It's cut and modified version of Makefile.host
On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote:
The makefile.prog is added only, will be used in sample/bpf/Makefile
later in order to switch cross-compiling on CC from HOSTCC.
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.prog 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.
So this is really Makefile.host or Makefile.user, right?
In BPF, 'prog' can refers to user prog or bpf prog.Makefile.target? as target = host not always.
To avoid ambiguity, maybe Makefile.host?
Another kind of samples...with c++ for instance.
Makefile.prog contains only stuff needed for samples/bpf, potentially
can be reused and extended for other prog sets later and now needed
What do you mean 'extended for other prog sets'? I am wondering whether
we could just include 'scripts/Makefile.host'? How hard it is?It's bound to HOSTCC and it's environment. It is included by default and
will drop it.
only for unblocking tricky samples/bpf cross compilation.
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
samples/bpf/Makefile.prog | 77 +++++++++++++++++++++++++++++++++++++++
1 file changed, 77 insertions(+)
create mode 100644 samples/bpf/Makefile.prog
diff --git a/samples/bpf/Makefile.prog b/samples/bpf/Makefile.prog
new file mode 100644
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0
+# Building binaries on the host system
+# Binaries are not used during the compilation of the kernel, and intendent
+# to be build for target board, target board can be host ofc. Added to build
+# binaries to run not on host system.
+# Only C is supported, but can be extended for C++.
The above comment is not needed.
samples/bpf/ only have C now. I am wondering whether your below scriptsI think yes, will try
can be simplified, e.g., removing cxxobjs.
+# Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
+# progs-y := xsk_example
+# Will compile xdpsock_example.c and create an executable named xsk_example
+# progs-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
+__progs := $(sort $(progs-y))
+# C code
+# Executables compiled from a single .c file
+prog-csingle := $(foreach m,$(__progs), \
+ $(if $($(m)-objs)$($(m)-cxxobjs),,$(m)))
+# C executables linked based on several .o files
+prog-cmulti := $(foreach m,$(__progs),\
+ $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
+# Object (.o) files compiled from .c files
+prog-cobjs := $(sort $(foreach m,$(__progs),$($(m)-objs)))
+prog-csingle := $(addprefix $(obj)/,$(prog-csingle))
+prog-cmulti := $(addprefix $(obj)/,$(prog-cmulti))
+prog-cobjs := $(addprefix $(obj)/,$(prog-cobjs))
+# Handle options to gcc. Support building with separate output directory
+_progc_flags = $(PROGS_CFLAGS) \
+# $(objtree)/$(obj) for including generated headers from checkin source files
+_progc_flags += -I $(objtree)/$(obj)
+progc_flags = -Wp,-MD,$(depfile) $(_progc_flags)
+# Create executable from a single .c file
+# prog-csingle -> Executable
+quiet_cmd_prog-csingle = CC $@
+ cmd_prog-csingle = $(CC) $(progc_flags) $(PROGS_LDFLAGS) -o $@ $< \
+ $(PROGS_LDLIBS) $(PROGLDLIBS_$(@F))
+$(prog-csingle): $(obj)/%: $(src)/%.c FORCE
+ $(call if_changed_dep,prog-csingle)
+# Link an executable based on list of .o files, all plain c
+# prog-cmulti -> executable
+quiet_cmd_prog-cmulti = LD $@
+ cmd_prog-cmulti = $(CC) $(progc_flags) $(PROGS_LDFLAGS) -o $@ \
+ $(addprefix $(obj)/,$($(@F)-objs)) \
+ $(PROGS_LDLIBS) $(PROGLDLIBS_$(@F))
+$(prog-cmulti): $(prog-cobjs) FORCE
+ $(call if_changed,prog-cmulti)
+$(call multi_depend, $(prog-cmulti), , -objs)
+# Create .o file from a single .c file
+# prog-cobjs -> .o
+quiet_cmd_prog-cobjs = CC $@
+ cmd_prog-cobjs = $(CC) $(progc_flags) -c -o $@ $<
+$(prog-cobjs): $(obj)/%.o: $(src)/%.c FORCE
+ $(call if_changed_dep,prog-cobjs)