| Message ID | 1301301631-6115-1-git-send-email-wd@denx.de |
|---|---|
| State | Superseded |
| Headers | show |
Hi Wolfgang, On Mon, Mar 28, 2011 at 4:40 PM, Wolfgang Denk <wd@denx.de> wrote: > Commit 44c6e65 "rename _end to __bss_end__ broke building of a large > number of systems (at least all PowerPC?): > > libstubs.o: In function `app_startup': > examples/standalone/stubs.c:197: undefined reference to `__bss_end__' > > As a workaround (instead of introducing linker scripts) we can > add a --defsym=__bss_end__=_end > > Signed-off-by: Wolfgang Denk <wd@denx.de> > Cc: Po-Yu Chuang <ratbert@faraday-tech.com> > Cc: Albert Aribaud <albert.aribaud@free.fr> > --- > > > What I really do not understand is why we don't see the same type of > undefined reference errors on ARM? ALso, on ARM we see __bss_end__ > and _bss_end__, and __bss_start und __bss_start__ - where are the > other names coming from? [On PPC we see only __bss_start and > __bss_end__]. Do you mean _end here? If there is __bss_end__ on PPC, then there is no problem, right? > examples/standalone/Makefile | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile > index c1dfdce..06cf14f 100644 > --- a/examples/standalone/Makefile > +++ b/examples/standalone/Makefile > @@ -96,6 +96,7 @@ $(LIB): $(obj).depend $(LIBOBJS) > $(ELF): > $(obj)%: $(obj)%.o $(LIB) > $(LD) -g -Ttext $(STANDALONE_LOAD_ADDR) \ > + --defsym=__bss_end__=_end \ > -o $@ -e $(SYM_PREFIX)$(notdir $(<:.o=)) $< $(LIB) \ > -L$(gcclibdir) -lgcc > > -- > 1.7.4 > > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot >
Dear Po-Yu Chuang, In message <AANLkTin6cEHSQSquvocW_kXr4-dbtnUGu9XZzEJiTdJ_@mail.gmail.com> you wrote: > > > What I really do not understand is why we don't see the same type of > > undefined reference errors on ARM? =C2=A0ALso, on ARM we see __bss_end__ > > and _bss_end__, and __bss_start und __bss_start__ - where are the > > other names coming from? [On PPC we see only __bss_start and > > __bss_end__]. > > Do you mean _end here? If there is __bss_end__ on PPC, then there is > no problem, right? No, I mean exactly what I wrote. On PPC I do not see any _end (with your previous patch), only the symbols defined in the linker script. Best regards, Wolfgang Denk
Hi Wolfgang, On Mon, Mar 28, 2011 at 4:54 PM, Wolfgang Denk <wd@denx.de> wrote: > Dear Po-Yu Chuang, > > In message <AANLkTin6cEHSQSquvocW_kXr4-dbtnUGu9XZzEJiTdJ_@mail.gmail.com> you wrote: >> >> > What I really do not understand is why we don't see the same type of >> > undefined reference errors on ARM? =C2=A0ALso, on ARM we see __bss_end__ >> > and _bss_end__, and __bss_start und __bss_start__ - where are the >> > other names coming from? [On PPC we see only __bss_start and >> > __bss_end__]. >> >> Do you mean _end here? If there is __bss_end__ on PPC, then there is >> no problem, right? > > No, I mean exactly what I wrote. On PPC I do not see any _end (with > your previous patch), only the symbols defined in the linker script. All those symbols come from default linker script in one of ${toolchain}/arm-none-linux-gnueabi/lib/ldscripts/armelfb_linux_eabi.*. It defines __bss_start, __bss_start__, _bss_end__ and __bss_end__. Is ARM the only platform doing this? Best regards, Po-Yu Chuang
