diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index d90a7c2e4f..943acd4943 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -229,6 +229,7 @@ SRC_C = \
 	systick.c  \
 	powerctrl.c \
 	pybthread.c \
+	factoryreset.c \
 	timer.c \
 	led.c \
 	pin.c \
diff --git a/ports/stm32/factoryreset.c b/ports/stm32/factoryreset.c
new file mode 100644
index 0000000000..6b0c289a78
--- /dev/null
+++ b/ports/stm32/factoryreset.c
@@ -0,0 +1,98 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013-2019 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/runtime.h"
+#include "factoryreset.h"
+
+#if MICROPY_HW_ENABLE_STORAGE
+
+static const char fresh_boot_py[] =
+"# boot.py -- run on boot-up\r\n"
+"# can run arbitrary Python, but best to keep it minimal\r\n"
+"\r\n"
+"import machine\r\n"
+"import pyb\r\n"
+"#pyb.main('main.py') # main script to run after this one\r\n"
+#if MICROPY_HW_ENABLE_USB
+"#pyb.usb_mode('VCP+MSC') # act as a serial and a storage device\r\n"
+"#pyb.usb_mode('VCP+HID') # act as a serial device and a mouse\r\n"
+#endif
+;
+
+static const char fresh_main_py[] =
+"# main.py -- put your code here!\r\n"
+;
+
+#if MICROPY_HW_ENABLE_USB
+static const char fresh_pybcdc_inf[] =
+#include "genhdr/pybcdc_inf.h"
+;
+
+static const char fresh_readme_txt[] =
+"This is a MicroPython board\r\n"
+"\r\n"
+"You can get started right away by writing your Python code in 'main.py'.\r\n"
+"\r\n"
+"For a serial prompt:\r\n"
+" - Windows: you need to go to 'Device manager', right click on the unknown device,\r\n"
+"   then update the driver software, using the 'pybcdc.inf' file found on this drive.\r\n"
+"   Then use a terminal program like Hyperterminal or putty.\r\n"
+" - Mac OS X: use the command: screen /dev/tty.usbmodem*\r\n"
+" - Linux: use the command: screen /dev/ttyACM0\r\n"
+"\r\n"
+"Please visit http://micropython.org/help/ for further help.\r\n"
+;
+#endif
+
+typedef struct _factory_file_t {
+    const char *name;
+    size_t len;
+    const char *data;
+} factory_file_t;
+
+static const factory_file_t factory_files[] = {
+    {"boot.py", sizeof(fresh_boot_py) - 1, fresh_boot_py},
+    {"main.py", sizeof(fresh_main_py) - 1, fresh_main_py},
+    #if MICROPY_HW_ENABLE_USB
+    {"pybcdc.inf", sizeof(fresh_pybcdc_inf) - 1, fresh_pybcdc_inf},
+    {"README.txt", sizeof(fresh_readme_txt) - 1, fresh_readme_txt},
+    #endif
+};
+
+MP_WEAK void factory_reset_make_files(FATFS *fatfs) {
+    for (int i = 0; i < MP_ARRAY_SIZE(factory_files); ++i) {
+        const factory_file_t *f = &factory_files[i];
+        FIL fp;
+        FRESULT res = f_open(fatfs, &fp, f->name, FA_WRITE | FA_CREATE_ALWAYS);
+        if (res == FR_OK) {
+            UINT n;
+            f_write(&fp, f->data, f->len, &n);
+            f_close(&fp);
+        }
+    }
+}
+
+#endif // MICROPY_HW_ENABLE_STORAGE
diff --git a/ports/stm32/factoryreset.h b/ports/stm32/factoryreset.h
new file mode 100644
index 0000000000..85226f880b
--- /dev/null
+++ b/ports/stm32/factoryreset.h
@@ -0,0 +1,33 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef MICROPY_INCLUDED_STM32_FACTORYRESET_H
+#define MICROPY_INCLUDED_STM32_FACTORYRESET_H
+
+#include "lib/oofatfs/ff.h"
+
+void factory_reset_make_files(FATFS *fatfs);
+
+#endif // MICROPY_INCLUDED_STM32_FACTORYRESET_H
diff --git a/ports/stm32/main.c b/ports/stm32/main.c
index a37c6f8979..ff4589f9d4 100644
--- a/ports/stm32/main.c
+++ b/ports/stm32/main.c
@@ -45,6 +45,7 @@
 #include "pendsv.h"
 #include "pybthread.h"
 #include "gccollect.h"
+#include "factoryreset.h"
 #include "modmachine.h"
 #include "i2c.h"
 #include "spi.h"
@@ -148,42 +149,6 @@ STATIC mp_obj_t pyb_main(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_a
 MP_DEFINE_CONST_FUN_OBJ_KW(pyb_main_obj, 1, pyb_main);
 
