On Mon, Sep 16, 2019 at 3:58 AM Ivan Khoronzhuk <ivan.khoronz...@linaro.org> wrote: > > The makefile.target is added only and will be used in
typo: Makefile > sample/bpf/Makefile later in order to switch cross-compiling on CC on -> to > from HOSTCC environment. > > The HOSTCC is supposed to build binaries and tools running on the host > afterwards, in order to simplify build or so, like "fixdep" or else. > In case of cross compiling "fixdep" is executed on host when the rest > samples should run on target arch. In order to build binaries for > target arch with CC and tools running on host with HOSTCC, lets add > Makefile.target for simplicity, having definition and routines similar > to ones, used in script/Makefile.host. This allows later add > cross-compilation to samples/bpf with minimum changes. > > The tprog stands for target programs built with CC. Why tprog? Could we just use prog: hostprog vs prog. > > Makefile.target contains only stuff needed for samples/bpf, potentially > can be reused later and now needed only for unblocking tricky > samples/bpf cross compilation. > > Signed-off-by: Ivan Khoronzhuk <ivan.khoronz...@linaro.org> > --- > samples/bpf/Makefile.target | 75 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 75 insertions(+) > create mode 100644 samples/bpf/Makefile.target > > diff --git a/samples/bpf/Makefile.target b/samples/bpf/Makefile.target > new file mode 100644 > index 000000000000..fb6de63f7d2f > --- /dev/null > +++ b/samples/bpf/Makefile.target > @@ -0,0 +1,75 @@ > +# SPDX-License-Identifier: GPL-2.0 > +# ========================================================================== > +# Building binaries on the host system > +# Binaries are not used during the compilation of the kernel, and intendent typo: intended > +# to be build for target board, target board can be host ofc. Added to build What's ofc, is it "of course"? > +# binaries to run not on host system. > +# > +# Sample syntax (see Documentation/kbuild/makefiles.rst for reference) > +# tprogs-y := xsk_example > +# Will compile xdpsock_example.c and create an executable named xsk_example You mix references to xsk_example and xdpsock_example, which is very confusing. I'm guessing you meant to use xdpsock_example consistently. > +# > +# tprogs-y := xdpsock > +# xdpsock-objs := xdpsock_1.o xdpsock_2.o > +# Will compile xdpsock_1.c and xdpsock_2.c, and then link the executable > +# xdpsock, based on xdpsock_1.o and xdpsock_2.o > +# > +# Inherited from scripts/Makefile.host "Inspired by" or "Derived from" would be probably more appropriate term :) > +# > +__tprogs := $(sort $(tprogs-y)) > + > +# C code > +# Executables compiled from a single .c file > +tprog-csingle := $(foreach m,$(__tprogs), \ > + $(if $($(m)-objs),,$(m))) > + > +# C executables linked based on several .o files > +tprog-cmulti := $(foreach m,$(__tprogs),\ > + $(if $($(m)-objs),$(m))) > + > +# Object (.o) files compiled from .c files > +tprog-cobjs := $(sort $(foreach m,$(__tprogs),$($(m)-objs))) > + > +tprog-csingle := $(addprefix $(obj)/,$(tprog-csingle)) > +tprog-cmulti := $(addprefix $(obj)/,$(tprog-cmulti)) > +tprog-cobjs := $(addprefix $(obj)/,$(tprog-cobjs)) > + > +##### > +# Handle options to gcc. Support building with separate output directory > + > +_tprogc_flags = $(TPROGS_CFLAGS) \ > + $(TPROGCFLAGS_$(basetarget).o) > + > +# $(objtree)/$(obj) for including generated headers from checkin source files > +ifeq ($(KBUILD_EXTMOD),) > +ifdef building_out_of_srctree > +_tprogc_flags += -I $(objtree)/$(obj) > +endif > +endif > + > +tprogc_flags = -Wp,-MD,$(depfile) $(_tprogc_flags) > + > +# Create executable from a single .c file > +# tprog-csingle -> Executable > +quiet_cmd_tprog-csingle = CC $@ > + cmd_tprog-csingle = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o > $@ $< \ > + $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F)) > +$(tprog-csingle): $(obj)/%: $(src)/%.c FORCE > + $(call if_changed_dep,tprog-csingle) > + > +# Link an executable based on list of .o files, all plain c > +# tprog-cmulti -> executable > +quiet_cmd_tprog-cmulti = LD $@ > + cmd_tprog-cmulti = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ \ > + $(addprefix $(obj)/,$($(@F)-objs)) \ > + $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F)) > +$(tprog-cmulti): $(tprog-cobjs) FORCE > + $(call if_changed,tprog-cmulti) > +$(call multi_depend, $(tprog-cmulti), , -objs) > + > +# Create .o file from a single .c file > +# tprog-cobjs -> .o > +quiet_cmd_tprog-cobjs = CC $@ > + cmd_tprog-cobjs = $(CC) $(tprogc_flags) -c -o $@ $< > +$(tprog-cobjs): $(obj)/%.o: $(src)/%.c FORCE > + $(call if_changed_dep,tprog-cobjs) > -- > 2.17.1 > tprogs is quite confusing, but overall looks good to me.
