diff --git a/extmod/btstack/btstack.mk b/extmod/btstack/btstack.mk
index 14b8d08bf1..ca95931562 100644
--- a/extmod/btstack/btstack.mk
+++ b/extmod/btstack/btstack.mk
@@ -3,17 +3,19 @@
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
 
 GIT_SUBMODULES += lib/btstack
+
 MICROPY_BLUETOOTH_BTSTACK_USB ?= 0
+MICROPY_BLUETOOTH_BTSTACK_H4 ?= 1
 
 BTSTACK_EXTMOD_DIR = extmod/btstack
 
-EXTMOD_SRC_C += extmod/btstack/modbluetooth_btstack.c
+SRC_EXTMOD_C += $(BTSTACK_EXTMOD_DIR)/modbluetooth_btstack.c
 
 INC += -I$(TOP)/$(BTSTACK_EXTMOD_DIR)
 
-CFLAGS_MOD += -DMICROPY_BLUETOOTH_BTSTACK=1
-CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS=1
-CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING=1
+CFLAGS_EXTMOD += -DMICROPY_BLUETOOTH_BTSTACK=1
+CFLAGS_EXTMOD += -DMICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS=1
+CFLAGS_EXTMOD += -DMICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING=1
 
 BTSTACK_DIR = $(TOP)/lib/btstack
 
@@ -28,44 +30,50 @@ INC += -I$(BTSTACK_DIR)/3rd-party/bluedroid/encoder/include
 INC += -I$(BTSTACK_DIR)/3rd-party/md5
 INC += -I$(BTSTACK_DIR)/3rd-party/yxml
 
-SRC_BTSTACK = \
+SRC_BTSTACK_C = \
 	$(addprefix lib/btstack/src/, $(SRC_FILES)) \
 	$(addprefix lib/btstack/src/ble/, $(filter-out %_tlv.c, $(SRC_BLE_FILES))) \
 
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK_USB),1)
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK_H4),1)
-	$(error Cannot specifiy both MICROPY_BLUETOOTH_BTSTACK_USB and MICROPY_BLUETOOTH_BTSTACK_H4)
+	$(error Cannot enable both MICROPY_BLUETOOTH_BTSTACK_USB and MICROPY_BLUETOOTH_BTSTACK_H4)
+endif
+endif
+
+ifneq ($(MICROPY_BLUETOOTH_BTSTACK_USB),1)
+ifneq ($(MICROPY_BLUETOOTH_BTSTACK_H4),1)
+	$(error Must enable one of MICROPY_BLUETOOTH_BTSTACK_USB or MICROPY_BLUETOOTH_BTSTACK_H4)
 endif
 endif
 
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK_USB),1)
-SRC_BTSTACK += \
+SRC_BTSTACK_C += \
 	lib/btstack/platform/libusb/hci_transport_h2_libusb.c
 
-CFLAGS_MOD += -DMICROPY_BLUETOOTH_BTSTACK_USB=1
+CFLAGS_EXTMOD += -DMICROPY_BLUETOOTH_BTSTACK_USB=1
 
-CFLAGS  += $(shell pkg-config libusb-1.0 --cflags)
-LDFLAGS += $(shell pkg-config libusb-1.0 --libs)
+CFLAGS_THIRDPARTY += $(shell pkg-config libusb-1.0 --cflags)
+LDFLAGS_THIRDPARTY += $(shell pkg-config libusb-1.0 --libs)
 endif
 
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK_H4),1)
-SRC_BTSTACK += \
+SRC_BTSTACK_C += \
 	lib/btstack/src/hci_transport_h4.c \
 	lib/btstack/chipset/zephyr/btstack_chipset_zephyr.c
 
-EXTMOD_SRC_C += \
+SRC_BTSTACK_C += \
 	extmod/btstack/btstack_hci_uart.c \
 
-CFLAGS_MOD += -DMICROPY_BLUETOOTH_BTSTACK_H4=1
+CFLAGS_EXTMOD += -DMICROPY_BLUETOOTH_BTSTACK_H4=1
 endif
 
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK_ENABLE_CLASSIC),1)
 include $(BTSTACK_DIR)/src/classic/Makefile.inc
-SRC_BTSTACK += \
+SRC_BTSTACK_C += \
 	$(addprefix lib/btstack/src/classic/, $(SRC_CLASSIC_FILES))
 endif
 
-LIB_SRC_C += $(SRC_BTSTACK)
+SRC_THIRDPARTY_C += $(SRC_BTSTACK_C)
 
 # Suppress some warnings.
 BTSTACK_WARNING_CFLAGS = -Wno-old-style-definition -Wno-unused-variable -Wno-unused-parameter -Wno-implicit-fallthrough
diff --git a/extmod/extmod.mk b/extmod/extmod.mk
index bd89719917..3b10fc857c 100644
--- a/extmod/extmod.mk
+++ b/extmod/extmod.mk
@@ -1,55 +1,66 @@
 # This makefile fragment adds the source code files for the core extmod modules
 # and provides rules to build 3rd-party components for extmod modules.
 
-PY_EXTMOD_O_BASENAME = \
-	extmod/moduasyncio.o \
-	extmod/moductypes.o \
-	extmod/modujson.o \
-	extmod/moduos.o \
-	extmod/modure.o \
-	extmod/moduzlib.o \
-	extmod/moduheapq.o \
-	extmod/modutimeq.o \
-	extmod/moduhashlib.o \
-	extmod/moducryptolib.o \
-	extmod/modubinascii.o \
-	extmod/virtpin.o \
-	extmod/machine_bitstream.o \
-	extmod/machine_mem.o \
-	extmod/machine_pinbase.o \
-	extmod/machine_signal.o \
-	extmod/machine_pulse.o \
-	extmod/machine_pwm.o \
-	extmod/machine_i2c.o \
-	extmod/machine_spi.o \
-	extmod/modbluetooth.o \
-	extmod/modlwip.o \
-	extmod/modussl_axtls.o \
-	extmod/modussl_mbedtls.o \
-	extmod/moduplatform.o\
-	extmod/modurandom.o \
-	extmod/moduselect.o \
-	extmod/moduwebsocket.o \
-	extmod/modwebrepl.o \
-	extmod/modframebuf.o \
-	extmod/vfs.o \
-	extmod/vfs_blockdev.o \
-	extmod/vfs_reader.o \
-	extmod/vfs_posix.o \
-	extmod/vfs_posix_file.o \
-	extmod/vfs_fat.o \
-	extmod/vfs_fat_diskio.o \
-	extmod/vfs_fat_file.o \
-	extmod/vfs_lfs.o \
-	extmod/utime_mphal.o \
-	extmod/uos_dupterm.o \
-	shared/libc/abort_.o \
-	shared/libc/printf.o \
+SRC_EXTMOD_C += \
+	extmod/machine_bitstream.c \
+	extmod/machine_i2c.c \
+	extmod/machine_mem.c \
+	extmod/machine_pinbase.c \
+	extmod/machine_pulse.c \
+	extmod/machine_pwm.c \
+	extmod/machine_signal.c \
+	extmod/machine_spi.c \
+	extmod/modbluetooth.c \
+	extmod/modbtree.c \
+	extmod/modframebuf.c \
+	extmod/modlwip.c \
+	extmod/modnetwork.c \
+	extmod/modonewire.c \
+	extmod/moduasyncio.c \
+	extmod/modubinascii.c \
+	extmod/moducryptolib.c \
+	extmod/moductypes.c \
+	extmod/moduhashlib.c \
+	extmod/moduheapq.c \
+	extmod/modujson.c \
+	extmod/moduos.c \
+	extmod/moduplatform.c\
+	extmod/modurandom.c \
+	extmod/modure.c \
+	extmod/moduselect.c \
+	extmod/modusocket.c \
+	extmod/modussl_axtls.c \
+	extmod/modussl_mbedtls.c \
+	extmod/modutimeq.c \
+	extmod/moduwebsocket.c \
+	extmod/moduzlib.c \
+	extmod/modwebrepl.c \
+	extmod/network_cyw43.c \
+	extmod/network_ninaw10.c \
+	extmod/network_wiznet5k.c \
+	extmod/uos_dupterm.c \
+	extmod/utime_mphal.c \
+	extmod/vfs.c \
+	extmod/vfs_blockdev.c \
+	extmod/vfs_fat.c \
+	extmod/vfs_fat_diskio.c \
+	extmod/vfs_fat_file.c \
+	extmod/vfs_lfs.c \
+	extmod/vfs_posix.c \
+	extmod/vfs_posix_file.c \
+	extmod/vfs_reader.c \
+	extmod/virtpin.c \
+	shared/libc/abort_.c \
+	shared/libc/printf.c \
 
