AndroidKernel.mk: Parameterize ARCH and CROSS_COMPILE compile flags

Allow overriding of the ARCH and CROSS_COMPILE parameters passed
to kernel make, with fallback to previous hardcoded values if
the overrides are not defined.

Change-Id: I33b571e22363fdc06eb9b867e13d4487a7b5bf55
Signed-off-by: David Ng <dave@codeaurora.org>

AndroidKernel.mk

@@ -1,14 +1,28 @@
 #Android makefile to build kernel as a part of Android Build
 PERL		= perl
 
+TARGET_KERNEL_ARCH := $(strip $(TARGET_KERNEL_ARCH))
+ifeq ($(TARGET_KERNEL_ARCH),)
+KERNEL_ARCH := arm
+else
+KERNEL_ARCH := $(TARGET_KERNEL_ARCH)
+endif
+
+TARGET_KERNEL_CROSS_COMPILE_PREFIX := $(strip $(TARGET_KERNEL_CROSS_COMPILE_PREFIX))
+ifeq ($(TARGET_KERNEL_CROSS_COMPILE_PREFIX),)
+KERNEL_CROSS_COMPILE := arm-eabi-
+else
+KERNEL_CROSS_COMPILE := $(TARGET_KERNEL_CROSS_COMPILE_PREFIX)
+endif
+
 ifeq ($(TARGET_PREBUILT_KERNEL),)
 
 KERNEL_OUT := $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ
 KERNEL_CONFIG := $(KERNEL_OUT)/.config
 ifeq ($(TARGET_KERNEL_APPEND_DTB), true)
-TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/arm/boot/zImage-dtb
+TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/zImage-dtb
 else
-TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/arm/boot/zImage
+TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/zImage
 endif
 KERNEL_HEADERS_INSTALL := $(KERNEL_OUT)/usr
 KERNEL_MODULES_INSTALL := system
@@ -41,30 +55,30 @@ $(KERNEL_OUT):
 	mkdir -p $(KERNEL_OUT)
 
 $(KERNEL_CONFIG): $(KERNEL_OUT)
-	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=arm CROSS_COMPILE=arm-eabi- $(KERNEL_DEFCONFIG)
+	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(KERNEL_DEFCONFIG)
 
 $(KERNEL_OUT)/piggy : $(TARGET_PREBUILT_INT_KERNEL)
-	$(hide) gunzip -c $(KERNEL_OUT)/arch/arm/boot/compressed/piggy.gzip > $(KERNEL_OUT)/piggy
+	$(hide) gunzip -c $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/compressed/piggy.gzip > $(KERNEL_OUT)/piggy
 
 $(TARGET_PREBUILT_INT_KERNEL): $(KERNEL_OUT) $(KERNEL_CONFIG) $(KERNEL_HEADERS_INSTALL)
-	$(hide) rm -rf $(KERNEL_OUT)/arch/arm/boot/dts
-	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=arm CROSS_COMPILE=arm-eabi-
-	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=arm CROSS_COMPILE=arm-eabi- modules
-	$(MAKE) -C kernel O=../$(KERNEL_OUT) INSTALL_MOD_PATH=../../$(KERNEL_MODULES_INSTALL) INSTALL_MOD_STRIP=1 ARCH=arm CROSS_COMPILE=arm-eabi- modules_install
+	$(hide) rm -rf $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/dts
+	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE)
+	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) modules
+	$(MAKE) -C kernel O=../$(KERNEL_OUT) INSTALL_MOD_PATH=../../$(KERNEL_MODULES_INSTALL) INSTALL_MOD_STRIP=1 ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) modules_install
 	$(mv-modules)
 	$(clean-module-folder)
 
 $(KERNEL_HEADERS_INSTALL): $(KERNEL_OUT) $(KERNEL_CONFIG)
-	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=arm CROSS_COMPILE=arm-eabi- headers_install
+	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) headers_install
 
 kerneltags: $(KERNEL_OUT) $(KERNEL_CONFIG)
-	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=arm CROSS_COMPILE=arm-eabi- tags
+	$(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) tags
 
 kernelconfig: $(KERNEL_OUT) $(KERNEL_CONFIG)
 	env KCONFIG_NOTIMESTAMP=true \
-	     $(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=arm CROSS_COMPILE=arm-eabi- menuconfig
+	     $(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) menuconfig
 	env KCONFIG_NOTIMESTAMP=true \
-	     $(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=arm CROSS_COMPILE=arm-eabi- savedefconfig
-	cp $(KERNEL_OUT)/defconfig kernel/arch/arm/configs/$(KERNEL_DEFCONFIG)
+	     $(MAKE) -C kernel O=../$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) savedefconfig
+	cp $(KERNEL_OUT)/defconfig kernel/arch/$(KERNEL_ARCH)/configs/$(KERNEL_DEFCONFIG)
 
 endif