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

[Peter Kjellerstedt]

> -----Original Message-----
> From: openembedded-core-bounces at lists.openembedded.org <openembedded-core-
> bounces at lists.openembedded.org> On Behalf Of Junling Zheng
> Sent: den 3 mars 2020 04:11
> To: Khem Raj <raj.khem at gmail.com>; openembedded-
> core at lists.openembedded.org
> Cc: wangnan0 at 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 at 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)}"

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