Merge pull request #2 from adafruit/5.0.x

5.0.x

18 files changed, 494 insertions, 69 deletions

diff --git a/supervisor/shared/bluetooth.c b/supervisor/shared/bluetooth.c
index 02258de74..b463160cf 100644
--- a/supervisor/shared/bluetooth.c
+++ b/supervisor/shared/bluetooth.c
@@ -51,8 +51,12 @@ 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;
+
+// This is the base UUID for CircuitPython services and characteristics.
 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 }; 
+// This standard advertisement advertises the CircuitPython editing service and a CIRCUITPY short name.
+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 };
+// This scan response advertises the full CIRCUITPYXXXX device name.
 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];
@@ -60,6 +64,9 @@ mp_obj_list_t characteristic_list;
 mp_obj_t characteristic_list_items[4];
 
 void supervisor_bluetooth_start_advertising(void) {
+    #if !CIRCUITPY_BLE_FILE_SERVICE
+    return;
+    #endif
     bool is_connected = common_hal_bleio_adapter_get_connected(&common_hal_bleio_adapter_obj);
     if (is_connected) {
         return;
@@ -75,6 +82,10 @@ void supervisor_bluetooth_start_advertising(void) {
 }
 
 void supervisor_start_bluetooth(void) {
+    #if !CIRCUITPY_BLE_FILE_SERVICE
+    return;
+    #endif
+
     common_hal_bleio_adapter_set_enabled(&common_hal_bleio_adapter_obj, true);
 
     supervisor_ble_service_uuid.base.type = &bleio_uuid_type;
@@ -86,7 +97,7 @@ void supervisor_start_bluetooth(void) {
     characteristic_list.len = 0;
     characteristic_list.items = characteristic_list_items;
     mp_seq_clear(characteristic_list.items, 0, characteristic_list.alloc, sizeof(*characteristic_list.items));
-    
+
     _common_hal_bleio_service_construct(&supervisor_ble_service, &supervisor_ble_service_uuid, false /* is secondary */, &characteristic_list);
 
     // File length
@@ -199,6 +210,9 @@ uint32_t current_command[1024 / sizeof(uint32_t)];
 volatile size_t current_offset;
 
 void supervisor_bluetooth_background(void) {
+    #if !CIRCUITPY_BLE_FILE_SERVICE
+    return;
+    #endif
     if (!run_ble_background) {
         return;
     }
@@ -225,7 +239,7 @@ void supervisor_bluetooth_background(void) {
     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];
@@ -274,7 +288,7 @@ void supervisor_bluetooth_background(void) {
                     f_write(&active_file, &data, 1, &actual);
                 }
             }
-            
+
             f_lseek(&active_file, offset);
             uint8_t* data = (uint8_t *) (current_command + 4);
             UINT written;
@@ -292,6 +306,9 @@ void supervisor_bluetooth_background(void) {
 
 // This happens in an interrupt so we need to be quick.
 bool supervisor_bluetooth_hook(ble_evt_t *ble_evt) {
+    #if !CIRCUITPY_BLE_FILE_SERVICE
+    return false;
+    #endif
     // Catch writes to filename or contents. Length is read-only.
 
