feature-arm-thumb.inc, arch-armv4.inc: Add "arm" to TUNE_FEATURES

* it will be inherited by most DEFAULTTUNEs, except few exceptions which
  support only thumb and not arm
* respect missing "arm" in TUNE_FEATURES in feature-arm-thumb.inc, so
  when recipe asks for "arm" and MACHINE supports only "thumb" ignore
  recipe and try to build with "thumb"
* show warning when overriding ARM_INSTRUCTION_SET set by recipe from tune
  config

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>

1 files changed, 23 insertions, 6 deletions

diff --git a/meta/conf/machine/include/arm/feature-arm-thumb.inc b/meta/conf/machine/include/arm/feature-arm-thumb.inc
index d58c4b4bda..8a3866568c 100644
--- a/meta/conf/machine/include/arm/feature-arm-thumb.inc
+++ b/meta/conf/machine/include/arm/feature-arm-thumb.inc
@@ -5,14 +5,30 @@
 # but requires more instructions (140% for 70% smaller code) so may be
 # slower.
 TUNEVALID[thumb] = "Use thumb instructions instead of ARM"
-ARM_THUMB_M_OPT = "${@['-marm', '-mthumb'][d.getVar('ARM_INSTRUCTION_SET', True) == 'thumb']}"
-TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', ' ${ARM_THUMB_M_OPT}', '', d)}"
+ARM_THUMB_OPT = "${@['arm', 'thumb'][d.getVar('ARM_INSTRUCTION_SET', True) == 'thumb']}"
+ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv4',  't',  '', d)}"
+ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv5',  't',  '', d)}"
+ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv6',  't',  '', d)}"
+ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7a', 't2', '', d)}"
+ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7r', 't2', '', d)}"
+ARM_THUMB_SUFFIX .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7m', 't2', '', d)}"
+
+# If the device supports ARM, then respect ARM_THUMB_OPT (which can be "arm" or "thumb")
+# If the defice doesn't support ARM, then always set "thumb" even when
+# some recipe explicitly sets ARM_INSTRUCTION_SET to "arm"
+ARM_M_OPT = "${@bb.utils.contains('TUNE_FEATURES', 'arm', '${ARM_THUMB_OPT}', 'thumb', d)}"
+python () {
+    selected = d.getVar('ARM_INSTRUCTION_SET', True)
+    used = d.getVar('ARM_M_OPT', True)
+    if selected != used:
+        pn = d.getVar('PN', True)
+        bb.warn("Recipe '%s' selects ARM_INSTRUCTION_SET to be '%s', but tune configuration overrides it to '%s'" % (pn, selected, used))
+}
+
+TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', ' -m${ARM_M_OPT}', '', d)}"
 OVERRIDES .= "${@bb.utils.contains('TUNE_FEATURES', 'thumb', ':thumb', '', d)}"
 
-ARMPKGSFX_THUMB .= "${@bb.utils.contains('TUNE_FEATURES', [ 'armv4', 'thumb' ], 't', '', d)}"
-ARMPKGSFX_THUMB .= "${@bb.utils.contains('TUNE_FEATURES', [ 'armv5', 'thumb' ], 't', '', d)}"
-ARMPKGSFX_THUMB .= "${@bb.utils.contains('TUNE_FEATURES', [ 'armv6', 'thumb' ], 't', '', d)}"
-ARMPKGSFX_THUMB .= "${@bb.utils.contains('TUNE_FEATURES', [ 'armv7a', 'thumb' ], 't2', '', d)}"
+ARMPKGSFX_THUMB .= "${ARM_THUMB_SUFFIX}"
 
 # Whether to compile with code to allow interworking between the two
 # instruction sets. This allows thumb code to be executed on a primarily
@@ -22,4 +38,5 @@ TUNEVALID[no-thumb-interwork] = "Disable mixing of thumb and ARM functions"
 TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'no-thumb-interwork', ' -mno-thumb-interwork', ' -mthumb-interwork', d)}"
 OVERRIDES .= "${@bb.utils.contains('TUNE_FEATURES', 'no-thumb-interwork', ':thumb-interwork', '', d)}"
 
+# what about armv7m devices which don't support -marm (e.g. Cortex-M3)?
 TARGET_CC_KERNEL_ARCH += "-mno-thumb-interwork -marm"