zephyr: Add initial ubluetooth module integration.

Currently only advertising and scanning are supported, using the ring
buffer for events (ie not synchronous events at this stage).

The ble_gap_advertise.py multi-test passes (tested on a nucleo_wb55rg
board).
Signed-off-by: Damien George <damien@micropython.org>

ports/zephyr/CMakeLists.txt

@@ -40,6 +40,7 @@ set(MICROPY_SOURCE_PORT
     machine_i2c.c
     machine_pin.c
     machine_uart.c
+    modbluetooth_zephyr.c
     modmachine.c
     moduos.c
     modusocket.c

ports/zephyr/main.c

@@ -49,6 +49,7 @@
 #include "py/stackctrl.h"
 #include "lib/utils/pyexec.h"
 #include "lib/mp-readline/readline.h"
+#include "extmod/modbluetooth.h"
 
 #if MICROPY_VFS
 #include "extmod/vfs.h"
@@ -168,6 +169,9 @@ soft_reset:
 
     printf("soft reboot\n");
 
+    #if MICROPY_PY_BLUETOOTH
+    mp_bluetooth_deinit();
+    #endif
     #if MICROPY_PY_MACHINE
     machine_pin_deinit();
     #endif

ports/zephyr/mpconfigport.h

@@ -52,6 +52,7 @@
 #define MICROPY_PY_BUILTINS_REVERSED (0)
 #define MICROPY_PY_BUILTINS_SET     (0)
 #define MICROPY_PY_BUILTINS_STR_COUNT (0)
+#define MICROPY_PY_BUILTINS_MEMORYVIEW (1)
 #define MICROPY_PY_BUILTINS_HELP    (1)
 #define MICROPY_PY_BUILTINS_HELP_TEXT zephyr_help_text
 #define MICROPY_PY_ARRAY            (0)
@@ -69,6 +70,13 @@
 #define MICROPY_PY_UERRNO           (1)
 #define MICROPY_PY_USOCKET          (1)
 #endif
+#ifdef CONFIG_BT
+#define MICROPY_PY_BLUETOOTH        (1)
+#ifdef CONFIG_BT_CENTRAL
+#define MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE (1)
+#endif
+#define MICROPY_PY_BLUETOOTH_ENABLE_GATT_CLIENT (0)
+#endif
 #define MICROPY_PY_UBINASCII        (1)
 #define MICROPY_PY_UHASHLIB         (1)
 #define MICROPY_PY_UOS              (1)
@@ -123,7 +131,8 @@ typedef long mp_off_t;
 
 #define MICROPY_PORT_ROOT_POINTERS \
     const char *readline_hist[8]; \
-    void *machine_pin_irq_list; /* Linked list of pin irq objects */
+    void *machine_pin_irq_list; /* Linked list of pin irq objects */ \
+    struct _mp_bluetooth_zephyr_root_pointers_t *bluetooth_zephyr_root_pointers;
 
 extern const struct _mp_obj_module_t mp_module_machine;
 extern const struct _mp_obj_module_t mp_module_time;

ports/zephyr/src/zephyr_start.c

@@ -36,4 +36,8 @@ void main(void) {
     zephyr_getchar_init();
 #endif
     real_main();
+
+    // This is needed so the linker includes k_timer_init, z_impl_k_timer_start
+    // and z_impl_k_timer_stop, as used by libmicropython.a.
+    k_timer_start(NULL, K_MSEC(0), K_MSEC(0));
 }