[Buildroot] how to tune powerpc e500v2 cpus in BR

raymond zhao raymond.zhao.ml at gmail.com
Mon Jun 27 20:10:04 UTC 2011


On Sun, Jun 26, 2011 at 11:59 PM, Baruch Siach <baruch at tkos.co.il> wrote:
> Hi Raymond, Matias,
>
> On Fri, Jun 24, 2011 at 01:31:26PM -0400, Matias Garcia wrote:
>> You can put those in the BR2_TARGET_OPTIMIZATIONS setting under the
>> Toolchain page e.g.
>>
>> (-mcpu=8548 -mspe=yes -mabi=spe -mhard-float -mfloat-gprs=double)
>> Target Optimizations
>>
>> I selected a generic powerpc target because I didn't need the -mtune
>> when I was specifying -mcpu already. As far as I know, 8548 and 8540
>> work out to the same code.
>>
>> I switched to the external CodeSourcery build tools for two reasons:
>> (1) it allowed us to compile our application with -O3 (which we
>> need) while the standard GNU toolchain caused some errors, and (2)
>> they're supported by the Freescale/Mentor/CodeSourcery relationship,
>> and not all of the patches get applied to mainline (particularly for
>> newer processors). I had to add an option to the external wrapper so
>> that it would call the toolchain with '-te500v2' which is a shortcut
>> for the optimizations you list below. In that case, you can build
>> your own applications without calling any options explicitly.
>
> I'm also using the CodeSourcery toolchain for the e500v2 target (P1011), and I
> figured out that I must pass -te500v2 to gcc at link time as well. Since there
> is no generic way to add LDFLAGS options in Buildroot, I've posted the patch
> at http://lists.busybox.net/pipermail/buildroot/2011-June/043668.html. Did you
> find a better solution?
>
> baruch
>
>> On 11-06-24 10:27 AM, raymond zhao wrote:
>> >Hi,
>> >I am using freescale's p1020 CPU. It is a e500v2 core. How could I
>> >config the build root to tune the tool chain for the following
>> >options:
>> >
>> >-mcpu=8548 -mspe=yes -mabi=spe -mhard-float -mfloat-gprs=double
>> >
>> > From the menuconfig, I can only select CPU as 8540.
>
> --
>                                                     ~. .~   Tk Open Systems
> =}------------------------------------------------ooO--U--Ooo------------{=
>   - baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
>

Hi, Baruch
I took a look at the CodeSourcery. Looks it doesn't support uCLibc.
Best regards,
changbing



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