Add Intel Core 2 machine support (prescott and nocona)

Add Intel Core 2 machine support (prescott and nocona)

[Leon Woestenberg]

Hello,

I would like to add support for Intel's Core 2 processors, in both 32
and 64 bit mode.

I am wondering what namespace to use for the PACKAGE ARCHs?

Given all the options[*], I think "x86-prescott" and "x86_64-nocona"
are suitable:

x86_64-prescott= x86_32-core = x86_32-core2
x86_64-nocona = x86_64-core2

The naming is a bit to long to suite my taste, maybe prescott and
nocona are enough?

I would like some input on this before I commit anything and pollute
the namespace.

Regards,
-- 
Leon

[*]
http://gentoo-wiki.com/Safe_Cflags#Intel_Core_2_Duo.2FQuad_.2F_Xeon_51xx.2F53xx

Re: Add Intel Core 2 machine support (prescott and nocona)

[Khem Raj]

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Leon Woestenberg wrote:
> Hello,
> 
> I would like to add support for Intel's Core 2 processors, in both 32
> and 64 bit mode.
> 
> I am wondering what namespace to use for the PACKAGE ARCHs?
> 
> Given all the options[*], I think "x86-prescott" and "x86_64-nocona"
> are suitable:
> 
> x86_64-prescott= x86_32-core = x86_32-core2
> x86_64-nocona = x86_64-core2
> 
> The naming is a bit to long to suite my taste, maybe prescott and
> nocona are enough?
> 
> I would like some input on this before I commit anything and pollute
> the namespace.
> 
> Regards,

I would suggest just add conf/machine/core2.conf and another
conf/machine/tune-core2.inc file to have the special gcc flags.  I would
not add it as a separate arch but stick with x86. To me it sounds more
confusing to have x86 and core separated out into two different basic
arches.

Just my 2 cents.

- -Khem

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Re: Add Intel Core 2 machine support (prescott and nocona)

[Leon Woestenberg]

Hello Khem,

thanks for the feedback.

On 8/20/07, Khem Raj <raj.khem@gmail.com> wrote:
> I would suggest just add conf/machine/core2.conf and another
> conf/machine/tune-core2.inc file to have the special gcc flags.  I would
> not add it as a separate arch but stick with x86. To me it sounds more
> confusing to have x86 and core separated out into two different basic
> arches.
>
My current proposal is:

conf/machine/x86_32-prescott.conf
conf/machine/include/x86_32-prescott.conf
-arch=prescott
TARGET_ARCH=i686

conf/machine/x86_64-nocona.conf
conf/machine/include/x86_64-nocona.conf
-arch=nocona
TARGET_ARCH=x86_64

starting with GCC 4.3:
conf/machine/x86_64-core2.conf
conf/machine/include/x86_64-core2.conf
-arch=core2
TARGET_ARCH=x86_64

The remaining issue is that the TARGET_ARCH suggests that the
resulting packages run on any i686 or x86_64 which is not necessarely
true due to the instruction set being used.

Although we could create more generic machines, my direct interest is
in (live) media encoding and some packages will use SSE3 and SSSE3.

Regards,

Leon.

Re: Add Intel Core 2 machine support (prescott and nocona)

[Richard Purdie]

On Mon, 2007-08-20 at 23:52 +0200, Leon Woestenberg wrote:
> My current proposal is:
> 
> conf/machine/x86_32-prescott.conf
> conf/machine/include/x86_32-prescott.conf
> -arch=prescott
> TARGET_ARCH=i686
> 
> conf/machine/x86_64-nocona.conf
> conf/machine/include/x86_64-nocona.conf
> -arch=nocona
> TARGET_ARCH=x86_64
> 
> starting with GCC 4.3:
> conf/machine/x86_64-core2.conf
> conf/machine/include/x86_64-core2.conf
> -arch=core2
> TARGET_ARCH=x86_64

Please don't use '_' in the names. It may work but it has the potential
to mess up bitbake's override handling and would be better avoided. I
know people have had issues with "x86_64" already due to this.

> The remaining issue is that the TARGET_ARCH suggests that the
> resulting packages run on any i686 or x86_64 which is not necessarely
> true due to the instruction set being used.
> 
> Although we could create more generic machines, my direct interest is
> in (live) media encoding and some packages will use SSE3 and SSSE3.

When using optimised output like that you really do need to use a
different TARGET_ARCH since as you say, the packages will not run on
standard i686/x86_64...

Cheers,

Richard

Re: Add Intel Core 2 machine support (prescott and nocona)

[Leon Woestenberg]

Hello Richard,

thanks for your feedback!

On 8/21/07, Richard Purdie <rpurdie@rpsys.net> wrote:
> On Mon, 2007-08-20 at 23:52 +0200, Leon Woestenberg wrote:
> > My current proposal is:
> >
> > ...
> > conf/machine/x86_64-nocona.conf
> > conf/machine/include/x86_64-nocona.conf
> > -arch=nocona
> > TARGET_ARCH=x86_64
> >
> > starting with GCC 4.3:
> > conf/machine/x86_64-core2.conf
> > conf/machine/include/x86_64-core2.conf
> > -arch=core2
> > TARGET_ARCH=x86_64
>
> Please don't use '_' in the names. It may work but it has the potential
> to mess up bitbake's override handling and would be better avoided. I
> know people have had issues with "x86_64" already due to this.
>

What are the constraints TARGET_ARCH should meet?

Does it have anything to do with the GNU machine tuple?

Doesn't TARGET_ARCH propogated into several package's configure/Makefile's etc?

For example:

linux-libc-headers:

do_configure () {
    case ${TARGET_ARCH} in
        alpha*)   ARCH=alpha ;;
        arm*)     ARCH=arm ;;
        cris*)    ARCH=cris ;;
        hppa*)    ARCH=parisc ;;
        i*86*)    ARCH=i386 ;;
        ia64*)    ARCH=ia64 ;;
        mips*)    ARCH=mips ;;
        m68k*)    ARCH=m68k ;;
        powerpc*) ARCH=ppc ;;
        s390*)    ARCH=s390 ;;
        sh*)      ARCH=sh ;;
        sparc64*) ARCH=sparc64 ;;
        sparc*)   ARCH=sparc ;;
        x86_64*)  ARCH=x86_64 ;;
    esac
    if test !  -e include/asm-$ARCH; then
        oefatal unable to create asm symlink in kernel headers
    fi



> When using optimised output like that you really do need to use a
> different TARGET_ARCH since as you say, the packages will not run on
> standard i686/x86_64...
>
That's why I suggested "x86_64-nocona".

I could only think of using "amd64" instead of "x86_64" but most
distributions are favouring the last one over the first one recently.


Regards,

Leon.

Re: Add Intel Core 2 machine support (prescott and nocona)

[Leon Woestenberg]

Hello Richard,

On 8/22/07, Leon Woestenberg <leon.woestenberg@gmail.com> wrote:
> > When using optimised output like that you really do need to use a
> > different TARGET_ARCH since as you say, the packages will not run on
> > standard i686/x86_64...
> >
> That's why I suggested "x86_64-nocona".
>
Whoops, I didn't actually suggest x86_64-nocona as TARGET_ARCH.

BTW, I don't understand how the *value* of a variable may not contain
underscores.

Do I misunderstand when I think bitbake overrides apply to variable names only?

Regards,

Leon