From 44aa5b220073830e3cc1477c803cac7acabfcc17 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:23:44 +1100
Subject: [PATCH 01/15] stm32/modnetwork: Remove redundant call to nimble_poll
 in lwip poll.

The bluetooth stack has its own dedicated polling function, see
mod_bluetooth_nimble_poll_wrapper().
---
 ports/stm32/modnetwork.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/ports/stm32/modnetwork.c b/ports/stm32/modnetwork.c
index 8f10612d8c4da..4419bf47684ab 100644
--- a/ports/stm32/modnetwork.c
+++ b/ports/stm32/modnetwork.c
@@ -63,11 +63,6 @@ STATIC void pyb_lwip_poll(void) {
 
     // Run the lwIP internal updates
     sys_check_timeouts();
-
-    #if MICROPY_BLUETOOTH_NIMBLE
-    extern void nimble_poll(void);
-    nimble_poll();
-    #endif
 }
 
 void mod_network_lwip_poll_wrapper(uint32_t ticks_ms) {

From c44d52f33e4ec626c7f6293323300baaeb55e856 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:27:30 +1100
Subject: [PATCH 02/15] extmod/modbluetooth_nimble: Move nimble specific code,
 factor nimble.mk.

Move extmod/modbluetooth_nimble.* to extmod/nimble.  And move common
Makefile lines to extmod/nimble/nimble.mk (which was previously only used
by stm32).  This allows (upcoming) btstack to follow a similar structure.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/{ => nimble}/modbluetooth_nimble.c |  4 ++--
 extmod/{ => nimble}/modbluetooth_nimble.h |  6 +++---
 extmod/nimble/nimble.mk                   | 19 +++++++++++++++----
 ports/esp32/Makefile                      | 14 +++++++-------
 ports/stm32/Makefile                      |  6 +++++-
 ports/stm32/nimble.c                      |  2 +-
 6 files changed, 33 insertions(+), 18 deletions(-)
 rename extmod/{ => nimble}/modbluetooth_nimble.c (99%)
 rename extmod/{ => nimble}/modbluetooth_nimble.h (91%)

diff --git a/extmod/modbluetooth_nimble.c b/extmod/nimble/modbluetooth_nimble.c
similarity index 99%
rename from extmod/modbluetooth_nimble.c
rename to extmod/nimble/modbluetooth_nimble.c
index aa1b032f27a05..f7602c35fd1f2 100644
--- a/extmod/modbluetooth_nimble.c
+++ b/extmod/nimble/modbluetooth_nimble.c
@@ -31,8 +31,8 @@
 
 #if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE
 
-#include "modbluetooth_nimble.h"
-#include "modbluetooth.h"
+#include "extmod/nimble/modbluetooth_nimble.h"
+#include "extmod/modbluetooth.h"
 
 #include "host/ble_hs.h"
 #include "host/util/util.h"
diff --git a/extmod/modbluetooth_nimble.h b/extmod/nimble/modbluetooth_nimble.h
similarity index 91%
rename from extmod/modbluetooth_nimble.h
rename to extmod/nimble/modbluetooth_nimble.h
index e2474a6ee50b9..c70c3bc90ae63 100644
--- a/extmod/modbluetooth_nimble.h
+++ b/extmod/nimble/modbluetooth_nimble.h
@@ -24,8 +24,8 @@
  * THE SOFTWARE.
  */
 
-#ifndef MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_NIMBLE_H
-#define MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_NIMBLE_H
+#ifndef MICROPY_INCLUDED_EXTMOD_NIMBLE_MODBLUETOOTH_NIMBLE_H
+#define MICROPY_INCLUDED_EXTMOD_NIMBLE_MODBLUETOOTH_NIMBLE_H
 
 #define MP_BLUETOOTH_NIMBLE_MAX_SERVICES (8)
 
@@ -51,4 +51,4 @@ void mp_bluetooth_nimble_port_postinit(void);
 void mp_bluetooth_nimble_port_deinit(void);
 void mp_bluetooth_nimble_port_start(void);
 
-#endif // MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_NIMBLE_H
+#endif // MICROPY_INCLUDED_EXTMOD_NIMBLE_MODBLUETOOTH_NIMBLE_H
diff --git a/extmod/nimble/nimble.mk b/extmod/nimble/nimble.mk
index e554e9ff0619f..4d2c6637a4f39 100644
--- a/extmod/nimble/nimble.mk
+++ b/extmod/nimble/nimble.mk
@@ -1,10 +1,21 @@
-# Makefile directives for Apache mynewt nimble BLE component
+# Makefile directives for Apache Mynewt NimBLE component
 
 ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
 
-NIMBLE_LIB_DIR = lib/mynewt-nimble
+EXTMOD_SRC_C += extmod/nimble/modbluetooth_nimble.c
+
+CFLAGS_MOD += -DMICROPY_BLUETOOTH_NIMBLE=1
+
 NIMBLE_EXTMOD_DIR = extmod/nimble
 
+# 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
+
+ifeq ($(MICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY),0)
+
+NIMBLE_LIB_DIR = lib/mynewt-nimble
+
 SRC_LIB += $(addprefix $(NIMBLE_LIB_DIR)/, \
 	$(addprefix ext/tinycrypt/src/, \
 		aes_encrypt.c \
@@ -76,8 +87,6 @@ EXTMOD_SRC_C += $(addprefix $(NIMBLE_EXTMOD_DIR)/, \
 	nimble/hci_uart.c \
 	)
 
-CFLAGS_MOD += -DMICROPY_BLUETOOTH_NIMBLE=1
-
 INC += -I$(TOP)/$(NIMBLE_EXTMOD_DIR)
 INC += -I$(TOP)/$(NIMBLE_LIB_DIR)
 INC += -I$(TOP)/$(NIMBLE_LIB_DIR)/ext/tinycrypt/include
@@ -93,3 +102,5 @@ INC += -I$(TOP)/$(NIMBLE_LIB_DIR)/porting/nimble/include
 $(BUILD)/$(NIMBLE_LIB_DIR)/%.o: CFLAGS += -Wno-maybe-uninitialized -Wno-pointer-arith -Wno-unused-but-set-variable -Wno-format
 
 endif
+
+endif
diff --git a/ports/esp32/Makefile b/ports/esp32/Makefile
index fe4787b7ae338..7033a3dd26c27 100644
--- a/ports/esp32/Makefile
+++ b/ports/esp32/Makefile
@@ -118,7 +118,12 @@ endif
 MICROPY_PY_BLUETOOTH ?= 1
 ifeq ($(MICROPY_PY_BLUETOOTH),1)
 SDKCONFIG += boards/sdkconfig.ble
-MICROPY_BLUETOOTH_NIMBLE = 1
+
+# Use NimBLE on ESP32.
+MICROPY_BLUETOOTH_NIMBLE ?= 1
+# Use Nimble bindings, but ESP32 IDF provides the Nimble library.
+MICROPY_BLUETOOTH_NIMBLE_BINDINGS_ONLY = 1
+include $(TOP)/extmod/nimble/nimble.mk
 endif
 
 # include sdkconfig to get needed configuration values
@@ -244,10 +249,6 @@ INC_NEWLIB += -I$(ESPCOMP)/newlib/include
 ifeq ($(MICROPY_PY_BLUETOOTH),1)
 CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH=1
 CFLAGS_MOD += -DMICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE=1
-
-ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
-CFLAGS_MOD += -DMICROPY_BLUETOOTH_NIMBLE=1
-endif
 endif
 
 # these flags are common to C and C++ compilation
@@ -354,9 +355,8 @@ SRC_C = \
 	$(wildcard $(BOARD_DIR)/*.c) \
 	$(SRC_MOD)
 
-EXTMOD_SRC_C = $(addprefix extmod/,\
+EXTMOD_SRC_C += $(addprefix extmod/,\
 	modonewire.c \
-	modbluetooth_nimble.c \
 	)
 
 LIB_SRC_C = $(addprefix lib/,\
diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index 11db9dfbabf0b..235b251644fb6 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -458,14 +458,18 @@ CFLAGS_MOD += -DMBEDTLS_CONFIG_FILE='"mbedtls/mbedtls_config.h"'
 SRC_MOD += mbedtls/mbedtls_port.c
 endif
 
+ifeq ($(MICROPY_PY_BLUETOOTH),1)
+
 ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
 include $(TOP)/extmod/nimble/nimble.mk
 SRC_C += nimble.c
 SRC_C += nimble_hci_uart.c
-EXTMOD_SRC_C += extmod/modbluetooth_nimble.c
+endif
+
 ifeq ($(MICROPY_PY_NETWORK_CYW43),1)
 DRIVERS_SRC_C += drivers/cyw43/cywbt.c
 endif
+
 endif
 
 OBJ =
diff --git a/ports/stm32/nimble.c b/ports/stm32/nimble.c
index b8fdc8f8866ef..b21b2bede7e90 100644
--- a/ports/stm32/nimble.c
+++ b/ports/stm32/nimble.c
@@ -36,7 +36,7 @@
 #include "transport/uart/ble_hci_uart.h"
 #include "host/ble_hs.h"
 
-#include "extmod/modbluetooth_nimble.h"
+#include "extmod/nimble/modbluetooth_nimble.h"
 
 extern void nimble_uart_process(void);
 extern void os_eventq_run_all(void);

From 894c550c866211c9f176875d40c15fcf3bf74149 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:35:07 +1100
Subject: [PATCH 03/15] stm32: Refactor bluetooth stack/hci/driver bindings.

This makes a cleaner separation between the: driver, HCI UART and BT stack.
Also updated the naming to be more consistent (mp_bluetooth_hci_*).

Work done in collaboration with Jim Mussared aka @jimmo.
---
 drivers/cyw43/cywbt.c                         | 100 +++++++---
 .../cywbt.h => extmod/modbluetooth_hci.h      |  34 +++-
 .../{nimble/hci_uart.c => hal/hal_uart.c}     |  27 ++-
 extmod/nimble/hal/hal_uart.h                  |   1 +
 extmod/nimble/nimble.mk                       |   2 +-
 .../nimble/{hci_uart.h => nimble_hci_uart.h}  |  23 +--
 extmod/nimble/nimble/npl_os.c                 |   4 +-
 ports/stm32/Makefile                          |   3 +-
 ports/stm32/main.c                            |   8 +-
 ports/stm32/modbluetooth_hci.c                | 158 ++++++++++++++++
 ports/stm32/nimble.c                          |  59 ++++--
 ports/stm32/nimble_hci_uart.c                 | 176 ------------------
 ports/stm32/pendsv.h                          |   4 +-
 ports/stm32/systick.h                         |   4 +-
 14 files changed, 338 insertions(+), 265 deletions(-)
 rename drivers/cyw43/cywbt.h => extmod/modbluetooth_hci.h (50%)
 rename extmod/nimble/{nimble/hci_uart.c => hal/hal_uart.c} (78%)
 rename extmod/nimble/nimble/{hci_uart.h => nimble_hci_uart.h} (70%)
 create mode 100644 ports/stm32/modbluetooth_hci.c
 delete mode 100644 ports/stm32/nimble_hci_uart.c

diff --git a/drivers/cyw43/cywbt.c b/drivers/cyw43/cywbt.c
index fae661608dc36..79318f4483ba4 100644
--- a/drivers/cyw43/cywbt.c
+++ b/drivers/cyw43/cywbt.c
@@ -3,7 +3,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (c) 2019 Damien P. George
+ * Copyright (c) 2019-2020 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
@@ -31,8 +31,7 @@
 #include "py/mphal.h"
 #include "pin_static_af.h"
 #include "uart.h"
-#include "cywbt.h"
-#include "nimble/hci_uart.h"
+#include "extmod/modbluetooth_hci.h"
 
 #if MICROPY_PY_NETWORK_CYW43
 
@@ -42,7 +41,7 @@ extern const char fw_4343WA1_7_45_98_50_start;
 /******************************************************************************/
 // CYW BT HCI low-level driver
 
-static void cywbt_wait_cts_low(void) {
+STATIC void cywbt_wait_cts_low(void) {
     mp_hal_pin_config(pyb_pin_BT_CTS, MP_HAL_PIN_MODE_INPUT, MP_HAL_PIN_PULL_UP, 0);
     for (int i = 0; i < 200; ++i) {
         if (mp_hal_pin_read(pyb_pin_BT_CTS) == 0) {
@@ -53,13 +52,13 @@ static void cywbt_wait_cts_low(void) {
     mp_hal_pin_config_alt_static(pyb_pin_BT_CTS, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_UP, STATIC_AF_USART6_CTS);
 }
 
-static int cywbt_hci_cmd_raw(size_t len, uint8_t *buf) {
-    uart_tx_strn(&bt_hci_uart_obj, (void*)buf, len);
+STATIC int cywbt_hci_cmd_raw(size_t len, uint8_t *buf) {
+    uart_tx_strn(&mp_bluetooth_hci_uart_obj, (void*)buf, len);
     for (int i = 0; i < 6; ++i) {
-        while (!uart_rx_any(&bt_hci_uart_obj)) {
+        while (!uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
             MICROPY_EVENT_POLL_HOOK
         }
-        buf[i] = uart_rx_char(&bt_hci_uart_obj);
+        buf[i] = uart_rx_char(&mp_bluetooth_hci_uart_obj);
     }
 
     // expect a comand complete event (event 0x0e)
@@ -76,17 +75,17 @@ static int cywbt_hci_cmd_raw(size_t len, uint8_t *buf) {
 
     int sz = buf[2] - 3;
     for (int i = 0; i < sz; ++i) {
-        while (!uart_rx_any(&bt_hci_uart_obj)) {
+        while (!uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
             MICROPY_EVENT_POLL_HOOK
         }
-        buf[i] = uart_rx_char(&bt_hci_uart_obj);
+        buf[i] = uart_rx_char(&mp_bluetooth_hci_uart_obj);
     }
 
     return 0;
 }
 
-static int cywbt_hci_cmd(int ogf, int ocf, size_t param_len, const uint8_t *param_buf) {
-    uint8_t *buf = bt_hci_cmd_buf;
+STATIC int cywbt_hci_cmd(int ogf, int ocf, size_t param_len, const uint8_t *param_buf) {
+    uint8_t *buf = mp_bluetooth_hci_cmd_buf;
     buf[0] = 0x01;
     buf[1] = ocf;
     buf[2] = ogf << 2 | ocf >> 8;
@@ -97,19 +96,19 @@ static int cywbt_hci_cmd(int ogf, int ocf, size_t param_len, const uint8_t *para
     return cywbt_hci_cmd_raw(4 + param_len, buf);
 }
 
-static void put_le16(uint8_t *buf, uint16_t val) {
+STATIC void put_le16(uint8_t *buf, uint16_t val) {
     buf[0] = val;
     buf[1] = val >> 8;
 }
 
-static void put_le32(uint8_t *buf, uint32_t val) {
+STATIC void put_le32(uint8_t *buf, uint32_t val) {
     buf[0] = val;
     buf[1] = val >> 8;
     buf[2] = val >> 16;
     buf[3] = val >> 24;
 }
 
-static int cywbt_set_baudrate(uint32_t baudrate) {
+STATIC int cywbt_set_baudrate(uint32_t baudrate) {
     uint8_t buf[6];
     put_le16(buf, 0);
     put_le32(buf + 2, baudrate);
@@ -117,12 +116,12 @@ static int cywbt_set_baudrate(uint32_t baudrate) {
 }
 
 // download firmware
-static int cywbt_download_firmware(const uint8_t *firmware) {
+STATIC int cywbt_download_firmware(const uint8_t *firmware) {
     cywbt_hci_cmd(0x3f, 0x2e, 0, NULL);
 
     bool last_packet = false;
     while (!last_packet) {
-        uint8_t *buf = bt_hci_cmd_buf;
+        uint8_t *buf = mp_bluetooth_hci_cmd_buf;
         memcpy(buf + 1, firmware, 3);
         firmware += 3;
         last_packet = buf[1] == 0x4e;
@@ -149,15 +148,15 @@ static int cywbt_download_firmware(const uint8_t *firmware) {
     cywbt_wait_cts_low();
     mp_hal_pin_config(pyb_pin_WL_GPIO_1, MP_HAL_PIN_MODE_INPUT, MP_HAL_PIN_PULL_DOWN, 0); // Select chip antenna (could also select external)
 
-    nimble_hci_uart_set_baudrate(115200);
+    mp_bluetooth_hci_uart_set_baudrate(115200);
     cywbt_set_baudrate(3000000);
-    nimble_hci_uart_set_baudrate(3000000);
+    mp_bluetooth_hci_uart_set_baudrate(3000000);
 
     return 0;
 }
 
-int cywbt_init(void) {
-    // This is called from Nimble via hal_uart_config which will have already initialized the UART.
+int mp_bluetooth_hci_controller_init(void) {
+    // This is called immediately after the UART is initialised during stack initialisation.
 
     mp_hal_pin_output(pyb_pin_BT_REG_ON);
     mp_hal_pin_low(pyb_pin_BT_REG_ON);
@@ -172,11 +171,11 @@ int cywbt_init(void) {
     return 0;
 }
 
-int cywbt_activate(void) {
+int mp_bluetooth_hci_controller_activate(void) {
     uint8_t buf[256];
 
     mp_hal_pin_low(pyb_pin_BT_REG_ON);
-    nimble_hci_uart_set_baudrate(115200);
+    mp_bluetooth_hci_uart_set_baudrate(115200);
     mp_hal_delay_ms(100);
     mp_hal_pin_high(pyb_pin_BT_REG_ON);
     cywbt_wait_cts_low();
@@ -186,7 +185,7 @@ int cywbt_activate(void) {
 
     // Change baudrate
     cywbt_set_baudrate(3000000);
-    nimble_hci_uart_set_baudrate(3000000);
+    mp_bluetooth_hci_uart_set_baudrate(3000000);
 
     cywbt_download_firmware((const uint8_t*)CYWBT_FW_ADDR);
 
@@ -220,4 +219,57 @@ int cywbt_activate(void) {
     return 0;
 }
 
+int mp_bluetooth_hci_controller_deactivate(void) {
+    mp_hal_pin_low(pyb_pin_BT_REG_ON);
+
+    return 0;
+}
+
+#ifdef pyb_pin_BT_DEV_WAKE
+STATIC uint32_t bt_sleep_ticks;
+#endif
+
+int mp_bluetooth_hci_controller_sleep_maybe(void) {
+    #ifdef pyb_pin_BT_DEV_WAKE
+    if (mp_hal_pin_read(pyb_pin_BT_DEV_WAKE) == 0) {
+        if (mp_hal_ticks_ms() - bt_sleep_ticks > 500) {
+            mp_hal_pin_high(pyb_pin_BT_DEV_WAKE); // let sleep
+        }
+    }
+    #endif
+    return 0;
+}
+
+bool mp_bluetooth_hci_controller_woken(void) {
+    #ifdef pyb_pin_BT_HOST_WAKE
+    bool host_wake = mp_hal_pin_read(pyb_pin_BT_HOST_WAKE);
+    /*
+    // this is just for info/tracing purposes
+    static bool last_host_wake = false;
+    if (host_wake != last_host_wake) {
+        printf("HOST_WAKE change %d -> %d\n", last_host_wake, host_wake);
+        last_host_wake = host_wake;
+    }
+    */
+    return host_wake;
+    #else
+    return true;
+    #endif
+}
+
+int mp_bluetooth_hci_controller_wakeup(void) {
+    #ifdef pyb_pin_BT_DEV_WAKE
+    bt_sleep_ticks = mp_hal_ticks_ms();
+
+    if (mp_hal_pin_read(pyb_pin_BT_DEV_WAKE) == 1) {
+        mp_hal_pin_low(pyb_pin_BT_DEV_WAKE); // wake up
+        // Use delay_us rather than delay_ms to prevent running the scheduler (which
+        // might result in more BLE operations).
+        mp_hal_delay_us(5000); // can't go lower than this
+    }
+    #endif
+
+    return 0;
+}
+
 #endif
diff --git a/drivers/cyw43/cywbt.h b/extmod/modbluetooth_hci.h
similarity index 50%
rename from drivers/cyw43/cywbt.h
rename to extmod/modbluetooth_hci.h
index 9809d7f41a5b2..6d44761a4efbe 100644
--- a/drivers/cyw43/cywbt.h
+++ b/extmod/modbluetooth_hci.h
@@ -23,13 +23,33 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-#ifndef MICROPY_INCLUDED_DRIVERS_CYW43_CYWBT_H
-#define MICROPY_INCLUDED_DRIVERS_CYW43_CYWBT_H
 
