Refine _bleio

This PR refines the _bleio API. It was originally motivated by
the addition of a new CircuitPython service that enables reading
and modifying files on the device. Moving the BLE lifecycle outside
of the VM motivated a number of changes to remove heap allocations
in some APIs.

It also motivated unifying connection initiation to the Adapter class
rather than the Central and Peripheral classes which have been removed.
Adapter now handles the GAP portion of BLE including advertising, which
has moved but is largely unchanged, and scanning, which has been enhanced
to return an iterator of filtered results.

Once a connection is created (either by us (aka Central) or a remote
device (aka Peripheral)) it is represented by a new Connection class.
This class knows the current connection state and can discover and
instantiate remote Services along with their Characteristics and
Descriptors.

Relates to #586

6 files changed, 392 insertions, 1 deletions

diff --git a/supervisor/shared/autoreload.c b/supervisor/shared/autoreload.c
index 14b21902c..a6212c1a9 100644
--- a/supervisor/shared/autoreload.c
+++ b/supervisor/shared/autoreload.c
@@ -76,3 +76,11 @@ void autoreload_stop() {
     autoreload_delay_ms = 0;
     reload_requested = false;
 }
+
+void autoreload_now() {
+    if (!autoreload_enabled || autoreload_suspended || reload_requested) {
+        return;
+    }
+    mp_raise_reload_exception();
+    reload_requested = true;
+}
diff --git a/supervisor/shared/autoreload.h b/supervisor/shared/autoreload.h
index bcb100151..fbd482c19 100644
--- a/supervisor/shared/autoreload.h
+++ b/supervisor/shared/autoreload.h
@@ -43,4 +43,6 @@ bool autoreload_is_enabled(void);
 void autoreload_suspend(void);
 void autoreload_resume(void);
 
