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author | Khem Raj <raj.khem@gmail.com> | 2025-07-22 18:29:36 -0700 |
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committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2025-07-23 22:46:57 +0100 |
commit | 2a9a844ee316ca0ace23e63ca8a7964911c08c0c (patch) | |
tree | 2cfa2adad7c5eeb12a2a31bd7b2826db19a550d8 /meta-yocto-bsp/README.hardware.md | |
parent | 2576664b5a2852d83cd4856ba20377aac8e24dfc (diff) | |
download | poky-master-next.tar.gz |
feature-arm-crypto: Add +nocrypto to -mcpu when crypto not in featuresmaster-next
When crypto is not in tune features then add +nocryto to
-mcpu explicitly. This makes the behavior between clang
and gcc match. Currently -mcpu=cortex-a72 has different
behavior in clang and gcc in terms of what features are
considered default. Clang enables different set of common
features than gcc on other hand. For example clang
enables crypto with default set but gcc
does not, gcc recommends to disable unavailable extentions
in -mcpu [1] explicitly. crypto is optional on cortext-a53
and cortex-a72 while, this is not as common but Broadcom
SOCs in raspberrypi3/4 have dropped crypto for cost
reasons [2]. This results in illegal instruction
traps [3] [4] when building components e.g. chromium,
qtwebengine, weston etc. with clang using -mcpu=cortex-a72
for rpi4 target.
Adding +nocrypto makes it behave like gcc does today. We
do have separate tune if crypto enabled cortex-a72 cores
are to be targeted (cortexa72-cryto) as DEFAULTTUNE
They are added to default feature file since crypto extension
is available in multiple arm architecture versions e.g. armv8,
armv9. It is optional extention as per spec [5]
[1] https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html#index-mcpu-2
[2] https://forums.raspberrypi.com/viewtopic.php?f=63&t=207888#p1332960
[3] https://github.com/llvm/llvm-project/issues/85699
[4] https://github.com/llvm/llvm-project/issues/90365
[5] https://developer.arm.com/documentation/109697/2025_06/Feature-descriptions/The-Armv9-0-architecture-extension
(From OE-Core rev: 0d9a8026656579e0e6956963f96964aa623a1313)
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Quentin Schulz <quentin.schulz@cherry.de>
Acked-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'meta-yocto-bsp/README.hardware.md')
0 files changed, 0 insertions, 0 deletions