diff --git a/scripts/gen_target.sh b/scripts/gen_target.sh
index 93c154857..dd9924cbe 100755
--- a/scripts/gen_target.sh
+++ b/scripts/gen_target.sh
@@ -5,7 +5,7 @@ GEN_DIR=$2
 YAML_PARSER="dasel -n -p yaml --plain -f"
 TARGET_NAME=$(basename "$YAML_FILE" .yml)
 OUT_HEADER="$GEN_DIR"/Target.h
-OUT_MAKEFILE="$GEN_DIR"/Defines.mk
+OUT_MAKEFILE="$GEN_DIR"/Makefile
 
 #generated header contains cpp code
 #generate USB names in dedicated header since this one is included in .c files
diff --git a/src/Defines.mk b/src/Defines.mk
index 4eaf99757..e8962df0b 100644
--- a/src/Defines.mk
+++ b/src/Defines.mk
@@ -1,3 +1,7 @@
+SW_VERSION_MAJOR            := $(shell git describe --tags --abbrev=0 | cut -c 2- | cut -d. -f1)
+SW_VERSION_MINOR            := $(shell git describe --tags --abbrev=0 | cut -c 2- | cut -d. -f2)
+SW_VERSION_REVISION         := $(shell git describe --tags --abbrev=0 | cut -c 2- | cut -d. -f3)
+
 GEN_DIR_BASE                := board/gen
 GEN_DIR_TARGET_BASE         := $(GEN_DIR_BASE)/target
 GEN_DIR_MCU_BASE            := $(GEN_DIR_BASE)/mcu
@@ -5,6 +9,16 @@ GEN_DIR_VENDOR_BASE         := $(GEN_DIR_BASE)/vendor
 GEN_DIR_ARCH_BASE           := $(GEN_DIR_BASE)/arch
 GEN_DIR_TARGET              := $(GEN_DIR_TARGET_BASE)/$(TARGET)
 GEN_DIR_TSCREEN_BASE        := application/io/touchscreen/gen
+
+-include $(MAKEFILE_INCLUDE_PREFIX)$(GEN_DIR_TARGET)/Makefile
+
+#these makefiles are specific only to firmware, which is why they don't have MAKEFILE_INCLUDE_PREFIX
+#the prefix is used to specify the directory of main, target makefile
+#needed for tests since they are outside of src/
+-include board/arch/$(ARCH)/$(VENDOR)/Makefile
+-include board/arch/$(ARCH)/$(VENDOR)/variants/$(MCU_FAMILY)/$(MCU)/Makefile
+-include board/arch/$(ARCH)/Makefile
+
 COMMAND_FW_UPDATE_START     := 0x4F70456E6E45704F
 COMMAND_FW_UPDATE_END       := 0x4465436B
 SYSEX_MANUFACTURER_ID_0     := 0x00
@@ -14,13 +28,14 @@ FW_METADATA_SIZE            := 4
 UART_BAUDRATE_MIDI_STD      := 31250
 UART_BAUDRATE_USB           := 38400
 UART_BAUDRATE_TOUCHSCREEN   := 38400
-USB_OVER_SERIAL_BUFFER_SIZE := 16
-I2C_TX_BUFFER_SIZE          := 64
 ESTA_ID                     := 0x6555
 
-SW_VERSION_MAJOR    := $(shell git describe --tags --abbrev=0 | cut -c 2- | cut -d. -f1)
-SW_VERSION_MINOR    := $(shell git describe --tags --abbrev=0 | cut -c 2- | cut -d. -f2)
-SW_VERSION_REVISION := $(shell git describe --tags --abbrev=0 | cut -c 2- | cut -d. -f3)
+#these can be overriden by target/vendor/arch/mcu etc.
+USB_OVER_SERIAL_BUFFER_SIZE ?= 16
+I2C_TX_BUFFER_SIZE          ?= 64
+UART_TX_BUFFER_SIZE         ?= 128
+UART_RX_BUFFER_SIZE         ?= 128
+MIDI_SYSEX_ARRAY_SIZE       ?= 100
 
