[PATCH] Makefile: Generate Map file for each firmware

[Cheehong Ang]

> -----Original Message-----
> From: Jessica Clarke <jrtc27 at jrtc27.com>
> Sent: Tuesday, March 21, 2023 12:33 AM
> To: JunLiang Tan <junliang.tan at starfivetech.com>
> Cc: opensbi at lists.infradead.org; Cheehong Ang
> <cheehong.ang at starfivetech.com>
> Subject: Re: [PATCH] Makefile: Generate Map file for each firmware
> 
> On 19 Mar 2023, at 18:22, Jun Liang Tan <junliang.tan at starfivetech.com>
> wrote:
> >
> > Currently, OpenSBI does not generate Map file.
> > This patch allows OpenSBI generates Map file for each firmware. This
> > comes in handy in debugging process as Map file gives detailed
> > information about the symbols in our program.
> 
> How and why? Isn’t this just a bunch of tracing for how the linker laid the binary
> out? I really don’t see how this is particularly useful, it definitely shouldn’t be on
> by default and the file format varies wildly between GNU ld and LLVM LLD
> anyway.
> 
> What are you trying to do that you can’t do with an unstripped ELF?
Yes. We knew there are other ways to trace the binary layout.
We find it handy to generate .map file (just like U-Boot did) for quick reference in editor.
Just pass this one if it's not relevant.
> 
> > Signed-off-by: Jun Liang Tan <junliang.tan at starfivetech.com>
> > Reviewed-by: Chee Hong Ang <cheehong.ang at starfivetech.com>
> > ---
> > Makefile | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/Makefile b/Makefile
> > index a26a39b..e46b67a 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -445,7 +445,7 @@ compile_as = $(CMD_PREFIX)mkdir -p `dirname $(1)`;
> \
> > 	     $(AS) $(ASFLAGS) $(call dynamic_flags,$(1),$(2)) -c $(2) -o $(1)
> > compile_elf = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> > 	     echo " ELF       $(subst $(build_dir)/,,$(1))"; \
> > -	     $(CC) $(CFLAGS) $(3) $(ELFFLAGS) -Wl,-T$(2) -o $(1)
> > +	     $(CC) $(CFLAGS) -Wl,-Map=$(basename $(1)).map $(3) $(ELFFLAGS)
> > +-Wl,-T$(2) -o $(1)
> 
> This is clearly not the right path to use.
> 
> Jess
> 
> > compile_ar = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
> > 	     echo " AR        $(subst $(build_dir)/,,$(1))"; \
> > 	     $(AR) $(ARFLAGS) $(1) $(2)
> > @@ -669,6 +669,8 @@ clean:
> > 	$(CMD_PREFIX)find $(build_dir) -type f -name "*.bin" -exec rm -rf {} +
> > 	$(if $(V), @echo " RM        $(build_dir)/*.dtb")
> > 	$(CMD_PREFIX)find $(build_dir) -type f -name "*.dtb" -exec rm -rf {}
> > +
> > +	$(if $(V), @echo " RM        $(build_dir)/*.map")
> > +	$(CMD_PREFIX)find $(build_dir) -type f -name "*.map" -exec rm -rf {}
> > ++
> >
> > # Rule for "make distclean"
> > .PHONY: distclean
> > --
> > 2.38.1
> >
> >
> > --
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> > opensbi at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi