[OE-core] GCC 9 Drops Support For Older ARM Microarchitecture Versions

[akuster808]

On 05/19/2018 05:57 PM, Denys Dmytriyenko wrote:
> On Sat, May 19, 2018 at 02:26:13PM -0700, Khem Raj wrote:
>> On Sat, May 19, 2018 at 12:33 PM, Denys Dmytriyenko <denis at denix.org> wrote:
>>> On Sat, May 19, 2018 at 11:07:55AM -0700, Khem Raj wrote:
>>>> On Sat, May 19, 2018 at 9:21 AM, Denys Dmytriyenko <denis at denix.org> wrote:
>>>>> https://www.phoronix.com/scan.php?page=news_item&px=GCC-9-Dropping-Older-ARM
>>>>>
>>>>> Particularly, ARMv5 and ARMv5E are being dropped (but T and TE variants
>>>>> remain)
>>>>>
>>>>> Are there any concerns from OE community perspective?
>>>> From yocto project perspctive qemuarm which is emulating arm926ejs
>>>> with default tune armv5te is used.
>>>> so we are right at the trailing edge and wont be affected. However, I
>>>> know there were OE users who had
>>>> devices using other armv5 or v4 variants
>>>>
>>>> I have been suggesting to switch qemuarm to use armv7 based board
>>>> emulator for few years now.
>>>> may be this is the time to make that call for next YP release.
>>> Valid point about qemuarm, but see below.
>>>
>>>
>>>>> At least for binutils we needed this patch even for armv5te:
>>>>> http://cgit.openembedded.org/openembedded-core/tree/meta/recipes-devtools/binutils/binutils/0007-Add-the-armv5e-architecture-to-binutils.patch
>>>>>
>>>> this patch technically required to support one of OEs available tune
>>>> values. namely armv5e, we should be able to drop it.
>>> $ grep conf/machine meta/conf/machine/qemuarm.conf
>>> require conf/machine/include/qemu.inc
>>> require conf/machine/include/tune-arm926ejs.inc
>>> #require conf/machine/include/tune-arm1136jf-s.inc
>>>
>>> $ MACHINE=qemuarm bitbake virtual/kernel -e|grep -E '^DEFAULTTUNE=|^ARMPKGSFX_THUMB=|^TUNE_PKGARCH=|^TUNE_CCARGS='
>>> ARMPKGSFX_THUMB=""
>>> DEFAULTTUNE="armv5te"
>>> TUNE_CCARGS=" -march=armv5e -marm"
>>> TUNE_PKGARCH="armv5e"
>>>
>>>
>>> I have already tried binutils w/o that patch for arm926ejs/armv5te machine and
>>> it fails, because as you can see above, -march=armv5e is being passed...
>> What happens if you drop setting TUNE_CCARGS and  TUNE_PKGARCH ?
> From OE-Core?
>
> http://cgit.openembedded.org/openembedded-core/tree/meta/conf/machine/include/arm/arch-armv5.inc#n5
> http://cgit.openembedded.org/openembedded-core/tree/meta/conf/machine/include/arm/arch-arm.inc#n11
>
> From the README:
> A small set of ARM specific variables have been defined to allow 
> TUNE_PKGARCH to be automatically defined.  Optimized tunings must NOT 
> change the definiton of TUNE_PKGARCH.  TUNE_PKGACH_tune-<tune> will be 
> ignored.  The format of the package arch is enforced by the TUNE_PKGARCH
> default.  The format must be of the form:
> <armversion>[t][e][hf][b][-vfp][-neon]

Maybe a bug is in order and then we might be able to add it to the 2.6
planning?

Maybe a QEMU strategy for OE going forward may also be a topic.

- armin