 DEFINES += \
 UART_BAUDRATE_MIDI_STD=$(UART_BAUDRATE_MIDI_STD) \
@@ -29,6 +44,7 @@ UART_BAUDRATE_TOUCHSCREEN=$(UART_BAUDRATE_TOUCHSCREEN) \
 USB_OVER_SERIAL_BUFFER_SIZE=$(USB_OVER_SERIAL_BUFFER_SIZE) \
 TSCREEN_CDC_PASSTHROUGH_BUFFER_SIZE=$(USB_OVER_SERIAL_BUFFER_SIZE) \
 I2C_TX_BUFFER_SIZE=$(I2C_TX_BUFFER_SIZE) \
+MIDI_SYSEX_ARRAY_SIZE=$(MIDI_SYSEX_ARRAY_SIZE) \
 FIXED_NUM_CONFIGURATIONS=1 \
 SYSEX_MANUFACTURER_ID_0=$(SYSEX_MANUFACTURER_ID_0) \
 SYSEX_MANUFACTURER_ID_1=$(SYSEX_MANUFACTURER_ID_1) \
@@ -44,30 +60,8 @@ ifeq ($(DEBUG), 1)
     DEFINES += DEBUG
 endif
 
--include $(MAKEFILE_INCLUDE_PREFIX)$(GEN_DIR_TARGET)/Defines.mk
-
-ifneq (,$(findstring USB_LINK_MCU,$(DEFINES)))
-    ifeq ($(MCU), atmega16u2)
-        ifeq ($(TYPE),boot)
-            #save flash - this feature doesn't fit into 4k
-            DEFINES := $(filter-out LED_INDICATORS_CTL,$(DEFINES))
-            DEFINES += UART_TX_BUFFER_SIZE=32
-            DEFINES += UART_RX_BUFFER_SIZE=32
-        else ifeq ($(TYPE),app)
-            DEFINES += UART_TX_BUFFER_SIZE=64
-            DEFINES += UART_RX_BUFFER_SIZE=64
-        endif
-    endif
-else
-    DEFINES += UART_TX_BUFFER_SIZE=128
-    DEFINES += UART_RX_BUFFER_SIZE=128
-    DEFINES += MIDI_SYSEX_ARRAY_SIZE=100
-endif
-
-ifeq ($(CPU),cortex-m4)
-    DEFINES += \
-    CORE_ARM_M4
-endif
+DEFINES += UART_TX_BUFFER_SIZE=$(UART_TX_BUFFER_SIZE)
+DEFINES += UART_RX_BUFFER_SIZE=$(UART_RX_BUFFER_SIZE)
 
 ifeq ($(TYPE),boot)
     DEFINES += FW_BOOT
diff --git a/src/Sources.mk b/src/Sources.mk
index 75ea956fa..35d1012c5 100644
--- a/src/Sources.mk
+++ b/src/Sources.mk
@@ -2,34 +2,17 @@ vpath modules/%.cpp ../
 vpath modules/%.c ../
 
 #common include dirs
-INCLUDE_DIRS := \
+INCLUDE_DIRS += \
 -I"../modules/" \
 -I"$(GEN_DIR_MCU_BASE)/$(MCU)" \
 -I"$(GEN_DIR_TARGET)/" \
 -I"application/" \
+-I"bootloader/" \
 -I"board/arch/$(ARCH)/$(VENDOR)/variants/$(MCU_FAMILY)" \
 -I"board/arch/$(ARCH)/$(VENDOR)" \
 -I"board/common" \
 -I"./"
 
-ifeq (,$(findstring gen,$(TYPE)))
-    ifeq ($(VENDOR), atmel)
-        INCLUDE_DIRS += \
-        -I"../modules/lufa/" \
-        -I"../modules/avr-libstdcpp/include"
-    else ifeq ($(VENDOR),st)
-        INCLUDE_DIRS += \
-        $(addprefix -I,$(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/common -type d -not -path "*Src*")) \
-        $(addprefix -I,$(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/common -type d -not -path "*Src*")) \
-        $(addprefix -I,$(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/$(MCU_BASE)/Drivers -type d -not -path "*Src*"))
-    endif
-
-    ifeq ($(TYPE),boot)
-        INCLUDE_DIRS += \
-        -I"bootloader/"
-    endif
-endif
-
 LINKER_FILE       := $(MCU_DIR)/$(MCU).ld
 TARGET_GEN_HEADER := $(GEN_DIR_TARGET)/Target.h
 
@@ -40,52 +23,6 @@ endif
 ifeq (,$(findstring gen,$(TYPE)))
     SOURCES += $(TSCREEN_GEN_SOURCE)
 