     bool done = false;
diff --git a/supervisor/shared/board.c b/supervisor/shared/board.c
new file mode 100644
index 000000000..e3eb8fd0d
--- /dev/null
+++ b/supervisor/shared/board.c
@@ -0,0 +1,49 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Dan Halbert 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 "supervisor/shared/board.h"
+
+#include "shared-bindings/digitalio/DigitalInOut.h"
+#include "shared-bindings/neopixel_write/__init__.h"
+
+#ifdef USER_NEOPIXELS_PIN
+
+// The maximum number of user neopixels right now is 10, on Circuit Playgrounds.
+// PyBadge and PyGamer have max 5
+#define USER_NEOPIXELS_MAX_COUNT 10
+
+void board_reset_user_neopixels(void) {
+    // Turn off on-board NeoPixel string
+    uint8_t empty[USER_NEOPIXELS_MAX_COUNT * 3] = { 0 };
+    digitalio_digitalinout_obj_t neopixel_pin;
+    common_hal_digitalio_digitalinout_construct(&neopixel_pin, USER_NEOPIXELS_PIN);
+    common_hal_digitalio_digitalinout_switch_to_output(&neopixel_pin, false,
+        DRIVE_MODE_PUSH_PULL);
+    common_hal_neopixel_write(&neopixel_pin, empty, USER_NEOPIXELS_MAX_COUNT * 3);
+    common_hal_digitalio_digitalinout_deinit(&neopixel_pin);
+}
+
+#endif
diff --git a/supervisor/shared/board.h b/supervisor/shared/board.h
new file mode 100644
index 000000000..0e4d73455
--- /dev/null
+++ b/supervisor/shared/board.h
@@ -0,0 +1,38 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Dan Halbert 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_BOARD_H
+#define MICROPY_INCLUDED_SUPERVISOR_BOARD_H
+
+#include "py/mpconfig.h"
+
+#ifdef USER_NEOPIXELS_PIN
+
+void board_reset_user_neopixels(void);
+
+#endif
+
+#endif  // MICROPY_INCLUDED_SUPERVISOR_BOARD_H
diff --git a/supervisor/shared/display.c b/supervisor/shared/display.c
index c6fda0f16..855432d64 100644
--- a/supervisor/shared/display.c
+++ b/supervisor/shared/display.c
@@ -81,6 +81,7 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
     grid->pixel_width = width_in_tiles * grid->tile_width;
     grid->pixel_height = height_in_tiles * grid->tile_height;
     grid->tiles = tiles;
+    grid->full_change = true;
 
     common_hal_terminalio_terminal_construct(&supervisor_terminal, grid, &supervisor_terminal_font);
 }
diff --git a/supervisor/shared/external_flash/devices.h b/supervisor/shared/external_flash/devices.h
index 08d0a78fd..50263e5d6 100644
--- a/supervisor/shared/external_flash/devices.h
+++ b/supervisor/shared/external_flash/devices.h
@@ -105,6 +105,25 @@ typedef struct {
     .single_status_byte = false, \
 }
 
+// Settings for the Adesto Tech AT25SF041 1MiB SPI flash. It's on the SparkFun
+// SAMD51 Thing Plus board
+// Datasheet: https://www.adestotech.com/wp-content/uploads/DS-AT25SF041_044.pdf
+#define AT25SF041A {\
+    .total_size = (1 << 19), /* 512 KiB */ \
+    .start_up_time_us = 10000, \
+    .manufacturer_id = 0x1f, \
+    .memory_type = 0x84, \
+    .capacity = 0x01, \
+    .max_clock_speed_mhz = 85, \
+    .quad_enable_bit_mask = 0x00, \
+    .has_sector_protection = false, \
+    .supports_fast_read = true, \
+    .supports_qspi = false, \
+    .supports_qspi_writes = false, \
+    .write_status_register_split = false, \
+    .single_status_byte = false, \
+}
+
 // Settings for the Gigadevice GD25Q16C 2MiB SPI flash.
 // Datasheet: http://www.gigadevice.com/datasheet/gd25q16c/
 #define GD25Q16C {\
@@ -371,6 +390,23 @@ typedef struct {
     .single_status_byte = false, \
 }
 
+// Settings for the Winbond W25Q80DV 1MiB SPI flash.. Note that W25Q80DL has a different memory type (0x60)
+// Datasheet: https://www.winbond.com/resource-files/w25q80dv%20dl_revh_10022015.pdf
+#define W25Q80DV {\
+    .total_size = (1 << 20), /* 1 MiB */ \
+    .start_up_time_us = 5000, \
+    .manufacturer_id = 0xef, \
+    .memory_type = 0x40, \
+    .capacity = 0x14, \
+    .max_clock_speed_mhz = 104, \
+    .quad_enable_bit_mask = 0x02, \
+    .has_sector_protection = false, \
+    .supports_fast_read = true, \
+    .supports_qspi = true, \
+    .supports_qspi_writes = false, \
+    .write_status_register_split = false, \
+    .single_status_byte = false, \
+}
 
