[OE-core] [PATCH] feature-arm-thumb.inc: Do not tie generating thumb ISA to -march

[Khem Raj]

On Wed, Jan 2, 2019 at 11:27 PM Martin Jansa <martin.jansa at gmail.com> wrote:
>
> I think this will include it not only in -march parameter but also in TUNE_PKGARCH.
> So the packages built with and without thumb ISA will have the same file name and package feed which is wrong.
>

I did ponder over it before following the approach I took, but I think
you have to point to maintain separate feeds for thumb and arm ISA
generated packages.
I think since we do not support OABI and EABI demands interwork, so
using 't' unconditionally in -march is a workable approach too.

> It should probably be fixed only when adding march to TUNE_CCARGS:
> meta/conf/machine/include/arm/arch-armv4.inc:TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv4', ' -march=armv4${ARMPKGSFX_THUMB}', '', d)}"
> meta/conf/machine/include/arm/arch-armv5.inc:TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv5', ' -march=armv5${ARMPKGSFX_THUMB}${ARMPKGSFX_DSP}', '', d)}"
> meta/conf/machine/include/arm/arch-armv6.inc:TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv6', ' -march=armv6', '', d)}"
> meta/conf/machine/include/arm/arch-armv7a.inc:TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7a', ' -march=armv7-a', '', d)}"
> meta/conf/machine/include/arm/arch-armv7ve.inc:TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7ve', ' -march=armv7ve', '', d)}"
>
>
> On Thu, Jan 3, 2019 at 8:10 AM Khem Raj <raj.khem at gmail.com> wrote:
>>
>> -march=armv5't'e means that CPU can execute thumb ISA, we do not need to
>> tie this to exclusively generating thumb ISA, this change means that
>> when we have thumb in tune features then it can use 't' in -march
>> options irrespective of ISA being thumb or arm.
>>
>> This fixes derivative of armv5 tunes and paves way for gcc9 where e.g.
>> armv5e is dropped and minimum arch supported is armv5te
>>
>> Signed-off-by: Khem Raj <raj.khem at gmail.com>
>> ---
>>  meta/conf/machine/include/arm/feature-arm-thumb.inc | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/meta/conf/machine/include/arm/feature-arm-thumb.inc b/meta/conf/machine/include/arm/feature-arm-thumb.inc
>> index 0b47ccad02..36bda6c67a 100644
>> --- a/meta/conf/machine/include/arm/feature-arm-thumb.inc
>> +++ b/meta/conf/machine/include/arm/feature-arm-thumb.inc
>> @@ -24,7 +24,7 @@ python () {
>>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', ' -m${ARM_M_OPT}', '', d)}"
>>
>>  # Add suffix from ARM_THUMB_SUFFIX only if after all this we still set ARM_M_OPT to thumb
>> -ARMPKGSFX_THUMB .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', '${ARM_THUMB_SUFFIX}', '', d) if d.getVar('ARM_M_OPT') == 'thumb' else ''}"
>> +ARMPKGSFX_THUMB .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', '${ARM_THUMB_SUFFIX}', '', d)}"
>>
>>  # what about armv7m devices which don't support -marm (e.g. Cortex-M3)?
>>  TARGET_CC_KERNEL_ARCH += "${@bb.utils.contains('TUNE_FEATURES', 'thumb', '-mno-thumb-interwork -marm', '', d)}"
>> --
>> 2.20.1
>>
>> --
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