-PY_EXTMOD_O = $(addprefix $(BUILD)/, $(PY_EXTMOD_O_BASENAME))
+SRC_THIRDPARTY_C += \
 
-PY_O += $(PY_EXTMOD_O)
-SRC_QSTR += $(PY_EXTMOD_O_BASENAME:.o=.c)
+PY_O += $(addprefix $(BUILD)/, $(SRC_EXTMOD_C:.c=.o))
+PY_O += $(addprefix $(BUILD)/, $(SRC_THIRDPARTY_C:.c=.o))
+SRC_QSTR += $(SRC_EXTMOD_C)
+
+CFLAGS += $(CFLAGS_EXTMOD) $(CFLAGS_THIRDPARTY)
+LDFLAGS += $(LDFLAGS_EXTMOD) $(LDFLAGS_THIRDPARTY)
 
 ################################################################################
 # VFS FAT FS
@@ -57,11 +68,11 @@ SRC_QSTR += $(PY_EXTMOD_O_BASENAME:.o=.c)
 OOFATFS_DIR = lib/oofatfs
 
 # this sets the config file for FatFs
-CFLAGS_MOD += -DFFCONF_H=\"$(OOFATFS_DIR)/ffconf.h\"
+CFLAGS_THIRDPARTY += -DFFCONF_H=\"$(OOFATFS_DIR)/ffconf.h\"
 
 ifeq ($(MICROPY_VFS_FAT),1)
-CFLAGS_MOD += -DMICROPY_VFS_FAT=1
-SRC_MOD += $(addprefix $(OOFATFS_DIR)/,\
+CFLAGS_EXTMOD += -DMICROPY_VFS_FAT=1
+SRC_THIRDPARTY_C += $(addprefix $(OOFATFS_DIR)/,\
 	ff.c \
 	ffunicode.c \
 	)
@@ -73,18 +84,18 @@ endif
 LITTLEFS_DIR = lib/littlefs
 
 ifeq ($(MICROPY_VFS_LFS1),1)
-CFLAGS_MOD += -DMICROPY_VFS_LFS1=1
-CFLAGS_MOD += -DLFS1_NO_MALLOC -DLFS1_NO_DEBUG -DLFS1_NO_WARN -DLFS1_NO_ERROR -DLFS1_NO_ASSERT
-SRC_MOD += $(addprefix $(LITTLEFS_DIR)/,\
+CFLAGS_EXTMOD += -DMICROPY_VFS_LFS1=1
+CFLAGS_THIRDPARTY += -DLFS1_NO_MALLOC -DLFS1_NO_DEBUG -DLFS1_NO_WARN -DLFS1_NO_ERROR -DLFS1_NO_ASSERT
+SRC_THIRDPARTY_C += $(addprefix $(LITTLEFS_DIR)/,\
 	lfs1.c \
 	lfs1_util.c \
 	)
 endif
 
 ifeq ($(MICROPY_VFS_LFS2),1)
-CFLAGS_MOD += -DMICROPY_VFS_LFS2=1
-CFLAGS_MOD += -DLFS2_NO_MALLOC -DLFS2_NO_DEBUG -DLFS2_NO_WARN -DLFS2_NO_ERROR -DLFS2_NO_ASSERT
-SRC_MOD += $(addprefix $(LITTLEFS_DIR)/,\
+CFLAGS_EXTMOD += -DMICROPY_VFS_LFS2=1
+CFLAGS_THIRDPARTY += -DLFS2_NO_MALLOC -DLFS2_NO_DEBUG -DLFS2_NO_WARN -DLFS2_NO_ERROR -DLFS2_NO_ASSERT
+SRC_THIRDPARTY_C += $(addprefix $(LITTLEFS_DIR)/,\
 	lfs2.c \
 	lfs2_util.c \
 	)
@@ -96,13 +107,13 @@ endif
 # ussl
 
 ifeq ($(MICROPY_PY_USSL),1)
-CFLAGS_MOD += -DMICROPY_PY_USSL=1
+CFLAGS_EXTMOD += -DMICROPY_PY_USSL=1
 ifeq ($(MICROPY_SSL_AXTLS),1)
-CFLAGS_MOD += -DMICROPY_SSL_AXTLS=1 -I$(TOP)/lib/axtls/ssl -I$(TOP)/lib/axtls/crypto -I$(TOP)/extmod/axtls-include
 AXTLS_DIR = lib/axtls
 GIT_SUBMODULES += $(AXTLS_DIR)
+CFLAGS_EXTMOD += -DMICROPY_SSL_AXTLS=1 -I$(TOP)/lib/axtls/ssl -I$(TOP)/lib/axtls/crypto -I$(TOP)/extmod/axtls-include
 $(BUILD)/$(AXTLS_DIR)/%.o: CFLAGS += -Wno-all -Wno-unused-parameter -Wno-uninitialized -Wno-sign-compare -Wno-old-style-definition -Dmp_stream_errno=errno $(AXTLS_DEFS_EXTRA)
-SRC_MOD += $(addprefix $(AXTLS_DIR)/,\
+SRC_THIRDPARTY_C += $(addprefix $(AXTLS_DIR)/,\
 	ssl/asn1.c \
 	ssl/loader.c \
 	ssl/tls1.c \
@@ -120,8 +131,9 @@ SRC_MOD += $(addprefix $(AXTLS_DIR)/,\
 else ifeq ($(MICROPY_SSL_MBEDTLS),1)
 MBEDTLS_DIR = lib/mbedtls
 GIT_SUBMODULES += $(MBEDTLS_DIR)
-SRC_MOD += lib/mbedtls_errors/mp_mbedtls_errors.c
-SRC_MOD += $(addprefix $(MBEDTLS_DIR)/library/,\
+CFLAGS_EXTMOD += -DMICROPY_SSL_MBEDTLS=1 -I$(TOP)/$(MBEDTLS_DIR)/include
+SRC_THIRDPARTY_C += lib/mbedtls_errors/mp_mbedtls_errors.c
+SRC_THIRDPARTY_C += $(addprefix $(MBEDTLS_DIR)/library/,\
 	aes.c \
 	aesni.c \
 	arc4.c \
@@ -204,10 +216,10 @@ GIT_SUBMODULES += lib/lwip
 # A port should add an include path where lwipopts.h can be found (eg extmod/lwip-include)
 LWIP_DIR = lib/lwip/src
 INC += -I$(TOP)/$(LWIP_DIR)/include
-CFLAGS_MOD += -DMICROPY_PY_LWIP=1
-$(BUILD)/$(LWIP_DIR)/core/ipv4/dhcp.o: CFLAGS_MOD += -Wno-address
-SRC_MOD += shared/netutils/netutils.c
-SRC_MOD += $(addprefix $(LWIP_DIR)/,\
+CFLAGS_EXTMOD += -DMICROPY_PY_LWIP=1
+$(BUILD)/$(LWIP_DIR)/core/ipv4/dhcp.o: CFLAGS += -Wno-address
+SRC_THIRDPARTY_C += shared/netutils/netutils.c
+SRC_THIRDPARTY_C += $(addprefix $(LWIP_DIR)/,\
 	apps/mdns/mdns.c \
 	core/def.c \
 	core/dns.c \
@@ -246,8 +258,8 @@ SRC_MOD += $(addprefix $(LWIP_DIR)/,\
 	netif/ethernet.c \
 	)
 ifeq ($(MICROPY_PY_LWIP_SLIP),1)
-CFLAGS_MOD += -DMICROPY_PY_LWIP_SLIP=1
-SRC_MOD += $(LWIP_DIR)/netif/slipif.c
+CFLAGS_EXTMOD += -DMICROPY_PY_LWIP_SLIP=1
+SRC_THIRDPARTY_C += $(LWIP_DIR)/netif/slipif.c
 endif
 endif
 
