qemu-cortex-m3: new MACHINE

Various changes to properly handle QEMU for Cortex M3.
This was solved by creating a new MACHINE qemu-cortex-m3.
Specifying MACHINE=qemu-cortex-m3 will select proper tuning
for the cross-compiler.

Typical usage:

    $ MACHINE=qemu-cortex-m3 bitbake zephyr-philosophers

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>

conf/distro/zephyr.conf

@@ -1,6 +1,4 @@
 
-require conf/distro/machine/include/tune-cortexm3.inc
-
 DISTRO = "zephyr"
 DISTRO_NAME = "Zephyr"
 DISTRO_VERSION = "1.0"
@@ -13,7 +11,5 @@ TCLIBCAPPEND = ""
 TEST_TARGET = "QemuTargetZephyr"
 TEST_SUITES = "zephyr"
 
-DEFAULTTUNE_arm ?= "cortexm3"
-
 BOARD_arm ?= "qemu_cortex_m3"
 BOARD_x86 ?= "qemu_x86"

conf/machine/include/tune-cortexm3.inc

@@ -1,6 +1,6 @@
 DEFAULTTUNE ?= "cortexm3"
 
-#require conf/machine/include/arm/arch-armv7a.inc
+require conf/machine/include/arm/arch-armv7a.inc
 
 TUNEVALID[cortexm3] = "Enable Cortex-M3 specific processor optimizations"
 TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'cortexm3', ' -mcpu=cortex-m3', '', d)}"

conf/machine/qemu-cortex-m3.conf

@@ -0,0 +1,11 @@
+#@TYPE: Machine
+#@NAME: lm3s6965evb
+#@DESCRIPTION: lm3s6965evb
+
+require conf/machine/include/qemu.inc
+require conf/machine/include/tune-cortexm3.inc
+
+# For runqemu (TBD)
+QB_SYSTEM_NAME = "qemu-system-arm"
+QB_MACHINE = "-machine lm3s6965evb"
+QB_OPT_APPEND = "-nographic -vga none -cpu=cortex-m3"