diff --git a/.gitmodules b/.gitmodules
index 07beebb916..075894e4e9 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,3 +7,6 @@
 [submodule "vendor/micropython"]
 	path = vendor/micropython
 	url = https://github.com/trezor/micropython.git
+[submodule "vendor/norcow"]
+	path = vendor/norcow
+	url = https://github.com/trezor/norcow.git
diff --git a/micropython/extmod/modtrezorconfig/Makefile b/micropython/extmod/modtrezorconfig/Makefile
deleted file mode 100644
index 8da1a6d3ae..0000000000
--- a/micropython/extmod/modtrezorconfig/Makefile
+++ /dev/null
@@ -1,15 +0,0 @@
-NAME=norcow_test
-CC=gcc
-CFLAGS=-Wall -Wextra -Werror -DUNIX
-LDFLAGS=
-LIBS=
-OBJ=$(NAME).o norcow.o
-
-$(NAME): $(OBJ)
-	$(CC) $(LDFLAGS) $(LIBS) $(OBJ) -o $(NAME)
-
-%.o: %.c
-	$(CC) $(CFLAGS) -c $< -o $@
-
-clean:
-	rm -f $(NAME) $(OBJ)
diff --git a/micropython/extmod/modtrezorconfig/norcow.c b/micropython/extmod/modtrezorconfig/norcow.c
deleted file mode 100644
index 2afe5399e3..0000000000
--- a/micropython/extmod/modtrezorconfig/norcow.c
+++ /dev/null
@@ -1,343 +0,0 @@
-#include "norcow.h"
-#include "norcow_config.h"
-
-#include <string.h>
-
-#ifdef NORCOW_UNIX
-#ifndef NORCOW_FILE
-#error Undefined NORCOW_FILE
-#endif
-#include <stdio.h>
-static uint8_t norcow_buffer[NORCOW_SECTOR_COUNT * NORCOW_SECTOR_SIZE];
-#endif
-
-#ifdef NORCOW_STM
-#ifndef NORCOW_START_SECTOR
-#error Undefined NORCOW_START_SECTOR
-#endif
-#ifndef NORCOW_START_ADDRESS
-#error Undefined NORCOW_START_ADDRESS
-#endif
-#include STM32_HAL_H
-#endif
-
-static uint8_t norcow_active_sector = 0;
-static uint32_t norcow_active_offset = 0;
-
-/*
- * Synchronizes in-memory storage with file on disk (UNIX only)
- */
-#ifdef NORCOW_UNIX
-static void norcow_sync(void)
-{
-    FILE *f = fopen(NORCOW_FILE, "wb");
-    if (f) {
-        fwrite(norcow_buffer, sizeof(norcow_buffer), 1, f);
-        fclose(f);
-    }
-}
-#endif
-
-/*
- * Erases sector
- */
-static bool norcow_erase(uint8_t sector)
-{
-    if (sector >= NORCOW_SECTOR_COUNT) {
-        return false;
-    }
-#ifdef NORCOW_UNIX
-    memset(norcow_buffer + sector * NORCOW_SECTOR_SIZE, 0xFF, NORCOW_SECTOR_SIZE);
-    norcow_sync();
-    return true;
-#endif
-#ifdef NORCOW_STM
-    HAL_FLASH_Unlock();
-    FLASH_EraseInitTypeDef EraseInitStruct;
-    __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR |
-                           FLASH_FLAG_PGAERR | FLASH_FLAG_PGPERR | FLASH_FLAG_PGSERR);
-    EraseInitStruct.TypeErase = TYPEERASE_SECTORS;
-    EraseInitStruct.VoltageRange = VOLTAGE_RANGE_3; // voltage range needs to be 2.7V to 3.6V
-    EraseInitStruct.NbSectors = 1;
-    EraseInitStruct.Sector = NORCOW_START_SECTOR + sector;
-    HAL_StatusTypeDef r;
-    uint32_t SectorError = 0;
-    r = HAL_FLASHEx_Erase(&EraseInitStruct, &SectorError);
-    HAL_FLASH_Lock();
-    return r == HAL_OK;
-#endif
-    return false;
-}
-
-/*
- * Returns pointer to sector, starting with offset
- * Fails when there is not enough space for data of given size
- */
-static const void *norcow_ptr(uint8_t sector, uint32_t offset, uint32_t size)
-{
-    if (sector >= NORCOW_SECTOR_COUNT) {
-        return NULL;
-    }
-    if (offset + size > NORCOW_SECTOR_SIZE) {
-        return NULL;
-    }
-#ifdef NORCOW_UNIX
-    return (const void *)(norcow_buffer + sector * NORCOW_SECTOR_SIZE + offset);
-#endif