Dear Po-Yu Chuang, In message <AANLkTik-a8oL2CEnb3wf43uwd0r0MGCy8Nnu5DmTWwzw@mail.gmail.com> you wrote: > > > No, I mean exactly what I wrote. On PPC I do not see any _end (with > > your previous patch), only the symbols defined in the linker script. > > All those symbols come from default linker script in one of > ${toolchain}/arm-none-linux-gnueabi/lib/ldscripts/armelfb_linux_eabi.*. > > It defines __bss_start, __bss_start__, _bss_end__ and __bss_end__. > Is ARM the only platform doing this? No. Not even ARM is doing this in general. It's your specific tool chain that does it this way. It appears that ARM has both *bss_start* and *bss_end*, while PPC has only __bss_start (and __sbss_start and ___sbss_start), but no *bss_end (there are __sbss_end and ___sbss_end, though). I have no idea if there is any rationale for this inconsistency or if it's a bug. Verified with both ELDK 4.2 and recent Yocto/Poky tool chains. Best regards, Wolfgang Denk
Le 28/03/2011 10:40, Wolfgang Denk a écrit : > Commit 44c6e65 "rename _end to __bss_end__ broke building of a large > number of systems (at least all PowerPC?): > > libstubs.o: In function `app_startup': > examples/standalone/stubs.c:197: undefined reference to `__bss_end__' > > As a workaround (instead of introducing linker scripts) we can > add a --defsym=__bss_end__=_end > > Signed-off-by: Wolfgang Denk<wd@denx.de> > Cc: Po-Yu Chuang<ratbert@faraday-tech.com> > Cc: Albert Aribaud<albert.aribaud@free.fr> > --- Hmm... The change from _end to __bss_end__ should not have been applied to the standalone apps, I believe. They are not compiled with start.S but with the standard lib, which will use _end. > What I really do not understand is why we don't see the same type of > undefined reference errors on ARM? ALso, on ARM we see __bss_end__ > and _bss_end__, and __bss_start und __bss_start__ - where are the > other names coming from? [On PPC we see only __bss_start and > __bss_end__]. I believe these come from the toolchain's standard lib. Amicalement,
Dear Albert ARIBAUD, In message <4D90BA8B.3080200@free.fr> you wrote: > > > Commit 44c6e65 "rename _end to __bss_end__ broke building of a large > > number of systems (at least all PowerPC?): > > > > libstubs.o: In function `app_startup': > > examples/standalone/stubs.c:197: undefined reference to `__bss_end__' ... > Hmm... The change from _end to __bss_end__ should not have been applied > to the standalone apps, I believe. They are not compiled with start.S > but with the standard lib, which will use _end. Good point. Will send an updated patch. Best regards, Wolfgang Denk
diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile index c1dfdce..06cf14f 100644 --- a/examples/standalone/Makefile +++ b/examples/standalone/Makefile @@ -96,6 +96,7 @@ $(LIB): $(obj).depend $(LIBOBJS) $(ELF): $(obj)%: $(obj)%.o $(LIB) $(LD) -g -Ttext $(STANDALONE_LOAD_ADDR) \ + --defsym=__bss_end__=_end \ -o $@ -e $(SYM_PREFIX)$(notdir $(<:.o=)) $< $(LIB) \ -L$(gcclibdir) -lgcc
Commit 44c6e65 "rename _end to __bss_end__ broke building of a large number of systems (at least all PowerPC?): libstubs.o: In function `app_startup': examples/standalone/stubs.c:197: undefined reference to `__bss_end__' As a workaround (instead of introducing linker scripts) we can add a --defsym=__bss_end__=_end Signed-off-by: Wolfgang Denk <wd@denx.de> Cc: Po-Yu Chuang <ratbert@faraday-tech.com> Cc: Albert Aribaud <albert.aribaud@free.fr> --- What I really do not understand is why we don't see the same type of undefined reference errors on ARM? ALso, on ARM we see __bss_end__ and _bss_end__, and __bss_start und __bss_start__ - where are the other names coming from? [On PPC we see only __bss_start and __bss_end__]. examples/standalone/Makefile | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)