@@ -258,8 +270,7 @@ 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
-SRC_MOD += $(addprefix $(BTREE_DIR)/,\
+SRC_THIRDPARTY_C += $(addprefix $(BTREE_DIR)/,\
 	btree/bt_close.c \
 	btree/bt_conv.c \
 	btree/bt_debug.c \
@@ -275,10 +286,67 @@ SRC_MOD += $(addprefix $(BTREE_DIR)/,\
 	btree/bt_utils.c \
 	mpool/mpool.c \
 	)
-CFLAGS_MOD += -DMICROPY_PY_BTREE=1
+CFLAGS_EXTMOD += -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
 $(BUILD)/$(BTREE_DIR)/%.o: CFLAGS += -Wno-old-style-definition -Wno-sign-compare -Wno-unused-parameter $(BTREE_DEFS)
 $(BUILD)/extmod/modbtree.o: CFLAGS += $(BTREE_DEFS)
 endif
 
+################################################################################
+# networking
+
+ifeq ($(MICROPY_PY_NETWORK_CYW43),1)
+CFLAGS_EXTMOD += -DMICROPY_PY_NETWORK_CYW43=1
+DRIVERS_SRC_C += drivers/cyw43/cyw43_ctrl.c drivers/cyw43/cyw43_lwip.c
+LIBS += $(TOP)/drivers/cyw43/libcyw43.a
+endif
+
+ifneq ($(MICROPY_PY_NETWORK_WIZNET5K),)
+ifneq ($(MICROPY_PY_NETWORK_WIZNET5K),0)
+WIZNET5K_DIR=lib/wiznet5k
+GIT_SUBMODULES += lib/wiznet5k
+INC += -I$(TOP)/$(WIZNET5K_DIR) -I$(TOP)/$(WIZNET5K_DIR)/Ethernet
+CFLAGS += -DMICROPY_PY_NETWORK_WIZNET5K=$(MICROPY_PY_NETWORK_WIZNET5K) -D_WIZCHIP_=$(MICROPY_PY_NETWORK_WIZNET5K)
+CFLAGS_THIRDPARTY += -DWIZCHIP_PREFIXED_EXPORTS=1
+ifeq ($(MICROPY_PY_LWIP),1)
+# When using MACRAW mode (with lwIP), maximum buffer space must be used for the raw socket
+CFLAGS_THIRDPARTY += -DWIZCHIP_USE_MAX_BUFFER
+endif
+SRC_THIRDPARTY_C += $(addprefix $(WIZNET5K_DIR)/,\
+	Ethernet/W$(MICROPY_PY_NETWORK_WIZNET5K)/w$(MICROPY_PY_NETWORK_WIZNET5K).c \
+	Ethernet/wizchip_conf.c \
+	Ethernet/socket.c \
+	Internet/DNS/dns.c \
+	Internet/DHCP/dhcp.c \
+	)
+endif
+endif
+
+################################################################################
+# bluetooth
+
+ifeq ($(MICROPY_PY_BLUETOOTH),1)
+CFLAGS_EXTMOD += -DMICROPY_PY_BLUETOOTH=1
+
+ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
+$(error Cannot enable both NimBLE and BTstack at the same time)
+endif
+endif
+
+ifneq ($(MICROPY_BLUETOOTH_NIMBLE),1)
+ifneq ($(MICROPY_BLUETOOTH_BTSTACK),1)
+$(error Must enable one of MICROPY_BLUETOOTH_NIMBLE or MICROPY_BLUETOOTH_BTSTACK)
+endif
+endif
+
+ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
+include $(TOP)/extmod/nimble/nimble.mk
+endif
+
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
+include $(TOP)/extmod/btstack/btstack.mk
+endif
+
+endif
diff --git a/extmod/network_wiznet5k.c b/extmod/network_wiznet5k.c
index af20145081..78cbff4ce2 100644
--- a/extmod/network_wiznet5k.c
+++ b/extmod/network_wiznet5k.c
@@ -33,6 +33,9 @@
 #include "py/stream.h"
 #include "py/mperrno.h"
 #include "py/mphal.h"
+
+#if MICROPY_PY_NETWORK_WIZNET5K
+
 #include "shared/netutils/netutils.h"
 #include "extmod/modnetwork.h"
 #include "extmod/machine_spi.h"
@@ -40,8 +43,6 @@
 #include "modmachine.h"
 #include "drivers/bus/spi.h"
 
-#if MICROPY_PY_NETWORK_WIZNET5K
-
 #include "lib/wiznet5k/Ethernet/wizchip_conf.h"
 
 // The WIZNET5K module supports two usage modes:
diff --git a/extmod/nimble/nimble.mk b/extmod/nimble/nimble.mk
index e825261eea..fc1709f0e5 100644
--- a/extmod/nimble/nimble.mk
+++ b/extmod/nimble/nimble.mk
@@ -5,15 +5,15 @@ ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
 EXTMOD_DIR = extmod
 NIMBLE_EXTMOD_DIR = $(EXTMOD_DIR)/nimble
 
-EXTMOD_SRC_C += $(NIMBLE_EXTMOD_DIR)/modbluetooth_nimble.c
+SRC_EXTMOD_C += $(NIMBLE_EXTMOD_DIR)/modbluetooth_nimble.c
 
-CFLAGS_MOD += -DMICROPY_BLUETOOTH_NIMBLE=1
+CFLAGS_EXTMOD += -DMICROPY_BLUETOOTH_NIMBLE=1
 
 # Use NimBLE from the submodule in lib/mynewt-nimble by default,
 # allowing a port to use their own system version (e.g. ESP32).
 MICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY ?= 0
 
-CFLAGS_MOD += -DMICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY=$(MICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY)
+CFLAGS_EXTMOD += -DMICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY=$(MICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY)
 
 ifeq ($(MICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY),0)
 
@@ -24,16 +24,16 @@ GIT_SUBMODULES += lib/mynewt-nimble
 # case, all NimBLE events are run by the MicroPython scheduler. On Unix, the
 # scheduler is also responsible for polling the UART, whereas on STM32 the
 # UART is also polled by the RX IRQ.
-CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS=1
+CFLAGS_EXTMOD += -DMICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS=1
 
 # Without the ringbuffer, and with the full implementation, we can also
 # enable pairing and bonding. This requires both synchronous events and
 # some customisation of the key store.
-CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING=1
+CFLAGS_EXTMOD += -DMICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING=1
 
