On Thu, Mar 03, 2022 at 11:29:36AM +0100, Jan Beulich wrote: > On 25.01.2022 12:00, Anthony PERARD wrote: > > Rework "arch/x86/boot/Makefile" to allow it to build both file > > "cmdline.S" and "reloc.S" without "build32.mk". > > > > These will now use the main rules for "%.o: %.c", and thus generate a > > dependency file. (We will not need to track the dependency manually > > anymore.) > > > > But for that, we need to override the main CFLAGS to do a 32bit build. > > We introduce XEN_TREEWIDE_CFLAGS which can be reused in boot/Makefile, > > and avoid the need to reparse Config.mk with a different value for > > XEN_TARGET_ARCH. From this new $(XEN_TREEWIDE_CFLAGS), we only need to > > change -m64 to have the 32bit flags. Then those are applied only to > > "cmdline.o" and "reloc.o". > > > > Specifically apply the rule "%.S: %.bin" to both cmdline.S and reloc.S > > to avoid make trying to regenerate other %.S files with it. > > > > There is no change expected to the resulting "cmdline.S" and > > "reloc.S", only the *.o file changes as their symbol for FILE goes > > from "cmdline.c" to "arch/x86//cmdline.c". (No idea why "boot" is > > missing from the string.) (I've only check with GCC, not clang.) > > > > Signed-off-by: Anthony PERARD <anthony.per...@citrix.com> > > Reviewed-by: Jan Beulich <jbeul...@suse.com> > with one question, just to be sure I understand things right: > > > --- a/xen/arch/x86/boot/Makefile > > +++ b/xen/arch/x86/boot/Makefile > > @@ -1,25 +1,42 @@ > > obj-bin-y += head.o > > +head-srcs := cmdline.S reloc.S > > > > -DEFS_H_DEPS = $(abs_srctree)/$(src)/defs.h > > $(abs_srctree)/include/xen/stdbool.h > > +nocov-y += $(head-srcs:.S=.o) > > +noubsan-y += $(head-srcs:.S=.o) > > +targets += $(head-srcs:.S=.o) > > > > -CMDLINE_DEPS = $(DEFS_H_DEPS) $(abs_srctree)/$(src)/video.h \ > > - $(BASEDIR)/include/xen/kconfig.h \ > > - $(BASEDIR)/include/generated/autoconf.h > > +head-srcs := $(addprefix $(obj)/, $(head-srcs)) > > > > -RELOC_DEPS = $(DEFS_H_DEPS) \ > > - $(BASEDIR)/include/generated/autoconf.h \ > > - $(BASEDIR)/include/xen/kconfig.h \ > > - $(BASEDIR)/include/xen/multiboot.h \ > > - $(BASEDIR)/include/xen/multiboot2.h \ > > - $(BASEDIR)/include/xen/const.h \ > > - $(BASEDIR)/include/public/arch-x86/hvm/start_info.h > > +$(obj)/head.o: $(head-srcs) > > > > -$(obj)/head.o: $(obj)/cmdline.S $(obj)/reloc.S > > +CFLAGS_x86_32 := $(subst -m64,-m32 -march=i686,$(XEN_TREEWIDE_CFLAGS)) > > +$(call cc-options-add,CFLAGS_x86_32,CC,$(EMBEDDED_EXTRA_CFLAGS)) > > +CFLAGS_x86_32 += -Werror -fno-builtin -g0 -msoft-float > > +CFLAGS_x86_32 += -I$(srctree)/include > > > > -$(obj)/cmdline.S: $(src)/cmdline.c $(CMDLINE_DEPS) $(src)/build32.lds > > - $(MAKE) -f $(abs_srctree)/$(src)/build32.mk -C $(obj) $(@F) > > CMDLINE_DEPS="$(CMDLINE_DEPS)" > > +# override for 32bit binaries > > +$(head-srcs:.S=.o): CFLAGS_stack_boundary := > > You overriding CFLAGS_stack_boundary but not object_label_flags is > merely because the latter has no (unwanted) effect on the compilation?
Yes. Thanks, -- Anthony PERARD