-extern uint8_t bt_hci_cmd_buf[4 + 256];
-extern pyb_uart_obj_t bt_hci_uart_obj;
+#ifndef MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_HCI_H
+#define MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_HCI_H
 
-int cywbt_init(void);
-int cywbt_activate(void);
+#include "uart.h"
 
-#endif // MICROPY_INCLUDED_DRIVERS_CYW43_CYWBT_H
+// Optionally can be implemented by the driver.
+int mp_bluetooth_hci_controller_init(void);
+int mp_bluetooth_hci_controller_activate(void);
+int mp_bluetooth_hci_controller_deactivate(void);
+
+// Tell the controller to go to sleep (e.g. on RX if we don't think we're expecting anything more).
+int mp_bluetooth_hci_controller_sleep_maybe(void);
+// True if the controller woke us up.
+bool mp_bluetooth_hci_controller_woken(void);
+// Wake up the controller (e.g. we're about to TX).
+int mp_bluetooth_hci_controller_wakeup(void);
+
+// Storage and bindings that need to be implemented by the port.
+// These are used by the stack bindings (e.g. nimble/hal_uart.c)
+// as well as potentially the driver (e.g. cywbt.c).
+extern uint8_t mp_bluetooth_hci_cmd_buf[4 + 256];
+extern pyb_uart_obj_t mp_bluetooth_hci_uart_obj;
+
+int mp_bluetooth_hci_uart_init(uint32_t port);
+int mp_bluetooth_hci_uart_activate(void);
+int mp_bluetooth_hci_uart_set_baudrate(uint32_t baudrate);
+int mp_bluetooth_hci_uart_write(const uint8_t *buf, size_t len);
+
+#endif // MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_HCI_H
diff --git a/extmod/nimble/nimble/hci_uart.c b/extmod/nimble/hal/hal_uart.c
similarity index 78%
rename from extmod/nimble/nimble/hci_uart.c
rename to extmod/nimble/hal/hal_uart.c
index b4ac4e738828e..fba82b830438a 100644
--- a/extmod/nimble/nimble/hci_uart.c
+++ b/extmod/nimble/hal/hal_uart.c
@@ -28,14 +28,11 @@
 #include "py/mphal.h"
 #include "pin_static_af.h"
 #include "nimble/ble.h"
-#include "hal/hal_uart.h"
-#include "hci_uart.h"
+#include "extmod/nimble/hal/hal_uart.h"
+#include "extmod/modbluetooth_hci.h"
+#include "extmod/nimble/nimble/nimble_hci_uart.h"
 
-#if MICROPY_BLUETOOTH_NIMBLE
-
-/******************************************************************************/
-// Bindings Uart to Nimble
-uint8_t bt_hci_cmd_buf[4 + 256];
+#if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE
 
 static hal_uart_tx_cb_t hal_uart_tx_cb;
 static void *hal_uart_tx_arg;
@@ -51,9 +48,9 @@ int hal_uart_init_cbs(uint32_t port, hal_uart_tx_cb_t tx_cb, void *tx_arg, hal_u
 }
 
 int hal_uart_config(uint32_t port, uint32_t baudrate, uint32_t bits, uint32_t stop, uint32_t parity, uint32_t flow) {
-    nimble_hci_uart_configure(port);
-    nimble_hci_uart_set_baudrate(baudrate);
-    return nimble_hci_uart_activate();
+    mp_bluetooth_hci_uart_init(port);
+    mp_bluetooth_hci_uart_set_baudrate(baudrate);
+    return mp_bluetooth_hci_uart_activate();
 }
 
 void hal_uart_start_tx(uint32_t port) {
@@ -63,7 +60,7 @@ void hal_uart_start_tx(uint32_t port) {
         if (data == -1) {
             break;
         }
-        bt_hci_cmd_buf[len++] = data;
+        mp_bluetooth_hci_cmd_buf[len++] = data;
     }
 
     #if 0
@@ -74,15 +71,15 @@ void hal_uart_start_tx(uint32_t port) {
     printf("\n");
     #endif
 
-    nimble_hci_uart_tx_strn((void*)bt_hci_cmd_buf, len);
+    mp_bluetooth_nimble_hci_uart_tx_strn((void*)mp_bluetooth_hci_cmd_buf, len);
 }
 
 int hal_uart_close(uint32_t port) {
     return 0; // success
 }
 
-void nimble_uart_process(void) {
-    nimble_hci_uart_rx(hal_uart_rx_cb, hal_uart_rx_arg);
+void mp_bluetooth_nimble_hci_uart_process(void) {
+    mp_bluetooth_nimble_hci_uart_rx(hal_uart_rx_cb, hal_uart_rx_arg);
 }
 
-#endif // MICROPY_BLUETOOTH_NIMBLE
+#endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE
diff --git a/extmod/nimble/hal/hal_uart.h b/extmod/nimble/hal/hal_uart.h
index 294dfb50dd451..0ef04bc81e026 100644
--- a/extmod/nimble/hal/hal_uart.h
+++ b/extmod/nimble/hal/hal_uart.h
@@ -10,6 +10,7 @@
 typedef int (*hal_uart_tx_cb_t)(void *arg);
 typedef int (*hal_uart_rx_cb_t)(void *arg, uint8_t data);
 
+// Called by NimBLE, implemented in hal_uart.c.
 int hal_uart_init_cbs(uint32_t port, hal_uart_tx_cb_t tx_cb, void *tx_arg, hal_uart_rx_cb_t rx_cb, void *rx_arg);
 int hal_uart_config(uint32_t port, uint32_t baud, uint32_t bits, uint32_t stop, uint32_t parity, uint32_t flow);
 void hal_uart_start_tx(uint32_t port);
diff --git a/extmod/nimble/nimble.mk b/extmod/nimble/nimble.mk
index 4d2c6637a4f39..60dbe60b0a24d 100644
--- a/extmod/nimble/nimble.mk
+++ b/extmod/nimble/nimble.mk
@@ -84,7 +84,7 @@ SRC_LIB += $(addprefix $(NIMBLE_LIB_DIR)/, \
 
 EXTMOD_SRC_C += $(addprefix $(NIMBLE_EXTMOD_DIR)/, \
 	nimble/npl_os.c \
-	nimble/hci_uart.c \
+	hal/hal_uart.c \
 	)
 
 INC += -I$(TOP)/$(NIMBLE_EXTMOD_DIR)
diff --git a/extmod/nimble/nimble/hci_uart.h b/extmod/nimble/nimble/nimble_hci_uart.h
similarity index 70%
rename from extmod/nimble/nimble/hci_uart.h
rename to extmod/nimble/nimble/nimble_hci_uart.h
index 3d4a2a9835f17..646a12dac1460 100644
--- a/extmod/nimble/nimble/hci_uart.h
+++ b/extmod/nimble/nimble/nimble_hci_uart.h
@@ -23,21 +23,18 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-#ifndef MICROPY_INCLUDED_EXTMOD_NIMBLE_NIMBLE_HCI_UART_H
-#define MICROPY_INCLUDED_EXTMOD_NIMBLE_NIMBLE_HCI_UART_H
+#ifndef MICROPY_INCLUDED_EXTMOD_NIMBLE_NIMBLE_NIMBLE_HCI_UART_H
+#define MICROPY_INCLUDED_EXTMOD_NIMBLE_NIMBLE_NIMBLE_HCI_UART_H
 
-#include "extmod/nimble/hal/hal_uart.h"
-
-// To be implemented by the port.
+// Extensions to extmod/modbluetooth_hci.h specific to NimBLE.
 
-int nimble_hci_uart_configure(uint32_t port);
-
-// This will default to MICROPY_HW_BLE_UART_BAUDRATE, but can be updated later.
-int nimble_hci_uart_set_baudrate(uint32_t baudrate);
+#include "extmod/nimble/hal/hal_uart.h"
 
-int nimble_hci_uart_activate(void);
+// Helpers called from ports.
+void mp_bluetooth_nimble_hci_uart_process(void);
 
-void nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg);
-void nimble_hci_uart_tx_strn(const char *str, uint len);
+// Must be provided by the port.
+void mp_bluetooth_nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg);
+void mp_bluetooth_nimble_hci_uart_tx_strn(const char *str, uint len);
 
-#endif // MICROPY_INCLUDED_EXTMOD_NIMBLE_NIMBLE_HCI_UART_H
+#endif // MICROPY_INCLUDED_EXTMOD_NIMBLE_NIMBLE_NIMBLE_HCI_UART_H
diff --git a/extmod/nimble/nimble/npl_os.c b/extmod/nimble/nimble/npl_os.c
index 4875d2d1ad45c..57ab689e6b6c1 100644
--- a/extmod/nimble/nimble/npl_os.c
+++ b/extmod/nimble/nimble/npl_os.c
@@ -29,6 +29,7 @@
 #include "py/runtime.h"
 #include "nimble/ble.h"
 #include "nimble/nimble_npl.h"
+#include "nimble/nimble_hci_uart.h"
 
 #define DEBUG_OS_printf(...) //printf(__VA_ARGS__)
 #define DEBUG_MALLOC_printf(...) //printf(__VA_ARGS__)
@@ -234,8 +235,7 @@ ble_npl_error_t ble_npl_sem_pend(struct ble_npl_sem *sem, ble_npl_time_t timeout
     if (sem->count == 0) {
         uint32_t t0 = mp_hal_ticks_ms();
         while (sem->count == 0 && mp_hal_ticks_ms() - t0 < timeout) {
-            extern void nimble_uart_process(void);
-            nimble_uart_process();
+            mp_bluetooth_nimble_hci_uart_process();
             if (sem->count != 0) {
                 break;
             }
diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index 235b251644fb6..fab2f621b22a2 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -460,10 +460,11 @@ endif
 
 ifeq ($(MICROPY_PY_BLUETOOTH),1)
 
+SRC_C += modbluetooth_hci.c
+
 ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
 include $(TOP)/extmod/nimble/nimble.mk
 SRC_C += nimble.c
-SRC_C += nimble_hci_uart.c
 endif
 
 ifeq ($(MICROPY_PY_NETWORK_CYW43),1)
diff --git a/ports/stm32/main.c b/ports/stm32/main.c
index e221df0d0fa74..78973f41184d7 100644
--- a/ports/stm32/main.c
+++ b/ports/stm32/main.c
@@ -49,7 +49,7 @@
 #include "drivers/cyw43/cyw43.h"
 #endif
 
-#if MICROPY_BLUETOOTH_NIMBLE
+#if MICROPY_PY_BLUETOOTH
 #include "extmod/modbluetooth.h"
 #endif
 
@@ -539,9 +539,9 @@ void stm32_main(uint32_t reset_mode) {
     #endif
     systick_enable_dispatch(SYSTICK_DISPATCH_LWIP, mod_network_lwip_poll_wrapper);
     #endif
-    #if MICROPY_BLUETOOTH_NIMBLE
-    extern void mod_bluetooth_nimble_poll_wrapper(uint32_t ticks_ms);
-    systick_enable_dispatch(SYSTICK_DISPATCH_NIMBLE, mod_bluetooth_nimble_poll_wrapper);
+    #if MICROPY_PY_BLUETOOTH
+    extern void mp_bluetooth_hci_poll_wrapper(uint32_t ticks_ms);
+    systick_enable_dispatch(SYSTICK_DISPATCH_BLUETOOTH_HCI, mp_bluetooth_hci_poll_wrapper);
     #endif
 
     #if MICROPY_PY_NETWORK_CYW43
diff --git a/ports/stm32/modbluetooth_hci.c b/ports/stm32/modbluetooth_hci.c
new file mode 100644
index 0000000000000..c6937b2b2a169
--- /dev/null
+++ b/ports/stm32/modbluetooth_hci.c
@@ -0,0 +1,158 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018-2020 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 "py/mphal.h"
+#include "extmod/modbluetooth_hci.h"
+#include "systick.h"
+#include "pendsv.h"
+
+#include "py/obj.h"
+
+#if MICROPY_PY_BLUETOOTH
+
+uint8_t mp_bluetooth_hci_cmd_buf[4 + 256];
+
+// Must be provided by the stack bindings.
+extern void mp_bluetooth_hci_poll(void);
+
+// Hook for pendsv poller to run this periodically every 128ms
+#define BLUETOOTH_HCI_TICK(tick) (((tick) & ~(SYSTICK_DISPATCH_NUM_SLOTS - 1) & 0x7f) == 0)
+
+// Called periodically (systick) or directly (e.g. uart irq).
+void mp_bluetooth_hci_poll_wrapper(uint32_t ticks_ms) {
+    if (ticks_ms == 0 || BLUETOOTH_HCI_TICK(ticks_ms)) {
+        pendsv_schedule_dispatch(PENDSV_DISPATCH_BLUETOOTH_HCI, mp_bluetooth_hci_poll);
+    }
+}
+
+#if defined(STM32WB)
+
+/******************************************************************************/
+// HCI over IPCC
+
+#include "rfcore.h"
+
+int mp_bluetooth_hci_controller_deactivate(void) {
+    return 0;
+}
+
+int mp_bluetooth_hci_controller_sleep_maybe(void) {
+    return 0;
+}
+
+bool mp_bluetooth_hci_controller_woken(void) {
+    return true;
+}
+
+int mp_bluetooth_hci_controller_wakeup(void) {
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_init(uint32_t port) {
+    (void)port;
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_activate(void) {
+    rfcore_ble_init();
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_set_baudrate(uint32_t baudrate) {
+    (void)baudrate;
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_write(const uint8_t *buf, size_t len) {
+    MICROPY_PY_BLUETOOTH_ENTER
+    rfcore_ble_hci_cmd(len, (const uint8_t *)buf);
+    MICROPY_PY_BLUETOOTH_EXIT
+    return 0;
+}
+
+#else
+
+/******************************************************************************/
+// HCI over UART
+
+#include "pendsv.h"
+#include "uart.h"
+
+pyb_uart_obj_t mp_bluetooth_hci_uart_obj;
+
+static uint8_t hci_uart_rxbuf[512];
+
+mp_obj_t mp_uart_interrupt(mp_obj_t self_in) {
+    // New HCI data, schedule mp_bluetooth_hci_poll to make the stack handle it.
+    mp_bluetooth_hci_poll_wrapper(0);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(mp_uart_interrupt_obj, mp_uart_interrupt);
+
+int mp_bluetooth_hci_uart_init(uint32_t port) {
+    // bits (8), stop (1), parity (none) and flow (rts/cts) are assumed to match MYNEWT_VAL_BLE_HCI_UART_ constants in syscfg.h.
+    mp_bluetooth_hci_uart_obj.base.type = &pyb_uart_type;
+    mp_bluetooth_hci_uart_obj.uart_id = port;
+    mp_bluetooth_hci_uart_obj.is_static = true;
+    mp_bluetooth_hci_uart_obj.timeout = 2;
+    mp_bluetooth_hci_uart_obj.timeout_char = 2;
+    MP_STATE_PORT(pyb_uart_obj_all)[mp_bluetooth_hci_uart_obj.uart_id - 1] = &mp_bluetooth_hci_uart_obj;
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_set_baudrate(uint32_t baudrate) {
+    uart_init(&mp_bluetooth_hci_uart_obj, baudrate, UART_WORDLENGTH_8B, UART_PARITY_NONE, UART_STOPBITS_1, UART_HWCONTROL_RTS | UART_HWCONTROL_CTS);
+    uart_set_rxbuf(&mp_bluetooth_hci_uart_obj, sizeof(hci_uart_rxbuf), hci_uart_rxbuf);
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_activate(void) {
+    // Interrupt on RX chunk received (idle)
+    // Trigger stack poll when this happens
+    mp_obj_t uart_irq_fn = mp_load_attr(MP_OBJ_FROM_PTR(&mp_bluetooth_hci_uart_obj), MP_QSTR_irq);
+    mp_obj_t uargs[] = {
+        MP_OBJ_FROM_PTR(&mp_uart_interrupt_obj),
+        MP_OBJ_NEW_SMALL_INT(UART_FLAG_IDLE),
+        mp_const_true,
+    };
+    mp_call_function_n_kw(uart_irq_fn, 3, 0, uargs);
+
+    mp_bluetooth_hci_controller_init();
+    mp_bluetooth_hci_controller_activate();
+
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_write(const uint8_t *buf, size_t len) {
+    mp_bluetooth_hci_controller_wakeup();
+    uart_tx_strn(&mp_bluetooth_hci_uart_obj, (void *)buf, len);
+    return 0;
+}
+
+#endif // defined(STM32WB)
+
+#endif // MICROPY_PY_BLUETOOTH
diff --git a/ports/stm32/nimble.c b/ports/stm32/nimble.c
index b21b2bede7e90..ff78a0a1a3d55 100644
--- a/ports/stm32/nimble.c
+++ b/ports/stm32/nimble.c
@@ -4,6 +4,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Jim Mussared
+ * Copyright (c) 2020 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
@@ -30,37 +31,26 @@
 
 #if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE
 
-#include "systick.h"
-#include "pendsv.h"
-
 #include "transport/uart/ble_hci_uart.h"
 #include "host/ble_hs.h"
 
+#include "extmod/modbluetooth_hci.h"
 #include "extmod/nimble/modbluetooth_nimble.h"
+#include "extmod/nimble/nimble/nimble_hci_uart.h"
 
-extern void nimble_uart_process(void);
 extern void os_eventq_run_all(void);
 extern void os_callout_process(void);
 
-// Hook for pendsv poller to run this periodically every 128ms
-#define NIMBLE_TICK(tick) (((tick) & ~(SYSTICK_DISPATCH_NUM_SLOTS - 1) & 0x7f) == 0)
-
-void nimble_poll(void) {
+void mp_bluetooth_hci_poll(void) {
     if (mp_bluetooth_nimble_ble_state == MP_BLUETOOTH_NIMBLE_BLE_STATE_OFF) {
         return;
     }
 
-    nimble_uart_process();
+    mp_bluetooth_nimble_hci_uart_process();
     os_callout_process();
     os_eventq_run_all();
 }
 