 NIMBLE_LIB_DIR = lib/mynewt-nimble
 
-LIB_SRC_C += $(addprefix $(NIMBLE_LIB_DIR)/, \
+SRC_THIRDPARTY_C += $(addprefix $(NIMBLE_LIB_DIR)/, \
 	$(addprefix ext/tinycrypt/src/, \
 		aes_encrypt.c \
 		cmac_mode.c \
@@ -98,7 +98,7 @@ LIB_SRC_C += $(addprefix $(NIMBLE_LIB_DIR)/, \
 	)
 	# nimble/host/store/ram/src/ble_store_ram.c \
 
-EXTMOD_SRC_C += $(addprefix $(NIMBLE_EXTMOD_DIR)/, \
+SRC_THIRDPARTY_C += $(addprefix $(NIMBLE_EXTMOD_DIR)/, \
 	nimble/nimble_npl_os.c \
 	hal/hal_uart.c \
 	)
diff --git a/mpy-cross/Makefile b/mpy-cross/Makefile
index 4b6e03df8e..7a71577e2b 100644
--- a/mpy-cross/Makefile
+++ b/mpy-cross/Makefile
@@ -19,7 +19,7 @@ INC += -I$(TOP)
 # compiler settings
 CWARN = -Wall -Werror
 CWARN += -Wextra -Wno-unused-parameter -Wpointer-arith
-CFLAGS += $(INC) $(CWARN) -std=gnu99 $(CFLAGS_MOD) $(COPT) $(CFLAGS_EXTRA)
+CFLAGS += $(INC) $(CWARN) -std=gnu99 $(COPT) $(CFLAGS_EXTRA)
 CFLAGS += -fdata-sections -ffunction-sections -fno-asynchronous-unwind-tables
 
 # Debugging/Optimization
diff --git a/ports/cc3200/Makefile b/ports/cc3200/Makefile
index 6c034c5863..61af0bfd98 100644
--- a/ports/cc3200/Makefile
+++ b/ports/cc3200/Makefile
@@ -23,7 +23,6 @@ CFLAGS_CORTEX_M4 = -mthumb -mtune=cortex-m4 -march=armv7e-m -mabi=aapcs -mcpu=co
 CFLAGS += -Wall -Wpointer-arith -Werror -std=gnu99 -nostdlib $(CFLAGS_CORTEX_M4) -Os
 CFLAGS += -g -ffunction-sections -fdata-sections -fno-common -fsigned-char -mno-unaligned-access
 CFLAGS += -Iboards/$(BOARD)
-CFLAGS += $(CFLAGS_MOD)
 
 # Workaround gcc 12.1 bug.
 CFLAGS += -Wno-array-bounds
diff --git a/ports/esp8266/Makefile b/ports/esp8266/Makefile
index 6002dc5e5a..168d1d9f6a 100644
--- a/ports/esp8266/Makefile
+++ b/ports/esp8266/Makefile
@@ -58,11 +58,11 @@ CFLAGS_XTENSA = -fsingle-precision-constant -Wdouble-promotion \
 	-DLWIP_OPEN_SRC
 
 CFLAGS += $(INC) -Wall -Wpointer-arith -Werror -std=gnu99 -nostdlib -DUART_OS=$(UART_OS) \
-	$(CFLAGS_XTENSA) $(CFLAGS_MOD) $(COPT) $(CFLAGS_EXTRA) -I$(BOARD_DIR)
+	$(CFLAGS_XTENSA) $(COPT) $(CFLAGS_EXTRA) -I$(BOARD_DIR)
 
 LD_FILES ?= boards/esp8266_2m.ld
 LDFLAGS += -nostdlib -T $(LD_FILES) -Map=$(@:.elf=.map) --cref
-LIBS += -L$(ESP_SDK)/lib -lmain -ljson -llwip_open -lpp -lnet80211 -lwpa -lphy -lnet80211 $(LDFLAGS_MOD)
+LIBS += -L$(ESP_SDK)/lib -lmain -ljson -llwip_open -lpp -lnet80211 -lwpa -lphy -lnet80211
 
 LIBGCC_FILE_NAME = $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
 LIBS += -L$(dir $(LIBGCC_FILE_NAME)) -lgcc
@@ -107,11 +107,6 @@ SRC_C = \
 	posix_helpers.c \
 	hspi.c \
 	$(wildcard $(BOARD_DIR)/*.c) \
-	$(SRC_MOD)
-
-EXTMOD_SRC_C = $(addprefix extmod/,\
-	modonewire.c \
-        )
 
 LIB_SRC_C = $(addprefix lib/,\
 	libm/math.c \
@@ -163,17 +158,15 @@ DRIVERS_SRC_C = $(addprefix drivers/,\
 SRC_S = \
 	gchelper.s \
 
-OBJ =
 OBJ += $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_S:.s=.o))
-OBJ += $(addprefix $(BUILD)/, $(EXTMOD_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SHARED_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(LIB_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(DRIVERS_SRC_C:.c=.o))
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(EXTMOD_SRC_C) $(SHARED_SRC_C) $(DRIVERS_SRC_C)
+SRC_QSTR += $(SRC_C) $(SHARED_SRC_C)
 # Append any auto-generated sources that are needed by sources listed in SRC_QSTR
 SRC_QSTR_AUTO_DEPS +=
 
diff --git a/ports/mimxrt/Makefile b/ports/mimxrt/Makefile
index b8b08cb011..640864e582 100644
--- a/ports/mimxrt/Makefile
+++ b/ports/mimxrt/Makefile
@@ -150,10 +150,6 @@ SRC_C += \
 	drivers/bus/softspi.c \
 	drivers/dht/dht.c \
 	eth.c \
-	extmod/modnetwork.c \
-	extmod/modonewire.c \
-	extmod/modusocket.c \
-	extmod/uos_dupterm.c \
 	fatfs_port.c \
 	hal/pwm_backport.c \
 	led.c \
@@ -257,16 +253,6 @@ SRC_S += shared/runtime/gchelper_m3.s \
 # QSTR Sources
 # =============================================================================
 
-# All settings for Ethernet support are controller by the value of MICROPY_PY_LWIP
-ifeq ($(MICROPY_PY_LWIP),1)
-SRC_QSTR += \
-	extmod/modlwip.c \
-	extmod/modnetwork.c \
-	extmod/modusocket.c \
-	extmod/moduwebsocket.c \
-	network_lan.c
-endif
-
 # List of sources for qstr extraction
 SRC_QSTR += \
 	extmod/modonewire.c \
@@ -386,7 +372,7 @@ CFLAGS += \
 	-DMBEDTLS_CONFIG_FILE='"mbedtls/mbedtls_config.h"'
 endif
 
-CFLAGS += $(CFLAGS_MOD) $(CFLAGS_EXTRA)
+CFLAGS += $(CFLAGS_EXTRA)
 
 # =============================================================================
 # Linker Flags
@@ -433,7 +419,6 @@ OBJ += $(LIBM_O)
 OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_S:.s=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_SS:.S=.o))
-OBJ += $(addprefix $(BUILD)/, $(SRC_MOD:.c=.o))
 OBJ += $(GEN_PINS_SRC:.c=.o)
 
 # Workaround for bug in older gcc, warning on "static usbd_device_t _usbd_dev = { 0 };"
diff --git a/ports/minimal/Makefile b/ports/minimal/Makefile
index 2e85bd912e..1a20412e0d 100644
--- a/ports/minimal/Makefile
+++ b/ports/minimal/Makefile
@@ -44,11 +44,6 @@ endif
 