-#ifdef NORCOW_STM
-    return (const void *)(NORCOW_START_ADDRESS + sector * NORCOW_SECTOR_SIZE + offset);
-#endif
-    return NULL;
-}
-
-/*
- * Writes data to given sector, starting from offset
- */
-static bool norcow_write(uint8_t sector, uint32_t offset, uint32_t prefix, const uint8_t *data, uint16_t len)
-{
-    if (offset % 4) { // we write only at 4-byte boundary
-        return false;
-    }
-    const uint8_t *ptr = (const uint8_t *)norcow_ptr(sector, offset, sizeof(uint32_t) + len);
-    if (!ptr) {
-        return false;
-    }
-#ifdef NORCOW_UNIX
-    // check whether we are about just change 1s to 0s
-    // and bailout if not
-    if ((*(uint32_t *)ptr & prefix) != prefix) {
-        return false;
-    }
-    for (uint16_t i = 0; i < len; i++) {
-        if ((ptr[sizeof(uint32_t) + i] & data[i]) != data[i]) {
-            return false;
-        }
-    }
-    memcpy((void *)ptr, &prefix, sizeof(uint32_t));
-    memcpy((void *)(ptr + sizeof(uint32_t)), data, len);
-    norcow_sync();
-    return true;
-#endif
-#ifdef NORCOW_STM
-    HAL_FLASH_Unlock();
-    HAL_FLASH_Program(TYPEPROGRAM_WORD, NORCOW_START_ADDRESS + sector * NORCOW_SECTOR_SIZE + offset, prefix);
-    for (int i = 0; i < (len + 3) / sizeof(uint32_t); i++) {
-        const uint32_t *d = (const uint32_t *)(data + i * sizeof(uint32_t));
-        HAL_FLASH_Program(TYPEPROGRAM_WORD, NORCOW_START_ADDRESS + sector * NORCOW_SECTOR_SIZE + offset + (1 + i) * sizeof(uint32_t), *d);
-    }
-    HAL_FLASH_Lock();
-    return true;
-#endif
-    return false;
-}
-
-/*
- * Aligns position to 4-byte boundary
- */
-static inline void align4(uint32_t *pos)
-{
-    if (*pos & 3) {
-        *pos = (*pos + 3) & ~3;
-    }
-}
-
-/*
- * Reads one item starting from offset
- */
-static bool read_item(uint8_t sector, uint32_t offset, uint16_t *key, const void **val, uint16_t *len, uint32_t *pos)
-{
-    *pos = offset;
-
-    const void *k = norcow_ptr(sector, *pos, 2);
-    if (k == NULL) return false;
-    *pos += 2;
-    memcpy(key, k, sizeof(uint16_t));
-    if (*key == 0xFFFF) {
-        return false;
-    }
-
-    const void *l = norcow_ptr(sector, *pos, 2);
-    if (l == NULL) return false;
-    *pos += 2;
-    memcpy(len, l, sizeof(uint16_t));
-
-    *val = norcow_ptr(sector, *pos, *len);
-    if (*val == NULL) return false;
-    *pos += *len;
-    align4(pos);
-    return true;
-}
-
-/*
- * Writes one item starting from offset
- */
-static bool write_item(uint8_t sector, uint32_t offset, uint16_t key, const void *val, uint16_t len, uint32_t *pos)
-{
-    uint32_t prefix = (len << 16) | key;
-    *pos = offset + sizeof(uint32_t) + len;
-    align4(pos);
-    return norcow_write(sector, offset, prefix, val, len);
-}
-
-/*
- * Finds item in given sector
- */
-static bool find_item(uint8_t sector, uint16_t key, const void **val, uint16_t *len)
-{
-    *val = 0;
-    *len = 0;
-    uint32_t offset = 0;
-    for (;;) {
-        uint16_t k, l;
-        const void *v;
-        uint32_t pos;
-        bool r = read_item(sector, offset, &k, &v, &l, &pos);
-        if (!r) break;
-        if (key == k) {
-            *val = v;
-            *len = l;
-        }
-        offset = pos;
-    }
-    return (*val);
-}
-
-/*
- * Finds first unused offset in given sector
- */
-static uint32_t find_free_offset(uint8_t sector)
-{
