Re: [PATCH] arch-arm64.inc: Do not append aarch64 in MACHINEOVERRIDES

[Peter Kjellerstedt <peter.kjellerstedt@axis.com>]

> -----Original Message-----
> From: Junling Zheng <zhengjunling@huawei.com>
> Sent: den 3 mars 2020 15:14
> To: Peter Kjellerstedt <peter.kjellerstedt@axis.com>; Khem Raj
> <raj.khem@gmail.com>; openembedded-core@lists.openembedded.org
> Cc: wangnan0@huawei.com
> Subject: Re: [OE-core] [PATCH] arch-arm64.inc: Do not append aarch64 in
> MACHINEOVERRIDES
> 
> On 2020/3/3 19:59, Peter Kjellerstedt wrote:
> >> -----Original Message-----
> >> From: openembedded-core-bounces@lists.openembedded.org <openembedded-
> core-
> >> bounces@lists.openembedded.org> On Behalf Of Junling Zheng
> >> Sent: den 3 mars 2020 04:11
> >> To: Khem Raj <raj.khem@gmail.com>; openembedded-
> >> core@lists.openembedded.org
> >> Cc: wangnan0@huawei.com
> >> Subject: Re: [OE-core] [PATCH] arch-arm64.inc: Do not append aarch64 in
> >> MACHINEOVERRIDES
> >>
> >> On 2020/3/3 2:29, Khem Raj wrote:
> >>>
> >>>
> >>> On 3/2/20 9:11 AM, Junling Zheng wrote:
> >>>> Currently, for arch-arm64, poky will append the MACHINEOVERRIDES with
> >>>> "aarch64:", which has the higher priority than
> TRANSLATED_TARGET_ARCH.
> >>>> So, for aarch64 big endian, the variable '<foo>_aarch64' will
> override
> >>>> not only '<foo>', but also '<foo>_aarch64-be', thus we will get an
> >>>> incorrect variable.
> >>>>
> >>>> Signed-off-by: Junling Zheng <zhengjunling@huawei.com>
> >>>> ---
> >>>>   meta/conf/machine/include/arm/arch-arm64.inc | 2 --
> >>>>   1 file changed, 2 deletions(-)
> >>>>
> >>>> diff --git a/meta/conf/machine/include/arm/arch-arm64.inc
> >> b/meta/conf/machine/include/arm/arch-arm64.inc
> >>>> index 53f4566815..32294bd218 100644
> >>>> --- a/meta/conf/machine/include/arm/arch-arm64.inc
> >>>> +++ b/meta/conf/machine/include/arm/arch-arm64.inc
> >>>> @@ -4,8 +4,6 @@ require conf/machine/include/arm/arch-armv7ve.inc
> >>>>     TUNEVALID[aarch64] = "Enable instructions for aarch64"
> >>>>   -MACHINEOVERRIDES =. "${@bb.utils.contains('TUNE_FEATURES',
> 'aarch64', 'aarch64:', '' ,d)}"
> >>>> -
> >>>
> >>> if its removed here, where is it being added for other machines,
> >> question is, should we treat aarch64 as LE equivalent of aarch64_be
> >>> or should be treated as common aarch64 and a new define like
> aarch64_le
> >> defined.
> >>>
> >>
> >> Currently, for arm64, we have aarch64_be to represent big endian, but
> no
> >> overrides to represent little endian only.
> >>
> >> So, IMO, we should treat aarch64 as little enaian only, like arm and
> >> armeb.
> >>
> >>>>   # Little Endian base configs
> >>>>   AVAILTUNES += "aarch64 aarch64_be"
> >>>>   ARMPKGARCH_tune-aarch64 ?= "aarch64"
> >
> > Please, before removing "aarch64" from MACHINEOVERRIDES, add "armv8a" or
> > similar. This is how it is done for the armv7* based chips. E.g., I
> would
> > expect to see tune-cortexa53.inc have:
> >
> > MACHINEOVERRIDES =. "${@bb.utils.contains('TUNE_FEATURES', 'cortexa53', 'armv8a:', '' ,d)}"
> >
> 
> arch-armv8a.inc has set "armv8a:" as overrides, and tune-cortexa53.inc
> requires arch-armv8a.inc.

But it never adds "armv8a" (or ${TUNE_FEATURES_tune-armv8a}) to 
TUNE_FEATURES, it adds "aarch64", so the above is never triggered...

> > Which corresponds to how it is done for armv7*.
> >
> > At least we currently rely on being able to do, e.g.:
> >
> > COMPATIBLE_MACHINE = "aarch64|armv7a|armv7ve"
> >
> > and if you remove "aarch64" from MACHINEOVERRIDES, we need a suitable
> > substitute.
> >
> > //Peter

//Peter