glibc: Compile using thumb2 for arch > armv5 if user chooses

For arm we enforce ARM mode regardless of ARM_INSTRUCTION_SET
choice from config metadata, glibc works fine with thumb2 for
armv7+ so limit the restriction to armv5 and lower, tested on
rpi3 works equally well as arm mode glibc and sheds about 0.5MB
in size for main package alone. Other glibc build packages also
gets smaller

ARM:    2696   KiB     libc6
Thumb2: 2132   KiB     libc6

(From OE-Core rev: a22b97aff811566399765d755daffddb28f82857)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/meta/recipes-core/glibc/glibc-collateral.inc b/meta/recipes-core/glibc/glibc-collateral.inc
index de859d5ce9..aa871ac83d 100644
--- a/meta/recipes-core/glibc/glibc-collateral.inc
+++ b/meta/recipes-core/glibc/glibc-collateral.inc
@@ -7,7 +7,8 @@ HOMEPAGE = "http://www.gnu.org/software/libc/index.html"
 # This needs to match with glibc.inc, otherwise glibc-scripts and glibc-locale
 # will fail to find main glibc, for details see
 # http://lists.openembedded.org/pipermail/openembedded-core/2015-January/100679.html
-ARM_INSTRUCTION_SET = "arm"
+ARM_INSTRUCTION_SET_armv4 = "arm"
+ARM_INSTRUCTION_SET_armv5 = "arm"
 
 deltask do_fetch
 deltask do_unpack