From: Vladimir Murzin <hidden> Date: 2021-12-03 09:30:43
On 12/2/21 10:20 PM, Giulio Benetti wrote:
ARM_SINGLE_ARMV7M implies Arm Cortex M7 too, so let's add it to
description with M0/M3/M4.
Well it also implies M33 and M55. I'd suggest drop specific implementations
from description - so we do not need to update it each time new compatible
core is released. To account newest cores like M33 and M55 you can rephrase
to:
- ARMv7-M/v8-M
- ARMv7-M and above
Cheers
Vladimir
Hi Vladimir,
On 03/12/21 10:30, Vladimir Murzin wrote:
On 12/2/21 10:20 PM, Giulio Benetti wrote:
quoted
ARM_SINGLE_ARMV7M implies Arm Cortex M7 too, so let's add it to
description with M0/M3/M4.
Well it also implies M33 and M55. I'd suggest drop specific implementations
from description - so we do not need to update it each time new compatible
core is released. To account newest cores like M33 and M55 you can rephrase
to:
- ARMv7-M/v8-M
This ^^^ is ok for me. Also, I don't see any M0 used at the moment so no
ARMv6-M makes sense, if any in the future we can update. I see M3,M4,M7
for the moment, so ARMv7-M. But at the moment no ARMv8-M, or am I wrong?
Maybe it would be better to add ARMv8-M when there will really be the
support, considering also that ARM_SINGLE_ARMV7M is a bit ambiguous to
be used with ARMv8-M. So maybe that could be modified too when an
ARMv8-M is added.
What do you think about this?
Best regards
--
Giulio Benetti
Benetti Engineering sas
From: Vladimir Murzin <hidden> Date: 2021-12-03 17:01:09
On 12/3/21 4:41 PM, Giulio Benetti wrote:
Hi Vladimir,
On 03/12/21 10:30, Vladimir Murzin wrote:
quoted
On 12/2/21 10:20 PM, Giulio Benetti wrote:
quoted
ARM_SINGLE_ARMV7M implies Arm Cortex M7 too, so let's add it to
description with M0/M3/M4.
Well it also implies M33 and M55. I'd suggest drop specific implementations
from description - so we do not need to update it each time new compatible
core is released. To account newest cores like M33 and M55 you can rephrase
to:
- ARMv7-M/v8-M
This ^^^ is ok for me. Also, I don't see any M0 used at the moment so no ARMv6-M makes sense, if any in the future we can update. I see M3,M4,M7 for the moment, so ARMv7-M. But at the moment no ARMv8-M, or am I wrong?
We already support PMSAv8 which is ARMv8-M, M33/M55 is in flight [1].
Maybe it would be better to add ARMv8-M when there will really be the support, considering also that ARM_SINGLE_ARMV7M is a bit ambiguous to be used with ARMv8-M. So maybe that could be modified too when an ARMv8-M is added.
What do you think about this?
Well, I prefer to touch this as rare as possible, and if we touch
it then ensure we do not need to touch it for a long time ;)
Look at A-class cores,
config ARCH_MULTI_V7
bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
it doesn't mention ARMv8, yet it is pretty much possible to run it
on some cores either bare-metal or as a guest (just look under
arch/arm/include/asm/cputype.h)
These are just config options, not a legal deeds...
[1] https://lore.kernel.org/linux-arm-kernel/20211201132908.106711-1-vladimir.murzin@arm.com/T/
Cheers
Vladimir
Hi Vladimir,
On 03/12/21 10:30, Vladimir Murzin wrote:
quoted
On 12/2/21 10:20 PM, Giulio Benetti wrote:
quoted
ARM_SINGLE_ARMV7M implies Arm Cortex M7 too, so let's add it to
description with M0/M3/M4.
Well it also implies M33 and M55. I'd suggest drop specific implementations
from description - so we do not need to update it each time new compatible
core is released. To account newest cores like M33 and M55 you can rephrase
to:
- ARMv7-M/v8-M
This ^^^ is ok for me. Also, I don't see any M0 used at the moment so no ARMv6-M makes sense, if any in the future we can update. I see M3,M4,M7 for the moment, so ARMv7-M. But at the moment no ARMv8-M, or am I wrong?
We already support PMSAv8 which is ARMv8-M, M33/M55 is in flight [1].
Ah, I've missed that. And great for M33!
quoted
Maybe it would be better to add ARMv8-M when there will really be the support, considering also that ARM_SINGLE_ARMV7M is a bit ambiguous to be used with ARMv8-M. So maybe that could be modified too when an ARMv8-M is added.
What do you think about this?
Well, I prefer to touch this as rare as possible, and if we touch
it then ensure we do not need to touch it for a long time ;)
Look at A-class cores,
config ARCH_MULTI_V7
bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
it doesn't mention ARMv8, yet it is pretty much possible to run it
on some cores either bare-metal or as a guest (just look under
arch/arm/include/asm/cputype.h)
Ah yeah, thanks for pointing, then I'm going with ARMv7-M/v8-M
These are just config options, not a legal deeds...
+1
Thank you
Best regards
--
Giulio Benetti
Benetti Engineering sas