[U-Boot] [PATCH 2/2] SPL: Allow ARM926EJS to avoid compiling in the CPU support code

Tom Rini tom.rini at gmail.com
Sat Oct 22 02:04:52 CEST 2011


On Fri, Oct 21, 2011 at 4:45 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
> On Saturday, October 22, 2011 01:08:43 AM Albert ARIBAUD wrote:
>> Le 22/10/2011 00:46, Marek Vasut a écrit :
>> > On Saturday, October 22, 2011 12:44:06 AM Albert ARIBAUD wrote:
>> >> Le 22/10/2011 00:00, Marek Vasut a écrit :
>> >>> On Friday, October 21, 2011 11:52:23 PM Albert ARIBAUD wrote:
>> >>>> Hi Marek,
>> >>>>
>> >>>> Le 21/10/2011 22:44, Marek Vasut a écrit :
>> >>>>> On Thursday, October 06, 2011 02:13:26 AM Marek Vasut wrote:
>> >>>>>> This allows the SPL to avoid compiling in the CPU support code.
>> >>>>>>
>> >>>>>> Signed-off-by: Marek Vasut<marek.vasut at gmail.com>
>> >>>>>> Cc: Stefano Babic<sbabic at denx.de>
>> >>>>>> Cc: Wolfgang Denk<wd at denx.de>
>> >>>>>> Cc: Detlev Zundel<dzu at denx.de>
>> >>>>>> Cc: Scott Wood<scottwood at freescale.com>
>> >>>>>> ---
>> >>>>>>
>> >>>>>>     arch/arm/cpu/arm926ejs/Makefile |    7 +++++++
>> >>>>>>     1 files changed, 7 insertions(+), 0 deletions(-)
>> >>>>>>
>> >>>>>> diff --git a/arch/arm/cpu/arm926ejs/Makefile
>> >>>>>> b/arch/arm/cpu/arm926ejs/Makefile index 930e0d1..3f9b0f1 100644
>> >>>>>> --- a/arch/arm/cpu/arm926ejs/Makefile
>> >>>>>> +++ b/arch/arm/cpu/arm926ejs/Makefile
>> >>>>>> @@ -28,6 +28,13 @@ LIB = $(obj)lib$(CPU).o
>> >>>>>>
>> >>>>>>     START      = start.o
>> >>>>>>     COBJS      = cpu.o
>> >>>>>>
>> >>>>>> +ifdef CONFIG_SPL_BUILD
>> >>>>>> +ifdef CONFIG_SPL_NO_CPU_SUPPORT_CODE
>> >>>>>> +START :=
>> >>>>>> +COBJS :=
>> >>>>>> +endif
>> >>>>>> +endif
>> >>>>>> +
>> >>>>>>
>> >>>>>>     SRCS       := $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)
>> >>>>>>     OBJS       := $(addprefix $(obj),$(COBJS) $(SOBJS))
>> >>>>>>     START      := $(addprefix $(obj),$(START))
>> >>>>>
>> >>>>> Hi Albert,
>> >>>>>
>> >>>>> can we get this applied please?
>> >>>>
>> >>>> I still don't understand what this is supposed to do -- why not
>> >>>> linking this code is required.
>> >>>>
>> >>>> Amicalement,
>> >>>
>> >>> Hi Albert,
>> >>>
>> >>> I use very different start.S in SPL. And I don't need cpu.o at all.
>> >>
>> >> That I understand; but is there a /problem/ in linking cpu.o in?
>> >
>> > I suppose it'll be optimized out at link time ?
>>
>> That indirectly answers my question: what you want to achieve is
>> removing dead code.
>
> The code IS USED in U-Boot, but IS NOT USED in SPL !

Right, but linked and unused code in SPL is (or should be!) thrown
away, is what's
trying to be driven home right now.  If the file is going to go away,
and it's compiled
thrown away at final link of SPL, lets just ignore that it exists for
a little longer, and
then it won't.

-- 
Tom


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