-void mod_bluetooth_nimble_poll_wrapper(uint32_t ticks_ms) {
-    if (NIMBLE_TICK(ticks_ms)) {
-        pendsv_schedule_dispatch(PENDSV_DISPATCH_NIMBLE, nimble_poll);
-    }
-}
-
 void mp_bluetooth_nimble_port_preinit(void) {
     MP_STATE_PORT(bluetooth_nimble_memory) = NULL;
     ble_hci_uart_init();
@@ -70,13 +60,46 @@ void mp_bluetooth_nimble_port_postinit(void) {
 }
 
 void mp_bluetooth_nimble_port_deinit(void) {
-    #ifdef pyb_pin_BT_REG_ON
-    mp_hal_pin_low(pyb_pin_BT_REG_ON);
-    #endif
+    mp_bluetooth_hci_controller_deactivate();
 }
 
 void mp_bluetooth_nimble_port_start(void) {
     ble_hs_start();
 }
 
+#if defined(STM32WB)
+
+#include "rfcore.h"
+
+void mp_bluetooth_nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg) {
+    // Protect in case it's called from ble_npl_sem_pend at thread-level
+    MICROPY_PY_LWIP_ENTER
+    rfcore_ble_check_msg(rx_cb, rx_arg);
+    MICROPY_PY_LWIP_EXIT
+}
+
+#else
+
+#include "uart.h"
+
+void mp_bluetooth_nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg) {
+    bool host_wake = mp_bluetooth_hci_controller_woken();
+
+    while (uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
+        uint8_t data = uart_rx_char(&mp_bluetooth_hci_uart_obj);
+        //printf("UART RX: %02x\n", data);
+        rx_cb(rx_arg, data);
+    }
+
+    if (host_wake) {
+        mp_bluetooth_hci_controller_sleep_maybe();
+    }
+}
+
+#endif // defined(STM32WB)
+
+void mp_bluetooth_nimble_hci_uart_tx_strn(const char *str, uint len) {
+    mp_bluetooth_hci_uart_write((const uint8_t *)str, len);
+}
+
 #endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE
diff --git a/ports/stm32/nimble_hci_uart.c b/ports/stm32/nimble_hci_uart.c
deleted file mode 100644
index 11608558780b6..0000000000000
--- a/ports/stm32/nimble_hci_uart.c
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2018-2019 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 "py/mphal.h"
-#include "extmod/nimble/nimble/hci_uart.h"
-
-#if MICROPY_BLUETOOTH_NIMBLE
-
-#if defined(STM32WB)
-
-/******************************************************************************/
-// HCI over IPCC
-
-#include "rfcore.h"
-
-int nimble_hci_uart_configure(uint32_t port) {
-    (void)port;
-    return 0;
-}
-
-int nimble_hci_uart_set_baudrate(uint32_t baudrate) {
-    (void)baudrate;
-    return 0;
-}
-
-int nimble_hci_uart_activate(void) {
-    rfcore_ble_init();
-    return 0;
-}
-
-void nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg) {
-    // Protect in case it's called from ble_npl_sem_pend at thread-level
-    MICROPY_PY_LWIP_ENTER
-    rfcore_ble_check_msg(rx_cb, rx_arg);
-    MICROPY_PY_LWIP_EXIT
-}
-
-void nimble_hci_uart_tx_strn(const char *str, uint len) {
-    MICROPY_PY_LWIP_ENTER
-    rfcore_ble_hci_cmd(len, (const uint8_t *)str);
-    MICROPY_PY_LWIP_EXIT
-}
-
-#else
-
-/******************************************************************************/
-// HCI over UART
-
-#include "pendsv.h"
-#include "uart.h"
-#include "drivers/cyw43/cywbt.h"
-
-pyb_uart_obj_t bt_hci_uart_obj;
-static uint8_t hci_uart_rxbuf[512];
-
-#ifdef pyb_pin_BT_DEV_WAKE
-static uint32_t bt_sleep_ticks;
-#endif
-
-extern void nimble_poll(void);
-
-mp_obj_t mp_uart_interrupt(mp_obj_t self_in) {
-    pendsv_schedule_dispatch(PENDSV_DISPATCH_NIMBLE, nimble_poll);
-    return mp_const_none;
-}
-MP_DEFINE_CONST_FUN_OBJ_1(mp_uart_interrupt_obj, mp_uart_interrupt);
-
-int nimble_hci_uart_set_baudrate(uint32_t baudrate) {
-    uart_init(&bt_hci_uart_obj, baudrate, UART_WORDLENGTH_8B, UART_PARITY_NONE, UART_STOPBITS_1, UART_HWCONTROL_RTS | UART_HWCONTROL_CTS);
-    uart_set_rxbuf(&bt_hci_uart_obj, sizeof(hci_uart_rxbuf), hci_uart_rxbuf);
-    return 0;
-}
-
-int nimble_hci_uart_configure(uint32_t port) {
-    // bits (8), stop (1), parity (none) and flow (rts/cts) are assumed to match MYNEWT_VAL_BLE_HCI_UART_ constants in syscfg.h.
-    bt_hci_uart_obj.base.type = &pyb_uart_type;
-    bt_hci_uart_obj.uart_id = port;
-    bt_hci_uart_obj.is_static = true;
-    bt_hci_uart_obj.timeout = 2;
-    bt_hci_uart_obj.timeout_char = 2;
-    MP_STATE_PORT(pyb_uart_obj_all)[bt_hci_uart_obj.uart_id - 1] = &bt_hci_uart_obj;
-    return 0;
-}
-
-int nimble_hci_uart_activate(void) {
-    // Interrupt on RX chunk received (idle)
-    // Trigger nimble poll when this happens
-    mp_obj_t uart_irq_fn = mp_load_attr(MP_OBJ_FROM_PTR(&bt_hci_uart_obj), MP_QSTR_irq);
-    mp_obj_t uargs[] = {
-        MP_OBJ_FROM_PTR(&mp_uart_interrupt_obj),
-        MP_OBJ_NEW_SMALL_INT(UART_FLAG_IDLE),
-        mp_const_true,
-    };
-    mp_call_function_n_kw(uart_irq_fn, 3, 0, uargs);
-
-    #if MICROPY_PY_NETWORK_CYW43
-    cywbt_init();
-    cywbt_activate();
-    #endif
-
-    return 0;
-}
-
-void nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg) {
-    #ifdef pyb_pin_BT_HOST_WAKE
-    int host_wake = 0;
-    host_wake = mp_hal_pin_read(pyb_pin_BT_HOST_WAKE);
-    /*
-    // this is just for info/tracing purposes
-    static int last_host_wake = 0;
-    if (host_wake != last_host_wake) {
-        printf("HOST_WAKE change %d -> %d\n", last_host_wake, host_wake);
-        last_host_wake = host_wake;
-    }
-    */
-    #endif
-
-    while (uart_rx_any(&bt_hci_uart_obj)) {
-        uint8_t data = uart_rx_char(&bt_hci_uart_obj);
-        //printf("UART RX: %02x\n", data);
-        rx_cb(rx_arg, data);
-    }
-
-    #ifdef pyb_pin_BT_DEV_WAKE
-    if (host_wake == 1 && mp_hal_pin_read(pyb_pin_BT_DEV_WAKE) == 0) {
-        if (mp_hal_ticks_ms() - bt_sleep_ticks > 500) {
-            //printf("BT SLEEP\n");
-            mp_hal_pin_high(pyb_pin_BT_DEV_WAKE); // let sleep
-        }
-    }
-    #endif
-}
-
-void nimble_hci_uart_tx_strn(const char *str, uint len) {
-    #ifdef pyb_pin_BT_DEV_WAKE
-    bt_sleep_ticks = mp_hal_ticks_ms();
-
-    if (mp_hal_pin_read(pyb_pin_BT_DEV_WAKE) == 1) {
-        //printf("BT WAKE for TX\n");
-        mp_hal_pin_low(pyb_pin_BT_DEV_WAKE); // wake up
-        // Use delay_us rather than delay_ms to prevent running the scheduler (which
-        // might result in more BLE operations).
-        mp_hal_delay_us(5000); // can't go lower than this
-    }
-    #endif
-
-    uart_tx_strn(&bt_hci_uart_obj, str, len);
-}
-
-#endif // defined(STM32WB)
-
-#endif // MICROPY_BLUETOOTH_NIMBLE
diff --git a/ports/stm32/pendsv.h b/ports/stm32/pendsv.h
index dd3f8f2cb38b8..585f81e8bd441 100644
--- a/ports/stm32/pendsv.h
+++ b/ports/stm32/pendsv.h
@@ -34,8 +34,8 @@ enum {
     PENDSV_DISPATCH_CYW43,
     #endif
     #endif
-    #if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE
-    PENDSV_DISPATCH_NIMBLE,
+    #if MICROPY_PY_BLUETOOTH
+    PENDSV_DISPATCH_BLUETOOTH_HCI,
     #endif
     PENDSV_DISPATCH_MAX
 };
diff --git a/ports/stm32/systick.h b/ports/stm32/systick.h
index a70f03e176a30..6aef3f2e4e731 100644
--- a/ports/stm32/systick.h
+++ b/ports/stm32/systick.h
@@ -37,8 +37,8 @@ enum {
     #if MICROPY_PY_NETWORK && MICROPY_PY_LWIP
     SYSTICK_DISPATCH_LWIP,
     #endif
-    #if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE
-    SYSTICK_DISPATCH_NIMBLE,
+    #if MICROPY_PY_BLUETOOTH
+    SYSTICK_DISPATCH_BLUETOOTH_HCI,
     #endif
     SYSTICK_DISPATCH_MAX
 };

From 0ac06a510af8290e2c5e3a1f43c87d232e460b9b Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:37:32 +1100
Subject: [PATCH 04/15] extmod/modbluetooth: Extract out gatts_db functionality
 from nimble.

For use by other stacks, if they need it.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/modbluetooth.c               | 62 +++++++++++++++++++++
 extmod/modbluetooth.h               | 36 ++++++++++++-
 extmod/nimble/modbluetooth_nimble.c | 83 +++++------------------------
 extmod/nimble/modbluetooth_nimble.h |  4 +-
 4 files changed, 113 insertions(+), 72 deletions(-)

diff --git a/extmod/modbluetooth.c b/extmod/modbluetooth.c
index 1d8a73848fef2..75fbeedb508b6 100644
--- a/extmod/modbluetooth.c
+++ b/extmod/modbluetooth.c
@@ -1088,4 +1088,66 @@ bool mp_bluetooth_gatts_on_read_request(uint16_t conn_handle, uint16_t value_han
 }
 #endif
 
+void mp_bluetooth_gatts_db_create_entry(mp_gatts_db_t db, uint16_t handle, size_t len) {
+    mp_map_elem_t *elem = mp_map_lookup(db, MP_OBJ_NEW_SMALL_INT(handle), MP_MAP_LOOKUP_ADD_IF_NOT_FOUND);
+    mp_bluetooth_gatts_db_entry_t *entry = m_new(mp_bluetooth_gatts_db_entry_t, 1);
+    entry->data = m_new(uint8_t, len);
+    entry->data_alloc = len;
+    entry->data_len = 0;
+    entry->append = false;
+    elem->value = MP_OBJ_FROM_PTR(entry);
+}
+
+mp_bluetooth_gatts_db_entry_t *mp_bluetooth_gatts_db_lookup(mp_gatts_db_t db, uint16_t handle) {
+    mp_map_elem_t *elem = mp_map_lookup(db, MP_OBJ_NEW_SMALL_INT(handle), MP_MAP_LOOKUP);
+    if (!elem) {
+        return NULL;
+    }
+    return MP_OBJ_TO_PTR(elem->value);
+}
+
+int mp_bluetooth_gatts_db_read(mp_gatts_db_t db, uint16_t handle, uint8_t **value, size_t *value_len) {
+    mp_bluetooth_gatts_db_entry_t *entry = mp_bluetooth_gatts_db_lookup(db, handle);
+    if (!entry) {
+        return MP_EINVAL;
+    }
+
+    *value = entry->data;
+    *value_len = entry->data_len;
+    if (entry->append) {
+        entry->data_len = 0;
+    }
+
+    return 0;
+}
+
+int mp_bluetooth_gatts_db_write(mp_gatts_db_t db, uint16_t handle, const uint8_t *value, size_t value_len) {
+    mp_bluetooth_gatts_db_entry_t *entry = mp_bluetooth_gatts_db_lookup(db, handle);
+    if (!entry) {
+        return MP_EINVAL;
+    }
+
+    if (value_len > entry->data_alloc) {
+        entry->data = m_new(uint8_t, value_len);
+        entry->data_alloc = value_len;
+    }
+
+    memcpy(entry->data, value, value_len);
+    entry->data_len = value_len;
+
+    return 0;
+}
+
+int mp_bluetooth_gatts_db_resize(mp_gatts_db_t db, uint16_t handle, size_t len, bool append) {
+    mp_bluetooth_gatts_db_entry_t *entry = mp_bluetooth_gatts_db_lookup(db, handle);
+    if (!entry) {
+        return MP_EINVAL;
+    }
+    entry->data = m_renew(uint8_t, entry->data, entry->data_alloc, len);
+    entry->data_alloc = len;
+    entry->data_len = 0;
+    entry->append = append;
+    return 0;
+}
+
 #endif // MICROPY_PY_BLUETOOTH
diff --git a/extmod/modbluetooth.h b/extmod/modbluetooth.h
index 5e4e2c25a68bb..661130802a319 100644
--- a/extmod/modbluetooth.h
+++ b/extmod/modbluetooth.h
@@ -54,10 +54,12 @@
 #endif
 
 // Common constants.
-#ifndef MP_BLUETOOTH_MAX_ATTR_SIZE
-#define MP_BLUETOOTH_MAX_ATTR_SIZE (20)
+#ifndef MP_BLUETOOTH_DEFAULT_ATTR_LEN
+#define MP_BLUETOOTH_DEFAULT_ATTR_LEN (20)
 #endif
 
+#define MP_BLUETOOTH_CCCB_LEN (2)
+
 // Advertisement packet lengths
 #define MP_BLUETOOTH_GAP_ADV_MAX_LEN (32)
 
@@ -267,4 +269,34 @@ void mp_bluetooth_gattc_on_data_available_end(void);
 void mp_bluetooth_gattc_on_write_status(uint16_t conn_handle, uint16_t value_handle, uint16_t status);
 #endif
 
+// For stacks that don't manage attribute value data (currently all of them), helpers
+// to store this in a map, keyed by value handle.
+
+typedef struct {
+    // Pointer to heap-allocated data.
+    uint8_t *data;
+    // Allocated size of data.
+    size_t data_alloc;
+    // Current bytes in use.
+    size_t data_len;
+    // Whether new writes append or replace existing data (default false).
+    bool append;
+} mp_bluetooth_gatts_db_entry_t;
+
+typedef mp_map_t *mp_gatts_db_t;
+
+STATIC inline void mp_bluetooth_gatts_db_create(mp_gatts_db_t *db) {
+    *db = m_new(mp_map_t, 1);
+}
+
+STATIC inline void mp_bluetooth_gatts_db_reset(mp_gatts_db_t db) {
+    mp_map_init(db, 0);
+}
+
+void mp_bluetooth_gatts_db_create_entry(mp_gatts_db_t db, uint16_t handle, size_t len);
+mp_bluetooth_gatts_db_entry_t *mp_bluetooth_gatts_db_lookup(mp_gatts_db_t db, uint16_t handle);
+int mp_bluetooth_gatts_db_read(mp_gatts_db_t db, uint16_t handle, uint8_t **value, size_t *value_len);
+int mp_bluetooth_gatts_db_write(mp_gatts_db_t db, uint16_t handle, const uint8_t *value, size_t value_len);
+int mp_bluetooth_gatts_db_resize(mp_gatts_db_t db, uint16_t handle, size_t len, bool append);
+
 #endif // MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_H
diff --git a/extmod/nimble/modbluetooth_nimble.c b/extmod/nimble/modbluetooth_nimble.c
index f7602c35fd1f2..8ef7c6f31d809 100644
--- a/extmod/nimble/modbluetooth_nimble.c
+++ b/extmod/nimble/modbluetooth_nimble.c
@@ -153,17 +153,6 @@ STATIC ble_addr_t create_nimble_addr(uint8_t addr_type, const uint8_t *addr) {
 
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
 
-typedef struct {
-    // Pointer to heap-allocated data.
-    uint8_t *data;
-    // Allocated size of data.
-    size_t data_alloc;
-    // Current bytes in use.
-    size_t data_len;
-    // Whether new writes append or replace existing data (default false).
-    bool append;
-} gatts_db_entry_t;
-
 volatile int mp_bluetooth_nimble_ble_state = MP_BLUETOOTH_NIMBLE_BLE_STATE_OFF;
 
 STATIC void reset_cb(int reason) {
@@ -195,8 +184,8 @@ STATIC void sync_cb(void) {
         assert(rc == 0);
     }
 
-    if (MP_BLUETOOTH_MAX_ATTR_SIZE > 20) {
-        rc = ble_att_set_preferred_mtu(MP_BLUETOOTH_MAX_ATTR_SIZE + 3);
+    if (MP_BLUETOOTH_DEFAULT_ATTR_LEN > 20) {
+        rc = ble_att_set_preferred_mtu(MP_BLUETOOTH_DEFAULT_ATTR_LEN + 3);
         assert(rc == 0);
     }
 
@@ -205,16 +194,6 @@ STATIC void sync_cb(void) {
     mp_bluetooth_nimble_ble_state = MP_BLUETOOTH_NIMBLE_BLE_STATE_ACTIVE;
 }
 
-STATIC void create_gatts_db_entry(uint16_t handle) {
-    mp_map_elem_t *elem = mp_map_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, MP_OBJ_NEW_SMALL_INT(handle), MP_MAP_LOOKUP_ADD_IF_NOT_FOUND);
-    gatts_db_entry_t *entry = m_new(gatts_db_entry_t, 1);
-    entry->data = m_new(uint8_t, MP_BLUETOOTH_MAX_ATTR_SIZE);
-    entry->data_alloc = MP_BLUETOOTH_MAX_ATTR_SIZE;
-    entry->data_len = 0;
-    entry->append = false;
-    elem->value = MP_OBJ_FROM_PTR(entry);
-}
-
 STATIC void gatts_register_cb(struct ble_gatt_register_ctxt *ctxt, void *arg) {
     switch (ctxt->op) {
         case BLE_GATT_REGISTER_OP_SVC:
@@ -232,7 +211,7 @@ STATIC void gatts_register_cb(struct ble_gatt_register_ctxt *ctxt, void *arg) {
 
             // Allocate the gatts_db storage for this characteristic.
             // Although this function is a callback, it's called synchronously from ble_hs_sched_start/ble_gatts_start, so safe to allocate.
-            create_gatts_db_entry(ctxt->chr.val_handle);
+            mp_bluetooth_gatts_db_create_entry(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, ctxt->chr.val_handle, MP_BLUETOOTH_DEFAULT_ATTR_LEN);
             break;
 
         case BLE_GATT_REGISTER_OP_DSC:
@@ -241,7 +220,7 @@ STATIC void gatts_register_cb(struct ble_gatt_register_ctxt *ctxt, void *arg) {
             DEBUG_EVENT_printf("gatts_register_cb: dsc uuid=%p handle=%d\n", &ctxt->dsc.dsc_def->uuid, ctxt->dsc.handle);
 
             // See above, safe to alloc.
-            create_gatts_db_entry(ctxt->dsc.handle);
+            mp_bluetooth_gatts_db_create_entry(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, ctxt->dsc.handle, MP_BLUETOOTH_DEFAULT_ATTR_LEN);
 
             // Unlike characteristics, we have to manually provide a way to get the handle back to the register method.
             *((uint16_t *)ctxt->dsc.dsc_def->arg) = ctxt->dsc.handle;
@@ -291,7 +270,7 @@ int mp_bluetooth_init(void) {
     ble_hs_cfg.store_status_cb = ble_store_util_status_rr;
 
     MP_STATE_PORT(bluetooth_nimble_root_pointers) = m_new0(mp_bluetooth_nimble_root_pointers_t, 1);
-    MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db = m_new(mp_map_t, 1);
+    mp_bluetooth_gatts_db_create(&MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db);
 
     mp_bluetooth_nimble_ble_state = MP_BLUETOOTH_NIMBLE_BLE_STATE_STARTING;
 
@@ -408,8 +387,7 @@ void mp_bluetooth_gap_advertise_stop(void) {
 
 static int characteristic_access_cb(uint16_t conn_handle, uint16_t value_handle, struct ble_gatt_access_ctxt *ctxt, void *arg) {
     DEBUG_EVENT_printf("characteristic_access_cb: conn_handle=%u value_handle=%u op=%u\n", conn_handle, value_handle, ctxt->op);
-    mp_map_elem_t *elem;
-    gatts_db_entry_t *entry;
+    mp_bluetooth_gatts_db_entry_t *entry;
     switch (ctxt->op) {
         case BLE_GATT_ACCESS_OP_READ_CHR:
         case BLE_GATT_ACCESS_OP_READ_DSC:
@@ -420,22 +398,20 @@ static int characteristic_access_cb(uint16_t conn_handle, uint16_t value_handle,
             }
             #endif
 
