/config.mk
@@ -32,7 +32,7 @@
 #	0x00100000   boot from RAM (for testing only)
 #
 
-sinclude $(TOPDIR)/board/$(BOARDDIR)/config.tmp
+sinclude $(OBJTREE)/board/$(BOARDDIR)/config.tmp
 
 ifndef TEXT_BASE
 ## Standard: boot high