[OE-core] [PATCH] arch-armv7a.inc: default to Thumb2 instruction set for armv7a and above

Andre McCurdy armccurdy at gmail.com
Fri May 18 22:50:40 UTC 2018


Although there may still be specific cases which can benefit from the
ARM instruction set, the Thumb2 instruction set is generally a better
default for armv7a class CPUs. Distros such as Debian and Fedora have
been targeting Thumb2 by default for some time.

Note that setting ARM_INSTRUCTION_SET has no effect unless
TUNE_FEATURES contains "thumb" (which is controlled by the "t" suffix
in DEFAULTTUNE, e.g. armv7vehf-neon -vs- armv7vethf-neon, etc) so out
of tree machine configs may need to update their DEFAULTTUNE to take
advantage of this change.

Signed-off-by: Andre McCurdy <armccurdy at gmail.com>
---
 meta/conf/machine/include/arm/arch-armv7a.inc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/meta/conf/machine/include/arm/arch-armv7a.inc b/meta/conf/machine/include/arm/arch-armv7a.inc
index bad1c27..a2663d8 100644
--- a/meta/conf/machine/include/arm/arch-armv7a.inc
+++ b/meta/conf/machine/include/arm/arch-armv7a.inc
@@ -1,4 +1,5 @@
 DEFAULTTUNE ?= "armv7athf"
+ARM_INSTRUCTION_SET ?= "thumb"
 
 TUNEVALID[armv7a] = "Enable instructions for ARMv7-a"
 TUNECONFLICTS[armv7a] = "armv4 armv5 armv6 armv7"
-- 
1.9.1




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