-    #arch specific
-    ifeq ($(ARCH),avr)
-        ifneq (,$(findstring USB_SUPPORTED,$(DEFINES)))
-            #common for bootloader and application
-            SOURCES += \
-            modules/lufa/LUFA/Drivers/USB/Core/AVR8/Device_AVR8.c \
-            modules/lufa/LUFA/Drivers/USB/Core/AVR8/EndpointStream_AVR8.c \
-            modules/lufa/LUFA/Drivers/USB/Core/AVR8/Endpoint_AVR8.c \
-            modules/lufa/LUFA/Drivers/USB/Core/AVR8/PipeStream_AVR8.c \
-            modules/lufa/LUFA/Drivers/USB/Core/AVR8/Pipe_AVR8.c \
-            modules/lufa/LUFA/Drivers/USB/Core/AVR8/USBController_AVR8.c \
-            modules/lufa/LUFA/Drivers/USB/Core/AVR8/USBInterrupt_AVR8.c \
-            modules/lufa/LUFA/Drivers/USB/Core/ConfigDescriptors.c \
-            modules/lufa/LUFA/Drivers/USB/Core/DeviceStandardReq.c \
-            modules/lufa/LUFA/Drivers/USB/Core/Events.c \
-            modules/lufa/LUFA/Drivers/USB/Core/USBTask.c \
-            modules/lufa/LUFA/Drivers/USB/Class/Device/AudioClassDevice.c \
-            modules/lufa/LUFA/Drivers/USB/Class/Device/MIDIClassDevice.c \
-            modules/lufa/LUFA/Drivers/USB/Class/Device/CDCClassDevice.c
-        endif
-    else ifeq ($(ARCH),arm)
-        SOURCES += modules/EmuEEPROM/src/EmuEEPROM.cpp
-
-        #clang-specific defines
-        ifneq (,$(findstring clang,$(CC_ARM)))
-            TOOLCHAIN_DIR := $(shell dirname $(shell which arm-none-eabi-gcc) | rev | cut -c5- | rev)
-            CPP_VER := $(shell $(FIND) $(TOOLCHAIN_DIR)/arm-none-eabi/include/c++ -mindepth 1 -maxdepth 1 | rev | cut -d/ -f 1 | rev)
-
-            INCLUDE_DIRS += \
-            -isystem"$(TOOLCHAIN_DIR)/lib/gcc/arm-none-eabi/$(CPP_VER)/include" \
-            -isystem"$(TOOLCHAIN_DIR)/lib/gcc/arm-none-eabi/$(CPP_VER)/include-fixed" \
-            -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include/c++/$(CPP_VER)" \
-            -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include/c++/$(CPP_VER)/arm-none-eabi" \
-            -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include/c++/$(CPP_VER)/backward" \
-            -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include"
-        endif
-    endif
-
-    #vendor specific
-    ifeq ($(VENDOR),st)
-        SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/common -regex '.*\.\(s\|c\)')
-        SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/common -regex '.*\.\(s\|c\)')
-        SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/$(MCU_BASE) -regex '.*\.\(s\|c\)')
-        SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/variants/$(MCU_FAMILY) -maxdepth 1 -name "*.cpp")
-    endif
-
     SOURCES += $(shell $(FIND) ./board/common -maxdepth 1 -type f -name "*.cpp")
     SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/common/ -type f -name "*.cpp")
     SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/common/ -type f -name "*.cpp")
diff --git a/src/board/arch/arm/Makefile b/src/board/arch/arm/Makefile
new file mode 100644
index 000000000..865eacad5
--- /dev/null
+++ b/src/board/arch/arm/Makefile
@@ -0,0 +1,22 @@
+ifeq (,$(findstring gen,$(TYPE)))
+    SOURCES += modules/EmuEEPROM/src/EmuEEPROM.cpp
+
+    #clang-specific defines
+    ifneq (,$(findstring clang,$(CC_ARM)))
+        TOOLCHAIN_DIR := $(shell dirname $(shell which arm-none-eabi-gcc) | rev | cut -c5- | rev)
+        CPP_VER := $(shell $(FIND) $(TOOLCHAIN_DIR)/arm-none-eabi/include/c++ -mindepth 1 -maxdepth 1 | rev | cut -d/ -f 1 | rev)
+
+        INCLUDE_DIRS += \
+        -isystem"$(TOOLCHAIN_DIR)/lib/gcc/arm-none-eabi/$(CPP_VER)/include" \
+        -isystem"$(TOOLCHAIN_DIR)/lib/gcc/arm-none-eabi/$(CPP_VER)/include-fixed" \
+        -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include/c++/$(CPP_VER)" \
+        -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include/c++/$(CPP_VER)/arm-none-eabi" \
+        -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include/c++/$(CPP_VER)/backward" \
+        -isystem"$(TOOLCHAIN_DIR)/arm-none-eabi/include"
+    endif
+endif
+
+ifeq ($(CPU),cortex-m4)
+    DEFINES += \
+    CORE_ARM_M4
+endif
\ No newline at end of file
diff --git a/src/board/arch/arm/st/Makefile b/src/board/arch/arm/st/Makefile
new file mode 100644
index 000000000..30a9d030f
--- /dev/null
+++ b/src/board/arch/arm/st/Makefile
@@ -0,0 +1,11 @@
+ifeq (,$(findstring gen,$(TYPE)))
+    INCLUDE_DIRS += \
+    $(addprefix -I,$(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/common -type d -not -path "*Src*")) \
+    $(addprefix -I,$(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/common -type d -not -path "*Src*")) \
+    $(addprefix -I,$(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/$(MCU_BASE)/Drivers -type d -not -path "*Src*"))
+
+    SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/common -regex '.*\.\(s\|c\)')
+    SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/common -regex '.*\.\(s\|c\)')
+    SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/gen/$(MCU_FAMILY)/$(MCU_BASE) -regex '.*\.\(s\|c\)')
+    SOURCES += $(shell $(FIND) ./board/arch/$(ARCH)/$(VENDOR)/variants/$(MCU_FAMILY) -maxdepth 1 -name "*.cpp")
+endif
\ No newline at end of file
diff --git a/src/board/arch/avr/Makefile b/src/board/arch/avr/Makefile
new file mode 100644
index 000000000..c63aab04a
--- /dev/null
+++ b/src/board/arch/avr/Makefile
@@ -0,0 +1,24 @@
+ifeq (,$(findstring gen,$(TYPE)))
+    INCLUDE_DIRS += \
+    -I"../modules/lufa/" \
+    -I"../modules/avr-libstdcpp/include"
+
+    ifneq (,$(findstring USB_SUPPORTED,$(DEFINES)))
+        #common for bootloader and application
+        SOURCES += \
+        modules/lufa/LUFA/Drivers/USB/Core/AVR8/Device_AVR8.c \
+        modules/lufa/LUFA/Drivers/USB/Core/AVR8/EndpointStream_AVR8.c \
+        modules/lufa/LUFA/Drivers/USB/Core/AVR8/Endpoint_AVR8.c \
+        modules/lufa/LUFA/Drivers/USB/Core/AVR8/PipeStream_AVR8.c \
+        modules/lufa/LUFA/Drivers/USB/Core/AVR8/Pipe_AVR8.c \
+        modules/lufa/LUFA/Drivers/USB/Core/AVR8/USBController_AVR8.c \
+        modules/lufa/LUFA/Drivers/USB/Core/AVR8/USBInterrupt_AVR8.c \
+        modules/lufa/LUFA/Drivers/USB/Core/ConfigDescriptors.c \
+        modules/lufa/LUFA/Drivers/USB/Core/DeviceStandardReq.c \
+        modules/lufa/LUFA/Drivers/USB/Core/Events.c \
+        modules/lufa/LUFA/Drivers/USB/Core/USBTask.c \
+        modules/lufa/LUFA/Drivers/USB/Class/Device/AudioClassDevice.c \
+        modules/lufa/LUFA/Drivers/USB/Class/Device/MIDIClassDevice.c \
+        modules/lufa/LUFA/Drivers/USB/Class/Device/CDCClassDevice.c
+    endif
+endif
\ No newline at end of file
diff --git a/src/board/arch/avr/atmel/variants/avr8/atmega16u2/Makefile b/src/board/arch/avr/atmel/variants/avr8/atmega16u2/Makefile
new file mode 100644
index 000000000..4cff6c9e1
--- /dev/null
+++ b/src/board/arch/avr/atmel/variants/avr8/atmega16u2/Makefile
@@ -0,0 +1,9 @@
+ifeq ($(TYPE),boot)
+    #save flash - this feature doesn't fit into 4k
+    DEFINES := $(filter-out LED_INDICATORS_CTL,$(DEFINES))
+    UART_TX_BUFFER_SIZE := 32
+    UART_RX_BUFFER_SIZE := 32
+else ifeq ($(TYPE),app)
+    UART_TX_BUFFER_SIZE := 64
+    UART_RX_BUFFER_SIZE := 64
+endif
\ No newline at end of file