GCC 9 Drops Support For Older ARM Microarchitecture Versions

GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Denys Dmytriyenko]

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?

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

Any other way this change will affect us? Thanks.

-- 
Denys

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Khem Raj]

On Sat, May 19, 2018 at 9:21 AM, Denys Dmytriyenko <denis@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.

>
> 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.


> Any other way this change will affect us? Thanks.
>
> --
> Denys
> --
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-core

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Denys Dmytriyenko]

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@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...

-- 
Denys

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Khem Raj]

On Sat, May 19, 2018 at 12:33 PM, Denys Dmytriyenko <denis@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@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 ?

> --
> Denys

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Denys Dmytriyenko]

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@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@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]

Re: 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@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@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

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Randy MacLeod]

On 05/20/2018 10:59 AM, akuster808 wrote:
> Maybe a bug is in order and then we might be able to add it to the 2.6
> planning?

Not my bug to file... anyone?
> 
> Maybe a QEMU strategy for OE going forward may also be a topic.

There is meta-qemuarma9:
   https://github.com/OverC/meta-qemuarma9.git
I'm not an arm man but would it make sense for oe-core to
drop qemuarm and use qemuarma9?

-- 
# Randy MacLeod
# Wind River Linux

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Andre McCurdy]

On Wed, May 23, 2018 at 12:48 PM, Randy MacLeod
<randy.macleod@windriver.com> wrote:
> On 05/20/2018 10:59 AM, akuster808 wrote:
>>
>> Maybe a bug is in order and then we might be able to add it to the 2.6
>> planning?
>
> There is meta-qemuarma9:
>   https://github.com/OverC/meta-qemuarma9.git
> I'm not an arm man but would it make sense for oe-core to
> drop qemuarm and use qemuarma9?

Presumably that name was chosen just to avoid a clash with the qemuarm
machine name used in oe-core?

If/when we update the CPU used in the oe-core qemu ARM machine, I vote
we continue to just call it "qemuarm".

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Randy MacLeod]

Add Bruce.

On 05/23/2018 05:01 PM, Andre McCurdy wrote:
> Presumably that name was chosen just to avoid a clash with the qemuarm
> machine name used in oe-core?

That seems likely.

Here's an early commit lo from the repo made by Bruce that
shows the output of /proc/cpuinfo:

commit 3f23b7954861bc55f8c10ebbe9934fbd052d2a6d
Author: Bruce Ashfield <bruce.ashfield@windriver.com>
Date:   Thu May 17 14:24:28 2012 -0400

     wr-bsps: add qemuarma9

     This is the out-of-tree port of the CoreTile Express A9x4 platform,
     running under qemu.

     root@qemuarma9:~# cat /proc/cpuinfo
     Processor       : ARMv7 Processor rev 0 (v7l)
     processor       : 0
     BogoMIPS        : 498.89

     Features        : swp half thumb fastmult vfp edsp neon vfpv3 tls
     CPU implementer : 0x41
     CPU architecture: 7
     CPU variant     : 0x0
     CPU part        : 0xc09
     CPU revision    : 0

     Hardware        : ARM-Versatile Express
     Revision        : 0000
     Serial          : 0000000000000000

     Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>


Again, I'm not an arm man so maybe this is old hat to toolchain and
BSP people. I'm just trying to suggest a tested short-cut.

> 
> If/when we update the CPU used in the oe-core qemu ARM machine, I vote
> we continue to just call it "qemuarm".

That would surprise me as a user of qemuarm so my vote is to change the
name unless there's precedent to support your vote.

-- 
# Randy MacLeod
# Wind River Linux

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Andre McCurdy]

On Wed, May 23, 2018 at 2:40 PM, Randy MacLeod
<randy.macleod@windriver.com> wrote:
> On 05/23/2018 05:01 PM, Andre McCurdy wrote:
>>
>> If/when we update the CPU used in the oe-core qemu ARM machine, I vote
>> we continue to just call it "qemuarm".
>
> That would surprise me as a user of qemuarm so my vote is to change the
> name unless there's precedent to support your vote.

I think we've updated the CPU used by qemux86 a few times (and with
kvm doesn't it even change depending on the host?).

Re: GCC 9 Drops Support For Older ARM Microarchitecture Versions

[Bruce Ashfield]

On 05/23/2018 05:59 PM, Andre McCurdy wrote:
> On Wed, May 23, 2018 at 2:40 PM, Randy MacLeod
> <randy.macleod@windriver.com> wrote:
>> On 05/23/2018 05:01 PM, Andre McCurdy wrote:
>>>
>>> If/when we update the CPU used in the oe-core qemu ARM machine, I vote
>>> we continue to just call it "qemuarm".
>>
>> That would surprise me as a user of qemuarm so my vote is to change the
>> name unless there's precedent to support your vote.
> 
> I think we've updated the CPU used by qemux86 a few times (and with
> kvm doesn't it even change depending on the host?).

Correct. There's no requirement to update the board emulation just
to tweak the cpu ISA.

The qemuarma9 board has some gaps with respect to the old versatile926ejs.
So unless the cpu update doesn't work, I'm all for leaving the
board the same but just changing the cpu.

Bruce

>