-            elem = mp_map_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, MP_OBJ_NEW_SMALL_INT(value_handle), MP_MAP_LOOKUP);
-            if (!elem) {
+            entry = mp_bluetooth_gatts_db_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, value_handle);
+            if (!entry) {
                 return BLE_ATT_ERR_ATTR_NOT_FOUND;
             }
-            entry = MP_OBJ_TO_PTR(elem->value);
 
             os_mbuf_append(ctxt->om, entry->data, entry->data_len);
 
             return 0;
         case BLE_GATT_ACCESS_OP_WRITE_CHR:
         case BLE_GATT_ACCESS_OP_WRITE_DSC:
-            elem = mp_map_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, MP_OBJ_NEW_SMALL_INT(value_handle), MP_MAP_LOOKUP);
-            if (!elem) {
+            entry = mp_bluetooth_gatts_db_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, value_handle);
+            if (!entry) {
                 return BLE_ATT_ERR_ATTR_NOT_FOUND;
             }
-            entry = MP_OBJ_TO_PTR(elem->value);
 
             size_t offset = 0;
             if (entry->append) {
@@ -458,7 +434,7 @@ int mp_bluetooth_gatts_register_service_begin(bool append) {
     }
 
     // Reset the gatt characteristic value db.
-    mp_map_init(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, 0);
+    mp_bluetooth_gatts_db_reset(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db);
 
     // By default, just register the default gap service.
     ble_svc_gap_init();
@@ -551,33 +527,11 @@ int mp_bluetooth_gap_disconnect(uint16_t conn_handle) {
 }
 
 int mp_bluetooth_gatts_read(uint16_t value_handle, uint8_t **value, size_t *value_len) {
-    mp_map_elem_t *elem = mp_map_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, MP_OBJ_NEW_SMALL_INT(value_handle), MP_MAP_LOOKUP);
-    if (!elem) {
-        return MP_EINVAL;
-    }
-    gatts_db_entry_t *entry = MP_OBJ_TO_PTR(elem->value);
-    *value = entry->data;
-    *value_len = entry->data_len;
-    if (entry->append) {
-        entry->data_len = 0;
-    }
-    return 0;
+    return mp_bluetooth_gatts_db_read(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, value_handle, value, value_len);
 }
 
 int mp_bluetooth_gatts_write(uint16_t value_handle, const uint8_t *value, size_t value_len) {
-    mp_map_elem_t *elem = mp_map_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, MP_OBJ_NEW_SMALL_INT(value_handle), MP_MAP_LOOKUP);
-    if (!elem) {
-        return MP_EINVAL;
-    }
-    gatts_db_entry_t *entry = MP_OBJ_TO_PTR(elem->value);
-    if (value_len > entry->data_alloc) {
-        entry->data = m_new(uint8_t, value_len);
-        entry->data_alloc = value_len;
-    }
-
-    memcpy(entry->data, value, value_len);
-    entry->data_len = value_len;
-    return 0;
+    return mp_bluetooth_gatts_db_write(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, value_handle, value, value_len);
 }
 
 // TODO: Could use ble_gatts_chr_updated to send to all subscribed centrals.
@@ -602,16 +556,7 @@ int mp_bluetooth_gatts_indicate(uint16_t conn_handle, uint16_t value_handle) {
 }
 
 int mp_bluetooth_gatts_set_buffer(uint16_t value_handle, size_t len, bool append) {
-    mp_map_elem_t *elem = mp_map_lookup(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, MP_OBJ_NEW_SMALL_INT(value_handle), MP_MAP_LOOKUP);
-    if (!elem) {
-        return MP_EINVAL;
-    }
-    gatts_db_entry_t *entry = MP_OBJ_TO_PTR(elem->value);
-    entry->data = m_renew(uint8_t, entry->data, entry->data_alloc, len);
-    entry->data_alloc = len;
-    entry->data_len = 0;
-    entry->append = append;
-    return 0;
+    return mp_bluetooth_gatts_db_resize(MP_STATE_PORT(bluetooth_nimble_root_pointers)->gatts_db, value_handle, len, append);
 }
 
 #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
diff --git a/extmod/nimble/modbluetooth_nimble.h b/extmod/nimble/modbluetooth_nimble.h
index c70c3bc90ae63..745ff968255dc 100644
--- a/extmod/nimble/modbluetooth_nimble.h
+++ b/extmod/nimble/modbluetooth_nimble.h
@@ -27,11 +27,13 @@
 #ifndef MICROPY_INCLUDED_EXTMOD_NIMBLE_MODBLUETOOTH_NIMBLE_H
 #define MICROPY_INCLUDED_EXTMOD_NIMBLE_MODBLUETOOTH_NIMBLE_H
 
+#include "extmod/modbluetooth.h"
+
 #define MP_BLUETOOTH_NIMBLE_MAX_SERVICES (8)
 
 typedef struct _mp_bluetooth_nimble_root_pointers_t {
     // Characteristic (and descriptor) value storage.
-    mp_map_t *gatts_db;
+    mp_gatts_db_t gatts_db;
 
     // Pending service definitions.
     size_t n_services;

From d35fefe30ac70a5f1c74e85f06ddbad2177f808a Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:39:50 +1100
Subject: [PATCH 05/15] lib: Add BlueKitchen BTstack submodule.

---
 .gitmodules | 3 +++
 lib/btstack | 1 +
 2 files changed, 4 insertions(+)
 create mode 160000 lib/btstack

diff --git a/.gitmodules b/.gitmodules
index 3880ea60a0df2..9d07e70449d47 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -30,3 +30,6 @@
 [submodule "lib/mynewt-nimble"]
 	path = lib/mynewt-nimble
 	url = https://github.com/apache/mynewt-nimble.git
+[submodule "lib/btstack"]
+	path = lib/btstack
+	url = https://github.com/bluekitchen/btstack.git
diff --git a/lib/btstack b/lib/btstack
new file mode 160000
index 0000000000000..a6121b51b229b
--- /dev/null
+++ b/lib/btstack
@@ -0,0 +1 @@
+Subproject commit a6121b51b229b883431c4a1600b0f46db31d32dc

From fbefcef1df377e9205392f8656ae70eab00d9559 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:40:55 +1100
Subject: [PATCH 06/15] extmod/btstack: Add empty modbluetooth implementation.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/btstack/btstack.mk             |  48 ++++++++++
 extmod/btstack/btstack_config.h       |  44 +++++++++
 extmod/btstack/modbluetooth_btstack.c | 128 ++++++++++++++++++++++++++
 extmod/btstack/modbluetooth_btstack.h |  30 ++++++
 4 files changed, 250 insertions(+)
 create mode 100644 extmod/btstack/btstack.mk
 create mode 100644 extmod/btstack/btstack_config.h
 create mode 100644 extmod/btstack/modbluetooth_btstack.c
 create mode 100644 extmod/btstack/modbluetooth_btstack.h

diff --git a/extmod/btstack/btstack.mk b/extmod/btstack/btstack.mk
new file mode 100644
index 0000000000000..0a6876b22762e
--- /dev/null
+++ b/extmod/btstack/btstack.mk
@@ -0,0 +1,48 @@
+# Makefile directives for BlueKitchen BTstack
+
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
+
+BTSTACK_EXTMOD_DIR = extmod/btstack
+
+EXTMOD_SRC_C += extmod/btstack/modbluetooth_btstack.c
+
+INC += -I$(TOP)/$(BTSTACK_EXTMOD_DIR)
+
+CFLAGS_MOD += -DMICROPY_BLUETOOTH_BTSTACK=1
+
+BTSTACK_DIR = $(TOP)/lib/btstack
+
+include $(BTSTACK_DIR)/src/Makefile.inc
+include $(BTSTACK_DIR)/src/ble/Makefile.inc
+
+INC += -I$(BTSTACK_DIR)/src
+INC += -I$(BTSTACK_DIR)/3rd-party/bluedroid/decoder/include
+INC += -I$(BTSTACK_DIR)/3rd-party/bluedroid/encoder/include
+INC += -I$(BTSTACK_DIR)/3rd-party/md5
+INC += -I$(BTSTACK_DIR)/3rd-party/yxml
+
+SRC_BTSTACK = \
+	$(addprefix lib/btstack/src/, $(SRC_FILES)) \
+	$(addprefix lib/btstack/src/ble/, $(filter-out %_tlv.c, $(SRC_BLE_FILES))) \
+	lib/btstack/platform/embedded/btstack_run_loop_embedded.c \
+
+ifeq ($MICROPY_BLUETOOTH_BTSTACK_ENABLE_CLASSIC,1)
+include $(BTSTACK_DIR)/src/classic/Makefile.inc
+SRC_BTSTACK += \
+	$(addprefix lib/btstack/src/classic/, $(SRC_CLASSIC_FILES))
+endif
+
+SRC_LIB += $(SRC_BTSTACK)
+
+#$(BUILD)/lib/btstack/src/classic/btstack_link_key_db_static.o: CFLAGS += -Wno-error=pointer-arith
+
+# Incorrect %u, should be %lu.
+$(BUILD)/lib/btstack/src/classic/a2dp_source.o: CFLAGS += -Wno-error=format=
+$(BUILD)/lib/btstack/src/classic/btstack_sbc_decoder_bluedroid.o: CFLAGS += -Wno-error=format=
+$(BUILD)/lib/btstack/src/classic/btstack_link_key_db_tlv.o: CFLAGS += -Wno-error=format=
+$(BUILD)/lib/btstack/src/classic/goep_client.o: CFLAGS += -Wno-error=format=
+$(BUILD)/lib/btstack/src/ble/le_device_db_tlv.o: CFLAGS += -Wno-error=format=
+
+
+
+endif
diff --git a/extmod/btstack/btstack_config.h b/extmod/btstack/btstack_config.h
new file mode 100644
index 0000000000000..0976bbe7284df
--- /dev/null
+++ b/extmod/btstack/btstack_config.h
@@ -0,0 +1,44 @@
+#ifndef MICROPY_INCLUDED_EXTMOD_BTSTACK_BTSTACK_CONFIG_H
+#define MICROPY_INCLUDED_EXTMOD_BTSTACK_BTSTACK_CONFIG_H
+
+// BTstack features that can be enabled
+#define ENABLE_BLE
+#define ENABLE_LE_PERIPHERAL
+#define ENABLE_LE_CENTRAL
+// #define ENABLE_CLASSIC
+#define ENABLE_LE_DATA_CHANNELS
+// #define ENABLE_LOG_INFO
+#define ENABLE_LOG_ERROR
+
+// BTstack configuration. buffers, sizes, ...
+#define HCI_ACL_PAYLOAD_SIZE 1021
+#define MAX_NR_GATT_CLIENTS 1
+#define MAX_NR_HCI_CONNECTIONS 1
+#define MAX_NR_L2CAP_SERVICES  3
+#define MAX_NR_L2CAP_CHANNELS  3
+#define MAX_NR_RFCOMM_MULTIPLEXERS 1
+#define MAX_NR_RFCOMM_SERVICES 1
+#define MAX_NR_RFCOMM_CHANNELS 1
+#define MAX_NR_BTSTACK_LINK_KEY_DB_MEMORY_ENTRIES  2
+#define MAX_NR_BNEP_SERVICES 1
+#define MAX_NR_BNEP_CHANNELS 1
+#define MAX_NR_HFP_CONNECTIONS 1
+#define MAX_NR_WHITELIST_ENTRIES 1
+#define MAX_NR_SM_LOOKUP_ENTRIES 3
+#define MAX_NR_SERVICE_RECORD_ITEMS 1
+#define MAX_NR_AVDTP_STREAM_ENDPOINTS 1
+#define MAX_NR_AVDTP_CONNECTIONS 1
+#define MAX_NR_AVRCP_CONNECTIONS 1
+
+#define MAX_NR_LE_DEVICE_DB_ENTRIES 4
+
+// Link Key DB and LE Device DB using TLV on top of Flash Sector interface
+// #define NVM_NUM_DEVICE_DB_ENTRIES 16
+
+// We don't give btstack a malloc, so use a fixed-size ATT DB.
+#define MAX_ATT_DB_SIZE 512
+
+// BTstack HAL configuration
+#define HAVE_EMBEDDED_TIME_MS
+
+#endif // MICROPY_INCLUDED_EXTMOD_BTSTACK_BTSTACK_CONFIG_H
diff --git a/extmod/btstack/modbluetooth_btstack.c b/extmod/btstack/modbluetooth_btstack.c
new file mode 100644
index 0000000000000..73f28ffad39ba
--- /dev/null
+++ b/extmod/btstack/modbluetooth_btstack.c
@@ -0,0 +1,128 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 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.
+ */
+
+#if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
+
+#include "extmod/btstack/modbluetooth_btstack.h"
+#include "extmod/modbluetooth.h"
+
+int mp_bluetooth_init(void) {
+    return 0;
+}
+
+void mp_bluetooth_deinit(void) {
+}
+
+bool mp_bluetooth_is_enabled(void) {
+    return false;
+}
+
+void mp_bluetooth_get_device_addr(uint8_t *addr) {
+    mp_hal_get_mac(MP_HAL_MAC_BDADDR, addr);
+}
+
+int mp_bluetooth_gap_advertise_start(bool connectable, int32_t interval_us, const uint8_t *adv_data, size_t adv_data_len, const uint8_t *sr_data, size_t sr_data_len) {
+    return 0;
+}
+
+void mp_bluetooth_gap_advertise_stop(void) {
+}
+
+int mp_bluetooth_gatts_register_service_begin(bool append) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_register_service(mp_obj_bluetooth_uuid_t *service_uuid, mp_obj_bluetooth_uuid_t **characteristic_uuids, uint8_t *characteristic_flags, mp_obj_bluetooth_uuid_t **descriptor_uuids, uint8_t *descriptor_flags, uint8_t *num_descriptors, uint16_t *handles, size_t num_characteristics) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_register_service_end(void) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_read(uint16_t value_handle, uint8_t **value, size_t *value_len) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_write(uint16_t value_handle, const uint8_t *value, size_t value_len) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_notify(uint16_t conn_handle, uint16_t value_handle) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_notify_send(uint16_t conn_handle, uint16_t value_handle, const uint8_t *value, size_t *value_len) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_indicate(uint16_t conn_handle, uint16_t value_handle) {
+    return 0;
+}
+
+int mp_bluetooth_gatts_set_buffer(uint16_t value_handle, size_t len, bool append) {
+    return 0;
+}
+
+int mp_bluetooth_gap_disconnect(uint16_t conn_handle) {
+    return 0;
+}
+
+#if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+int mp_bluetooth_gap_scan_start(int32_t duration_ms, int32_t interval_us, int32_t window_us) {
+    return 0;
+}
+
+int mp_bluetooth_gap_scan_stop(void) {
+    return 0;
+}
+
+int mp_bluetooth_gap_peripheral_connect(uint8_t addr_type, const uint8_t *addr, int32_t duration_ms) {
+    return 0;
+}
+
+int mp_bluetooth_gattc_discover_primary_services(uint16_t conn_handle) {
+    return 0;
+}
+
+int mp_bluetooth_gattc_discover_characteristics(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle) {
+    return 0;
+}
+
+int mp_bluetooth_gattc_discover_descriptors(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle) {
+    return 0;
+}
+
+int mp_bluetooth_gattc_read(uint16_t conn_handle, uint16_t value_handle) {
+    return 0;
+}
+
+int mp_bluetooth_gattc_write(uint16_t conn_handle, uint16_t value_handle, const uint8_t *value, size_t *value_len, unsigned int mode) {
+    return 0;
+}
+#endif
+
+#endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
diff --git a/extmod/btstack/modbluetooth_btstack.h b/extmod/btstack/modbluetooth_btstack.h
new file mode 100644
index 0000000000000..f58d3074807cc
--- /dev/null
+++ b/extmod/btstack/modbluetooth_btstack.h
@@ -0,0 +1,30 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 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_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
+#define MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
+
+#endif // MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H

From 0e95815bfbf9e0c1ca87437536c848e14f5dc6cf Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:41:34 +1100
Subject: [PATCH 07/15] stm32: Add bindings for BTstack implementation.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 ports/stm32/Makefile  |  11 +++
 ports/stm32/btstack.c | 222 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 233 insertions(+)
 create mode 100644 ports/stm32/btstack.c

diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index fab2f621b22a2..2dc740561816f 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -462,11 +462,22 @@ ifeq ($(MICROPY_PY_BLUETOOTH),1)
 
 SRC_C += modbluetooth_hci.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)
 include $(TOP)/extmod/nimble/nimble.mk
 SRC_C += nimble.c
 endif
 
+ifeq ($(MICROPY_BLUETOOTH_BTSTACK),1)
+include $(TOP)/extmod/btstack/btstack.mk
+SRC_C += btstack.c
+endif
+
 ifeq ($(MICROPY_PY_NETWORK_CYW43),1)
 DRIVERS_SRC_C += drivers/cyw43/cywbt.c
 endif
diff --git a/ports/stm32/btstack.c b/ports/stm32/btstack.c
new file mode 100644
index 0000000000000..f7669d1fc6447
--- /dev/null
+++ b/ports/stm32/btstack.c
@@ -0,0 +1,222 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 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 "py/mperrno.h"
+#include "py/mphal.h"
+
+#if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
+
+#include "lib/btstack/src/btstack.h"
+#include "lib/btstack/platform/embedded/btstack_run_loop_embedded.h"
+#include "lib/btstack/platform/embedded/hal_cpu.h"
+#include "lib/btstack/platform/embedded/hal_time_ms.h"
+
+#include "extmod/modbluetooth_hci.h"
+#include "extmod/btstack/modbluetooth_btstack.h"
+
+// We pass the bytes directly to the UART during a send, but then notify btstack in the next poll.
+STATIC bool send_done;
+STATIC void (*send_handler)(void);
+
+// btstack issues a read of len bytes, and gives us a buffer to asynchronously fill up.
+STATIC uint8_t *recv_buf;
+STATIC size_t recv_len;
+STATIC size_t recv_idx;
+STATIC void (*recv_handler)(void);
+
+// The IRQ functionality in btstack_run_loop_embedded.c is not used, so the
+// following three functions are empty.
+
+void hal_cpu_disable_irqs(void) {
+}
+
+void hal_cpu_enable_irqs(void) {
+}
+
+void hal_cpu_enable_irqs_and_sleep(void) {
+}
+
+uint32_t hal_time_ms(void) {
+    return mp_hal_ticks_ms();
+}
+
+STATIC int btstack_uart_init(const btstack_uart_config_t *uart_config) {
+    send_done = false;
+    recv_len = 0;
+    recv_idx = 0;
+    recv_handler = NULL;
+    send_handler = NULL;
+
+    // Set up the UART periperhal.
+    mp_bluetooth_hci_uart_init(MICROPY_HW_BLE_UART_ID);
+
+    return 0;
+}
+
+STATIC int btstack_uart_open(void) {
+    // Attach IRQ and power up the HCI controller.
+    mp_bluetooth_hci_uart_activate();
+    return 0;
+}
+
+STATIC int btstack_uart_close(void) {
+    return 0;
+}
+
+STATIC void btstack_uart_set_block_received(void (*block_handler)(void)) {
+    recv_handler = block_handler;
+}
+
+STATIC void btstack_uart_set_block_sent(void (*block_handler)(void)) {
+    send_handler = block_handler;
+}
+
+STATIC int btstack_uart_set_baudrate(uint32_t baudrate) {
+    mp_bluetooth_hci_uart_set_baudrate(baudrate);
+    return 0;
+}
+
+STATIC int btstack_uart_set_parity(int parity) {
+    return 0;
+}
+
+STATIC int btstack_uart_set_flowcontrol(int flowcontrol) {
+    return 0;
+}
+
+STATIC void btstack_uart_receive_block(uint8_t *buf, uint16_t len) {
+    recv_buf = buf;
+    recv_len = len;
+}
+
+STATIC void btstack_uart_send_block(const uint8_t *buf, uint16_t len) {
+    mp_bluetooth_hci_uart_write(buf, len);
+    send_done = true;
+}
+
+STATIC int btstack_uart_get_supported_sleep_modes(void) {
+    return 0;
+}
+
+STATIC void btstack_uart_set_sleep(btstack_uart_sleep_mode_t sleep_mode) {
+    // printf("btstack_uart_set_sleep %u\n", sleep_mode);
+}
+
+STATIC void btstack_uart_set_wakeup_handler(void (*wakeup_handler)(void)) {
+    // printf("btstack_uart_set_wakeup_handler\n");
+}
+
+STATIC const btstack_uart_block_t btstack_uart_block = {
+    &btstack_uart_init,
+    &btstack_uart_open,
+    &btstack_uart_close,
+    &btstack_uart_set_block_received,
+    &btstack_uart_set_block_sent,
+    &btstack_uart_set_baudrate,
+    &btstack_uart_set_parity,
+    &btstack_uart_set_flowcontrol,
+    &btstack_uart_receive_block,
+    &btstack_uart_send_block,
+    &btstack_uart_get_supported_sleep_modes,
+    &btstack_uart_set_sleep,
+    &btstack_uart_set_wakeup_handler,
+};
+
+STATIC const hci_transport_config_uart_t hci_transport_config_uart = {
+    HCI_TRANSPORT_CONFIG_UART,
+    MICROPY_HW_BLE_UART_BAUDRATE,
+    3000000,
+    0,
+    NULL,
+};
+
+STATIC void btstack_uart_process(void) {
+    if (send_done) {
+        // If we'd done a TX in the last interval, notify btstack that it's complete.
+        send_done = false;
+        if (send_handler) {
+            send_handler();
+        }
+    }
+
+    // Append any new bytes to the recv buffer, notifying bstack if we've got
+    // the number of bytes it was looking for.
+    while (uart_rx_any(&mp_bluetooth_hci_uart_obj) && recv_idx < recv_len) {
+        recv_buf[recv_idx++] = uart_rx_char(&mp_bluetooth_hci_uart_obj);
+        if (recv_idx == recv_len) {
+            recv_idx = 0;
+            recv_len = 0;
+            if (recv_handler) {
+                recv_handler();
+            }
+        }
+    }
+}
+
+void mp_bluetooth_hci_poll(void) {
+    if (mp_bluetooth_btstack_state == MP_BLUETOOTH_BTSTACK_STATE_OFF) {
+        return;
+    }
+
+    // Process uart data.
+    bool host_wake = mp_bluetooth_hci_controller_woken();
+    btstack_uart_process();
+    if (host_wake) {
+        mp_bluetooth_hci_controller_sleep_maybe();
+    }
+
+    // Call the BTstack run loop.
+    btstack_run_loop_embedded_execute_once();
+}
+
+void mp_bluetooth_btstack_port_init(void) {
+    static bool run_loop_init = false;
+    if (!run_loop_init) {
+        run_loop_init = true;
+        btstack_run_loop_init(btstack_run_loop_embedded_get_instance());
+    } else {
+        btstack_run_loop_embedded_get_instance()->init();
+    }
+
+    // hci_dump_open(NULL, HCI_DUMP_STDOUT);
+    const hci_transport_t *transport = hci_transport_h4_instance(&btstack_uart_block);
+    hci_init(transport, &hci_transport_config_uart);
+
+    // TODO: Probably not necessary for BCM (we have our own firmware loader),
+    // but might be worth investigating for other controllers in the future.
+    // hci_set_chipset(btstack_chipset_bcm_instance());
+}
+
+void mp_bluetooth_btstack_port_deinit(void) {
+    hci_power_control(HCI_POWER_OFF);
+}
+
+void mp_bluetooth_btstack_port_start(void) {
+    hci_power_control(HCI_POWER_ON);
+}
+
+#endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK

From 51f8591097cc58bfcb0449fccb5048db7e5473dc Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:42:15 +1100
Subject: [PATCH 08/15] stm32/boards/PYBD: Allow building with BTstack (via
 make command line).

Work done in collaboration with Jim Mussared aka @jimmo.
---
 ports/stm32/boards/PYBD_SF2/mpconfigboard.mk | 5 +++--
 ports/stm32/boards/PYBD_SF3/mpconfigboard.mk | 5 +++--
 ports/stm32/boards/PYBD_SF6/mpconfigboard.mk | 5 +++--
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/ports/stm32/boards/PYBD_SF2/mpconfigboard.mk b/ports/stm32/boards/PYBD_SF2/mpconfigboard.mk
index 69407345bd13a..ead8bb8c07cf3 100644
--- a/ports/stm32/boards/PYBD_SF2/mpconfigboard.mk
+++ b/ports/stm32/boards/PYBD_SF2/mpconfigboard.mk
@@ -10,8 +10,9 @@ TEXT0_SECTIONS = .isr_vector .text .data
 TEXT1_SECTIONS = .text_ext
 
 # MicroPython settings
-MICROPY_PY_BLUETOOTH = 1
-MICROPY_BLUETOOTH_NIMBLE = 1
+MICROPY_PY_BLUETOOTH ?= 1
+MICROPY_BLUETOOTH_NIMBLE ?= 1
+MICROPY_BLUETOOTH_BTSTACK ?= 0
 MICROPY_PY_LWIP = 1
 MICROPY_PY_NETWORK_CYW43 = 1
 MICROPY_PY_USSL = 1
diff --git a/ports/stm32/boards/PYBD_SF3/mpconfigboard.mk b/ports/stm32/boards/PYBD_SF3/mpconfigboard.mk
index f6d6e955b616b..119ec8f825b42 100644
--- a/ports/stm32/boards/PYBD_SF3/mpconfigboard.mk
+++ b/ports/stm32/boards/PYBD_SF3/mpconfigboard.mk
@@ -10,8 +10,9 @@ TEXT0_SECTIONS = .isr_vector .text .data
 TEXT1_SECTIONS = .text_ext
 
 # MicroPython settings
-MICROPY_PY_BLUETOOTH = 1
-MICROPY_BLUETOOTH_NIMBLE = 1
+MICROPY_PY_BLUETOOTH ?= 1
+MICROPY_BLUETOOTH_NIMBLE ?= 1
+MICROPY_BLUETOOTH_BTSTACK ?= 0
 MICROPY_PY_LWIP = 1
 MICROPY_PY_NETWORK_CYW43 = 1
 MICROPY_PY_USSL = 1
diff --git a/ports/stm32/boards/PYBD_SF6/mpconfigboard.mk b/ports/stm32/boards/PYBD_SF6/mpconfigboard.mk
index e33d62d86a931..ddc176e9cd422 100644
--- a/ports/stm32/boards/PYBD_SF6/mpconfigboard.mk
+++ b/ports/stm32/boards/PYBD_SF6/mpconfigboard.mk
@@ -7,8 +7,9 @@ LD_FILES = boards/PYBD_SF6/f767.ld
 TEXT0_ADDR = 0x08008000
 
 # MicroPython settings
-MICROPY_PY_BLUETOOTH = 1
-MICROPY_BLUETOOTH_NIMBLE = 1
+MICROPY_PY_BLUETOOTH ?= 1
+MICROPY_BLUETOOTH_NIMBLE ?= 1
+MICROPY_BLUETOOTH_BTSTACK ?= 0
 MICROPY_PY_LWIP = 1
 MICROPY_PY_NETWORK_CYW43 = 1
 MICROPY_PY_USSL = 1

From 0674917bc53d0a7346715d2af508a074ebf26c24 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:43:01 +1100
Subject: [PATCH 09/15] extmod/btstack: Implement advertising.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/btstack/modbluetooth_btstack.c | 68 ++++++++++++++++++++++++++-
 extmod/btstack/modbluetooth_btstack.h | 19 ++++++++
 ports/stm32/mpconfigport.h            | 10 +++-
 3 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/extmod/btstack/modbluetooth_btstack.c b/extmod/btstack/modbluetooth_btstack.c
index 73f28ffad39ba..3e3852e5c2e39 100644
--- a/extmod/btstack/modbluetooth_btstack.c
+++ b/extmod/btstack/modbluetooth_btstack.c
@@ -24,20 +24,52 @@
  * THE SOFTWARE.
  */
 
+#include "py/runtime.h"
+#include "py/mperrno.h"
+#include "py/mphal.h"
+
 #if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
 
 #include "extmod/btstack/modbluetooth_btstack.h"
 #include "extmod/modbluetooth.h"
 
+#include "lib/btstack/src/btstack.h"
+
+volatile int mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_OFF;
+
 int mp_bluetooth_init(void) {
+    btstack_memory_init();
+
+    MP_STATE_PORT(bluetooth_btstack_root_pointers) = m_new0(mp_bluetooth_btstack_root_pointers_t, 1);
+
+    mp_bluetooth_btstack_port_init();
+    mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_STARTING;
+
+    l2cap_init();
+    le_device_db_init();
+    sm_init();
+
+    // Set blank ER/IR keys to suppress BTstack warning.
+    // TODO handle this correctly.
+    sm_key_t dummy_key;
+    memset(dummy_key, 0, sizeof(dummy_key));
+    sm_set_er(dummy_key);
+    sm_set_ir(dummy_key);
+
+    mp_bluetooth_btstack_port_start();
+    mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_ACTIVE;
     return 0;
 }
 
 void mp_bluetooth_deinit(void) {
+    mp_bluetooth_btstack_port_deinit();
+    mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_OFF;
+
+    MP_STATE_PORT(bluetooth_btstack_root_pointers) = NULL;
 }
 
 bool mp_bluetooth_is_enabled(void) {
-    return false;
+    return mp_bluetooth_btstack_state == MP_BLUETOOTH_BTSTACK_STATE_ACTIVE;
 }
 
 void mp_bluetooth_get_device_addr(uint8_t *addr) {
@@ -45,10 +77,44 @@ void mp_bluetooth_get_device_addr(uint8_t *addr) {
 }
 
 int mp_bluetooth_gap_advertise_start(bool connectable, int32_t interval_us, const uint8_t *adv_data, size_t adv_data_len, const uint8_t *sr_data, size_t sr_data_len) {
+    uint16_t adv_int_min = interval_us / 625;
+    uint16_t adv_int_max = interval_us / 625;
+    uint8_t adv_type = connectable ? 0 : 2;
+    bd_addr_t null_addr = {0};
+
+    uint8_t direct_address_type = 0;
+    uint8_t channel_map = 0x07; // Use all three broadcast channels.
+    uint8_t filter_policy = 0x00; // None.
+
+    gap_advertisements_set_params(adv_int_min, adv_int_max, adv_type, direct_address_type, null_addr, channel_map, filter_policy);
+
+    // Copy the adv_data and sr_data into a persistent buffer (which is findable via the btstack root pointers).
+    size_t total_bytes = adv_data_len + sr_data_len;
+    if (total_bytes > MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data_alloc) {
+        // Resize if necessary.
+        MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data = m_new(uint8_t, total_bytes);
+        MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data_alloc = total_bytes;
+    }
+    uint8_t *data = MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data;
+
+    if (adv_data) {
+        memcpy(data, (uint8_t *)adv_data, adv_data_len);
+        gap_advertisements_set_data(adv_data_len, data);
+        data += adv_data_len;
+    }
+    if (sr_data) {
+        memcpy(data, (uint8_t *)sr_data, sr_data_len);
+        gap_scan_response_set_data(sr_data_len, data);
+    }
+
+    gap_advertisements_enable(true);
     return 0;
 }
 
 void mp_bluetooth_gap_advertise_stop(void) {
+    gap_advertisements_enable(false);
+    MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data_alloc = 0;
+    MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data = NULL;
 }
 
 int mp_bluetooth_gatts_register_service_begin(bool append) {
diff --git a/extmod/btstack/modbluetooth_btstack.h b/extmod/btstack/modbluetooth_btstack.h
index f58d3074807cc..9e8c6ad3fbc2b 100644
--- a/extmod/btstack/modbluetooth_btstack.h
+++ b/extmod/btstack/modbluetooth_btstack.h
@@ -27,4 +27,23 @@
 #ifndef MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
 #define MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
 
+typedef struct _mp_bluetooth_btstack_root_pointers_t {
+    // This stores both the advertising data and the scan response data, concatenated together.
+    uint8_t *adv_data;
+    // Total length of both.
+    size_t adv_data_alloc;
+} mp_bluetooth_btstack_root_pointers_t;
+
+enum {
+    MP_BLUETOOTH_BTSTACK_STATE_OFF,
+    MP_BLUETOOTH_BTSTACK_STATE_STARTING,
+    MP_BLUETOOTH_BTSTACK_STATE_ACTIVE,
+};
+
+extern volatile int mp_bluetooth_btstack_state;
+
+void mp_bluetooth_btstack_port_init(void);
+void mp_bluetooth_btstack_port_deinit(void);
+void mp_bluetooth_btstack_port_start(void);
+
 #endif // MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
diff --git a/ports/stm32/mpconfigport.h b/ports/stm32/mpconfigport.h
index ada4ce5af80a1..95442b6476b5b 100644
--- a/ports/stm32/mpconfigport.h
+++ b/ports/stm32/mpconfigport.h
@@ -269,6 +269,13 @@ struct _mp_bluetooth_nimble_root_pointers_t;
 #define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE
 #endif
 
+#if MICROPY_BLUETOOTH_BTSTACK
+struct _mp_bluetooth_btstack_root_pointers_t;
+#define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_BTSTACK void **bluetooth_nimble_memory; struct _mp_bluetooth_btstack_root_pointers_t *bluetooth_btstack_root_pointers;
+#else
+#define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_BTSTACK
+#endif
+
 #define MICROPY_PORT_ROOT_POINTERS \
     const char *readline_hist[8]; \
     \
@@ -301,7 +308,8 @@ struct _mp_bluetooth_nimble_root_pointers_t;
     mp_obj_list_t mod_network_nic_list; \
     \
     MICROPY_PORT_ROOT_POINTER_MBEDTLS \
-        MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE \
+    MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE \
+        MICROPY_PORT_ROOT_POINTER_BLUETOOTH_BTSTACK \
 
 // type definitions for the specific machine
 

From 86c26db3ff40b87a8d058a67ac5c71f71a3818b6 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:43:28 +1100
Subject: [PATCH 10/15] extmod/btstack: Implement service registration.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/btstack/modbluetooth_btstack.c | 122 ++++++++++++++++++++++++++
 extmod/modbluetooth.h                 |   1 +
 2 files changed, 123 insertions(+)

diff --git a/extmod/btstack/modbluetooth_btstack.c b/extmod/btstack/modbluetooth_btstack.c
index 3e3852e5c2e39..e7f9014048c48 100644
--- a/extmod/btstack/modbluetooth_btstack.c
+++ b/extmod/btstack/modbluetooth_btstack.c
@@ -37,6 +37,41 @@
 
 volatile int mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_OFF;
 
+static btstack_packet_callback_registration_t hci_event_callback_registration;
+
+STATIC void att_server_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
+    // printf("att_server_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
+    if (packet_type == HCI_EVENT_PACKET) {
+        uint8_t event_type = hci_event_packet_get_type(packet);
+        if (event_type == ATT_EVENT_CONNECTED) {
+            printf("  --> att connected\n");
+        } else if (event_type == ATT_EVENT_DISCONNECTED) {
+            printf("  --> att disconnected\n");
+        } else if (event_type == HCI_EVENT_LE_META) {
+            printf("  --> att le meta\n");
+        } else if (event_type == HCI_EVENT_DISCONNECTION_COMPLETE) {
+            printf("  --> att disconnect complete\n");
+        } else {
+            printf("  --> att type: unknown (%u)\n", event_type);
+        }
+    }
+}
+
+STATIC void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
+    // printf("hci_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
+    if (packet_type == HCI_EVENT_PACKET) {
+        uint8_t event_type = hci_event_packet_get_type(packet);
+        if (event_type == HCI_EVENT_TRANSPORT_PACKET_SENT || event_type == HCI_EVENT_COMMAND_COMPLETE) {
+        } else if (event_type == BTSTACK_EVENT_NR_CONNECTIONS_CHANGED) {
+            printf("  --> hci type: # conns changed\n");
+        } else if (event_type == HCI_EVENT_VENDOR_SPECIFIC) {
+            printf("  --> hci type: vendor specific\n");
+        } else {
+            printf("  --> hci type: unknown (%u)\n", event_type);
+        }
+    }
+}
+
 int mp_bluetooth_init(void) {
     btstack_memory_init();
 
@@ -58,6 +93,15 @@ int mp_bluetooth_init(void) {
 
     mp_bluetooth_btstack_port_start();
     mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_ACTIVE;
+
+    // Register for HCI events.
+    memset(&hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
+    hci_event_callback_registration.callback = &hci_packet_handler;
+    hci_add_event_handler(&hci_event_callback_registration);
+
+    // Register for ATT event.
+    att_server_register_packet_handler(&att_server_packet_handler);
+
     return 0;
 }
 
@@ -118,14 +162,92 @@ void mp_bluetooth_gap_advertise_stop(void) {
 }
 
 int mp_bluetooth_gatts_register_service_begin(bool append) {
+    if (!append) {
+        // This will reset the DB.
+        // Becase the DB is statically allocated, there's no problem with just re-initing it.
+        // Note this would be a memory leak if we enabled HAVE_MALLOC (there's no API to free the existing db).
+        att_db_util_init();
+
+        att_db_util_add_service_uuid16(GAP_SERVICE_UUID);
+        att_db_util_add_characteristic_uuid16(GAP_DEVICE_NAME_UUID, ATT_PROPERTY_READ, ATT_SECURITY_NONE, ATT_SECURITY_NONE, (uint8_t *)"MPY BTSTACK", 11);
+
+        att_db_util_add_service_uuid16(0x1801);
+        att_db_util_add_characteristic_uuid16(0x2a05, ATT_PROPERTY_READ, ATT_SECURITY_NONE, ATT_SECURITY_NONE, NULL, 0);
+
+    }
+
+    return 0;
+}
+
+STATIC uint16_t att_read_callback(hci_con_handle_t connection_handle, uint16_t att_handle, uint16_t offset, uint8_t *buffer, uint16_t buffer_size) {
+    printf("btstack: att_read_callback (handle: %u, offset: %u, buffer: %p, size: %u)\n", att_handle, offset, buffer, buffer_size);
+    return 0;
+}
+
+STATIC int att_write_callback(hci_con_handle_t connection_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size) {
+    printf("btstack: att_write_callback (handle: %u, mode: %u, offset: %u, buffer: %p, size: %u)\n", att_handle, transaction_mode, offset, buffer, buffer_size);
     return 0;
 }
 