 # Flags for optional C++ source code
 CXXFLAGS += $(filter-out -std=c99,$(CFLAGS))
-CXXFLAGS += $(CXXFLAGS_MOD)
-
-# Flags for user C modules
-CFLAGS += $(CFLAGS_MOD)
-LDFLAGS += $(LDFLAGS_MOD)
 
 LIBS =
 
@@ -65,14 +60,10 @@ ifeq ($(CROSS), 1)
 SRC_C += shared/libc/string0.c
 endif
 
-SRC_C += $(SRC_MOD)
-
-SRC_CXX += $(SRC_MOD_CXX)
-
 SRC_QSTR += shared/readline/readline.c shared/runtime/pyexec.c
-SRC_QSTR += $(SRC_MOD) $(SRC_MOD_CXX)
 
-OBJ += $(PY_CORE_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
+OBJ += $(PY_CORE_O)
+OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_CXX:.cpp=.o))
 
 ifeq ($(CROSS), 1)
diff --git a/ports/nrf/Makefile b/ports/nrf/Makefile
index 9e0354194d..4128404da4 100644
--- a/ports/nrf/Makefile
+++ b/ports/nrf/Makefile
@@ -132,9 +132,8 @@ CFLAGS += -ffunction-sections -fdata-sections
 LDFLAGS += -Wl,--gc-sections
 endif
 
-
 CFLAGS += $(CFLAGS_MCU_$(MCU_SERIES))
-CFLAGS += $(INC) -Wall -Werror -ansi -std=c11 -nostdlib $(COPT) $(NRF_DEFINES) $(CFLAGS_MOD) $(CFLAGS_EXTRA)
+CFLAGS += $(INC) -Wall -Werror -ansi -std=c11 -nostdlib $(COPT) $(NRF_DEFINES) $(CFLAGS_EXTRA)
 CFLAGS += -fno-strict-aliasing
 CFLAGS += -Iboards/$(BOARD)
 CFLAGS += -DNRF5_HAL_H='<$(MCU_VARIANT)_hal.h>'
@@ -357,8 +356,8 @@ SRC_C += \
 LIBGCC_FILE_NAME = $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
 LIBS += -L $(dir $(LIBGCC_FILE_NAME)) -lgcc
 
-OBJ += $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
-OBJ += $(addprefix $(BUILD)/, $(SRC_MOD:.c=.o))
+OBJ += $(PY_O)
+OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_NRFX:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_NRFX_HAL:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(DRIVERS_SRC_C:.c=.o))
@@ -515,11 +514,11 @@ flash: deploy
 
 $(BUILD)/$(OUTPUT_FILENAME).elf: $(OBJ)
 	$(ECHO) "LINK $@"
-	$(Q)$(CC) $(LDFLAGS) -o $@ $(OBJ) $(LDFLAGS_MOD) $(LIBS)
+	$(Q)$(CC) $(LDFLAGS) -o $@ $(OBJ) $(LIBS)
 	$(Q)$(SIZE) $@
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(SRC_LIB) $(DRIVERS_SRC_C) $(SRC_BOARD_MODULES) $(SRC_MOD)
+SRC_QSTR += $(SRC_C) $(SRC_LIB) $(DRIVERS_SRC_C) $(SRC_BOARD_MODULES)
 
 # Append any auto-generated sources that are needed by sources listed in
 # SRC_QSTR
diff --git a/ports/renesas-ra/Makefile b/ports/renesas-ra/Makefile
index 6c37aeb1e1..2b0358b270 100644
--- a/ports/renesas-ra/Makefile
+++ b/ports/renesas-ra/Makefile
@@ -121,7 +121,7 @@ CFLAGS_MCU_RA4W1 = $(CFLAGS_CORTEX_M) -mtune=cortex-m4 -mcpu=cortex-m4
 CFLAGS_MCU_RA6M1 = $(CFLAGS_CORTEX_M) -mtune=cortex-m4 -mcpu=cortex-m4
 CFLAGS_MCU_RA6M2 = $(CFLAGS_CORTEX_M) -mtune=cortex-m4 -mcpu=cortex-m4
 
-CFLAGS += $(INC) -Wall -Wpointer-arith -Werror -Wdouble-promotion -Wfloat-conversion -std=gnu99 -nostdlib $(CFLAGS_MOD) $(CFLAGS_EXTRA)
+CFLAGS += $(INC) -Wall -Wpointer-arith -Werror -Wdouble-promotion -Wfloat-conversion -std=gnu99 -nostdlib $(CFLAGS_EXTRA)
 #CFLAGS += -D$(CMSIS_MCU)
 CFLAGS += $(CFLAGS_MCU_$(CMSIS_MCU))
 CFLAGS += $(COPT)
@@ -161,8 +161,9 @@ endif
 
 # Flags for optional C++ source code
 CXXFLAGS += $(filter-out -Wmissing-prototypes -Wold-style-definition -std=gnu99,$(CFLAGS))
-CXXFLAGS += $(CXXFLAGS_MOD)
-ifneq ($(SRC_CXX)$(SRC_MOD_CXX),)
+
+# TODO make this common -- shouldn't be using these "private" vars from py.mk
+ifneq ($(SRC_CXX)$(SRC_USERMOD_CXX)$(SRC_USERMOD_LIB_CXX),)
 LIBSTDCPP_FILE_NAME = "$(shell $(CXX) $(CXXFLAGS) -print-file-name=libstdc++.a)"
 LDFLAGS += -L"$(shell dirname $(LIBSTDCPP_FILE_NAME))"
 endif
@@ -279,10 +280,6 @@ ifeq ($(MICROPY_FLOAT_IMPL),double)
 $(LIBM_O): CFLAGS := $(filter-out -Wdouble-promotion -Wfloat-conversion, $(CFLAGS))
 endif
 
-EXTMOD_SRC_C += $(addprefix extmod/,\
-	modonewire.c \
-	)
-
 DRIVERS_SRC_C += $(addprefix drivers/,\
 	bus/softspi.c \
 	bus/softqspi.c \
@@ -334,9 +331,6 @@ SRC_C += $(addprefix $(BOARD_DIR)/ra_gen/,\
 	vector_data.c \
 	)
 
-SRC_CXX += \
-	$(SRC_MOD_CXX)
-
 SRC_O += \
 	$(STARTUP_FILE) \
 	$(SYSTEM_FILE)
@@ -408,13 +402,11 @@ OBJ += $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(LIB_SRC_C:.c=.o))
 OBJ += $(LIBM_O)
 OBJ += $(addprefix $(BUILD)/, $(SHARED_SRC_C:.c=.o))
-OBJ += $(addprefix $(BUILD)/, $(EXTMOD_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(DRIVERS_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(HAL_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_CXX:.cpp=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_O))
-OBJ += $(addprefix $(BUILD)/, $(SRC_MOD:.c=.o))
 OBJ += $(BUILD)/pins_$(BOARD).o
 
 # This file contains performance critical functions so turn up the optimisation
@@ -514,7 +506,7 @@ GEN_PINS_AF_PY = $(BUILD)/pins_af.py
 FILE2H = $(TOP)/tools/file2h.py
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SRC_MOD) $(SHARED_SRC_C) $(EXTMOD_SRC_C)
+SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SHARED_SRC_C)
 
