unified/build: allow building the unified kernel

Added needed kconfig options. KERNEL_V2 selects MICROKERNEL to allow
middleware and application that differentiate between NANOKERNEL and
MICROKERNEL to run unmodified.

Build the unified/ kernel directory: do not touch the
nanokernel/microkernel directories.

Invoke sysgen for both microkernel and unified kernel. Only have sysgen
reference include/microkernel if building an original microkernel.

Change-Id: If74779146143434f7ee274bbef32d6c894b9f1a1
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>

kernel/Kconfig

@@ -16,6 +16,11 @@
 # limitations under the License.
 #
 
+config KERNEL_V2
+	bool
+	prompt "Unified Kernel"
+	default n
+
 choice
 prompt "Kernel Type"
 default MICROKERNEL
@@ -203,9 +208,15 @@ endmenu
 
 endmenu
 
+if !KERNEL_V2
 source "kernel/nanokernel/Kconfig"
+endif
 
-if MICROKERNEL
+if KERNEL_V2
+source "kernel/unified/Kconfig"
+endif
+
+if MICROKERNEL && !KERNEL_V2
 source "kernel/microkernel/Kconfig"
 endif
 
@@ -267,7 +278,7 @@ config TICKLESS_IDLE
 	bool
 	prompt "Tickless idle"
 	default y
-	depends on MICROKERNEL || NANOKERNEL_TICKLESS_IDLE_SUPPORTED
+	depends on !KERNEL_V2 && (MICROKERNEL || NANOKERNEL_TICKLESS_IDLE_SUPPORTED)
 	help
 	This option suppresses periodic system clock interrupts whenever the
 	kernel becomes idle. This permits the system to remain in a power

kernel/Makefile

@@ -1,2 +1,6 @@
+ifeq ($(CONFIG_KERNEL_V2),y)
+obj-y = unified/
+else
 obj-y = nanokernel/
 obj-$(CONFIG_MICROKERNEL) += microkernel/
+endif

misc/generated/Makefile

@@ -1,2 +1,2 @@
 obj-y = configs.o
-obj-$(CONFIG_MICROKERNEL) += sysgen/
+obj-$(CONFIG_MDEF) += sysgen/

misc/generated/sysgen/Makefile

@@ -1,4 +1,6 @@
-ccflags-y += -I$(srctree)/include/microkernel
+ifneq ($(CONFIG_KERNEL_V2),y)
+ccflags-$(CONFIG_MICROKERNEL) += -I$(srctree)/include/microkernel
+endif
 ccflags-y += -I$(CURDIR)/misc/generated/sysgen
 
 obj-y = kernel_main.o