+void autoreload_now(void);
+
 #endif  // MICROPY_INCLUDED_SUPERVISOR_AUTORELOAD_H
diff --git a/supervisor/shared/bluetooth.c b/supervisor/shared/bluetooth.c
new file mode 100644
index 000000000..64f3b55eb
--- /dev/null
+++ b/supervisor/shared/bluetooth.c
@@ -0,0 +1,341 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Scott Shawcroft for Adafruit Industries
+ *
+ * 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 <string.h>
+
+#include "extmod/vfs.h"
+#include "extmod/vfs_fat.h"
+
+#include "shared-bindings/_bleio/__init__.h"
+#include "shared-bindings/_bleio/Adapter.h"
+#include "shared-bindings/_bleio/Characteristic.h"
+#include "shared-bindings/_bleio/Service.h"
+#include "shared-bindings/_bleio/UUID.h"
+
+#include "common-hal/_bleio/__init__.h"
+
+#include "supervisor/shared/autoreload.h"
+
+#include "py/mpstate.h"
+
+bleio_service_obj_t supervisor_ble_service;
+bleio_uuid_obj_t supervisor_ble_service_uuid;
+bleio_characteristic_obj_t supervisor_ble_version_characteristic;
+bleio_uuid_obj_t supervisor_ble_version_uuid;
+bleio_characteristic_obj_t supervisor_ble_filename_characteristic;
+bleio_uuid_obj_t supervisor_ble_filename_uuid;
+bleio_characteristic_obj_t supervisor_ble_length_characteristic;
+bleio_uuid_obj_t supervisor_ble_length_uuid;
+bleio_characteristic_obj_t supervisor_ble_contents_characteristic;
+bleio_uuid_obj_t supervisor_ble_contents_uuid;
+const uint8_t circuitpython_base_uuid[16] = {0x6e, 0x68, 0x74, 0x79, 0x50, 0x74, 0x69, 0x75, 0x63, 0x72, 0x69, 0x43, 0x00, 0x00, 0xaf, 0xad };
+uint8_t circuitpython_advertising_data[] = { 0x02, 0x01, 0x06, 0x02, 0x0a, 0x00, 0x11, 0x07, 0x6e, 0x68, 0x74, 0x79, 0x50, 0x74, 0x69, 0x75, 0x63, 0x72, 0x69, 0x43, 0x00, 0x01, 0xaf, 0xad, 0x06, 0x08, 0x43, 0x49, 0x52, 0x43, 0x55 }; 
+uint8_t circuitpython_scan_response_data[15] = {0x0e, 0x09, 0x43, 0x49, 0x52, 0x43, 0x55, 0x49, 0x54, 0x50, 0x59, 0x00, 0x00, 0x00, 0x00};
+mp_obj_list_t service_list;
+mp_obj_t service_list_items[1];
+mp_obj_list_t characteristic_list;
+mp_obj_t characteristic_list_items[4];
+
+void supervisor_bluetooth_start_advertising(void) {
+    bool is_connected = common_hal_bleio_adapter_get_connected(&common_hal_bleio_adapter_obj);
+    if (is_connected) {
+        return;
+    }
+    // TODO: switch to Adafruit short UUID for the advertisement and add manufacturing data to distinguish ourselves from arduino.
+    _common_hal_bleio_adapter_start_advertising(&common_hal_bleio_adapter_obj,
+                                                   true,
+                                                   1.0,
+                                                   circuitpython_advertising_data,
+                                                   sizeof(circuitpython_advertising_data),
+                                                   circuitpython_scan_response_data,
+                                                   sizeof(circuitpython_scan_response_data));
+}
+
+void supervisor_start_bluetooth(void) {
+    common_hal_bleio_adapter_set_enabled(&common_hal_bleio_adapter_obj, true);
+
+    supervisor_ble_service_uuid.base.type = &bleio_uuid_type;
+    common_hal_bleio_uuid_construct(&supervisor_ble_service_uuid, 0x0100, circuitpython_base_uuid);
+
+    // We know we'll only be 1 characteristic so we can statically allocate it.
+    characteristic_list.base.type = &mp_type_list;
+    characteristic_list.alloc = sizeof(characteristic_list_items) / sizeof(characteristic_list_items[0]);
+    characteristic_list.len = 0;
+    characteristic_list.items = characteristic_list_items;
+    mp_seq_clear(characteristic_list.items, 0, characteristic_list.alloc, sizeof(*characteristic_list.items));
+    
+    const uint32_t err_code = _common_hal_bleio_service_construct(&supervisor_ble_service, &supervisor_ble_service_uuid, false /* is secondary */, &characteristic_list);
+
+    // File length
+    supervisor_ble_version_uuid.base.type = &bleio_uuid_type;
+    common_hal_bleio_uuid_construct(&supervisor_ble_version_uuid, 0x0203, circuitpython_base_uuid);
+    common_hal_bleio_characteristic_construct(&supervisor_ble_version_characteristic,
+                                              &supervisor_ble_service,
+                                              0, // handle (for remote only)
+                                              &supervisor_ble_version_uuid,
+                                              CHAR_PROP_READ,
+                                              SECURITY_MODE_OPEN,
+                                              SECURITY_MODE_NO_ACCESS,
+                                              4, // max length
+                                              true, // fixed length
+                                              NULL); // no initial value
+
+    uint32_t version = 1;
+    mp_buffer_info_t bufinfo;
+    bufinfo.buf = &version;
+    bufinfo.len = sizeof(version);
+    common_hal_bleio_characteristic_set_value(&supervisor_ble_version_characteristic, &bufinfo);
+
+    // Active filename.
+    supervisor_ble_filename_uuid.base.type = &bleio_uuid_type;
+    common_hal_bleio_uuid_construct(&supervisor_ble_filename_uuid, 0x0200, circuitpython_base_uuid);
+    common_hal_bleio_characteristic_construct(&supervisor_ble_filename_characteristic,
+                                              &supervisor_ble_service,
+                                              0, // handle (for remote only)
+                                              &supervisor_ble_filename_uuid,
+                                              CHAR_PROP_READ | CHAR_PROP_WRITE,
+                                              SECURITY_MODE_OPEN,