 # Making OBJ use an order-only depenedency on the generated pins.h file
 # has the side effect of making the pins.h file before we actually compile
diff --git a/ports/samd/Makefile b/ports/samd/Makefile
index 9386a8dacc..2c5f6a1ab2 100644
--- a/ports/samd/Makefile
+++ b/ports/samd/Makefile
@@ -60,11 +60,10 @@ CFLAGS_MCU_SAMD21 = -mtune=cortex-m0plus -mcpu=cortex-m0plus -msoft-float
 CFLAGS_MCU_SAMD51 = -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard
 CFLAGS += $(INC) -Wall -Werror -std=c99 -nostdlib -mthumb $(CFLAGS_MCU_$(MCU_SERIES)) -fsingle-precision-constant -Wdouble-promotion
 CFLAGS += -DMCU_$(MCU_SERIES) -D__$(CMSIS_MCU)__
-CFLAGS += $(CFLAGS_MOD) $(CFLAGS_EXTRA)
+CFLAGS += $(CFLAGS_EXTRA)
 CFLAGS += -DMPCONFIG_MCU_H='<boards/mpconfig_$(MCU_SERIES_LOWER).h>'
 
 LDFLAGS += -nostdlib $(addprefix -T,$(LD_FILES)) -Map=$@.map --cref
-LDFLAGS += $(LDFLAGS_MOD)
 
 LIBS += $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
 
@@ -80,7 +79,7 @@ endif
 
 # Flags for optional C++ source code
 CXXFLAGS += $(filter-out -std=c99,$(CFLAGS))
-CXXFLAGS += $(CXXFLAGS_MOD)
+
 # TODO make this common -- shouldn't be using these "private" vars from py.mk
 ifneq ($(SRC_CXX)$(SRC_USERMOD_CXX)$(SRC_USERMOD_LIB_CXX),)
 LIBSTDCPP_FILE_NAME = "$(shell $(CXX) $(CXXFLAGS) -print-file-name=libstdc++.a)"
@@ -114,10 +113,6 @@ SRC_C += \
 	lib/asf4/$(MCU_SERIES_LOWER)/hal/src/hal_atomic.c \
 	lib/asf4/$(MCU_SERIES_LOWER)/hal/src/hal_flash.c \
 	lib/asf4/$(MCU_SERIES_LOWER)/hpl/nvmctrl/hpl_nvmctrl.c \
-	lib/libm/ef_sqrt.c \
-	lib/libm/fmodf.c \
-	lib/libm/math.c \
-	lib/libm/nearbyintf.c \
 	lib/tinyusb/src/class/cdc/cdc_device.c \
 	lib/tinyusb/src/common/tusb_fifo.c \
 	lib/tinyusb/src/device/usbd.c \
@@ -125,7 +120,6 @@ SRC_C += \
 	lib/tinyusb/src/portable/microchip/samd/dcd_samd.c \
 	lib/tinyusb/src/tusb.c \
 	drivers/bus/softspi.c \
-	extmod/uos_dupterm.c \
 	shared/runtime/mpirq.c \
 	shared/libc/printf.c \
 	shared/libc/string0.c \
@@ -138,9 +132,11 @@ SRC_C += \
 	shared/runtime/sys_stdio_mphal.c \
 	shared/timeutils/timeutils.c \
 
-SRC_C += $(SRC_MOD)
-
-SRC_CXX += $(SRC_MOD_CXX)
+LIBM_SRC_C += \
+	lib/libm/ef_sqrt.c \
+	lib/libm/fmodf.c \
+	lib/libm/math.c \
+	lib/libm/nearbyintf.c \
 
 # List of sources for qstr extraction
 SRC_QSTR += \
@@ -159,17 +155,16 @@ SRC_QSTR += \
 	modsamd.c \
 	samd_flash.c \
 	shared/readline/readline.c \
-	extmod/uos_dupterm.c \
 	shared/runtime/mpirq.c \
 	shared/runtime/sys_stdio_mphal.c \
 
-SRC_QSTR += $(SRC_MOD) $(SRC_CXX)
+SRC_QSTR += $(SRC_CXX)
 
 OBJ += $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_CXX:.cpp=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_S:.s=.o))
-OBJ += $(addprefix $(BUILD)/, $(SRC_MOD:.c=.o))
+OBJ += $(addprefix $(BUILD)/, $(LIBM_SRC_C:.c=.o))
 OBJ += $(GEN_PINS_SRC:.c=.o)
 
 ifneq ($(FROZEN_MANIFEST),)
diff --git a/ports/samd/mcu/samd51/mpconfigmcu.mk b/ports/samd/mcu/samd51/mpconfigmcu.mk
index e83e8911dd..f8ed02f841 100644
--- a/ports/samd/mcu/samd51/mpconfigmcu.mk
+++ b/ports/samd/mcu/samd51/mpconfigmcu.mk
@@ -2,7 +2,7 @@ MICROPY_VFS_LFS2 ?= 1
 
 SRC_S += shared/runtime/gchelper_m3.s
 
-SRC_MOD +=  $(addprefix lib/libm/,\
+LIBM_SRC_C +=  $(addprefix lib/libm/,\
 	acoshf.c \
 	asinfacosf.c \
 	asinhf.c \
diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index 8b503112ae..79bf8b54bf 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -95,7 +95,7 @@ INC += -I$(USBDEV_DIR)/core/inc -I$(USBDEV_DIR)/class/inc
 #INC += -I$(USBHOST_DIR)
 INC += -Ilwip_inc
 
-CFLAGS += $(INC) -Wall -Wpointer-arith -Werror -Wdouble-promotion -Wfloat-conversion -std=gnu99 -nostdlib $(CFLAGS_MOD) $(CFLAGS_EXTRA)
+CFLAGS += $(INC) -Wall -Wpointer-arith -Werror -Wdouble-promotion -Wfloat-conversion -std=gnu99 -nostdlib $(CFLAGS_EXTRA)
 CFLAGS += -D$(CMSIS_MCU) -DUSE_FULL_LL_DRIVER
 CFLAGS += $(CFLAGS_MCU_$(MCU_SERIES))
 CFLAGS += $(COPT)
@@ -156,7 +156,7 @@ endif
 
 # Flags for optional C++ source code
 CXXFLAGS += $(filter-out -Wmissing-prototypes -Wold-style-definition -std=gnu99,$(CFLAGS))
-CXXFLAGS += $(CXXFLAGS_MOD)
+
 # TODO make this common -- shouldn't be using these "private" vars from py.mk
 ifneq ($(SRC_CXX)$(SRC_USERMOD_CXX)$(SRC_USERMOD_LIB_CXX),)
 LIBSTDCPP_FILE_NAME = "$(shell $(CXX) $(CXXFLAGS) -print-file-name=libstdc++.a)"
@@ -275,12 +275,6 @@ ifeq ($(MICROPY_FLOAT_IMPL),double)
 $(LIBM_O): CFLAGS := $(filter-out -Wdouble-promotion -Wfloat-conversion, $(CFLAGS))
 endif
 
-EXTMOD_SRC_C += $(addprefix extmod/,\
-	modonewire.c \
-	modnetwork.c \
-	modusocket.c \
-	)
-
 DRIVERS_SRC_C += $(addprefix drivers/,\
 	bus/softspi.c \
 	bus/softqspi.c \
@@ -358,11 +352,9 @@ SRC_C += \
 	servo.c \
 	dac.c \
 	adc.c \
+	sdio.c \
 	$(wildcard $(BOARD_DIR)/*.c)
 
-SRC_CXX += \
-	$(SRC_MOD_CXX)
-
 SRC_O += \
 	$(STARTUP_FILE) \
 	$(SYSTEM_FILE)
@@ -482,70 +474,26 @@ USBDEV_SRC_C += $(addprefix $(USBDEV_DIR)/,\
 	class/src/usbd_msc_scsi.c \
 	)
 