 // Settings for the Winbond W25Q128JV-SQ 16MiB SPI flash. Note that JV-IM has a different .memory_type (0x70)
 // Datasheet: https://www.winbond.com/resource-files/w25q128jv%20revf%2003272018%20plus.pdf
diff --git a/supervisor/shared/external_flash/external_flash.c b/supervisor/shared/external_flash/external_flash.c
index 99df553e1..9d38c07d8 100644
--- a/supervisor/shared/external_flash/external_flash.c
+++ b/supervisor/shared/external_flash/external_flash.c
@@ -324,6 +324,10 @@ static bool allocate_ram_cache(void) {
         return true;
     }
 
+    if (MP_STATE_MEM(gc_pool_start) == 0) {
+        return false;
+    }
+
     MP_STATE_VM(flash_ram_cache) = m_malloc_maybe(blocks_per_sector * pages_per_block * sizeof(uint32_t), false);
     if (MP_STATE_VM(flash_ram_cache) == NULL) {
         return false;
@@ -367,7 +371,7 @@ static void release_ram_cache(void) {
     if (supervisor_cache != NULL) {
         free_memory(supervisor_cache);
         supervisor_cache = NULL;
-    } else {
+    } else if (MP_STATE_MEM(gc_pool_start)) {
         m_free(MP_STATE_VM(flash_ram_cache));
     }
     MP_STATE_VM(flash_ram_cache) = NULL;
@@ -415,7 +419,7 @@ static bool flush_ram_cache(bool keep_cache) {
             write_flash(current_sector + (i * pages_per_block + j) * SPI_FLASH_PAGE_SIZE,
                         MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j],
                         SPI_FLASH_PAGE_SIZE);
-            if (!keep_cache && supervisor_cache == NULL) {
+            if (!keep_cache && supervisor_cache == NULL && MP_STATE_MEM(gc_pool_start)) {
                 m_free(MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j]);
             }
         }
diff --git a/supervisor/shared/external_flash/spi_flash.c b/supervisor/shared/external_flash/spi_flash.c
index 12888f2d3..67e64c970 100644
--- a/supervisor/shared/external_flash/spi_flash.c
+++ b/supervisor/shared/external_flash/spi_flash.c
@@ -36,33 +36,33 @@
 #include "py/mpconfig.h"
 
 digitalio_digitalinout_obj_t cs_pin;
-busio_spi_obj_t spi;
+busio_spi_obj_t supervisor_flash_spi_bus;
 
 const external_flash_device* flash_device;
 uint32_t spi_flash_baudrate;
 
 // Enable the flash over SPI.
 static void flash_enable(void) {
-    while (!common_hal_busio_spi_try_lock(&spi)) {}
+    while (!common_hal_busio_spi_try_lock(&supervisor_flash_spi_bus)) {}
     common_hal_digitalio_digitalinout_set_value(&cs_pin, false);
 }
 
 // Disable the flash over SPI.
 static void flash_disable(void) {
     common_hal_digitalio_digitalinout_set_value(&cs_pin, true);
-    common_hal_busio_spi_unlock(&spi);
+    common_hal_busio_spi_unlock(&supervisor_flash_spi_bus);
 }
 
 static bool transfer(uint8_t* command, uint32_t command_length, uint8_t* data_in, uint8_t* data_out, uint32_t data_length) {
     flash_enable();
-    bool status = common_hal_busio_spi_write(&spi, command, command_length);
+    bool status = common_hal_busio_spi_write(&supervisor_flash_spi_bus, command, command_length);
     if (status) {
         if (data_in != NULL && data_out != NULL) {
-            status = common_hal_busio_spi_transfer(&spi, data_out, data_in, data_length);
+            status = common_hal_busio_spi_transfer(&supervisor_flash_spi_bus, data_out, data_in, data_length);
         } else if (data_out != NULL) {
-            status = common_hal_busio_spi_read(&spi, data_out, data_length, 0xff);
+            status = common_hal_busio_spi_read(&supervisor_flash_spi_bus, data_out, data_length, 0xff);
         } else if (data_in != NULL) {
-            status = common_hal_busio_spi_write(&spi, data_in, data_length);
+            status = common_hal_busio_spi_write(&supervisor_flash_spi_bus, data_in, data_length);
         }
     }
     flash_disable();
@@ -103,10 +103,10 @@ bool spi_flash_write_data(uint32_t address, uint8_t* data, uint32_t data_length)
     // Write the SPI flash write address into the bytes following the command byte.
     address_to_bytes(address, request + 1);
     flash_enable();
-    common_hal_busio_spi_configure(&spi, spi_flash_baudrate, 0, 0, 8);
-    bool status = common_hal_busio_spi_write(&spi, request, 4);
+    common_hal_busio_spi_configure(&supervisor_flash_spi_bus, spi_flash_baudrate, 0, 0, 8);
+    bool status = common_hal_busio_spi_write(&supervisor_flash_spi_bus, request, 4);
     if (status) {
-        status = common_hal_busio_spi_write(&spi, data, data_length);
+        status = common_hal_busio_spi_write(&supervisor_flash_spi_bus, data, data_length);
     }
     flash_disable();
     return status;
@@ -122,10 +122,10 @@ bool spi_flash_read_data(uint32_t address, uint8_t* data, uint32_t data_length)
     // Write the SPI flash write address into the bytes following the command byte.
     address_to_bytes(address, request + 1);
     flash_enable();
-    common_hal_busio_spi_configure(&spi, spi_flash_baudrate, 0, 0, 8);
-    bool status = common_hal_busio_spi_write(&spi, request, command_length);
+    common_hal_busio_spi_configure(&supervisor_flash_spi_bus, spi_flash_baudrate, 0, 0, 8);
+    bool status = common_hal_busio_spi_write(&supervisor_flash_spi_bus, request, command_length);
     if (status) {
-        status = common_hal_busio_spi_read(&spi, data, data_length, 0xff);
+        status = common_hal_busio_spi_read(&supervisor_flash_spi_bus, data, data_length, 0xff);
     }
     flash_disable();
     return status;
@@ -140,9 +140,9 @@ void spi_flash_init(void) {
     common_hal_digitalio_digitalinout_switch_to_output(&cs_pin, true, DRIVE_MODE_PUSH_PULL);
     common_hal_digitalio_digitalinout_never_reset(&cs_pin);
 
-    spi.base.type = &busio_spi_type;
-    common_hal_busio_spi_construct(&spi, SPI_FLASH_SCK_PIN, SPI_FLASH_MOSI_PIN, SPI_FLASH_MISO_PIN);
-    common_hal_busio_spi_never_reset(&spi);
+    supervisor_flash_spi_bus.base.type = &busio_spi_type;
+    common_hal_busio_spi_construct(&supervisor_flash_spi_bus, SPI_FLASH_SCK_PIN, SPI_FLASH_MOSI_PIN, SPI_FLASH_MISO_PIN);
+    common_hal_busio_spi_never_reset(&supervisor_flash_spi_bus);
 }
 
 void spi_flash_init_device(const external_flash_device* device) {
diff --git a/supervisor/shared/filesystem.c b/supervisor/shared/filesystem.c
index c50d7f4ee..f6b94e38b 100644
--- a/supervisor/shared/filesystem.c
+++ b/supervisor/shared/filesystem.c
@@ -69,6 +69,19 @@ static void make_empty_file(FATFS *fatfs, const char *path) {
     f_close(&fp);
 }
 
+
+static void make_sample_code_file(FATFS *fatfs) {
+    #if CIRCUITPY_FULL_BUILD
+    FIL fs;
+    UINT char_written = 0;
+    const byte buffer[] = "print('Hello World!')\n";
+    //Create or modify existing code.py file
+    f_open(fatfs, &fs, "/code.py", FA_WRITE | FA_CREATE_ALWAYS);
+    f_write(&fs, buffer, sizeof(buffer) - 1, &char_written);
+    f_close(&fs);
+    #endif
+}
+
 // we don't make this function static because it needs a lot of stack and we
 // want it to be executed without using stack within main() function
 void filesystem_init(bool create_allowed, bool force_create) {
@@ -91,13 +104,19 @@ void filesystem_init(bool create_allowed, bool force_create) {
         }
 
         // set label
+#ifdef CIRCUITPY_DRIVE_LABEL
+        f_setlabel(&vfs_fat->fatfs, CIRCUITPY_DRIVE_LABEL);
+#else
         f_setlabel(&vfs_fat->fatfs, "CIRCUITPY");
+#endif
 
         // inhibit file indexing on MacOS
         f_mkdir(&vfs_fat->fatfs, "/.fseventsd");
         make_empty_file(&vfs_fat->fatfs, "/.metadata_never_index");
         make_empty_file(&vfs_fat->fatfs, "/.Trashes");
         make_empty_file(&vfs_fat->fatfs, "/.fseventsd/no_log");
+        // make a sample code.py file
+        make_sample_code_file(&vfs_fat->fatfs);
 
         // create empty lib directory
         f_mkdir(&vfs_fat->fatfs, "/lib");
diff --git a/supervisor/shared/memory.c b/supervisor/shared/memory.c
index 38040d11d..14c3b4979 100755
--- a/supervisor/shared/memory.c
+++ b/supervisor/shared/memory.c
@@ -39,11 +39,14 @@ uint32_t* low_address;
 uint32_t* high_address;
 
 void memory_init(void) {
-    low_address = port_stack_get_limit();
-    high_address = port_stack_get_top();
+    low_address = port_heap_get_bottom();
+    high_address = port_heap_get_top();
 }
 
 void free_memory(supervisor_allocation* allocation) {
+    if (allocation == NULL) {
+        return;
+    }
     int32_t index = 0;
     bool found = false;
     for (index = 0; index < CIRCUITPY_SUPERVISOR_ALLOC_COUNT; index++) {
diff --git a/supervisor/shared/rgb_led_status.c b/supervisor/shared/rgb_led_status.c
index 940cbf1f2..f751a7ffd 100644
--- a/supervisor/shared/rgb_led_status.c
+++ b/supervisor/shared/rgb_led_status.c
@@ -27,6 +27,7 @@
 #include "mphalport.h"
 #include "shared-bindings/microcontroller/Pin.h"
 #include "rgb_led_status.h"
+#include "supervisor/shared/tick.h"
 
 #ifdef MICROPY_HW_NEOPIXEL
 uint8_t rgb_status_brightness = 63;
@@ -360,7 +361,7 @@ void prep_rgb_status_animation(const pyexec_result_t* result,
                                rgb_status_animation_t* status) {
     #if defined(MICROPY_HW_NEOPIXEL) || (defined(MICROPY_HW_APA102_MOSI) && defined(MICROPY_HW_APA102_SCK)) || (defined(CP_RGB_STATUS_LED))
     new_status_color(ALL_DONE);
-    status->pattern_start = ticks_ms;
+    status->pattern_start = supervisor_ticks_ms32();
     status->safe_mode = safe_mode;
     status->found_main = found_main;
     status->total_exception_cycle = 0;
@@ -405,11 +406,11 @@ void prep_rgb_status_animation(const pyexec_result_t* result,
 
 void tick_rgb_status_animation(rgb_status_animation_t* status) {
     #if defined(MICROPY_HW_NEOPIXEL) || (defined(MICROPY_HW_APA102_MOSI) && defined(MICROPY_HW_APA102_SCK)) || (defined(CP_RGB_STATUS_LED))
-    uint32_t tick_diff = ticks_ms - status->pattern_start;
+    uint32_t tick_diff = supervisor_ticks_ms32() - status->pattern_start;
     if (status->ok) {
         // All is good. Ramp ALL_DONE up and down.
         if (tick_diff > ALL_GOOD_CYCLE_MS) {
-            status->pattern_start = ticks_ms;
+            status->pattern_start = supervisor_ticks_ms32();
             tick_diff = 0;
         }
 