+// Note: modbluetooth UUIDs store their data in LE.
+STATIC inline uint16_t get_uuid16(const mp_obj_bluetooth_uuid_t *uuid) {
+    return (uuid->data[1] << 8) | uuid->data[0];
+}
+
 int mp_bluetooth_gatts_register_service(mp_obj_bluetooth_uuid_t *service_uuid, mp_obj_bluetooth_uuid_t **characteristic_uuids, uint8_t *characteristic_flags, mp_obj_bluetooth_uuid_t **descriptor_uuids, uint8_t *descriptor_flags, uint8_t *num_descriptors, uint16_t *handles, size_t num_characteristics) {
+    // TODO: It's not clear which endian btstack needs for uuids.
+
+    uint16_t service_handle;
+    if (service_uuid->type == MP_BLUETOOTH_UUID_TYPE_16) {
+        service_handle = att_db_util_add_service_uuid16(get_uuid16(service_uuid));
+    } else if (service_uuid->type == MP_BLUETOOTH_UUID_TYPE_128) {
+        service_handle = att_db_util_add_service_uuid128(service_uuid->data);
+    } else {
+        return MP_EINVAL;
+    }
+
+    printf("Registered service with handle %u\n", service_handle);
+
+    size_t handle_index = 0;
+    size_t descriptor_index = 0;
+
+    for (size_t i = 0; i < num_characteristics; ++i) {
+        uint16_t props = characteristic_flags[i] | ATT_PROPERTY_DYNAMIC;
+        uint16_t read_permission = ATT_SECURITY_NONE;
+        uint16_t write_permission = ATT_SECURITY_NONE;
+        if (characteristic_uuids[i]->type == MP_BLUETOOTH_UUID_TYPE_16) {
+            handles[handle_index] = att_db_util_add_characteristic_uuid16(get_uuid16(characteristic_uuids[i]), props, read_permission, write_permission, NULL, 0);
+        } else if (characteristic_uuids[i]->type == MP_BLUETOOTH_UUID_TYPE_128) {
+            handles[handle_index] = att_db_util_add_characteristic_uuid128(characteristic_uuids[i]->data, props, read_permission, write_permission, NULL, 0);
+        } else {
+            return MP_EINVAL;
+        }
+        printf("Registered char with handle %u\n", handles[handle_index]);
+        ++handle_index;
+
+        for (size_t j = 0; j < num_descriptors[i]; ++j) {
+            uint16_t props = descriptor_flags[descriptor_index] | ATT_PROPERTY_DYNAMIC;
+            uint16_t read_permission = ATT_SECURITY_NONE;
+            uint16_t write_permission = ATT_SECURITY_NONE;
+
+            if (descriptor_uuids[descriptor_index]->type == MP_BLUETOOTH_UUID_TYPE_16) {
+                handles[handle_index] = att_db_util_add_descriptor_uuid16(get_uuid16(descriptor_uuids[descriptor_index]), props, read_permission, write_permission, NULL, 0);
+            } else if (descriptor_uuids[descriptor_index]->type == MP_BLUETOOTH_UUID_TYPE_128) {
+                handles[handle_index] = att_db_util_add_descriptor_uuid128(descriptor_uuids[descriptor_index]->data, props, read_permission, write_permission, NULL, 0);
+            } else {
+                return MP_EINVAL;
+            }
+            printf("Registered desc with handle %u\n", handles[handle_index]);
+            ++descriptor_index;
+            ++handle_index;
+        }
+    }
+
     return 0;
 }
 
 int mp_bluetooth_gatts_register_service_end(void) {
+    att_server_init(att_db_util_get_address(), &att_read_callback, &att_write_callback);
     return 0;
 }
 
diff --git a/extmod/modbluetooth.h b/extmod/modbluetooth.h
index 661130802a319..ed280e3897d31 100644
--- a/extmod/modbluetooth.h
+++ b/extmod/modbluetooth.h
@@ -63,6 +63,7 @@
 // Advertisement packet lengths
 #define MP_BLUETOOTH_GAP_ADV_MAX_LEN (32)
 
+// These match the spec values for these flags so can be passed directly to the stack.
 #define MP_BLUETOOTH_CHARACTERISTIC_FLAG_READ     (1 << 1)
 #define MP_BLUETOOTH_CHARACTERISTIC_FLAG_WRITE    (1 << 3)
 #define MP_BLUETOOTH_CHARACTERISTIC_FLAG_NOTIFY   (1 << 4)

From 372e5a280e666f988757a8945c66693a19c40d32 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:43:52 +1100
Subject: [PATCH 11/15] extmod/btstack: Implement gatts_db for btstack.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/btstack/modbluetooth_btstack.c | 148 ++++++++++++++++++++------
 extmod/btstack/modbluetooth_btstack.h |   5 +
 2 files changed, 122 insertions(+), 31 deletions(-)

diff --git a/extmod/btstack/modbluetooth_btstack.c b/extmod/btstack/modbluetooth_btstack.c
index e7f9014048c48..f285f3e45ce93 100644
--- a/extmod/btstack/modbluetooth_btstack.c
+++ b/extmod/btstack/modbluetooth_btstack.c
@@ -35,47 +35,69 @@
 
 #include "lib/btstack/src/btstack.h"
 
+#define DEBUG_EVENT_printf(...) //printf(__VA_ARGS__)
+
 volatile int mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_OFF;
 
 static btstack_packet_callback_registration_t hci_event_callback_registration;
 
+STATIC int btstack_error_to_errno(int err) {
+    if (err == ERROR_CODE_SUCCESS) {
+        return 0;
+    } else if (err == BTSTACK_ACL_BUFFERS_FULL) {
+        return MP_ENOMEM;
+    } else {
+        return MP_EINVAL;
+    }
+}
+
 STATIC void att_server_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
-    // printf("att_server_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
+    DEBUG_EVENT_printf("att_server_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
     if (packet_type == HCI_EVENT_PACKET) {
         uint8_t event_type = hci_event_packet_get_type(packet);
         if (event_type == ATT_EVENT_CONNECTED) {
-            printf("  --> att connected\n");
+            DEBUG_EVENT_printf("  --> att connected\n");
+            uint16_t conn_handle = att_event_connected_get_handle(packet);
+            uint8_t addr_type = att_event_connected_get_address_type(packet);
+            bd_addr_t addr;
+            att_event_connected_get_address(packet, addr);
+            mp_bluetooth_gap_on_connected_disconnected(MP_BLUETOOTH_IRQ_CENTRAL_CONNECT, conn_handle, addr_type, addr);
         } else if (event_type == ATT_EVENT_DISCONNECTED) {
-            printf("  --> att disconnected\n");
+            DEBUG_EVENT_printf("  --> att disconnected\n");
+            uint16_t conn_handle = att_event_disconnected_get_handle(packet);
+            bd_addr_t addr = {0};
+            mp_bluetooth_gap_on_connected_disconnected(MP_BLUETOOTH_IRQ_CENTRAL_DISCONNECT, conn_handle, 0, addr);
         } else if (event_type == HCI_EVENT_LE_META) {
-            printf("  --> att le meta\n");
+            DEBUG_EVENT_printf("  --> att le meta\n");
         } else if (event_type == HCI_EVENT_DISCONNECTION_COMPLETE) {
-            printf("  --> att disconnect complete\n");
+            DEBUG_EVENT_printf("  --> att disconnect complete\n");
         } else {
-            printf("  --> att type: unknown (%u)\n", event_type);
+            DEBUG_EVENT_printf("  --> att type: unknown (%u)\n", event_type);
         }
     }
 }
 
 STATIC void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
-    // printf("hci_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
+    DEBUG_EVENT_printf("hci_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
     if (packet_type == HCI_EVENT_PACKET) {
         uint8_t event_type = hci_event_packet_get_type(packet);
         if (event_type == HCI_EVENT_TRANSPORT_PACKET_SENT || event_type == HCI_EVENT_COMMAND_COMPLETE) {
         } else if (event_type == BTSTACK_EVENT_NR_CONNECTIONS_CHANGED) {
-            printf("  --> hci type: # conns changed\n");
+            DEBUG_EVENT_printf("  --> hci type: # conns changed\n");
         } else if (event_type == HCI_EVENT_VENDOR_SPECIFIC) {
-            printf("  --> hci type: vendor specific\n");
+            DEBUG_EVENT_printf("  --> hci type: vendor specific\n");
         } else {
-            printf("  --> hci type: unknown (%u)\n", event_type);
+            DEBUG_EVENT_printf("  --> hci type: unknown (%u)\n", event_type);
         }
     }
 }
 
 int mp_bluetooth_init(void) {
+    DEBUG_EVENT_printf("mp_bluetooth_init\n");
     btstack_memory_init();
 
     MP_STATE_PORT(bluetooth_btstack_root_pointers) = m_new0(mp_bluetooth_btstack_root_pointers_t, 1);
+    mp_bluetooth_gatts_db_create(&MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db);
 
     mp_bluetooth_btstack_port_init();
     mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_STARTING;
@@ -106,6 +128,7 @@ int mp_bluetooth_init(void) {
 }
 
 void mp_bluetooth_deinit(void) {
+    DEBUG_EVENT_printf("mp_bluetooth_deinit\n");
     mp_bluetooth_btstack_port_deinit();
     mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_OFF;
 
@@ -121,6 +144,7 @@ void mp_bluetooth_get_device_addr(uint8_t *addr) {
 }
 
 int mp_bluetooth_gap_advertise_start(bool connectable, int32_t interval_us, const uint8_t *adv_data, size_t adv_data_len, const uint8_t *sr_data, size_t sr_data_len) {
+    DEBUG_EVENT_printf("mp_bluetooth_gap_advertise_start\n");
     uint16_t adv_int_min = interval_us / 625;
     uint16_t adv_int_max = interval_us / 625;
     uint8_t adv_type = connectable ? 0 : 2;
@@ -156,12 +180,14 @@ int mp_bluetooth_gap_advertise_start(bool connectable, int32_t interval_us, cons
 }
 
 void mp_bluetooth_gap_advertise_stop(void) {
+    DEBUG_EVENT_printf("mp_bluetooth_gap_advertise_stop\n");
     gap_advertisements_enable(false);
     MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data_alloc = 0;
     MP_STATE_PORT(bluetooth_btstack_root_pointers)->adv_data = NULL;
 }
 
 int mp_bluetooth_gatts_register_service_begin(bool append) {
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_register_service_begin\n");
     if (!append) {
         // This will reset the DB.
         // Becase the DB is statically allocated, there's no problem with just re-initing it.
@@ -173,43 +199,68 @@ int mp_bluetooth_gatts_register_service_begin(bool append) {
 
         att_db_util_add_service_uuid16(0x1801);
         att_db_util_add_characteristic_uuid16(0x2a05, ATT_PROPERTY_READ, ATT_SECURITY_NONE, ATT_SECURITY_NONE, NULL, 0);
-
     }
 
     return 0;
 }
 
 STATIC uint16_t att_read_callback(hci_con_handle_t connection_handle, uint16_t att_handle, uint16_t offset, uint8_t *buffer, uint16_t buffer_size) {
-    printf("btstack: att_read_callback (handle: %u, offset: %u, buffer: %p, size: %u)\n", att_handle, offset, buffer, buffer_size);
-    return 0;
+    DEBUG_EVENT_printf("btstack: att_read_callback (handle: %u, offset: %u, buffer: %p, size: %u)\n", att_handle, offset, buffer, buffer_size);
+    mp_bluetooth_gatts_db_entry_t *entry = mp_bluetooth_gatts_db_lookup(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, att_handle);
+    if (!entry) {
+        DEBUG_EVENT_printf("btstack: att_read_callback handle not found\n");
+        return 0; // TODO: Find status code for not-found.
+    }
+
+    return att_read_callback_handle_blob(entry->data, entry->data_len, offset, buffer, buffer_size);
 }
 
 STATIC int att_write_callback(hci_con_handle_t connection_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size) {
-    printf("btstack: att_write_callback (handle: %u, mode: %u, offset: %u, buffer: %p, size: %u)\n", att_handle, transaction_mode, offset, buffer, buffer_size);
+    DEBUG_EVENT_printf("btstack: att_write_callback (handle: %u, mode: %u, offset: %u, buffer: %p, size: %u)\n", att_handle, transaction_mode, offset, buffer, buffer_size);
+    mp_bluetooth_gatts_db_entry_t *entry = mp_bluetooth_gatts_db_lookup(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, att_handle);
+    if (!entry) {
+        DEBUG_EVENT_printf("btstack: att_write_callback handle not found\n");
+        return 0; // TODO: Find status code for not-found.
+    }
+
+    // TODO: Use `offset` arg.
+    size_t append_offset = 0;
+    if (entry->append) {
+        append_offset = entry->data_len;
+    }
+    entry->data_len = MIN(entry->data_alloc, buffer_size + append_offset);
+    memcpy(entry->data + append_offset, buffer, entry->data_len - append_offset);
+
+    mp_bluetooth_gatts_on_write(connection_handle, att_handle);
+
     return 0;
 }
 
-// Note: modbluetooth UUIDs store their data in LE.
 STATIC inline uint16_t get_uuid16(const mp_obj_bluetooth_uuid_t *uuid) {
     return (uuid->data[1] << 8) | uuid->data[0];
 }
 
 int mp_bluetooth_gatts_register_service(mp_obj_bluetooth_uuid_t *service_uuid, mp_obj_bluetooth_uuid_t **characteristic_uuids, uint8_t *characteristic_flags, mp_obj_bluetooth_uuid_t **descriptor_uuids, uint8_t *descriptor_flags, uint8_t *num_descriptors, uint16_t *handles, size_t num_characteristics) {
-    // TODO: It's not clear which endian btstack needs for uuids.
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_register_service\n");
+    // Note: btstack expects BE UUIDs (which it immediately convertes to LE).
+    // So we have to convert all our modbluetooth LE UUIDs to BE just for the att_db_util_add_* methods (using get_uuid16 above, and reverse_128 from btstackutil.h).
+
+    // TODO: btstack's att_db_util_add_* methods have no bounds checking or validation.
+    // Need some way to prevent additional services being added if we're out of space in the static buffer.
 
-    uint16_t service_handle;
     if (service_uuid->type == MP_BLUETOOTH_UUID_TYPE_16) {
-        service_handle = att_db_util_add_service_uuid16(get_uuid16(service_uuid));
+        att_db_util_add_service_uuid16(get_uuid16(service_uuid));
     } else if (service_uuid->type == MP_BLUETOOTH_UUID_TYPE_128) {
-        service_handle = att_db_util_add_service_uuid128(service_uuid->data);
+        uint8_t buffer[16];
+        reverse_128(service_uuid->data, buffer);
+        att_db_util_add_service_uuid128(buffer);
     } else {
         return MP_EINVAL;
     }
 
-    printf("Registered service with handle %u\n", service_handle);
-
     size_t handle_index = 0;
     size_t descriptor_index = 0;
+    static uint8_t cccb_buf[2] = {0};
 
     for (size_t i = 0; i < num_characteristics; ++i) {
         uint16_t props = characteristic_flags[i] | ATT_PROPERTY_DYNAMIC;
@@ -218,11 +269,20 @@ int mp_bluetooth_gatts_register_service(mp_obj_bluetooth_uuid_t *service_uuid, m
         if (characteristic_uuids[i]->type == MP_BLUETOOTH_UUID_TYPE_16) {
             handles[handle_index] = att_db_util_add_characteristic_uuid16(get_uuid16(characteristic_uuids[i]), props, read_permission, write_permission, NULL, 0);
         } else if (characteristic_uuids[i]->type == MP_BLUETOOTH_UUID_TYPE_128) {
-            handles[handle_index] = att_db_util_add_characteristic_uuid128(characteristic_uuids[i]->data, props, read_permission, write_permission, NULL, 0);
+            uint8_t buffer[16];
+            reverse_128(characteristic_uuids[i]->data, buffer);
+            handles[handle_index] = att_db_util_add_characteristic_uuid128(buffer, props, read_permission, write_permission, NULL, 0);
         } else {
             return MP_EINVAL;
         }
-        printf("Registered char with handle %u\n", handles[handle_index]);
+        mp_bluetooth_gatts_db_create_entry(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, handles[handle_index], MP_BLUETOOTH_DEFAULT_ATTR_LEN);
+        // If a NOTIFY or INDICATE characteristic is added, then we need to manage a value for the CCCB.
+        if (props & (ATT_PROPERTY_NOTIFY | ATT_PROPERTY_INDICATE)) {
+            // btstack creates the CCCB as the next handle.
+            mp_bluetooth_gatts_db_create_entry(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, handles[handle_index] + 1, MP_BLUETOOTH_CCCB_LEN);
+            mp_bluetooth_gatts_db_write(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, handles[handle_index] + 1, cccb_buf, sizeof(cccb_buf));
+        }
+        DEBUG_EVENT_printf("Registered char with handle %u\n", handles[handle_index]);
         ++handle_index;
 
         for (size_t j = 0; j < num_descriptors[i]; ++j) {
@@ -233,11 +293,14 @@ int mp_bluetooth_gatts_register_service(mp_obj_bluetooth_uuid_t *service_uuid, m
             if (descriptor_uuids[descriptor_index]->type == MP_BLUETOOTH_UUID_TYPE_16) {
                 handles[handle_index] = att_db_util_add_descriptor_uuid16(get_uuid16(descriptor_uuids[descriptor_index]), props, read_permission, write_permission, NULL, 0);
             } else if (descriptor_uuids[descriptor_index]->type == MP_BLUETOOTH_UUID_TYPE_128) {
-                handles[handle_index] = att_db_util_add_descriptor_uuid128(descriptor_uuids[descriptor_index]->data, props, read_permission, write_permission, NULL, 0);
+                uint8_t buffer[16];
+                reverse_128(descriptor_uuids[descriptor_index]->data, buffer);
+                handles[handle_index] = att_db_util_add_descriptor_uuid128(buffer, props, read_permission, write_permission, NULL, 0);
             } else {
                 return MP_EINVAL;
             }
-            printf("Registered desc with handle %u\n", handles[handle_index]);
+            mp_bluetooth_gatts_db_create_entry(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, handles[handle_index], MP_BLUETOOTH_DEFAULT_ATTR_LEN);
+            DEBUG_EVENT_printf("Registered desc with handle %u\n", handles[handle_index]);
             ++descriptor_index;
             ++handle_index;
         }
@@ -247,68 +310,91 @@ int mp_bluetooth_gatts_register_service(mp_obj_bluetooth_uuid_t *service_uuid, m
 }
 
 int mp_bluetooth_gatts_register_service_end(void) {
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_register_service_end\n");
     att_server_init(att_db_util_get_address(), &att_read_callback, &att_write_callback);
     return 0;
 }
 
 int mp_bluetooth_gatts_read(uint16_t value_handle, uint8_t **value, size_t *value_len) {
-    return 0;
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_read\n");
+    return mp_bluetooth_gatts_db_read(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, value_handle, value, value_len);
 }
 
 int mp_bluetooth_gatts_write(uint16_t value_handle, const uint8_t *value, size_t value_len) {
-    return 0;
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_write\n");
+    return mp_bluetooth_gatts_db_write(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, value_handle, value, value_len);
 }
 
 int mp_bluetooth_gatts_notify(uint16_t conn_handle, uint16_t value_handle) {
-    return 0;
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_notify\n");
+    // Note: btstack doesn't appear to support sending a notification without a value, so include the stored value.
+    uint8_t *data = NULL;
+    size_t len = 0;
+    mp_bluetooth_gatts_db_read(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, value_handle, &data, &len);
+    return mp_bluetooth_gatts_notify_send(conn_handle, value_handle, data, &len);
 }
 
 int mp_bluetooth_gatts_notify_send(uint16_t conn_handle, uint16_t value_handle, const uint8_t *value, size_t *value_len) {
-    return 0;
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_notify_send\n");
+    // TODO: We need to use att_server_request_to_send_notification here as the stack may not be ready to send a notification.
+    int err = att_server_notify(conn_handle, value_handle, value, *value_len);
+    return btstack_error_to_errno(err);
 }
 
 int mp_bluetooth_gatts_indicate(uint16_t conn_handle, uint16_t value_handle) {
-    return 0;
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_indicate\n");
+    return btstack_error_to_errno(att_server_indicate(conn_handle, value_handle, NULL, 0));
 }
 
 int mp_bluetooth_gatts_set_buffer(uint16_t value_handle, size_t len, bool append) {
-    return 0;
+    DEBUG_EVENT_printf("mp_bluetooth_gatts_set_buffer\n");
+    return mp_bluetooth_gatts_db_resize(MP_STATE_PORT(bluetooth_btstack_root_pointers)->gatts_db, value_handle, len, append);
 }
 
 int mp_bluetooth_gap_disconnect(uint16_t conn_handle) {
+    DEBUG_EVENT_printf("mp_bluetooth_gap_disconnect\n");
+    gap_disconnect(conn_handle);
     return 0;
 }
 