-ifeq ($(MICROPY_PY_BLUETOOTH),1)
-CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH=1
-CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE=1
-endif
-
-ifeq ($(MICROPY_PY_NETWORK_CYW43),1)
-CFLAGS_MOD += -DMICROPY_PY_NETWORK_CYW43=1
-SRC_C += sdio.c
-EXTMOD_SRC_C += extmod/network_cyw43.c
-DRIVERS_SRC_C += drivers/cyw43/cyw43_ctrl.c drivers/cyw43/cyw43_lwip.c
-LIBS += $(TOP)/drivers/cyw43/libcyw43.a
-endif
-
-ifneq ($(MICROPY_PY_NETWORK_WIZNET5K),0)
-WIZNET5K_DIR=lib/wiznet5k
-GIT_SUBMODULES += lib/wiznet5k
-INC += -I$(TOP)/$(WIZNET5K_DIR) -I$(TOP)/$(WIZNET5K_DIR)/Ethernet
-CFLAGS_MOD += -DMICROPY_PY_NETWORK_WIZNET5K=$(MICROPY_PY_NETWORK_WIZNET5K) -D_WIZCHIP_=$(MICROPY_PY_NETWORK_WIZNET5K)
-CFLAGS_MOD += -DWIZCHIP_PREFIXED_EXPORTS=1
-ifeq ($(MICROPY_PY_LWIP),1)
-# When using MACRAW mode (with lwIP), maximum buffer space must be used for the raw socket
-CFLAGS_MOD += -DWIZCHIP_USE_MAX_BUFFER
-endif
-SRC_MOD += extmod/network_wiznet5k.c
-SRC_MOD += $(addprefix $(WIZNET5K_DIR)/,\
-	Ethernet/W$(MICROPY_PY_NETWORK_WIZNET5K)/w$(MICROPY_PY_NETWORK_WIZNET5K).c \
-	Ethernet/wizchip_conf.c \
-	Ethernet/socket.c \
-	Internet/DNS/dns.c \
-	Internet/DHCP/dhcp.c \
-	)
-endif
-
 ifeq ($(MICROPY_SSL_MBEDTLS),1)
-CFLAGS_MOD += -DMBEDTLS_CONFIG_FILE='"mbedtls/mbedtls_config.h"'
-SRC_MOD += mbedtls/mbedtls_port.c
+CFLAGS += -DMBEDTLS_CONFIG_FILE='"mbedtls/mbedtls_config.h"'
+LIB_SRC_C += mbedtls/mbedtls_port.c
 endif
 
 ifeq ($(MICROPY_PY_BLUETOOTH),1)
-
 SRC_C += mpbthciport.c
 
 ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
-ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
-$(error Cannot enable both NimBLE and BTstack at the same time)
-endif
-endif
-
-ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
-CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS=1
-include $(TOP)/extmod/nimble/nimble.mk
 SRC_C += mpnimbleport.c
 endif
 
 ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
-MICROPY_BLUETOOTH_BTSTACK_H4 ?= 1
-include $(TOP)/extmod/btstack/btstack.mk
 SRC_C += mpbtstackport.c
+MICROPY_BLUETOOTH_BTSTACK_H4 ?= 1
 endif
 
 ifeq ($(MICROPY_PY_NETWORK_CYW43),1)
 DRIVERS_SRC_C += drivers/cyw43/cywbt.c
 endif
-
 endif
 
 # SRC_O should be placed first to work around this LTO bug with binutils <2.35:
@@ -555,7 +503,6 @@ OBJ += $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(LIB_SRC_C:.c=.o))
 OBJ += $(LIBM_O)
 OBJ += $(addprefix $(BUILD)/, $(SHARED_SRC_C:.c=.o))
-OBJ += $(addprefix $(BUILD)/, $(EXTMOD_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(DRIVERS_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(HAL_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(USBDEV_SRC_C:.c=.o))
@@ -713,7 +660,7 @@ $(BUILD)/firmware.elf: $(OBJ)
 	$(call GENERATE_ELF,$@,$^)
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SRC_MOD) $(SHARED_SRC_C) $(EXTMOD_SRC_C)
+SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SHARED_SRC_C)
 # Append any auto-generated sources that are needed by sources listed in
 # SRC_QSTR
 SRC_QSTR_AUTO_DEPS += $(GEN_CDCINF_HEADER)
diff --git a/ports/stm32/mboot/Makefile b/ports/stm32/mboot/Makefile
index 176092f8c0..12ffdbc7e4 100755
--- a/ports/stm32/mboot/Makefile
+++ b/ports/stm32/mboot/Makefile
@@ -58,7 +58,7 @@ INC += -I../$(USBDEV_DIR)/core/inc -I../$(USBDEV_DIR)/class/inc
 # the compiler does not optimise these functions in terms of themselves.
 CFLAGS_BUILTIN ?= -ffreestanding -fno-builtin -fno-lto
 
-CFLAGS += $(INC) -Wall -Wpointer-arith -Wdouble-promotion -Wfloat-conversion -Werror -std=gnu99 -nostdlib $(CFLAGS_MOD) $(CFLAGS_EXTRA)
+CFLAGS += $(INC) -Wall -Wpointer-arith -Wdouble-promotion -Wfloat-conversion -Werror -std=gnu99 -nostdlib $(CFLAGS_EXTRA)
 CFLAGS += -D$(CMSIS_MCU)
 CFLAGS += $(CFLAGS_MCU_$(MCU_SERIES))
 CFLAGS += $(COPT)
diff --git a/ports/stm32/mpconfigport.h b/ports/stm32/mpconfigport.h
index 69b29e8ec3..34b3a6abad 100644
--- a/ports/stm32/mpconfigport.h
+++ b/ports/stm32/mpconfigport.h
@@ -309,6 +309,14 @@ static inline mp_uint_t disable_irq(void) {
 #define MICROPY_PY_BLUETOOTH_HCI_READ_MODE MICROPY_PY_BLUETOOTH_HCI_READ_MODE_BYTE
 #endif
 
+#ifndef MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+#define MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE (1)
+#endif
+
+#ifndef MICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS
+#define MICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS (MICROPY_BLUETOOTH_NIMBLE)
+#endif
+
 // We need an implementation of the log2 function which is not a macro
 #define MP_NEED_LOG2 (1)
 
diff --git a/ports/teensy/Makefile b/ports/teensy/Makefile
index 876ddf1c1d..89e5cbce9d 100644
--- a/ports/teensy/Makefile
+++ b/ports/teensy/Makefile
@@ -164,7 +164,10 @@ SRC_TEENSY = $(addprefix core/,\
 	yield.c \
 	)
 
-OBJ = $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o) $(STM_SRC_C:.c=.o) $(SRC_TEENSY:.c=.o))
+OBJ += $(PY_O)
+OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
+OBJ += $(addprefix $(BUILD)/, $(STM_SRC_C:.c=.o))
+OBJ += $(addprefix $(BUILD)/, $(SRC_TEENSY:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SHARED_SRC_C:.c=.o))
 OBJ += $(BUILD)/shared/runtime/gchelper_m3.o
 OBJ += $(GEN_PINS_SRC:.c=.o)
diff --git a/ports/unix/Makefile b/ports/unix/Makefile
index facdab2e04..360cdd6f8c 100644
--- a/ports/unix/Makefile
+++ b/ports/unix/Makefile
@@ -39,7 +39,7 @@ INC += -I$(BUILD)
 # compiler settings
 CWARN = -Wall -Werror
 CWARN += -Wextra -Wno-unused-parameter -Wpointer-arith -Wdouble-promotion -Wfloat-conversion
-CFLAGS += $(INC) $(CWARN) -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT) -I$(VARIANT_DIR) $(CFLAGS_EXTRA)
+CFLAGS += $(INC) $(CWARN) -std=gnu99 -DUNIX $(COPT) -I$(VARIANT_DIR) $(CFLAGS_EXTRA)
 