@@ -424,7 +425,7 @@ void tick_rgb_status_animation(rgb_status_animation_t* status) {
         }
     } else {
         if (tick_diff > status->total_exception_cycle) {
-            status->pattern_start = ticks_ms;
+            status->pattern_start = supervisor_ticks_ms32();
             tick_diff = 0;
         }
         // First flash the file color.
diff --git a/supervisor/shared/safe_mode.c b/supervisor/shared/safe_mode.c
index d8d3ab379..c957aee53 100644
--- a/supervisor/shared/safe_mode.c
+++ b/supervisor/shared/safe_mode.c
@@ -34,6 +34,7 @@
 #include "supervisor/shared/rgb_led_colors.h"
 #include "supervisor/shared/rgb_led_status.h"
 #include "supervisor/shared/translate.h"
+#include "supervisor/shared/tick.h"
 
 #define SAFE_MODE_DATA_GUARD 0xad0000af
 #define SAFE_MODE_DATA_GUARD_MASK 0xff0000ff
@@ -59,14 +60,14 @@ safe_mode_t wait_for_safe_mode_reset(void) {
     common_hal_digitalio_digitalinout_construct(&status_led, MICROPY_HW_LED_STATUS);
     common_hal_digitalio_digitalinout_switch_to_output(&status_led, true, DRIVE_MODE_PUSH_PULL);
     #endif
-    uint64_t start_ticks = ticks_ms;
+    uint64_t start_ticks = supervisor_ticks_ms64();
     uint64_t diff = 0;
     while (diff < 700) {
         #ifdef MICROPY_HW_LED_STATUS
         // Blink on for 100, off for 100, on for 100, off for 100 and on for 200
         common_hal_digitalio_digitalinout_set_value(&status_led, diff > 100 && diff / 100 != 2 && diff / 100 != 4);
         #endif
-        diff = ticks_ms - start_ticks;
+        diff = supervisor_ticks_ms64() - start_ticks;
     }
     #ifdef MICROPY_HW_LED_STATUS
     common_hal_digitalio_digitalinout_deinit(&status_led);
@@ -93,44 +94,75 @@ void __attribute__((noinline,)) reset_into_safe_mode(safe_mode_t reason) {
     reset_cpu();
 }
 