 #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
 int mp_bluetooth_gap_scan_start(int32_t duration_ms, int32_t interval_us, int32_t window_us) {
+    DEBUG_EVENT_printf("mp_bluetooth_gap_scan_start\n");
     return 0;
 }
 
 int mp_bluetooth_gap_scan_stop(void) {
+    DEBUG_EVENT_printf("mp_bluetooth_gap_scan_stop\n");
     return 0;
 }
 
 int mp_bluetooth_gap_peripheral_connect(uint8_t addr_type, const uint8_t *addr, int32_t duration_ms) {
+    DEBUG_EVENT_printf("mp_bluetooth_gap_peripheral_connect\n");
     return 0;
 }
 
 int mp_bluetooth_gattc_discover_primary_services(uint16_t conn_handle) {
+    DEBUG_EVENT_printf("mp_bluetooth_gattc_discover_primary_services\n");
     return 0;
 }
 
 int mp_bluetooth_gattc_discover_characteristics(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle) {
+    DEBUG_EVENT_printf("mp_bluetooth_gattc_discover_characteristics\n");
     return 0;
 }
 
 int mp_bluetooth_gattc_discover_descriptors(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle) {
+    DEBUG_EVENT_printf("mp_bluetooth_gattc_discover_descriptors\n");
     return 0;
 }
 
 int mp_bluetooth_gattc_read(uint16_t conn_handle, uint16_t value_handle) {
+    DEBUG_EVENT_printf("mp_bluetooth_gattc_read\n");
     return 0;
 }
 
 int mp_bluetooth_gattc_write(uint16_t conn_handle, uint16_t value_handle, const uint8_t *value, size_t *value_len, unsigned int mode) {
+    DEBUG_EVENT_printf("mp_bluetooth_gattc_write\n");
     return 0;
 }
 #endif
diff --git a/extmod/btstack/modbluetooth_btstack.h b/extmod/btstack/modbluetooth_btstack.h
index 9e8c6ad3fbc2b..50e690fd4cd4e 100644
--- a/extmod/btstack/modbluetooth_btstack.h
+++ b/extmod/btstack/modbluetooth_btstack.h
@@ -27,11 +27,16 @@
 #ifndef MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
 #define MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
 
+#include "extmod/modbluetooth.h"
+
 typedef struct _mp_bluetooth_btstack_root_pointers_t {
     // This stores both the advertising data and the scan response data, concatenated together.
     uint8_t *adv_data;
     // Total length of both.
     size_t adv_data_alloc;
+
+    // Characteristic (and descriptor) value storage.
+    mp_gatts_db_t gatts_db;
 } mp_bluetooth_btstack_root_pointers_t;
 
 enum {

From 018ce122ca6c073c0a9ed11b5ab4ca2f5e629350 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:44:13 +1100
Subject: [PATCH 12/15] extmod/btstack: Implement scan and gatt client, connect
 and disconnect.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/btstack/modbluetooth_btstack.c | 249 +++++++++++++++++++++-----
 1 file changed, 206 insertions(+), 43 deletions(-)

diff --git a/extmod/btstack/modbluetooth_btstack.c b/extmod/btstack/modbluetooth_btstack.c
index f285f3e45ce93..001d6102253ed 100644
--- a/extmod/btstack/modbluetooth_btstack.c
+++ b/extmod/btstack/modbluetooth_btstack.c
@@ -39,7 +39,7 @@
 
 volatile int mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_OFF;
 
-static btstack_packet_callback_registration_t hci_event_callback_registration;
+STATIC btstack_packet_callback_registration_t hci_event_callback_registration;
 
 STATIC int btstack_error_to_errno(int err) {
     if (err == ERROR_CODE_SUCCESS) {
@@ -51,46 +51,146 @@ STATIC int btstack_error_to_errno(int err) {
     }
 }
 
-STATIC void att_server_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
-    DEBUG_EVENT_printf("att_server_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
-    if (packet_type == HCI_EVENT_PACKET) {
-        uint8_t event_type = hci_event_packet_get_type(packet);
-        if (event_type == ATT_EVENT_CONNECTED) {
-            DEBUG_EVENT_printf("  --> att connected\n");
-            uint16_t conn_handle = att_event_connected_get_handle(packet);
-            uint8_t addr_type = att_event_connected_get_address_type(packet);
+STATIC mp_obj_bluetooth_uuid_t create_mp_uuid(uint16_t uuid16, const uint8_t *uuid128) {
+    mp_obj_bluetooth_uuid_t result;
+    if (uuid16 != 0) {
+        result.data[0] = uuid16 & 0xff;
+        result.data[1] = (uuid16 >> 8) & 0xff;
+        result.type = MP_BLUETOOTH_UUID_TYPE_16;
+    } else {
+        reverse_128(uuid128, result.data);
+        result.type = MP_BLUETOOTH_UUID_TYPE_128;
+    }
+    return result;
+}
+
+STATIC void btstack_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
+    DEBUG_EVENT_printf("btstack_packet_handler(packet_type=%u, channel=%u, packet=%p, size=%u)\n", packet_type, channel, packet, size);
+    if (packet_type != HCI_EVENT_PACKET) {
+        return;
+    }
+
+    uint8_t event_type = hci_event_packet_get_type(packet);
+    if (event_type == ATT_EVENT_CONNECTED) {
+        DEBUG_EVENT_printf("  --> att connected\n");
+    } else if (event_type == ATT_EVENT_DISCONNECTED) {
+        DEBUG_EVENT_printf("  --> att disconnected\n");
+    } else if (event_type == HCI_EVENT_LE_META) {
+        DEBUG_EVENT_printf("  --> hci le meta\n");
+        if (hci_event_le_meta_get_subevent_code(packet) == HCI_SUBEVENT_LE_CONNECTION_COMPLETE) {
+            uint16_t conn_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
+            uint8_t addr_type = hci_subevent_le_connection_complete_get_peer_address_type(packet);
             bd_addr_t addr;
-            att_event_connected_get_address(packet, addr);
-            mp_bluetooth_gap_on_connected_disconnected(MP_BLUETOOTH_IRQ_CENTRAL_CONNECT, conn_handle, addr_type, addr);
-        } else if (event_type == ATT_EVENT_DISCONNECTED) {
-            DEBUG_EVENT_printf("  --> att disconnected\n");
-            uint16_t conn_handle = att_event_disconnected_get_handle(packet);
-            bd_addr_t addr = {0};
-            mp_bluetooth_gap_on_connected_disconnected(MP_BLUETOOTH_IRQ_CENTRAL_DISCONNECT, conn_handle, 0, addr);
-        } else if (event_type == HCI_EVENT_LE_META) {
-            DEBUG_EVENT_printf("  --> att le meta\n");
-        } else if (event_type == HCI_EVENT_DISCONNECTION_COMPLETE) {
-            DEBUG_EVENT_printf("  --> att disconnect complete\n");
+            hci_subevent_le_connection_complete_get_peer_address(packet, addr);
+            uint16_t irq_event;
+            if (hci_subevent_le_connection_complete_get_role(packet) == 0) {
+                // Master role.
+                irq_event = MP_BLUETOOTH_IRQ_PERIPHERAL_CONNECT;
+            } else {
+                // Slave role.
+                irq_event = MP_BLUETOOTH_IRQ_CENTRAL_CONNECT;
+            }
+            mp_bluetooth_gap_on_connected_disconnected(irq_event, conn_handle, addr_type, addr);
+        }
+    } else if (event_type == BTSTACK_EVENT_STATE) {
+        DEBUG_EVENT_printf("  --> btstack event state 0x%02x\n", btstack_event_state_get_state(packet));
+    } else if (event_type == HCI_EVENT_TRANSPORT_PACKET_SENT) {
+        DEBUG_EVENT_printf("  --> hci transport packet set\n");
+    } else if (event_type == HCI_EVENT_COMMAND_COMPLETE) {
+        DEBUG_EVENT_printf("  --> hci command complete\n");
+    } else if (event_type == HCI_EVENT_COMMAND_STATUS) {
+        DEBUG_EVENT_printf("  --> hci command status\n");
+    } else if (event_type == HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS) {
+        DEBUG_EVENT_printf("  --> hci number of completed packets\n");
+    } else if (event_type == BTSTACK_EVENT_NR_CONNECTIONS_CHANGED) {
+        DEBUG_EVENT_printf("  --> btstack # conns changed\n");
+    } else if (event_type == HCI_EVENT_VENDOR_SPECIFIC) {
+        DEBUG_EVENT_printf("  --> hci vendor specific\n");
+    } else if (event_type == GAP_EVENT_ADVERTISING_REPORT) {
+        DEBUG_EVENT_printf("  --> gap advertising report\n");
+        bd_addr_t address;
+        gap_event_advertising_report_get_address(packet, address);
+        uint8_t adv_event_type = gap_event_advertising_report_get_advertising_event_type(packet);
+        uint8_t address_type = gap_event_advertising_report_get_address_type(packet);
+        int8_t rssi = gap_event_advertising_report_get_rssi(packet);
+        uint8_t length = gap_event_advertising_report_get_data_length(packet);
+        const uint8_t *data = gap_event_advertising_report_get_data(packet);
+        bool connectable = adv_event_type == 0 || adv_event_type == 1;
+        if (adv_event_type <= 2) {
+            mp_bluetooth_gap_on_scan_result(address_type, address, connectable, rssi, data, length);
+        } else if (adv_event_type == 4) {
+            // TODO: Scan response.
+        }
+    } else if (event_type == HCI_EVENT_DISCONNECTION_COMPLETE) {
+        DEBUG_EVENT_printf("  --> hci disconnect complete\n");
+        uint16_t conn_handle = hci_event_disconnection_complete_get_connection_handle(packet);
+        const hci_connection_t *conn = hci_connection_for_handle(conn_handle);
+        uint16_t irq_event;
+        if (conn == NULL || conn->role == 0) {
+            // Master role.
+            irq_event = MP_BLUETOOTH_IRQ_PERIPHERAL_DISCONNECT;
         } else {
-            DEBUG_EVENT_printf("  --> att type: unknown (%u)\n", event_type);
+            // Slave role.
+            irq_event = MP_BLUETOOTH_IRQ_CENTRAL_DISCONNECT;
         }
+        uint8_t addr[6] = {0};
+        mp_bluetooth_gap_on_connected_disconnected(irq_event, conn_handle, 0xff, addr);
+    } else if (event_type == GATT_EVENT_QUERY_COMPLETE) {
+        DEBUG_EVENT_printf("  --> gatt query complete\n");
+    } else if (event_type == GATT_EVENT_SERVICE_QUERY_RESULT) {
+        DEBUG_EVENT_printf("  --> gatt service query result\n");
+        uint16_t conn_handle = gatt_event_service_query_result_get_handle(packet);
+        gatt_client_service_t service;
+        gatt_event_service_query_result_get_service(packet, &service);
+        mp_obj_bluetooth_uuid_t service_uuid = create_mp_uuid(service.uuid16, service.uuid128);
+        mp_bluetooth_gattc_on_primary_service_result(conn_handle, service.start_group_handle, service.end_group_handle, &service_uuid);
+    } else if (event_type == GATT_EVENT_CHARACTERISTIC_QUERY_RESULT) {
+        DEBUG_EVENT_printf("  --> gatt characteristic query result\n");
+        uint16_t conn_handle = gatt_event_characteristic_query_result_get_handle(packet);
+        gatt_client_characteristic_t characteristic;
+        gatt_event_characteristic_query_result_get_characteristic(packet, &characteristic);
+        mp_obj_bluetooth_uuid_t characteristic_uuid = create_mp_uuid(characteristic.uuid16, characteristic.uuid128);
+        mp_bluetooth_gattc_on_characteristic_result(conn_handle, characteristic.start_handle, characteristic.value_handle, characteristic.properties, &characteristic_uuid);
+    } else if (event_type == GATT_EVENT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT) {
+        DEBUG_EVENT_printf("  --> gatt descriptor query result\n");
+        uint16_t conn_handle = gatt_event_all_characteristic_descriptors_query_result_get_handle(packet);
+        gatt_client_characteristic_descriptor_t descriptor;
+        gatt_event_all_characteristic_descriptors_query_result_get_characteristic_descriptor(packet, &descriptor);
+        mp_obj_bluetooth_uuid_t descriptor_uuid = create_mp_uuid(descriptor.uuid16, descriptor.uuid128);
+        mp_bluetooth_gattc_on_descriptor_result(conn_handle, descriptor.handle, &descriptor_uuid);
+    } else if (event_type == GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT) {
+        DEBUG_EVENT_printf("  --> gatt characteristic value query result\n");
+        uint16_t conn_handle = gatt_event_characteristic_value_query_result_get_handle(packet);
+        uint16_t value_handle = gatt_event_characteristic_value_query_result_get_value_handle(packet);
+        uint16_t len = gatt_event_characteristic_value_query_result_get_value_length(packet);
+        const uint8_t *data = gatt_event_characteristic_value_query_result_get_value(packet);
+        MICROPY_PY_BLUETOOTH_ENTER
+            len = mp_bluetooth_gattc_on_data_available_start(MP_BLUETOOTH_IRQ_GATTC_READ_RESULT, conn_handle, value_handle, len);
+        mp_bluetooth_gattc_on_data_available_chunk(data, len);
+        mp_bluetooth_gattc_on_data_available_end();
+        MICROPY_PY_BLUETOOTH_EXIT
+    } else {
+        DEBUG_EVENT_printf("  --> hci event type: unknown (0x%02x)\n", event_type);
     }
 }
 
-STATIC void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
-    DEBUG_EVENT_printf("hci_packet_handler: packet_type: %u, channel: %u, packet: %p, size: %u\n", packet_type, channel, packet, size);
-    if (packet_type == HCI_EVENT_PACKET) {
-        uint8_t event_type = hci_event_packet_get_type(packet);
-        if (event_type == HCI_EVENT_TRANSPORT_PACKET_SENT || event_type == HCI_EVENT_COMMAND_COMPLETE) {
-        } else if (event_type == BTSTACK_EVENT_NR_CONNECTIONS_CHANGED) {
-            DEBUG_EVENT_printf("  --> hci type: # conns changed\n");
-        } else if (event_type == HCI_EVENT_VENDOR_SPECIFIC) {
-            DEBUG_EVENT_printf("  --> hci type: vendor specific\n");
-        } else {
-            DEBUG_EVENT_printf("  --> hci type: unknown (%u)\n", event_type);
-        }
+#if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+STATIC void btstack_packet_handler_write_with_response(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) {
+    DEBUG_EVENT_printf("btstack_packet_handler_write_with_response(packet_type=%u, channel=%u, packet=%p, size=%u)\n", packet_type, channel, packet, size);
+    if (packet_type != HCI_EVENT_PACKET) {
+        return;
+    }
+
+    uint8_t event_type = hci_event_packet_get_type(packet);
+    if (event_type == GATT_EVENT_QUERY_COMPLETE) {
+        DEBUG_EVENT_printf("  --> gatt query complete\n");
+        uint16_t conn_handle = gatt_event_query_complete_get_handle(packet);
+        uint8_t status = gatt_event_query_complete_get_att_status(packet);
+        // TODO there is no value_handle to pass here
+        mp_bluetooth_gattc_on_write_status(conn_handle, 0, status);
     }
 }
+#endif
 
 int mp_bluetooth_init(void) {
     DEBUG_EVENT_printf("mp_bluetooth_init\n");
@@ -113,17 +213,18 @@ int mp_bluetooth_init(void) {
     sm_set_er(dummy_key);
     sm_set_ir(dummy_key);
 
+    #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+    gatt_client_init();
+    #endif
+
     mp_bluetooth_btstack_port_start();
     mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_ACTIVE;
 
     // Register for HCI events.
     memset(&hci_event_callback_registration, 0, sizeof(btstack_packet_callback_registration_t));
-    hci_event_callback_registration.callback = &hci_packet_handler;
+    hci_event_callback_registration.callback = &btstack_packet_handler;
     hci_add_event_handler(&hci_event_callback_registration);
 
-    // Register for ATT event.
-    att_server_register_packet_handler(&att_server_packet_handler);
-
     return 0;
 }
 
@@ -358,44 +459,106 @@ int mp_bluetooth_gap_disconnect(uint16_t conn_handle) {
 }
 
 #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+STATIC btstack_timer_source_t scan_duration_timeout;
+
+STATIC void hci_initialization_timeout_handler(btstack_timer_source_t *ds) {
+    mp_bluetooth_gap_scan_stop();
+}
+
 int mp_bluetooth_gap_scan_start(int32_t duration_ms, int32_t interval_us, int32_t window_us) {
     DEBUG_EVENT_printf("mp_bluetooth_gap_scan_start\n");
+
+    btstack_run_loop_set_timer(&scan_duration_timeout, duration_ms);
+    btstack_run_loop_set_timer_handler(&scan_duration_timeout, hci_initialization_timeout_handler);
+    btstack_run_loop_add_timer(&scan_duration_timeout);
+
+    // 0 = passive scan (we don't handle scan response).
+    gap_set_scan_parameters(0, interval_us / 625, window_us / 625);
+    gap_start_scan();
+
     return 0;
 }
 
 int mp_bluetooth_gap_scan_stop(void) {
     DEBUG_EVENT_printf("mp_bluetooth_gap_scan_stop\n");
+    btstack_run_loop_remove_timer(&scan_duration_timeout);
+    gap_stop_scan();
+    mp_bluetooth_gap_on_scan_complete();
     return 0;
 }
 
 int mp_bluetooth_gap_peripheral_connect(uint8_t addr_type, const uint8_t *addr, int32_t duration_ms) {
     DEBUG_EVENT_printf("mp_bluetooth_gap_peripheral_connect\n");
-    return 0;
+
+    uint16_t conn_scan_interval = 60000 / 625;
+    uint16_t conn_scan_window = 30000 / 625;
+    uint16_t conn_interval_min = 10000 / 1250;
+    uint16_t conn_interval_max = 30000 / 1250;
+    uint16_t conn_latency = 4;
+    uint16_t supervision_timeout = duration_ms / 10; // default = 720
+    uint16_t min_ce_length = 10000 / 625;
+    uint16_t max_ce_length = 30000 / 625;
+
+    gap_set_connection_parameters(conn_scan_interval, conn_scan_window, conn_interval_min, conn_interval_max, conn_latency, supervision_timeout, min_ce_length, max_ce_length);
+
+    bd_addr_t btstack_addr;
+    memcpy(btstack_addr, addr, BD_ADDR_LEN);
+    return btstack_error_to_errno(gap_connect(btstack_addr, addr_type));
 }
 
 int mp_bluetooth_gattc_discover_primary_services(uint16_t conn_handle) {
     DEBUG_EVENT_printf("mp_bluetooth_gattc_discover_primary_services\n");
-    return 0;
+    return btstack_error_to_errno(gatt_client_discover_primary_services(&btstack_packet_handler, conn_handle));
 }
 
 int mp_bluetooth_gattc_discover_characteristics(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle) {
     DEBUG_EVENT_printf("mp_bluetooth_gattc_discover_characteristics\n");
-    return 0;
+
+    gatt_client_service_t service = {
+        // Only start/end handles needed for gatt_client_discover_characteristics_for_service.
+        .start_group_handle = start_handle,
+        .end_group_handle = end_handle,
+        .uuid16 = 0,
+        .uuid128 = {0},
+    };
+    return btstack_error_to_errno(gatt_client_discover_characteristics_for_service(&btstack_packet_handler, conn_handle, &service));
 }
 
 int mp_bluetooth_gattc_discover_descriptors(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle) {
     DEBUG_EVENT_printf("mp_bluetooth_gattc_discover_descriptors\n");
-    return 0;
+    gatt_client_characteristic_t characteristic = {
+        // Only start/end handles needed for gatt_client_discover_characteristic_descriptors.
+        .start_handle = start_handle,
+        .value_handle = 0,
+        .end_handle = end_handle,
+        .properties = 0,
+        .uuid16 = 0,
+        .uuid128 = {0},
+    };
+    return btstack_error_to_errno(gatt_client_discover_characteristic_descriptors(&btstack_packet_handler, conn_handle, &characteristic));
 }
 
 int mp_bluetooth_gattc_read(uint16_t conn_handle, uint16_t value_handle) {
     DEBUG_EVENT_printf("mp_bluetooth_gattc_read\n");
-    return 0;
+    return btstack_error_to_errno(gatt_client_read_value_of_characteristic_using_value_handle(&btstack_packet_handler, conn_handle, value_handle));
 }
 
 int mp_bluetooth_gattc_write(uint16_t conn_handle, uint16_t value_handle, const uint8_t *value, size_t *value_len, unsigned int mode) {
     DEBUG_EVENT_printf("mp_bluetooth_gattc_write\n");
-    return 0;
+
+    // TODO the below gatt_client functions do not copy the data and require it to be valid
+    // until the write is done, so there should be some kind of buffering done here.
+
+    if (mode == MP_BLUETOOTH_WRITE_MODE_NO_RESPONSE) {
+        // TODO need to call gatt_client_request_can_write_without_response_event then do
+        // the actual write on the callback from that.
+        return btstack_error_to_errno(gatt_client_write_value_of_characteristic_without_response(conn_handle, value_handle, *value_len, (uint8_t *)value));
+    }
+    if (mode == MP_BLUETOOTH_WRITE_MODE_WITH_RESPONSE) {
+        return btstack_error_to_errno(gatt_client_write_value_of_characteristic(&btstack_packet_handler_write_with_response, conn_handle, value_handle, *value_len, (uint8_t *)value));
+    }
+
+    return MP_EINVAL;
 }
 #endif
 

From d7259f6b1c746d352c658bf94a4e0d4c92712ba5 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Fri, 6 Mar 2020 12:37:37 +1100
Subject: [PATCH 13/15] extmod/btstack: Implement notifications/indications for
 GATT clients.

Work done in collaboration with Jim Mussared aka @jimmo.
---
 extmod/btstack/modbluetooth_btstack.c | 37 ++++++++++++++++++++++++++-
 extmod/btstack/modbluetooth_btstack.h | 11 ++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/extmod/btstack/modbluetooth_btstack.c b/extmod/btstack/modbluetooth_btstack.c
index 001d6102253ed..f5ae40a3a0b50 100644
--- a/extmod/btstack/modbluetooth_btstack.c
+++ b/extmod/btstack/modbluetooth_btstack.c
@@ -135,6 +135,7 @@ STATIC void btstack_packet_handler(uint8_t packet_type, uint16_t channel, uint8_
         }
         uint8_t addr[6] = {0};
         mp_bluetooth_gap_on_connected_disconnected(irq_event, conn_handle, 0xff, addr);
+    #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
     } else if (event_type == GATT_EVENT_QUERY_COMPLETE) {
         DEBUG_EVENT_printf("  --> gatt query complete\n");
     } else if (event_type == GATT_EVENT_SERVICE_QUERY_RESULT) {
@@ -169,6 +170,25 @@ STATIC void btstack_packet_handler(uint8_t packet_type, uint16_t channel, uint8_
         mp_bluetooth_gattc_on_data_available_chunk(data, len);
         mp_bluetooth_gattc_on_data_available_end();
         MICROPY_PY_BLUETOOTH_EXIT
+    } else if (event_type == GATT_EVENT_NOTIFICATION) {
+        DEBUG_EVENT_printf("  --> gatt notification\n");
+        uint16_t conn_handle = gatt_event_notification_get_handle(packet);
+        uint16_t value_handle = gatt_event_notification_get_value_handle(packet);
+        uint16_t len = gatt_event_notification_get_value_length(packet);
+        const uint8_t *data = gatt_event_notification_get_value(packet);
+        len = mp_bluetooth_gattc_on_data_available_start(MP_BLUETOOTH_IRQ_GATTC_NOTIFY, conn_handle, value_handle, len);
+        mp_bluetooth_gattc_on_data_available_chunk(data, len);
+        mp_bluetooth_gattc_on_data_available_end();
+    } else if (event_type == GATT_EVENT_INDICATION) {
+        DEBUG_EVENT_printf("  --> gatt indication\n");
+        uint16_t conn_handle = gatt_event_indication_get_handle(packet);
+        uint16_t value_handle = gatt_event_indication_get_value_handle(packet);
+        uint16_t len = gatt_event_indication_get_value_length(packet);
+        const uint8_t *data = gatt_event_indication_get_value(packet);
+        len = mp_bluetooth_gattc_on_data_available_start(MP_BLUETOOTH_IRQ_GATTC_INDICATE, conn_handle, value_handle, len);
+        mp_bluetooth_gattc_on_data_available_chunk(data, len);
+        mp_bluetooth_gattc_on_data_available_end();
+    #endif
     } else {
         DEBUG_EVENT_printf("  --> hci event type: unknown (0x%02x)\n", event_type);
     }
@@ -225,11 +245,26 @@ int mp_bluetooth_init(void) {
     hci_event_callback_registration.callback = &btstack_packet_handler;
     hci_add_event_handler(&hci_event_callback_registration);
 
+    #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+    // Enable GATT_EVENT_NOTIFICATION/GATT_EVENT_INDICATION for all connections and handles.
+    gatt_client_listen_for_characteristic_value_updates(&MP_STATE_PORT(bluetooth_btstack_root_pointers)->notification, &btstack_packet_handler, GATT_CLIENT_ANY_CONNECTION, NULL);
+    #endif
+
     return 0;
 }
 
 void mp_bluetooth_deinit(void) {
     DEBUG_EVENT_printf("mp_bluetooth_deinit\n");
+
+    if (!MP_STATE_PORT(bluetooth_btstack_root_pointers)) {
+        return;
+    }
+
+    #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+    // Remove our registration for notify/indicate.
+    gatt_client_stop_listening_for_characteristic_value_updates(&MP_STATE_PORT(bluetooth_btstack_root_pointers)->notification);
+    #endif
+
     mp_bluetooth_btstack_port_deinit();
     mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_OFF;
 
@@ -560,6 +595,6 @@ int mp_bluetooth_gattc_write(uint16_t conn_handle, uint16_t value_handle, const
 
     return MP_EINVAL;
 }
-#endif
+#endif // MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
 
 #endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
diff --git a/extmod/btstack/modbluetooth_btstack.h b/extmod/btstack/modbluetooth_btstack.h
index 50e690fd4cd4e..ba1d9591dc3a1 100644
--- a/extmod/btstack/modbluetooth_btstack.h
+++ b/extmod/btstack/modbluetooth_btstack.h
@@ -27,8 +27,12 @@
 #ifndef MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
 #define MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H
 
+#if MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
+
 #include "extmod/modbluetooth.h"
 
+#include "lib/btstack/src/btstack.h"
+
 typedef struct _mp_bluetooth_btstack_root_pointers_t {
     // This stores both the advertising data and the scan response data, concatenated together.
     uint8_t *adv_data;
@@ -37,6 +41,11 @@ typedef struct _mp_bluetooth_btstack_root_pointers_t {
 
     // Characteristic (and descriptor) value storage.
     mp_gatts_db_t gatts_db;
+
+    #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE
+    // Registration for notify/indicate events.
+    gatt_client_notification_t notification;
+    #endif
 } mp_bluetooth_btstack_root_pointers_t;
 
 enum {
@@ -51,4 +60,6 @@ void mp_bluetooth_btstack_port_init(void);
 void mp_bluetooth_btstack_port_deinit(void);
 void mp_bluetooth_btstack_port_start(void);
 
+#endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_BTSTACK
+
 #endif // MICROPY_INCLUDED_EXTMOD_BTSTACK_MODBLUETOOTH_BTSTACK_H

From e965363b6b66785ff088c4e998a7e80783bdd97c Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Tue, 10 Mar 2020 01:47:16 +1100
Subject: [PATCH 14/15] stm32: Refactor Bluetooth HCI RX to be independent of
 transport layer.

Now all HCI specific code (eg UART vs WB55 internal messaging) is confined
to modbluetooth_hci.c.
---
 extmod/modbluetooth_hci.h      |  1 +
 extmod/nimble/nimble/npl_os.c  |  4 ++++
 ports/stm32/btstack.c          |  5 ++--
 ports/stm32/modbluetooth_hci.c | 42 ++++++++++++++++++++++++++++++++++
 ports/stm32/nimble.c           | 23 +++----------------
 ports/stm32/rfcore.c           | 15 +++++-------
 ports/stm32/rfcore.h           |  2 +-
 7 files changed, 60 insertions(+), 32 deletions(-)

diff --git a/extmod/modbluetooth_hci.h b/extmod/modbluetooth_hci.h
index 6d44761a4efbe..d6b432d224710 100644
--- a/extmod/modbluetooth_hci.h
+++ b/extmod/modbluetooth_hci.h
@@ -50,6 +50,7 @@ extern pyb_uart_obj_t mp_bluetooth_hci_uart_obj;
 int mp_bluetooth_hci_uart_init(uint32_t port);
 int mp_bluetooth_hci_uart_activate(void);
 int mp_bluetooth_hci_uart_set_baudrate(uint32_t baudrate);
+int mp_bluetooth_hci_uart_readchar(void);
 int mp_bluetooth_hci_uart_write(const uint8_t *buf, size_t len);
 
 #endif // MICROPY_INCLUDED_EXTMOD_MODBLUETOOTH_HCI_H
diff --git a/extmod/nimble/nimble/npl_os.c b/extmod/nimble/nimble/npl_os.c
index 57ab689e6b6c1..620dcb0aec13c 100644
--- a/extmod/nimble/nimble/npl_os.c
+++ b/extmod/nimble/nimble/npl_os.c
@@ -235,7 +235,11 @@ ble_npl_error_t ble_npl_sem_pend(struct ble_npl_sem *sem, ble_npl_time_t timeout
     if (sem->count == 0) {
         uint32_t t0 = mp_hal_ticks_ms();
         while (sem->count == 0 && mp_hal_ticks_ms() - t0 < timeout) {
+            // This function may be called at thread-level, so execute
+            // mp_bluetooth_nimble_hci_uart_process at raised priority.
+            MICROPY_PY_BLUETOOTH_ENTER
             mp_bluetooth_nimble_hci_uart_process();
+            MICROPY_PY_BLUETOOTH_EXIT
             if (sem->count != 0) {
                 break;
             }
diff --git a/ports/stm32/btstack.c b/ports/stm32/btstack.c
index f7669d1fc6447..cbb15a86cb972 100644
--- a/ports/stm32/btstack.c
+++ b/ports/stm32/btstack.c
@@ -165,8 +165,9 @@ STATIC void btstack_uart_process(void) {
 
     // Append any new bytes to the recv buffer, notifying bstack if we've got
     // the number of bytes it was looking for.
-    while (uart_rx_any(&mp_bluetooth_hci_uart_obj) && recv_idx < recv_len) {
-        recv_buf[recv_idx++] = uart_rx_char(&mp_bluetooth_hci_uart_obj);
+    int chr;
+    while (recv_idx < recv_len && (chr = mp_bluetooth_hci_uart_readchar()) >= 0) {
+        recv_buf[recv_idx++] = chr;
         if (recv_idx == recv_len) {
             recv_idx = 0;
             recv_len = 0;
diff --git a/ports/stm32/modbluetooth_hci.c b/ports/stm32/modbluetooth_hci.c
index c6937b2b2a169..4e016eae8451c 100644
--- a/ports/stm32/modbluetooth_hci.c
+++ b/ports/stm32/modbluetooth_hci.c
@@ -54,8 +54,13 @@ void mp_bluetooth_hci_poll_wrapper(uint32_t ticks_ms) {
 /******************************************************************************/
 // HCI over IPCC
 
+#include <string.h>
 #include "rfcore.h"
 
+STATIC uint16_t hci_uart_rx_buf_cur;
+STATIC uint16_t hci_uart_rx_buf_len;
+STATIC uint8_t hci_uart_rx_buf_data[256];
+
 int mp_bluetooth_hci_controller_deactivate(void) {
     return 0;
 }
@@ -79,6 +84,8 @@ int mp_bluetooth_hci_uart_init(uint32_t port) {
 
 int mp_bluetooth_hci_uart_activate(void) {
     rfcore_ble_init();
+    hci_uart_rx_buf_cur = 0;
+    hci_uart_rx_buf_len = 0;
     return 0;
 }
 
@@ -94,6 +101,31 @@ int mp_bluetooth_hci_uart_write(const uint8_t *buf, size_t len) {
     return 0;
 }
 
+// Callback to copy data into local hci_uart_rx_buf_data buffer for subsequent use.
+STATIC int mp_bluetooth_hci_uart_msg_cb(void *env, const uint8_t *buf, size_t len) {
+    (void)env;
+    if (hci_uart_rx_buf_len + len > MP_ARRAY_SIZE(hci_uart_rx_buf_data)) {
+        len = MP_ARRAY_SIZE(hci_uart_rx_buf_data) - hci_uart_rx_buf_len;
+    }
+    memcpy(hci_uart_rx_buf_data + hci_uart_rx_buf_len, buf, len);
+    hci_uart_rx_buf_len += len;
+    return 0;
+}
+
+int mp_bluetooth_hci_uart_readchar(void) {
+    if (hci_uart_rx_buf_cur >= hci_uart_rx_buf_len) {
+        hci_uart_rx_buf_cur = 0;
+        hci_uart_rx_buf_len = 0;
+        rfcore_ble_check_msg(mp_bluetooth_hci_uart_msg_cb, NULL);
+    }
+
+    if (hci_uart_rx_buf_cur < hci_uart_rx_buf_len) {
+        return hci_uart_rx_buf_data[hci_uart_rx_buf_cur++];
+    } else {
+        return -1;
+    }
+}
+
 #else
 
 /******************************************************************************/
@@ -153,6 +185,16 @@ int mp_bluetooth_hci_uart_write(const uint8_t *buf, size_t len) {
     return 0;
 }
 
+// This function expects the controller to be in the wake state via a previous call
+// to mp_bluetooth_hci_controller_woken.
+int mp_bluetooth_hci_uart_readchar(void) {
+    if (uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
+        return uart_rx_char(&mp_bluetooth_hci_uart_obj);
+    } else {
+        return -1;
+    }
+}
+
 #endif // defined(STM32WB)
 
 #endif // MICROPY_PY_BLUETOOTH
diff --git a/ports/stm32/nimble.c b/ports/stm32/nimble.c
index ff78a0a1a3d55..1f4aa4b2ce6cb 100644
--- a/ports/stm32/nimble.c
+++ b/ports/stm32/nimble.c
@@ -67,28 +67,13 @@ void mp_bluetooth_nimble_port_start(void) {
     ble_hs_start();
 }
 
-#if defined(STM32WB)
-
-#include "rfcore.h"
-
-void mp_bluetooth_nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg) {
-    // Protect in case it's called from ble_npl_sem_pend at thread-level
-    MICROPY_PY_LWIP_ENTER
-    rfcore_ble_check_msg(rx_cb, rx_arg);
-    MICROPY_PY_LWIP_EXIT
-}
-
-#else
-
-#include "uart.h"
-
 void mp_bluetooth_nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg) {
     bool host_wake = mp_bluetooth_hci_controller_woken();
 
-    while (uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
-        uint8_t data = uart_rx_char(&mp_bluetooth_hci_uart_obj);
+    int chr;
+    while ((chr = mp_bluetooth_hci_uart_readchar()) >= 0) {
         //printf("UART RX: %02x\n", data);
-        rx_cb(rx_arg, data);
+        rx_cb(rx_arg, chr);
     }
 
     if (host_wake) {
@@ -96,8 +81,6 @@ void mp_bluetooth_nimble_hci_uart_rx(hal_uart_rx_cb_t rx_cb, void *rx_arg) {
     }
 }
 
-#endif // defined(STM32WB)
-
 void mp_bluetooth_nimble_hci_uart_tx_strn(const char *str, uint len) {
     mp_bluetooth_hci_uart_write((const uint8_t *)str, len);
 }
diff --git a/ports/stm32/rfcore.c b/ports/stm32/rfcore.c
index 8221527658982..9b513839c8b43 100644
--- a/ports/stm32/rfcore.c
+++ b/ports/stm32/rfcore.c
@@ -56,7 +56,7 @@ typedef struct _tl_list_node_t {
 } tl_list_node_t;
 
 typedef struct _parse_hci_info_t {
-    int (*cb_fun)(void *, uint8_t);
+    int (*cb_fun)(void *, const uint8_t *, size_t);
     void *cb_env;
     bool was_hci_reset_evt;
 } parse_hci_info_t;
@@ -190,9 +190,7 @@ STATIC void tl_parse_hci_msg(const uint8_t *buf, parse_hci_info_t *parse) {
             // Standard BT HCI ACL packet
             kind = "HCI_ACL";
             if (parse != NULL) {
-                for (size_t i = 0; i < len; ++i) {
-                    parse->cb_fun(parse->cb_env, buf[i]);
-                }
+                parse->cb_fun(parse->cb_env, buf, len);
             }
             break;
         }
@@ -205,12 +203,11 @@ STATIC void tl_parse_hci_msg(const uint8_t *buf, parse_hci_info_t *parse) {
                     len -= 1;
                     fix = true;
                 }
-                for (size_t i = 0; i < len; ++i) {
-                    parse->cb_fun(parse->cb_env, buf[i]);
-                }
+                parse->cb_fun(parse->cb_env, buf, len);
                 if (fix) {
                     len += 1;
-                    parse->cb_fun(parse->cb_env, 0x00); // success
+                    uint8_t data = 0x00; // success
+                    parse->cb_fun(parse->cb_env, &data, 1);
                 }
                 // Check for successful HCI_Reset event
                 parse->was_hci_reset_evt = buf[1] == 0x0e && buf[2] == 0x04 && buf[3] == 0x01
@@ -403,7 +400,7 @@ void rfcore_ble_hci_cmd(size_t len, const uint8_t *src) {
     IPCC->C1SCR = ch << 16;
 }
 
-void rfcore_ble_check_msg(int (*cb)(void *, uint8_t), void *env) {
+void rfcore_ble_check_msg(int (*cb)(void *, const uint8_t *, size_t), void *env) {
     parse_hci_info_t parse = { cb, env, false };
     tl_check_msg(&ipcc_mem_ble_evt_queue, IPCC_CH_BLE, &parse);
 
diff --git a/ports/stm32/rfcore.h b/ports/stm32/rfcore.h
index 8a04075732559..138c438f12eae 100644
--- a/ports/stm32/rfcore.h
+++ b/ports/stm32/rfcore.h
@@ -32,6 +32,6 @@ void rfcore_init(void);
 
 void rfcore_ble_init(void);
 void rfcore_ble_hci_cmd(size_t len, const uint8_t *src);
-void rfcore_ble_check_msg(int (*cb)(void *, uint8_t), void *env);
+void rfcore_ble_check_msg(int (*cb)(void *, const uint8_t *, size_t), void *env);
 
 #endif // MICROPY_INCLUDED_STM32_RFCORE_H

From ecee6f2877aa5e1a9c486fdde5d47c3de5dee092 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 20 Feb 2020 14:46:17 +1100
Subject: [PATCH 15/15] travis: Build stm32 PYBD_SF6 with BTstack as bluetooth
 stack.

---
 .travis.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index e7fd13fd55962..2a993009d53e2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -53,10 +53,11 @@ jobs:
       script:
         - make ${MAKEOPTS} -C mpy-cross
         - make ${MAKEOPTS} -C ports/stm32 submodules
+        - git submodule update --init lib/btstack
         - make ${MAKEOPTS} -C ports/stm32 BOARD=NUCLEO_F091RC
         - make ${MAKEOPTS} -C ports/stm32 BOARD=PYBV11 MICROPY_PY_WIZNET5K=5200 MICROPY_PY_CC3K=1
         - make ${MAKEOPTS} -C ports/stm32 BOARD=PYBD_SF2
-        - make ${MAKEOPTS} -C ports/stm32 BOARD=PYBD_SF6 NANBOX=1
+        - make ${MAKEOPTS} -C ports/stm32 BOARD=PYBD_SF6 NANBOX=1 MICROPY_BLUETOOTH_NIMBLE=0 MICROPY_BLUETOOTH_BTSTACK=1
         - make ${MAKEOPTS} -C ports/stm32 BOARD=NUCLEO_H743ZI CFLAGS_EXTRA='-DMICROPY_PY_THREAD=1'
         - make ${MAKEOPTS} -C ports/stm32 BOARD=B_L072Z_LRWAN1
         - make ${MAKEOPTS} -C ports/stm32 BOARD=STM32L476DISC

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