Thanks, after a long google I figured it out. Will write a post about it on my blog.
On 9/19/13, Simon Glass <s...@chromium.org> wrote: > Hi MJ, > > On Mon, Sep 16, 2013 at 8:23 PM, MJ embd <mj.e...@gmail.com> wrote: > >> PS: Last message was sent without body, please ignore >> >> 0 down vote favorite >> >> >> I am trying to understand a second level makefile of uboot (this >> makefile was in a sub directory) >> >> a) What is the difference between $(COBJS:.o=.c) and COBJS := >> test_main.o >> > > $(COBJS:.o=.c) means to evaluate $(COBJS) but replace every .o with .c > > COBJS := test_main.o means that COBJS is assigned the value > test_main.o > > > >> b) What is the meaning of $(call cmd_link_o_target, $(OBJS)). What is >> the cmd_link_o_target and what is the call statement doing >> > > This is linking the object files together with a partial link (ld -r). See > config.mk for the definition. > > >> c) Does this line creating 2 targets ? >> >> ALL := $(obj).depend $(LIB) >> > > It defines variable ALL to be those two things (the depend file and the > library). So that > > all: $(ALL) > > means that we need to build the depend file and the library. > > >> ===================================Makefile=================== >> >> include $(TOPDIR)/config.mk >> >> LIB = $(obj)libtest.o >> >> SOBJS := test.o >> >> COBJS := test_main.o >> COBJS += diagnostic.o >> >> >> SRCS := $(SOBJS:.o=.S) $(COBJS:.o=.c) >> OBJS := $(addprefix $(obj),$(COBJS) $(SOBJS)) >> >> ALL := $(obj).depend $(LIB) >> >> all: $(ALL) >> >> $(LIB): $(OBJS) >> $(call cmd_link_o_target, $(OBJS)) >> >> ######################################################################### >> >> # defines $(obj).depend target >> include $(SRCTREE)/rules.mk >> >> sinclude $(obj).depend >> >> ######################################################################### >> >> > This might help a bit: > > http://www.gnu.org/software/make/manual/make.html > > Regards, > Simon > -- -mj _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