+                                              SECURITY_MODE_OPEN,
+                                              500, // max length
+                                              false, // fixed length
+                                              NULL); // no initial value
+
+    char code_py[] = "/code.py";
+    bufinfo.buf = code_py;
+    bufinfo.len = sizeof(code_py);
+    common_hal_bleio_characteristic_set_value(&supervisor_ble_filename_characteristic, &bufinfo);
+
+    // File length
+    supervisor_ble_length_uuid.base.type = &bleio_uuid_type;
+    common_hal_bleio_uuid_construct(&supervisor_ble_length_uuid, 0x0202, circuitpython_base_uuid);
+    common_hal_bleio_characteristic_construct(&supervisor_ble_length_characteristic,
+                                              &supervisor_ble_service,
+                                              0, // handle (for remote only)
+                                              &supervisor_ble_length_uuid,
+                                              CHAR_PROP_NOTIFY | CHAR_PROP_READ,
+                                              SECURITY_MODE_OPEN,
+                                              SECURITY_MODE_NO_ACCESS,
+                                              4, // max length
+                                              true, // fixed length
+                                              NULL); // no initial value
+
+    // File actions
+    supervisor_ble_contents_uuid.base.type = &bleio_uuid_type;
+    common_hal_bleio_uuid_construct(&supervisor_ble_contents_uuid, 0x0201, circuitpython_base_uuid);
+    common_hal_bleio_characteristic_construct(&supervisor_ble_contents_characteristic,
+                                              &supervisor_ble_service,
+                                              0, // handle (for remote only)
+                                              &supervisor_ble_contents_uuid,
+                                              CHAR_PROP_NOTIFY | CHAR_PROP_WRITE_NO_RESPONSE | CHAR_PROP_WRITE,
+                                              SECURITY_MODE_OPEN,
+                                              SECURITY_MODE_OPEN,
+                                              500, // max length
+                                              false, // fixed length
+                                              NULL); // no initial value
+
+    supervisor_bluetooth_start_advertising();
+    vm_used_ble = false;
+}
+
+FIL active_file;
+volatile bool new_filename;
+volatile bool run_ble_background;
+bool was_connected;
+
+void update_file_length(void) {
+    int32_t file_length = -1;
+    mp_buffer_info_t bufinfo;
+    bufinfo.buf = &file_length;
+    bufinfo.len = sizeof(file_length);
+    if (active_file.obj.fs != 0) {
+        file_length = (int32_t) f_size(&active_file);
+    }
+    common_hal_bleio_characteristic_set_value(&supervisor_ble_length_characteristic, &bufinfo);
+}
+
+void open_current_file(void) {
+    if (active_file.obj.fs != 0) {
+        return;
+    }
+    uint16_t max_len = supervisor_ble_filename_characteristic.max_length;
+    uint8_t path[max_len];
+    size_t length = common_hal_bleio_characteristic_get_value(&supervisor_ble_filename_characteristic, path, max_len - 1);
+    path[length] = '\0';
+
+    FATFS *fs = &((fs_user_mount_t *) MP_STATE_VM(vfs_mount_table)->obj)->fatfs;
+    FRESULT result = f_open(fs, &active_file, (char*) path, FA_READ | FA_WRITE);
+
+    update_file_length();
+}
+
+void close_current_file(void) {
+    f_close(&active_file);
+}
+
+uint32_t current_command[1024 / sizeof(uint32_t)];
+volatile size_t current_offset;
+
+void supervisor_bluetooth_background(void) {
+    if (!run_ble_background) {
+        return;
+    }
+    bool is_connected = common_hal_bleio_adapter_get_connected(&common_hal_bleio_adapter_obj);
+    if (!was_connected && is_connected) {
+        open_current_file();
+    } else if (was_connected && !is_connected) {
+        close_current_file();
+        new_filename = false;
+    }
+    was_connected = is_connected;
+    run_ble_background = false;
+    if (!is_connected) {
+        supervisor_bluetooth_start_advertising();
+        return;
+    }
+    if (new_filename) {
+        close_current_file();
+        open_current_file();
+
+        new_filename = false;
+        // get length and set the characteristic for it
+    }
+    uint16_t current_length = ((uint16_t*) current_command)[0];
+    if (current_length > 0 && current_length == current_offset) {
+        uint16_t command = ((uint16_t *) current_command)[1];
+        
+        if (command == 1) {
+            uint16_t max_len = 20; //supervisor_ble_contents_characteristic.max_length;
+            uint8_t buf[max_len];
+            mp_buffer_info_t bufinfo;
+            bufinfo.buf = buf;
+            f_lseek(&active_file, 0);
+            while (f_read(&active_file, buf, max_len, &bufinfo.len) == FR_OK) {
+                if (bufinfo.len == 0) {
+                    break;
+                }
+                common_hal_bleio_characteristic_set_value(&supervisor_ble_contents_characteristic, &bufinfo);
+            }
+        } else if (command == 2) { // patch
+            uint32_t offset = current_command[1];
+            uint32_t remove_length = current_command[2];
+            uint32_t insert_length = current_command[3];
+            uint32_t file_length =  (int32_t) f_size(&active_file);
+            //uint32_t data_shift_length = fileLength - offset - remove_length;
+            int32_t data_shift = insert_length - remove_length;
+            uint32_t new_length = file_length + data_shift;
+            FRESULT result;
+