 #if MICROPY_HW_ENABLE_STORAGE
-static const char fresh_boot_py[] =
-"# boot.py -- run on boot-up\r\n"
-"# can run arbitrary Python, but best to keep it minimal\r\n"
-"\r\n"
-"import machine\r\n"
-"import pyb\r\n"
-"#pyb.main('main.py') # main script to run after this one\r\n"
-#if MICROPY_HW_ENABLE_USB
-"#pyb.usb_mode('VCP+MSC') # act as a serial and a storage device\r\n"
-"#pyb.usb_mode('VCP+HID') # act as a serial device and a mouse\r\n"
-#endif
-;
-
-static const char fresh_main_py[] =
-"# main.py -- put your code here!\r\n"
-;
-
-static const char fresh_pybcdc_inf[] =
-#include "genhdr/pybcdc_inf.h"
-;
-
-static const char fresh_readme_txt[] =
-"This is a MicroPython board\r\n"
-"\r\n"
-"You can get started right away by writing your Python code in 'main.py'.\r\n"
-"\r\n"
-"For a serial prompt:\r\n"
-" - Windows: you need to go to 'Device manager', right click on the unknown device,\r\n"
-"   then update the driver software, using the 'pybcdc.inf' file found on this drive.\r\n"
-"   Then use a terminal program like Hyperterminal or putty.\r\n"
-" - Mac OS X: use the command: screen /dev/tty.usbmodem*\r\n"
-" - Linux: use the command: screen /dev/ttyACM0\r\n"
-"\r\n"
-"Please visit http://micropython.org/help/ for further help.\r\n"
-;
-
 // avoid inlining to avoid stack usage within main()
 MP_NOINLINE STATIC bool init_flash_fs(uint reset_mode) {
     // init the vfs object
@@ -213,23 +178,8 @@ MP_NOINLINE STATIC bool init_flash_fs(uint reset_mode) {
         // set label
         f_setlabel(&vfs_fat->fatfs, MICROPY_HW_FLASH_FS_LABEL);
 
-        // create empty main.py
-        FIL fp;
-        f_open(&vfs_fat->fatfs, &fp, "/main.py", FA_WRITE | FA_CREATE_ALWAYS);
-        UINT n;
-        f_write(&fp, fresh_main_py, sizeof(fresh_main_py) - 1 /* don't count null terminator */, &n);
-        // TODO check we could write n bytes
-        f_close(&fp);
-
-        // create .inf driver file
-        f_open(&vfs_fat->fatfs, &fp, "/pybcdc.inf", FA_WRITE | FA_CREATE_ALWAYS);
-        f_write(&fp, fresh_pybcdc_inf, sizeof(fresh_pybcdc_inf) - 1 /* don't count null terminator */, &n);
-        f_close(&fp);
-
-        // create readme file
-        f_open(&vfs_fat->fatfs, &fp, "/README.txt", FA_WRITE | FA_CREATE_ALWAYS);
-        f_write(&fp, fresh_readme_txt, sizeof(fresh_readme_txt) - 1 /* don't count null terminator */, &n);
-        f_close(&fp);
+        // populate the filesystem with factory files
+        factory_reset_make_files(&vfs_fat->fatfs);
 
         // keep LED on for at least 200ms
         systick_wait_at_least(start_tick, 200);
@@ -258,28 +208,6 @@ MP_NOINLINE STATIC bool init_flash_fs(uint reset_mode) {
     // It is set to the internal flash filesystem by default.
     MP_STATE_PORT(vfs_cur) = vfs;
 
-    // Make sure we have a /flash/boot.py.  Create it if needed.
-    FILINFO fno;
-    res = f_stat(&vfs_fat->fatfs, "/boot.py", &fno);
-    if (res != FR_OK) {
-        // doesn't exist, create fresh file
-
-        // LED on to indicate creation of boot.py
-        led_state(PYB_LED_GREEN, 1);
-        uint32_t start_tick = HAL_GetTick();
-
-        FIL fp;
-        f_open(&vfs_fat->fatfs, &fp, "/boot.py", FA_WRITE | FA_CREATE_ALWAYS);
-        UINT n;
-        f_write(&fp, fresh_boot_py, sizeof(fresh_boot_py) - 1 /* don't count null terminator */, &n);
-        // TODO check we could write n bytes
-        f_close(&fp);
-
-        // keep LED on for at least 200ms
-        systick_wait_at_least(start_tick, 200);
-        led_state(PYB_LED_GREEN, 0);
-    }
-
     return true;
 }
 #endif