U-BOOT源码分析及移植(3)

U-BOOT源码分析及移植

顶层makefile先调用各子目录的makefile，生成目标文件或者目标文件库。

然后再连接所有目标文件（库）生成最终的u-boot.bin。

连接的主要目标（库）如下：

OBJS = cpu/$(CPU)/start.o

LIBS = lib_generic/libgeneric.a

LIBS += board/$(BOARDDIR)/lib$(BOARD).a

LIBS += cpu/$(CPU)/lib$(CPU).a

ifdef SOC

LIBS += cpu/$(CPU)/$(SOC)/lib$(SOC).a

endif

LIBS += lib_$(ARCH)/lib$(ARCH).a

LIBS += fs/cramfs/libcramfs.a fs/fat/libfat.a fs/fdos/libfdos.a fs/jffs2/libjffs2.a \ fs/reiserfs/libreiserfs.a fs/ext2/libext2fs.a

LIBS += net/libnet.a

LIBS += disk/libdisk.a

LIBS += rtc/librtc.a

LIBS += dtt/libdtt.a

LIBS += drivers/libdrivers.a

LIBS += drivers/nand/libnand.a

LIBS += drivers/nand_legacy/libnand_legacy.a

LIBS += drivers/sk98lin/libsk98lin.a

LIBS += post/libpost.a post/cpu/libcpu.a

LIBS += common/libcommon.a

LIBS += $(BOARDLIBS)

显然跟平台相关的主要是：

cpu/$(CPU)/start.o

board/$(BOARDDIR)/lib$(BOARD).a

cpu/$(CPU)/lib$(CPU).a

cpu/$(CPU)/$(SOC)/lib$(SOC).a

lib_$(ARCH)/lib$(ARCH).a