+            // TODO: Make these loops smarter to read and write on sector boundaries.
+            if (data_shift < 0) {
+                for (uint32_t shift_offset = offset + insert_length; shift_offset < new_length; shift_offset++) {
+                    uint8_t data;
+                    UINT actual;
+                    f_lseek(&active_file, shift_offset - data_shift);
+                    result = f_read(&active_file, &data, 1, &actual);
+                    f_lseek(&active_file, shift_offset);
+                    result = f_write(&active_file, &data, 1, &actual);
+                }
+                f_truncate(&active_file);
+            } else if (data_shift > 0) {
+                result = f_lseek(&active_file, file_length);
+                // Fill end with 0xff so we don't need to erase.
+                uint8_t data = 0xff;
+                for (size_t i = 0; i < (size_t) data_shift; i++) {
+                    UINT actual;
+                    result = f_write(&active_file, &data, 1, &actual);
+                }
+                for (uint32_t shift_offset = new_length - 1; shift_offset >= offset + insert_length ; shift_offset--) {
+                    UINT actual;
+                    f_lseek(&active_file, shift_offset - data_shift);
+                    result = f_read(&active_file, &data, 1, &actual);
+                    f_lseek(&active_file, shift_offset);
+                    result = f_write(&active_file, &data, 1, &actual);
+                }
+            }
+            
+            f_lseek(&active_file, offset);
+            uint8_t* data = (uint8_t *) (current_command + 4);
+            UINT written;
+            result = f_write(&active_file, data, insert_length, &written);
+            f_sync(&active_file);
+            // Notify the new file length.
+            update_file_length();
+
+            // Trigger an autoreload
+            autoreload_now();
+        }
+        current_offset = 0;
+    }
+}
+
+// This happens in an interrupt so we need to be quick.
+bool supervisor_bluetooth_hook(ble_evt_t *ble_evt) {
+    // Catch writes to filename or contents. Length is read-only.
+
+    bool done = false;
+    switch (ble_evt->header.evt_id) {
+        case BLE_GAP_EVT_CONNECTED:
+            // We run our background task even if it wasn't us connected to because we may want to
+            // advertise if the user code stopped advertising.
+            run_ble_background = true;
+            break;
+        case BLE_GAP_EVT_DISCONNECTED:
+            run_ble_background = true;
+            break;
+        case BLE_GATTS_EVT_WRITE: {
+            // A client wrote to a characteristic.
+
+            ble_gatts_evt_write_t *evt_write = &ble_evt->evt.gatts_evt.params.write;
+            // Event handle must match the handle for my characteristic.
+            if (evt_write->handle == supervisor_ble_contents_characteristic.handle) {
+                // Handle events
+                //write_to_ringbuf(self, evt_write->data, evt_write->len);
+                // First packet includes a uint16_t le for length at the start.
+                uint16_t current_length = ((uint16_t*) current_command)[0];
+                memcpy(((uint8_t*) current_command) + current_offset, evt_write->data, evt_write->len);
+                current_offset += evt_write->len;
+                current_length = ((uint16_t*) current_command)[0];
+                if (current_offset == current_length) {
+                    run_ble_background = true;
+                    done = true;
+                }
+            } else if (evt_write->handle == supervisor_ble_filename_characteristic.handle) {
+                new_filename = true;
+                run_ble_background = true;
+                done = true;
+            } else {
+                return done;
+            }
+            break;
+        }
+
+        default:
+            // For debugging.
+            // mp_printf(&mp_plat_print, "Unhandled peripheral event: 0x%04x\n", ble_evt->header.evt_id);
+            break;
+    }
+    return done;
+}
diff --git a/supervisor/shared/bluetooth.h b/supervisor/shared/bluetooth.h
new file mode 100644
index 000000000..7ebcb953f
--- /dev/null
+++ b/supervisor/shared/bluetooth.h
@@ -0,0 +1,34 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Scott Shawcroft for Adafruit Industries
+ *
+ * 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_SUPERVISOR_SHARED_BLUETOOTH_H
+#define MICROPY_INCLUDED_SUPERVISOR_SHARED_BLUETOOTH_H
+
+void supervisor_start_bluetooth(void);
+bool supervisor_bluetooth_hook(ble_evt_t *ble_evt);
+void supervisor_bluetooth_background(void);
+
+#endif
\ No newline at end of file
diff --git a/supervisor/shared/safe_mode.h b/supervisor/shared/safe_mode.h
index ee0723cff..8c5dcd9c5 100644
--- a/supervisor/shared/safe_mode.h
+++ b/supervisor/shared/safe_mode.h
@@ -37,7 +37,8 @@ typedef enum {
   MICROPY_NLR_JUMP_FAIL,
   MICROPY_FATAL_ERROR,
   GC_ALLOC_OUTSIDE_VM,
-  PROGRAMMATIC_SAFE_MODE
+  PROGRAMMATIC_SAFE_MODE,
+  NORDIC_SOFT_DEVICE_ASSERT
 } safe_mode_t;
 
 safe_mode_t wait_for_safe_mode_reset(void);
diff --git a/supervisor/supervisor.mk b/supervisor/supervisor.mk
index 48697a94a..ad0f716fb 100644
--- a/supervisor/supervisor.mk
+++ b/supervisor/supervisor.mk
@@ -28,6 +28,11 @@ ifneq ($(SPI_FLASH_FILESYSTEM),)
 	CFLAGS += -DSPI_FLASH_FILESYSTEM=$(SPI_FLASH_FILESYSTEM) -DEXPRESS_BOARD
 endif
 
+
+ifeq ($(CIRCUITPY_BLEIO),1)
+	SRC_SUPERVISOR += supervisor/shared/bluetooth.c
+endif
+
 # Choose which flash filesystem impl to use.
 # (Right now INTERNAL_FLASH_FILESYSTEM and SPI_FLASH_FILESYSTEM are mutually exclusive.
 # But that might not be true in the future.)