Patchwork [04/20] tunearch/arm: Differentiate between thumb code generation and thumb capability

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Submitter Khem Raj
Date Feb. 6, 2012, 6:40 a.m.
Message ID <>
Download mbox | patch
Permalink /patch/20729/
State New
Headers show


Khem Raj - Feb. 6, 2012, 6:40 a.m.
We have diverged a bit from where thumb in OVERRIDES meant
the code was being compiled in thumb mode. With tunearch this got
a different meaning where it meant that if a core is capable of
generating thumb code them we will have this in overrides. With this
patch I am trying to address the problem where 'thumbmode' in TUNE_FEATURES
means that code will be compiled in thumb mode by default and
'thumb' is to denote that core is capable of thumb instruction set.

Signed-off-by: Khem Raj <>
 .../conf/machine/include/arm/ |   18 ++++++++++++++----
 1 files changed, 14 insertions(+), 4 deletions(-)


diff --git a/meta/conf/machine/include/arm/ b/meta/conf/machine/include/arm/
index da29102..68a8e73 100644
--- a/meta/conf/machine/include/arm/
+++ b/meta/conf/machine/include/arm/
@@ -4,10 +4,19 @@ 
 # encoded RISC sub-set. Thumb code is smaller (maybe 70% of the ARM size)
 # 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 = "${@['-marm', '-mthumb'][d.getVar('ARM_INSTRUCTION_SET', 1) == 'thumb']}"
-TUNE_CCARGS += "${@bb.utils.contains("TUNE_FEATURES", "thumb", "${ARM_THUMB_M_OPT}", "", d)}"
-OVERRIDES .= "${@bb.utils.contains("TUNE_FEATURES", "thumb", ":thumb", "", d)}"
+# 'thumbmode' in TUNE_FEATURES means default ISA for code generation is thumb
+# 'thumb' in TUNE_FEATURES means the core supports thumb ISA but code
+# generation can happen in arm or thumb
+# having 'thumbmode' would imply 'thumb' naturally
+TUNEVALID[thumbmode] = "Use THUMB instruction set instead of ARM"
+AVAILTUNES += "${@bb.utils.contains("ARM_INSTRUCTION_SET", "thumb", "thumbmode", "", d)}"
+TUNE_CCARGS += "${@bb.utils.contains("ARM_INSTRUCTION_SET", "thumb", "-mthumb", "-marm", d)}"
+OVERRIDES .= "${@bb.utils.contains("ARM_INSTRUCTION_SET", "thumb", ":thumb", "", d)}"
+TUNEVALID[thumb] = "THUMB instruction set capable ARM core"
 # Note armv7 will hit on armv7a as well
 ARMPKGSFX_THUMB .= "${@bb.utils.contains("TUNE_FEATURES", [ "armv4", "thumb" ], "t", "", d)}"
@@ -20,6 +29,7 @@  ARMPKGSFX_THUMB .= "${@bb.utils.contains("TUNE_FEATURES", [ "armv7", "thumb" ],
 # arm system and vice versa. It is strongly recommended that DISTROs not
 # turn this off - the actual cost is very small.
 TUNEVALID[no-thumb-interwork] = "Disable mixing of thumb and ARM functions"
+AVAILTUNES += "${@bb.utils.contains("TUNE_FEATURES", "no-thumb-interwork", "no-thumb-interwork", "thumb-interwork", d)}"
 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)}"