diff --git a/esp32/Makefile b/esp32/Makefile
index a92ab5d53a..2d3805268c 100644
--- a/esp32/Makefile
+++ b/esp32/Makefile
@@ -72,6 +72,10 @@ endif
 
 FROZEN_MPY_DIR = frozen
 
+MICROPY_PY_BTREE = 1
+
+GIT_SUBMODULES = lib/berkeley-db-1.xx
+
 include ../py/mkenv.mk
 
 CROSS_COMPILE = xtensa-esp32-elf-
diff --git a/esp32/application.mk b/esp32/application.mk
index 70c0f7d96d..2d87bd1249 100644
--- a/esp32/application.mk
+++ b/esp32/application.mk
@@ -94,6 +94,43 @@ APP_MAIN_SRC_C = \
 	pycom_config.c \
 	mpthreadport.c \
 
+################################################################################
+# btree
+
+ifeq ($(MICROPY_PY_BTREE), 1)
+BTREE_DIR = lib/berkeley-db-1.xx
+BTREE_DEFS = -D__DBINTERFACE_PRIVATE=1 -Dmpool_error=printf -Dabort=abort_ "-Dvirt_fd_t=void*" $(BTREE_DEFS_EXTRA)
+APP_INC += -I../lib/berkeley-db-1.xx/PORT/include
+
+APP_BTREE_SRC_C = $(addprefix $(BTREE_DIR)/,\
+	btree/bt_close.c \
+	btree/bt_conv.c \
+	btree/bt_debug.c \
+	btree/bt_delete.c \
+	btree/bt_get.c \
+	btree/bt_open.c \
+	btree/bt_overflow.c \
+	btree/bt_page.c \
+	btree/bt_put.c \
+	btree/bt_search.c \
+	btree/bt_seq.c \
+	btree/bt_split.c \
+	btree/bt_utils.c \
+	mpool/mpool.c \
+	)
+
+APP_BTREE_MOD_SRC_C = $(addprefix extmod/,\
+	modbtree.c \
+	)
+
+CFLAGS += -DMICROPY_PY_BTREE=1
+# we need to suppress certain warnings to get berkeley-db to compile cleanly
+# and we have separate BTREE_DEFS so the definitions don't interfere with other source code
+$(BTREE_DIR)/btree/%.o: CFLAGS += -Wno-old-style-definition -Wno-sign-compare -Wno-unused-parameter $(BTREE_DEFS)
+$(BTREE_DIR)/modbtree.o: CFLAGS += $(BTREE_DEFS)
+endif
+
+
 APP_HAL_SRC_C = $(addprefix hal/,\
 	esp32_mphal.c \
 	)
@@ -342,6 +379,10 @@ OBJ += $(addprefix $(BUILD)/, $(APP_FATFS_SRC_C:.c=.o) $(APP_LITTLEFS_SRC_C:.c=.
 OBJ += $(addprefix $(BUILD)/, $(APP_FTP_SRC_C:.c=.o) $(APP_CAN_SRC_C:.c=.o))
 OBJ += $(BUILD)/pins.o
 
+ifeq ($(MICROPY_PY_BTREE), 1)
+OBJ += $(addprefix $(BUILD)/, $(APP_BTREE_SRC_C:.c=.o) $(APP_BTREE_MOD_SRC_C:.c=.o))
+endif
+
 BOOT_OBJ = $(addprefix $(BUILD)/, $(BOOT_SRC_C:.c=.o))
 
 # List of sources for qstr extraction
@@ -362,6 +403,11 @@ SRC_QSTR += $(APP_MOD_MESH_SRC_C)
 endif
 endif # ifeq ($(OPENTHREAD), on)
 
+ifeq ($(MICROPY_PY_BTREE), 1)
+# SRC_QSTR += lib/berkeley-db-1.xx/modbtree.c
+SRC_QSTR += $(APP_BTREE_MOD_SRC_C)
+endif
+
 # Append any auto-generated sources that are needed by sources listed in
 # SRC_QSTR
 SRC_QSTR_AUTO_DEPS +=
diff --git a/esp32/mpconfigport.h b/esp32/mpconfigport.h
index 51a30b2e05..2c3a0eedd9 100644
--- a/esp32/mpconfigport.h
+++ b/esp32/mpconfigport.h
@@ -119,6 +119,7 @@
 #define MICROPY_PY_UZLIB                            (1)
 
 #define MICROPY_STREAMS_NON_BLOCK                   (1)
+#define MICROPY_STREAMS_POSIX_API                   (1)
 #define MICROPY_PY_BUILTINS_TIMEOUTERROR            (1)
 #define MICROPY_PY_ALL_SPECIAL_METHODS              (1)
 
diff --git a/esp32/tools/fw_updater/updater.py b/esp32/tools/fw_updater/updater.py
index e9bda31ce7..d57518164f 100755
--- a/esp32/tools/fw_updater/updater.py
+++ b/esp32/tools/fw_updater/updater.py
@@ -751,9 +751,9 @@ def set_pycom_config(self, config_block, boot_fs_type=None):
         return self.set_pybytes_config(new_config_block, force_update=True)
 
     def print_cb(self, config_block):
-	if DEBUG:
-	    for x in range(0, 30):
-                print(binascii.hexlify(config_block[x * 32:x * 32 + 32]))
+        if DEBUG:
+            for x in range(0, 30):
+                    print(binascii.hexlify(config_block[x * 32:x * 32 + 32]))
             
     def set_pybytes_config(self, config_block, userid=None, device_token=None, mqttServiceAddress=None, network_preferences=None, extra_preferences=None, force_update=None, auto_start=None):
         config_block = config_block.ljust(int(PARTITIONS.get('config')[1], 16), b'\x00')
diff --git a/py/py.mk b/py/py.mk
index 3d8d849e2b..830a133159 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -104,8 +104,7 @@ endif
 ifeq ($(MICROPY_PY_BTREE),1)
 BTREE_DIR = lib/berkeley-db-1.xx
 BTREE_DEFS = -D__DBINTERFACE_PRIVATE=1 -Dmpool_error=printf -Dabort=abort_ "-Dvirt_fd_t=void*" $(BTREE_DEFS_EXTRA)
-INC += -I$(TOP)/$(BTREE_DIR)/PORT/include
-SRC_MOD += extmod/modbtree.c
+INC += -I$(BTREE_DIR)/PORT/include
 SRC_MOD += $(addprefix $(BTREE_DIR)/,\
 btree/bt_close.c \
 btree/bt_conv.c \
@@ -122,6 +121,10 @@ btree/bt_split.c \
 btree/bt_utils.c \
 mpool/mpool.c \
 	)
+
+SRC_MOD += $(addprefix extmod/,\
+modbtree.c \
+	)
 CFLAGS_MOD += -DMICROPY_PY_BTREE=1
 # we need to suppress certain warnings to get berkeley-db to compile cleanly
 # and we have separate BTREE_DEFS so the definitions don't interfere with other source code