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

[Khem Raj]

On 3/3/20 3:59 AM, Peter Kjellerstedt wrote:
>> -----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.

I think armv8a or somesuch might be better in the above usecase, but so 
far I think we have treated aarch64 as common arm64 notation, so 
removing this might have more changes needed in rest of metadata, which 
would be not good.
> 
> //Peter
>