stm32: Extract port-specific Nimble implementation.

On other ports (e.g. ESP32) they provide a complete Nimble implementation
(i.e. we don't need to use the code in extmod/nimble). This change
extracts out the bits that we don't need to use in other ports:
 - malloc/free/realloc for Nimble memory.
 - pendsv poll handler
 - depowering the cywbt

Also cleans up the root pointer management.

3 files changed, 85 insertions, 1 deletions

diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index 40db2f756..1a4e3c690 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -436,6 +436,7 @@ endif
 
 ifeq ($(MICROPY_BLUETOOTH_NIMBLE),1)
 include $(TOP)/extmod/nimble/nimble.mk
+SRC_C += nimble.c
 SRC_C += nimble_hci_uart.c
 EXTMOD_SRC_C += extmod/modbluetooth_nimble.c
 ifeq ($(MICROPY_PY_NETWORK_CYW43),1)
diff --git a/ports/stm32/mpconfigport.h b/ports/stm32/mpconfigport.h
index 54e1c503c..580675511 100644
--- a/ports/stm32/mpconfigport.h
+++ b/ports/stm32/mpconfigport.h
@@ -298,7 +298,8 @@ extern const struct _mp_obj_module_t mp_module_onewire;
 #endif
 
 #if MICROPY_BLUETOOTH_NIMBLE
-#define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE void **bluetooth_nimble_memory;
+struct _mp_bluetooth_nimble_root_pointers_t;
+#define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE void **bluetooth_nimble_memory; struct _mp_bluetooth_nimble_root_pointers_t *bluetooth_nimble_root_pointers;
 #else
 #define MICROPY_PORT_ROOT_POINTER_BLUETOOTH_NIMBLE
 #endif
diff --git a/ports/stm32/nimble.c b/ports/stm32/nimble.c
new file mode 100644
index 000000000..b8fdc8f88
--- /dev/null
+++ b/ports/stm32/nimble.c
@@ -0,0 +1,82 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Jim Mussared
+ *
+ * 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_NIMBLE
+
+#include "systick.h"
+#include "pendsv.h"
+
+#include "transport/uart/ble_hci_uart.h"
+#include "host/ble_hs.h"
+
+#include "extmod/modbluetooth_nimble.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) {
+    if (mp_bluetooth_nimble_ble_state == MP_BLUETOOTH_NIMBLE_BLE_STATE_OFF) {
+        return;
+    }
+
+    nimble_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();
+}
+
+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
+}
+
+void mp_bluetooth_nimble_port_start(void) {
+    ble_hs_start();
+}
+
+#endif // MICROPY_PY_BLUETOOTH && MICROPY_BLUETOOTH_NIMBLE