-    uint32_t offset = 0;
-    for (;;) {
-        uint16_t key, len;
-        const void *val;
-        uint32_t pos;
-        bool r = read_item(sector, offset, &key, &val, &len, &pos);
-        if (!r) break;
-        offset = pos;
-    }
-    return offset;
-}
-
-/*
- * Compacts active sector and sets new active sector
- */
-static void compact()
-{
-    uint8_t norcow_next_sector = (norcow_active_sector + 1) % NORCOW_SECTOR_COUNT;
-
-    uint32_t offset = 0, offsetw = 0;
-
-    for (;;) {
-        // read item
-        uint16_t k, l;
-        const void *v;
-        uint32_t pos;
-        bool r = read_item(norcow_active_sector, offset, &k, &v, &l, &pos);
-        if (!r) break;
-        offset = pos;
-
-        // check if not already saved
-        const void *v2;
-        uint16_t l2;
-        r = find_item(norcow_next_sector, k, &v2, &l2);
-        if (r) {
-            continue;
-        }
-
-        // scan for latest instance
-        uint32_t offsetr = offset;
-        for (;;) {
-            uint16_t k2;
-            uint32_t posr;
-            r = read_item(norcow_active_sector, offsetr, &k2, &v2, &l2, &posr);
-            if (!r) break;
-            if (k == k2) {
-                v = v2;
-                l = l2;
-            }
-            offsetr = posr;
-        }
-
-        // copy the last item
-        uint32_t posw;
-        r = write_item(norcow_next_sector, offsetw, k, v, l, &posw);
-        if (!r) { } // TODO: error
-        offsetw = posw;
-    }
-
-    norcow_erase(norcow_active_sector);
-    norcow_active_sector = norcow_next_sector;
-    norcow_active_offset = find_free_offset(norcow_active_sector);
-}
-
-/*
- * Initializes storage
- */
-bool norcow_init(void)
-{
-#ifdef NORCOW_UNIX
-    memset(norcow_buffer, 0xFF, sizeof(norcow_buffer));
-    FILE *f = fopen(NORCOW_FILE, "rb");
-    if (f) {
-        size_t r = fread(norcow_buffer, sizeof(norcow_buffer), 1, f);
-        fclose(f);
-        printf("%d\n", (int)r);
-        if (r != 1) {
-            memset(norcow_buffer, 0xFF, sizeof(norcow_buffer));
-        }
-    }
-#endif
-    // detect active sector (inactive sectors are empty = start with 0xFF)
-    for (uint8_t i = 0; i < NORCOW_SECTOR_COUNT; i++) {
-        const uint8_t *b = norcow_ptr(i, 0, 1);
-        if (b != NULL && *b != 0xFF) {
-            norcow_active_sector = i;
-            break;
-        }
-    }
-    norcow_active_offset = find_free_offset(norcow_active_sector);
-    return true;
-}
-
-/*
- * Wipe the storage
- */
-bool norcow_wipe(void)
-{
-    for (uint8_t i = 0; i < NORCOW_SECTOR_COUNT; i++) {
-        if (!norcow_erase(i)) {
-            return false;
-        }
-    }
-    norcow_active_sector = 0;
-    norcow_active_offset = 0;
-    return true;
-}
-
-/*
- * Looks for the given key, returns status of the operation
- */
-bool norcow_get(uint16_t key, const void **val, uint16_t *len)
-{
-    return find_item(norcow_active_sector, key, val, len);
-}
-
-/*
- * Sets the given key, returns status of the operation
- */
-bool norcow_set(uint16_t key, const void *val, uint16_t len)
-{
-    // check whether there is enough free space
-    // and compact if full
-    if (norcow_active_offset + sizeof(uint32_t) + len > NORCOW_SECTOR_SIZE) {
-        compact();
-    }
-    // write item
-    uint32_t pos;
