diff --git a/Makefile.boardloader b/Makefile.boardloader
index 0ff07d1da..19d5aca06 100644
--- a/Makefile.boardloader
+++ b/Makefile.boardloader
@@ -118,6 +118,7 @@ CFLAGS += -mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi
 
 CFLAGS += -DSTM32F405xx -DMCU_SERIES_F4
 CFLAGS += -DSTM32_HAL_H='<stm32f4xx_hal.h>'
+CFLAGS += -DTREZOR_STM32
 
 LIBS = $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
 
diff --git a/Makefile.bootloader b/Makefile.bootloader
index 817570613..162c6e1d5 100644
--- a/Makefile.bootloader
+++ b/Makefile.bootloader
@@ -130,6 +130,7 @@ CFLAGS += -mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi
 
 CFLAGS += -DSTM32F405xx -DMCU_SERIES_F4
 CFLAGS += -DSTM32_HAL_H='<stm32f4xx_hal.h>'
+CFLAGS += -DTREZOR_STM32
 
 LIBS = $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
 
diff --git a/Makefile.firmware b/Makefile.firmware
index c0b556bc4..d7f937797 100644
--- a/Makefile.firmware
+++ b/Makefile.firmware
@@ -356,6 +356,7 @@ CFLAGS += -mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi
 
 CFLAGS += -DSTM32F405xx -DMCU_SERIES_F4
 CFLAGS += -DSTM32_HAL_H='<stm32f4xx_hal.h>'
+CFLAGS += -DTREZOR_STM32
 
 CFLAGS += -DMICROPY_QSTR_EXTRA_POOL=mp_qstr_frozen_const_pool
 CFLAGS += -DMICROPY_MODULE_FROZEN_MPY
diff --git a/micropython/extmod/modtrezorconfig/norcow_config.h b/micropython/extmod/modtrezorconfig/norcow_config.h
index 3a89769b2..49d68833c 100644
--- a/micropython/extmod/modtrezorconfig/norcow_config.h
+++ b/micropython/extmod/modtrezorconfig/norcow_config.h
@@ -1,10 +1,10 @@
-#ifdef UNIX
-#define NORCOW_UNIX 1
-#define NORCOW_FILE "/var/tmp/trezor.config"
-#endif
-
-#ifdef STM32_HAL_H
+#if defined TREZOR_STM32
 #define NORCOW_STM32 1
 #define NORCOW_START_SECTOR 2
 #define NORCOW_START_ADDRESS 0x08008000
+#elif defined TREZOR_UNIX
+#define NORCOW_UNIX 1
+#define NORCOW_FILE "/var/tmp/trezor.config"
+#else
+#error Unsupported TREZOR port. Only STM32 and UNIX ports are supported.
 #endif
diff --git a/micropython/extmod/modtrezormsg/modtrezormsg-stmhal.h b/micropython/extmod/modtrezormsg/modtrezormsg-stm32.h
similarity index 100%
rename from micropython/extmod/modtrezormsg/modtrezormsg-stmhal.h
rename to micropython/extmod/modtrezormsg/modtrezormsg-stm32.h
diff --git a/micropython/extmod/modtrezormsg/modtrezormsg.c b/micropython/extmod/modtrezormsg/modtrezormsg.c
index b5242f786..c3b4223da 100644
--- a/micropython/extmod/modtrezormsg/modtrezormsg.c
+++ b/micropython/extmod/modtrezormsg/modtrezormsg.c
@@ -15,12 +15,12 @@
 
 #if MICROPY_PY_TREZORMSG
 
-#if defined STM32_HAL_H
-#include "modtrezormsg-stmhal.h"
-#elif defined UNIX
+#if defined TREZOR_STM32
+#include "modtrezormsg-stm32.h"
+#elif defined TREZOR_UNIX
 #include "modtrezormsg-unix.h"
 #else
-#error Unsupported port. Only STMHAL and UNIX ports are supported.
+#error Unsupported TREZOR port. Only STM32 and UNIX ports are supported.
 #endif
 
 #define MAX_INTERFACES 8
diff --git a/micropython/extmod/modtrezorui/display-stmhal.h b/micropython/extmod/modtrezorui/display-stm32.h
similarity index 100%
rename from micropython/extmod/modtrezorui/display-stmhal.h
rename to micropython/extmod/modtrezorui/display-stm32.h
diff --git a/micropython/extmod/modtrezorui/display.c b/micropython/extmod/modtrezorui/display.c
index 362100b9c..16dc8ce87 100644
--- a/micropython/extmod/modtrezorui/display.c
+++ b/micropython/extmod/modtrezorui/display.c
@@ -20,10 +20,12 @@ static int DISPLAY_BACKLIGHT = 0;
 static int DISPLAY_ORIENTATION = 0;
 static int DISPLAY_OFFSET[2] = {0, 0};
 
-#if defined STM32_HAL_H
-#include "display-stmhal.h"
-#else
+#if defined TREZOR_STM32
+#include "display-stm32.h"
+#elif defined TREZOR_UNIX
 #include "display-unix.h"
+#else
+#error Unsupported TREZOR port. Only STM32 and UNIX ports are supported.
 #endif
 
 // common display functions
diff --git a/micropython/extmod/modtrezorutils/modtrezorutils.c b/micropython/extmod/modtrezorutils/modtrezorutils.c
index f46c29a54..2176360c2 100644
--- a/micropython/extmod/modtrezorutils/modtrezorutils.c
+++ b/micropython/extmod/modtrezorutils/modtrezorutils.c
@@ -8,16 +8,18 @@
 #include <stdio.h>
 #include <string.h>
 
-#if defined STM32_HAL_H
-#include "common.h"
-#elif defined UNIX
-#include <stdlib.h>
-#endif
-
 #include "py/runtime.h"
 
 #if MICROPY_PY_TREZORUTILS
 
+#if defined TREZOR_STM32
+#include "common.h"
+#elif defined TREZOR_UNIX
+#include <stdlib.h>
+#else
+#error Unsupported TREZOR port. Only STM32 and UNIX ports are supported.
+#endif
+
 /// def trezor.utils.memcpy(dst: bytearray, dst_ofs: int,
 ///                         src: bytearray, src_ofs: int,
 //                          n: int) -> int:
@@ -69,12 +71,12 @@ STATIC mp_obj_t mod_TrezorUtils_halt(size_t n_args, const mp_obj_t *args) {
         printf("HALT!\n");
     }
     // TODO: is this the best we can do?
-#if defined STM32_HAL_H
+#if defined TREZOR_STM32
     __fatal_error("HALT");
-#elif defined UNIX
+#elif defined TREZOR_UNIX
     exit(1);
 #else
-#error Unsupported port. Only STMHAL and UNIX ports are supported.
+#error Unsupported TREZOR port. Only STM32 and UNIX ports are supported.
 #endif
     return mp_const_none;
 }
diff --git a/micropython/unix/Makefile b/micropython/unix/Makefile
index 5d27cd02d..3c9f802da 100644
--- a/micropython/unix/Makefile
+++ b/micropython/unix/Makefile
@@ -121,6 +121,8 @@ CWARN = -Wall -Werror
 CWARN += -Wpointer-arith -Wuninitialized
 CFLAGS = $(INC) $(CWARN) -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT) $(CFLAGS_EXTRA)
 
+CFLAGS += -DTREZOR_UNIX
+
 # Debugging/Optimization
 ifdef DEBUG
 CFLAGS += -g