AndroidKernel: Add LLVM support for Kernel

Add necessary changes to be able to compile the Kernel
with LLVM.
Also update for KERNEL_VM_* specific rules.

Change-Id: I147a7abc29ec66828e9626a74125d391f8aaa329
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
Signed-off-by: Shadab Naseem <snaseem@codeaurora.org>
[schikk@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>

1 files changed, 18 insertions, 12 deletions

diff --git a/AndroidKernel.mk b/AndroidKernel.mk
index c7d3c22fa269..fea8e29a1d8e 100644
--- a/AndroidKernel.mk
+++ b/AndroidKernel.mk
@@ -50,9 +50,15 @@ endif
 ifeq ($(TARGET_PREBUILT_KERNEL),)
 
 KERNEL_GCC_NOANDROID_CHK := $(shell (echo "int main() {return 0;}" | $(KERNEL_CROSS_COMPILE)gcc -E -mno-android - > /dev/null 2>&1 ; echo $$?))
+
+real_cc :=
+ifeq ($(KERNEL_LLVM_SUPPORT),true)
+real_cc := REAL_CC=$(KERNEL_LLVM_BIN) CLANG_TRIPLE=aarch64-linux-gnu-
+else
 ifeq ($(strip $(KERNEL_GCC_NOANDROID_CHK)),0)
 KERNEL_CFLAGS := KCFLAGS=-mno-android
 endif
+endif
 
 mkfile_path := $(abspath $(lastword $(MAKEFILE_LIST)))
 current_dir := $(notdir $(patsubst %/,%,$(dir $(mkfile_path))))
@@ -138,43 +144,43 @@ $(KERNEL_OUT):
 	mkdir -p $(KERNEL_OUT)
 
 $(KERNEL_CONFIG): $(KERNEL_OUT)
-	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(KERNEL_DEFCONFIG)
+	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) $(KERNEL_DEFCONFIG)
 	$(hide) if [ ! -z "$(KERNEL_CONFIG_OVERRIDE)" ]; then \
 			echo "Overriding kernel config with '$(KERNEL_CONFIG_OVERRIDE)'"; \
 			echo $(KERNEL_CONFIG_OVERRIDE) >> $(KERNEL_OUT)/.config; \
-			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) oldconfig; fi
+			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) oldconfig; fi
 
 $(TARGET_PREBUILT_INT_KERNEL): $(KERNEL_OUT) $(KERNEL_HEADERS_INSTALL)
 	$(hide) echo "Building kernel..."
 	$(hide) rm -rf $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/dts
-	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(KERNEL_CFLAGS)
-	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(KERNEL_CFLAGS) modules
-	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) INSTALL_MOD_PATH=$(BUILD_ROOT_LOC)../$(KERNEL_MODULES_INSTALL) INSTALL_MOD_STRIP=1 $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) modules_install
+	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) $(KERNEL_CFLAGS)
+	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) $(KERNEL_CFLAGS) modules
+	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) INSTALL_MOD_PATH=$(BUILD_ROOT_LOC)../$(KERNEL_MODULES_INSTALL) INSTALL_MOD_STRIP=1 $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) modules_install
 	$(mv-modules)
 	$(clean-module-folder)
 
 $(KERNEL_HEADERS_INSTALL): $(KERNEL_OUT)
 	$(hide) if [ ! -z "$(KERNEL_HEADER_DEFCONFIG)" ]; then \
 			rm -f $(BUILD_ROOT_LOC)$(KERNEL_CONFIG); \
-			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_HEADER_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(KERNEL_HEADER_DEFCONFIG); \
-			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_HEADER_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) headers_install; fi
+			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_HEADER_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) $(KERNEL_HEADER_DEFCONFIG); \
+			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_HEADER_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) headers_install; fi
 	$(hide) if [ "$(KERNEL_HEADER_DEFCONFIG)" != "$(KERNEL_DEFCONFIG)" ]; then \
 			echo "Used a different defconfig for header generation"; \
 			rm -f $(BUILD_ROOT_LOC)$(KERNEL_CONFIG); \
-			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(KERNEL_DEFCONFIG); fi
+			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) $(KERNEL_DEFCONFIG); fi
 	$(hide) if [ ! -z "$(KERNEL_CONFIG_OVERRIDE)" ]; then \
 			echo "Overriding kernel config with '$(KERNEL_CONFIG_OVERRIDE)'"; \
 			echo $(KERNEL_CONFIG_OVERRIDE) >> $(KERNEL_OUT)/.config; \
-			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) oldconfig; fi
+			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) oldconfig; fi
 
 kerneltags: $(KERNEL_OUT) $(KERNEL_CONFIG)
-	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) tags
+	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) tags
 
 kernelconfig: $(KERNEL_OUT) $(KERNEL_CONFIG)
 	env KCONFIG_NOTIMESTAMP=true \
-	     $(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) menuconfig
+	     $(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) menuconfig
 	env KCONFIG_NOTIMESTAMP=true \
-	     $(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) savedefconfig
+	     $(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) savedefconfig
 	cp $(KERNEL_OUT)/defconfig $(TARGET_KERNEL_SOURCE)/arch/$(KERNEL_ARCH)/configs/$(KERNEL_DEFCONFIG)
 
 endif