 # Debugging/Optimization
 ifdef DEBUG
@@ -142,35 +142,10 @@ endif
 
 # If the variant enables it, enable modbluetooth.
 ifeq ($(MICROPY_PY_BLUETOOTH),1)
-
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
 HAVE_LIBUSB := $(shell (which pkg-config > /dev/null && pkg-config --exists libusb-1.0) 2>/dev/null && echo '1')
 
-# Only one stack can be enabled.
-ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
-ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
-$(error Cannot enable both NimBLE and BTstack at the same time)
-endif
-endif
-
-# Default to btstack, but a variant (or make command line) can set NimBLE
-# explicitly (which is always via H4 UART).
-ifneq ($(MICROPY_BLUETOOTH_NIMBLE),1)
-ifneq ($(MICROPY_BLUETOOTH_BTSTACK),1)
-MICROPY_BLUETOOTH_BTSTACK ?= 1
-endif
-endif
-
-CFLAGS += -DMICROPY_PY_BLUETOOTH=1
-CFLAGS += -DMICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE=1
-
-ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
-
 # Figure out which BTstack transport to use.
-ifeq ($(MICROPY_BLUETOOTH_BTSTACK_H4),1)
-ifeq ($(MICROPY_BLUETOOTH_BTSTACK_USB),1)
-$(error Cannot enable BTstack support for USB and H4 UART at the same time)
-endif
-else
 ifeq ($(HAVE_LIBUSB),1)
 # Default to btstack-over-usb.
 MICROPY_BLUETOOTH_BTSTACK_USB ?= 1
@@ -178,20 +153,9 @@ else
 # Fallback to HCI controller via a H4 UART (e.g. Zephyr on nRF) over a /dev/tty serial port.
 MICROPY_BLUETOOTH_BTSTACK_H4 ?= 1
 endif
+
+SRC_BTSTACK_C += lib/btstack/platform/embedded/btstack_run_loop_embedded.c
 endif
-
-# BTstack is enabled.
-include $(TOP)/extmod/btstack/btstack.mk
-SRC_BTSTACK += lib/btstack/platform/embedded/btstack_run_loop_embedded.c
-
-else
-
-# NimBLE is enabled.
-CFLAGS += -DMICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS=1
-include $(TOP)/extmod/nimble/nimble.mk
-
-endif
-
 endif
 
 ifeq ($(MICROPY_PY_FFI),1)
@@ -242,7 +206,6 @@ SRC_C += \
 	mpbtstackport_h4.c \
 	mpbtstackport_usb.c \
 	mpnimbleport.c \
-	$(SRC_MOD) \
 	modtermios.c \
 	modusocket.c \
 	modffi.c \
@@ -256,17 +219,14 @@ SHARED_SRC_C += $(addprefix shared/,\
 	)
 
 SRC_CXX += \
-	$(SRC_MOD_CXX)
 
 OBJ = $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_CXX:.cpp=.o))
 OBJ += $(addprefix $(BUILD)/, $(SHARED_SRC_C:.c=.o))
-OBJ += $(addprefix $(BUILD)/, $(EXTMOD_SRC_C:.c=.o))
-OBJ += $(addprefix $(BUILD)/, $(LIB_SRC_C:.c=.o))
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SHARED_SRC_C) $(EXTMOD_SRC_C)
+SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SHARED_SRC_C)
 # Append any auto-generated sources that are needed by sources listed in
 # SRC_QSTR
 SRC_QSTR_AUTO_DEPS +=
diff --git a/ports/unix/mpconfigport.h b/ports/unix/mpconfigport.h
index a67d11b9e7..a0b9192bfc 100644
--- a/ports/unix/mpconfigport.h
+++ b/ports/unix/mpconfigport.h
@@ -240,3 +240,11 @@ static inline unsigned long mp_urandom_seed_init(void) {
 // Configure the implementation of machine.idle().
 #include <sched.h>
 #define MICROPY_UNIX_MACHINE_IDLE sched_yield();
+
+#ifndef MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+#define MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE (1)
+#endif
+
+#ifndef MICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS
+#define MICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS (MICROPY_BLUETOOTH_NIMBLE)
+#endif
diff --git a/ports/windows/Makefile b/ports/windows/Makefile
index 64334bc18b..e7f0f2ff61 100644
--- a/ports/windows/Makefile
+++ b/ports/windows/Makefile
@@ -32,7 +32,7 @@ INC += -I$(BUILD)
 INC += -I$(VARIANT_DIR)
 
 # compiler settings
-CFLAGS += $(INC) -Wall -Wpointer-arith -Wdouble-promotion -Werror -std=gnu99 -DUNIX -D__USE_MINGW_ANSI_STDIO=1 $(CFLAGS_MOD) $(COPT) $(CFLAGS_EXTRA)
+CFLAGS += $(INC) -Wall -Wpointer-arith -Wdouble-promotion -Werror -std=gnu99 -DUNIX -D__USE_MINGW_ANSI_STDIO=1 $(COPT) $(CFLAGS_EXTRA)
 LDFLAGS += -lm -lbcrypt $(LDFLAGS_EXTRA)
 
 # Debugging/Optimization
@@ -56,31 +56,26 @@ SRC_C = \
 	realpath.c \
 	init.c \
 	fmode.c \
-	$(SRC_MOD) \
 	$(wildcard $(VARIANT_DIR)/*.c)
 
 SHARED_SRC_C += $(addprefix shared/,\
 	$(SHARED_SRC_C_EXTRA) \
 	)
 
-SRC_CXX += \
-	$(SRC_MOD_CXX)
-
 OBJ = $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_CXX:.cpp=.o))
 OBJ += $(addprefix $(BUILD)/, $(SHARED_SRC_C:.c=.o))
-OBJ += $(addprefix $(BUILD)/, $(EXTMOD_SRC_C:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(LIB_SRC_C:.c=.o))
 
 ifeq ($(MICROPY_USE_READLINE),1)
-CFLAGS_MOD += -DMICROPY_USE_READLINE=1
+CFLAGS += -DMICROPY_USE_READLINE=1
 SRC_C += shared/readline/readline.c
 endif
 
 LIB += -lws2_32
 
 # List of sources for qstr extraction
-SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SHARED_SRC_C) $(EXTMOD_SRC_C)
+SRC_QSTR += $(SRC_C) $(SRC_CXX) $(SHARED_SRC_C)
 # Append any auto-generated sources that are needed by sources listed in
 # SRC_QSTR
 SRC_QSTR_AUTO_DEPS +=
@@ -89,7 +84,7 @@ ifneq ($(FROZEN_MANIFEST),)
 CFLAGS += -DMICROPY_QSTR_EXTRA_POOL=mp_qstr_frozen_const_pool -DMICROPY_MODULE_FROZEN_MPY=1 -DMPZ_DIG_SIZE=16
 endif
 
-CXXFLAGS += $(filter-out -std=gnu99,$(CFLAGS) $(CXXFLAGS_MOD))
+CXXFLAGS += $(filter-out -std=gnu99,$(CFLAGS))
 
 include $(TOP)/py/mkrules.mk
 
diff --git a/py/py.mk b/py/py.mk
index ec69ca42d9..fde612d804 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -207,7 +207,7 @@ endif
 
 # Sources that may contain qstrings
 SRC_QSTR_IGNORE = py/nlr%
-SRC_QSTR += $(SRC_MOD) $(filter-out $(SRC_QSTR_IGNORE),$(PY_CORE_O_BASENAME:.o=.c))
+SRC_QSTR += $(filter-out $(SRC_QSTR_IGNORE),$(PY_CORE_O_BASENAME:.o=.c))
 
 # Anything that depends on FORCE will be considered out-of-date
 FORCE: