diff --git a/hw/bsp/broadcom_32bit/boards/raspberrypi_zero_w/board.mk b/hw/bsp/broadcom_32bit/boards/raspberrypi_zero_w/board.mk
index 77811d18d..052033230 100644
--- a/hw/bsp/broadcom_32bit/boards/raspberrypi_zero_w/board.mk
+++ b/hw/bsp/broadcom_32bit/boards/raspberrypi_zero_w/board.mk
@@ -1,5 +1,5 @@
-CFLAGS += -mcpu=arm1176jzf-s \
-          -DBCM_VERSION=2835 \
+CPU_CORE = arm1176
+CFLAGS += -DBCM_VERSION=2835 \
           -DCFG_TUSB_MCU=OPT_MCU_BCM2835
 
 SUFFIX =
diff --git a/hw/bsp/broadcom_64bit/boards/raspberrypi_cm4/board.mk b/hw/bsp/broadcom_64bit/boards/raspberrypi_cm4/board.mk
index 5706b8318..702f10137 100644
--- a/hw/bsp/broadcom_64bit/boards/raspberrypi_cm4/board.mk
+++ b/hw/bsp/broadcom_64bit/boards/raspberrypi_cm4/board.mk
@@ -1,3 +1,3 @@
-CFLAGS += -mcpu=cortex-a72 \
-          -DBCM_VERSION=2711 \
+CPU_CORE = cortex-a72
+CFLAGS += -DBCM_VERSION=2711 \
           -DCFG_TUSB_MCU=OPT_MCU_BCM2711
diff --git a/hw/bsp/broadcom_64bit/boards/raspberrypi_zero2w/board.mk b/hw/bsp/broadcom_64bit/boards/raspberrypi_zero2w/board.mk
index 3060b0571..da3fe17bc 100644
--- a/hw/bsp/broadcom_64bit/boards/raspberrypi_zero2w/board.mk
+++ b/hw/bsp/broadcom_64bit/boards/raspberrypi_zero2w/board.mk
@@ -1,3 +1,3 @@
-CFLAGS += -mcpu=cortex-a53 \
-          -DBCM_VERSION=2837 \
+CPU_CORE = cortex-a53
+CFLAGS += -DBCM_VERSION=2837 \
           -DCFG_TUSB_MCU=OPT_MCU_BCM2837
diff --git a/hw/bsp/kinetis_kl/family.mk b/hw/bsp/kinetis_kl/family.mk
index 2bed6b486..edb2f3366 100644
--- a/hw/bsp/kinetis_kl/family.mk
+++ b/hw/bsp/kinetis_kl/family.mk
@@ -3,11 +3,9 @@ DEPS_SUBMODULES += $(SDK_DIR) lib/CMSIS_5
 
 MCU_DIR = $(SDK_DIR)/devices/$(MCU)
 include $(TOP)/$(BOARD_PATH)/board.mk
+CPU_CORE ?= cortex-m0plus
 
 CFLAGS += \
-  -mthumb \
-  -mabi=aapcs \
-  -mcpu=cortex-m0plus \
   -DCFG_TUSB_MCU=OPT_MCU_KINETIS_KL \
 
 LDFLAGS += \
@@ -34,6 +32,3 @@ INC += \
 	$(TOP)/$(SDK_DIR)/drivers/port \
 	$(TOP)/$(SDK_DIR)/drivers/smc \
 	$(TOP)/$(SDK_DIR)/drivers/uart \
-
-# For freeRTOS port source
-FREERTOS_PORTABLE_SRC = $(FREERTOS_PORTABLE_PATH)/ARM_CM0
diff --git a/tools/make/cpu/arm1176.mk b/tools/make/cpu/arm1176.mk
new file mode 100644
index 000000000..022ccf7ad
--- /dev/null
+++ b/tools/make/cpu/arm1176.mk
@@ -0,0 +1,9 @@
+ifeq ($(TOOLCHAIN),gcc)
+  CFLAGS += \
+    -mcpu=arm1176jzf-s \
+
+else ifeq ($(TOOLCHAIN),iar)
+	#CFLAGS += --cpu cortex-a53
+	#ASFLAGS += --cpu cortex-a53
+
+endif
diff --git a/tools/make/cpu/cortex-a53.mk b/tools/make/cpu/cortex-a53.mk
new file mode 100644
index 000000000..42e522ecf
--- /dev/null
+++ b/tools/make/cpu/cortex-a53.mk
@@ -0,0 +1,12 @@
+ifeq ($(TOOLCHAIN),gcc)
+  CFLAGS += \
+    -mcpu=cortex-a53 \
+
+else ifeq ($(TOOLCHAIN),iar)
+	CFLAGS += \
+		--cpu cortex-a53 \
+
+	ASFLAGS += \
+		--cpu cortex-a53 \
+
+endif
diff --git a/tools/make/cpu/cortex-a72.mk b/tools/make/cpu/cortex-a72.mk
new file mode 100644
index 000000000..1b3d8da4a
--- /dev/null
+++ b/tools/make/cpu/cortex-a72.mk
@@ -0,0 +1,12 @@
+ifeq ($(TOOLCHAIN),gcc)
+  CFLAGS += \
+    -mcpu=cortex-a72 \
+
+else ifeq ($(TOOLCHAIN),iar)
+	CFLAGS += \
+		--cpu cortex-a72 \
+
+	ASFLAGS += \
+		--cpu cortex-a72 \
+
+endif
diff --git a/tools/make/cpu/cortex-m33.mk b/tools/make/cpu/cortex-m33.mk
index 240ed0d49..e53f5c2b1 100644
--- a/tools/make/cpu/cortex-m33.mk
+++ b/tools/make/cpu/cortex-m33.mk
@@ -13,6 +13,7 @@ else ifeq ($(TOOLCHAIN),iar)
 	ASFLAGS += \
 		--cpu cortex-m33 \
 		--fpu VFPv5-SP \
+
 endif
 
 FREERTOS_PORTABLE_SRC = $(FREERTOS_PORTABLE_PATH)/ARM_CM33_NTZ/non_secure