-    bool r = write_item(norcow_active_sector, norcow_active_offset, key, val, len, &pos);
-    if (r) {
-        norcow_active_offset = pos;
-    }
-    return r;
-}
diff --git a/micropython/extmod/modtrezorconfig/norcow.c b/micropython/extmod/modtrezorconfig/norcow.c
new file mode 120000
index 0000000000..0c15ca2f96
--- /dev/null
+++ b/micropython/extmod/modtrezorconfig/norcow.c
@@ -0,0 +1 @@
+../../../vendor/norcow/norcow.c
\ No newline at end of file
diff --git a/micropython/extmod/modtrezorconfig/norcow.h b/micropython/extmod/modtrezorconfig/norcow.h
deleted file mode 100644
index 1502b2f408..0000000000
--- a/micropython/extmod/modtrezorconfig/norcow.h
+++ /dev/null
@@ -1,34 +0,0 @@
-#ifndef __NORCOW_H__
-#define __NORCOW_H__
-
-#include <stdint.h>
-#include <stdbool.h>
-
-/*
- * Storage parameters:
- */
-
-#define NORCOW_SECTOR_COUNT  2
-#define NORCOW_SECTOR_SIZE   (16*1024)
-
-/*
- * Initialize storage
- */
-bool norcow_init(void);
-
-/*
- * Wipe the storage
- */
-bool norcow_wipe(void);
-
-/*
- * Looks for the given key, returns status of the operation
- */
-bool norcow_get(uint16_t key, const void **val, uint16_t *len);
-
-/*
- * Sets the given key, returns status of the operation
- */
-bool norcow_set(uint16_t key, const void *val, uint16_t len);
-
-#endif
diff --git a/micropython/extmod/modtrezorconfig/norcow.h b/micropython/extmod/modtrezorconfig/norcow.h
new file mode 120000
index 0000000000..f33ecb1577
--- /dev/null
+++ b/micropython/extmod/modtrezorconfig/norcow.h
@@ -0,0 +1 @@
+../../../vendor/norcow/norcow.h
\ No newline at end of file
diff --git a/micropython/extmod/modtrezorconfig/norcow_config.h b/micropython/extmod/modtrezorconfig/norcow_config.h
index 99738d61bf..3a89769b2d 100644
--- a/micropython/extmod/modtrezorconfig/norcow_config.h
+++ b/micropython/extmod/modtrezorconfig/norcow_config.h
@@ -4,7 +4,7 @@
 #endif
 
 #ifdef STM32_HAL_H
-#define NORCOW_STM 1
+#define NORCOW_STM32 1
 #define NORCOW_START_SECTOR 2
 #define NORCOW_START_ADDRESS 0x08008000
 #endif
diff --git a/micropython/extmod/modtrezorconfig/norcow_test.c b/micropython/extmod/modtrezorconfig/norcow_test.c
deleted file mode 100644
index 468c69c3f9..0000000000
--- a/micropython/extmod/modtrezorconfig/norcow_test.c
+++ /dev/null
@@ -1,44 +0,0 @@
-#include <assert.h>
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <time.h>
-
-#include "norcow.h"
-
-#define MAXVALLEN 1024
-
-uint8_t val[MAXVALLEN], *v;
-uint16_t key, vallen, vlen;
-
-int main()
-{
-    srand(time(0));
-
-    norcow_init();
-
-    bool r;
-    for (int i = 0; i < 10000; i++) {
-
-        vallen = rand() % (MAXVALLEN + 1);
-        for (uint32_t j = 0; j < vallen; j++) {
-            val[j] = rand() & 0xFF;
-        }
-
-        key = 0x1234 + (rand() % 32);
-
-        printf("#%d key=0x%04x size=%d\n", i, key, vallen);
-
-        r = norcow_set(key, val, vallen);
-        if (!r) {
-            printf("Write failed (full storage)\n");
-            continue;
-        }
-
-        r = norcow_get(key, (const void **)&v, &vlen);
-        assert(r == 1);
-
-        assert(vlen == vallen);
-        assert(0 == memcmp(val, v, vallen));
-    }
-}
diff --git a/vendor/norcow b/vendor/norcow
new file mode 160000
index 0000000000..5977b17a36
--- /dev/null
+++ b/vendor/norcow
@@ -0,0 +1 @@
+Subproject commit 5977b17a360df12af82a6c205a052f90e42e7db7