[U-Boot] [RFC PATCH 3/4] Add new folder and build system for SPL

[Daniel Schwierzeck]

[aneesh at ti.com:
1. Changed definition of OBJTREE for SPL
2. Added support for linker script from various places
4. $(OBJTREE)/spl/obj for objects
5. Minor cleanup
]

[daniel.schwierzeck at googlemail.com:
1. removed ALL and clean targets
2. fixed out-of-tree build error on u-boot-spl.lds generation
3. determine LDSCRIPT variable like top Makefiles does
4. fixed dependency error in target $(obj)u-boot-spl.lds
]

Signed-off-by: Aneesh V <aneesh at ti.com>
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at googlemail.com>
---
 spl/Makefile |   97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 97 insertions(+), 0 deletions(-)
 create mode 100644 spl/Makefile

diff --git a/spl/Makefile b/spl/Makefile
new file mode 100644
index 0000000..0521008
--- /dev/null
+++ b/spl/Makefile
@@ -0,0 +1,97 @@
+#
+# (C) Copyright 2011 Daniel Schwierzeck, daniel.schwierzeck at googlemail.com.
+#
+# (C) Copyright 2011
+# Texas Instruments Incorporated - http://www.ti.com/
+# Aneesh V <aneesh at ti.com>
+#
+# This file is released under the terms of GPL v2 and any later version.
+# See the file COPYING in the root directory of the source tree for details.
+#
+
+CONFIG_UBOOT_SPL_BUILD = y
+export CONFIG_UBOOT_SPL_BUILD
+
+# create 'spl/obj' within OBJTREE for spl
+OBJTREE := $(OBJTREE)/spl/obj
+LNDIR	:= $(OBJTREE)
+
+include $(TOPDIR)/config.mk
+# We want the final binaries in this directory
+obj	:= $(obj)../
+START	= $(OBJTREE)/$(CPUDIR)/start.o
+
+LIBS-y += $(shell if [ -f $(SRCTREE)/board/$(VENDOR)/common/Makefile ]; \
+	then echo "board/$(VENDOR)/common/lib$(VENDOR).o"; fi)
+LIBS-y += board/$(BOARDDIR)/lib$(BOARD).o
+LIBS-y += $(CPUDIR)/lib$(CPU).o
+ifdef SOC
+LIBS-y += $(CPUDIR)/$(SOC)/lib$(SOC).o
+endif
+LIBS-y += arch/$(ARCH)/lib/lib$(ARCH).o
+LIBS-$(CONFIG_SPL_SPI_SUPPORT) += drivers/spi/libspi.o
+LIBS-$(CONFIG_SPL_SPI_FLASH_SUPPORT) += drivers/mtd/spi/libspi_flash.o
+LIBS-$(CONFIG_SPL_GPIO_SUPPORT) += drivers/gpio/libgpio.o
+LIBS-$(CONFIG_SPL_NAND_BOOT) += spl/nand/libnand_spl.o
+LIBS-$(CONFIG_SPL_ONENAND_BOOT) += spl/nand/libonenand_spl.o
+
+LIBS = $(addprefix $(OBJTREE)/,$(sort $(LIBS-y)))
+
+__START = $(subst $(OBJTREE)/,,$(START))
+__LIBS = $(subst $(OBJTREE)/,,$(LIBS))
+
+# Linker Script
+ifdef CONFIG_SYS_SPL_LDSCRIPT
+# need to strip off double quotes
+LDSCRIPT := $(addprefix $(SRCTREE)/,$(subst ",,$(CONFIG_SYS_SPL_LDSCRIPT)))
+endif
+
+ifeq ($(wildcard $(LDSCRIPT)),)
+	LDSCRIPT := $(TOPDIR)/board/$(BOARDDIR)/u-boot-spl.lds
+endif
+ifeq ($(wildcard $(LDSCRIPT)),)
+	LDSCRIPT := $(TOPDIR)/$(CPUDIR)/u-boot-spl.lds
+endif
+ifeq ($(wildcard $(LDSCRIPT)),)
+$(error could not find linker script)
+endif
+
+# Special flags for CPP when processing the linker script.
+# Pass the version down so we can handle backwards compatibility
+# on the fly.
+LDPPFLAGS += \
+	-include $(TOPDIR)/include/u-boot/u-boot.lds.h \
+	-include $(OBJTREE)/../../include/config.h \
+	$(shell $(LD) --version | \
+	  sed -ne 's/GNU ld version \([0-9][0-9]*\)\.\([0-9][0-9]*\).*/-DLD_MAJOR=\1 -DLD_MINOR=\2/p')
+
+all:	$(obj)u-boot-spl.bin
+
+$(obj)u-boot-spl.bin:	$(obj)u-boot-spl
+	$(OBJCOPY) $(OBJCFLAGS) -O binary $< $@
+
+GEN_UBOOT = \
+	UNDEF_SYM=`$(OBJDUMP) -x $(LIBS) | \
+	sed  -n -e 's/.*\($(SYM_PREFIX)__u_boot_cmd_.*\)/-u\1/p'|sort|uniq`;\
+	cd $(LNDIR) && $(LD) $(LDFLAGS) $(LDFLAGS_$(@F)) $$UNDEF_SYM $(__START) \
+		--start-group $(__LIBS) --end-group $(PLATFORM_LIBS) \
+		-Map u-boot-spl.map -o u-boot-spl
+
+$(obj)u-boot-spl:	depend $(START) $(LIBS) $(obj)u-boot-spl.lds
+	$(GEN_UBOOT)
+
+$(START):	depend
+	$(MAKE) -C $(SRCTREE)/$(CPUDIR) $@
+
+$(LIBS):	depend
+	$(MAKE) -C $(SRCTREE)$(dir $(subst $(OBJTREE),,$@))
+
+$(obj)u-boot-spl.lds: $(LDSCRIPT) depend
+	$(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - < $< > $@
+
+depend:	$(obj).depend
+.PHONY: depend
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
-- 
1.7.5.4