+
+
+#define FILE_AN_ISSUE translate("\nPlease file an issue with the contents of your CIRCUITPY drive at \nhttps://github.com/adafruit/circuitpython/issues\n")
+
 void print_safe_mode_message(safe_mode_t reason) {
     if (reason == NO_SAFE_MODE) {
         return;
     }
-    serial_write("\r\n");
-    // Output a user safe mode string if its set.
+    serial_write("\n");
+    // Output a user safe mode string if it's set.
     #ifdef BOARD_USER_SAFE_MODE
     if (reason == USER_SAFE_MODE) {
         serial_write_compressed(translate("You requested starting safe mode by "));
         serial_write(BOARD_USER_SAFE_MODE_ACTION);
-        serial_write("\r\n");
-        serial_write_compressed(translate("To exit, please reset the board without "));
+        serial_write_compressed(translate("\nTo exit, please reset the board without "));
         serial_write(BOARD_USER_SAFE_MODE_ACTION);
-        serial_write("\r\n");
+        serial_write("\n");
     } else
     #endif
-    if (reason == MANUAL_SAFE_MODE) {
-        serial_write_compressed(translate("The reset button was pressed while booting CircuitPython. Press again to exit safe mode.\n"));
-    } else if (reason == PROGRAMMATIC_SAFE_MODE) {
-        serial_write_compressed(translate("The `microcontroller` module was used to boot into safe mode. Press reset to exit safe mode.\n"));
-    } else {
-        serial_write_compressed(translate("You are running in safe mode which means something unanticipated happened.\n"));
-        if (reason == HARD_CRASH || reason == MICROPY_NLR_JUMP_FAIL || reason == MICROPY_FATAL_ERROR || reason == GC_ALLOC_OUTSIDE_VM) {
-            serial_write_compressed(translate("Looks like our core CircuitPython code crashed hard. Whoops!\nPlease file an issue at https://github.com/adafruit/circuitpython/issues\n with the contents of your CIRCUITPY drive and this message:\n"));
-            if (reason == HARD_CRASH) {
-                serial_write_compressed(translate("Crash into the HardFault_Handler.\n"));
-            } else if (reason == MICROPY_NLR_JUMP_FAIL) {
-                serial_write_compressed(translate("MicroPython NLR jump failed. Likely memory corruption.\n"));
-            } else if (reason == MICROPY_FATAL_ERROR) {
-                serial_write_compressed(translate("MicroPython fatal error.\n"));
-            } else if (reason == GC_ALLOC_OUTSIDE_VM) {
-                serial_write_compressed(translate("Attempted heap allocation when MicroPython VM not running.\n"));
-            }
-        } else if (reason == BROWNOUT) {
-            serial_write_compressed(translate("The microcontroller's power dipped. Please make sure your power supply provides\nenough power for the whole circuit and press reset (after ejecting CIRCUITPY).\n"));
-        } else if (reason == HEAP_OVERWRITTEN) {
-            serial_write_compressed(translate("The CircuitPython heap was corrupted because the stack was too small.\nPlease increase stack size limits and press reset (after ejecting CIRCUITPY).\nIf you didn't change the stack, then file an issue here with the contents of your CIRCUITPY drive:\n"));
-            serial_write("https://github.com/adafruit/circuitpython/issues\r\n");
+        switch (reason) {
+            case MANUAL_SAFE_MODE:
+                serial_write_compressed(translate("CircuitPython is in safe mode because you pressed the reset button during boot. Press again to exit safe mode.\n"));
+                return;
+            case PROGRAMMATIC_SAFE_MODE:
+                serial_write_compressed(translate("The `microcontroller` module was used to boot into safe mode. Press reset to exit safe mode.\n"));
+                return;
+            default:
+                break;
         }
-    }
+
+        serial_write_compressed(translate("You are in safe mode: something unanticipated happened.\n"));
+        switch (reason) {
+            case BROWNOUT:
+                serial_write_compressed(translate("The microcontroller's power dipped. Make sure your power supply provides\nenough power for the whole circuit and press reset (after ejecting CIRCUITPY).\n"));
+                return;
+            case HEAP_OVERWRITTEN:
+                serial_write_compressed(translate("The CircuitPython heap was corrupted because the stack was too small.\nPlease increase the stack size if you know how, or if not:"));
+                serial_write_compressed(FILE_AN_ISSUE);
+                return;
+            default:
+                break;
+        }
+
+        serial_write_compressed(translate("CircuitPython core code crashed hard. Whoops!\n"));
+        switch (reason) {
+            case HARD_CRASH:
+                serial_write_compressed(translate("Crash into the HardFault_Handler."));
+                return;
+            case MICROPY_NLR_JUMP_FAIL:
+                serial_write_compressed(translate("MicroPython NLR jump failed. Likely memory corruption."));
+                return;
+            case MICROPY_FATAL_ERROR:
+                serial_write_compressed(translate("MicroPython fatal error."));
+                break;
+            case GC_ALLOC_OUTSIDE_VM:
+                serial_write_compressed(translate("Attempted heap allocation when MicroPython VM not running."));
+                break;
+            case NORDIC_SOFT_DEVICE_ASSERT:
+                serial_write_compressed(translate("Nordic Soft Device failure assertion."));
+                break;
+            case FLASH_WRITE_FAIL:
+                serial_write_compressed(translate("Failed to write internal flash."));
+                break;
+            case MEM_MANAGE:
+                serial_write_compressed(translate("Invalid memory access."));
+                break;
+            default:
+                serial_write_compressed(translate("Unknown reason."));
+                break;
+        }
+        serial_write_compressed(FILE_AN_ISSUE);
 }
diff --git a/supervisor/shared/safe_mode.h b/supervisor/shared/safe_mode.h
index 8c5dcd9c5..5b09c4b54 100644
--- a/supervisor/shared/safe_mode.h
+++ b/supervisor/shared/safe_mode.h
@@ -38,7 +38,9 @@ typedef enum {
   MICROPY_FATAL_ERROR,
   GC_ALLOC_OUTSIDE_VM,
   PROGRAMMATIC_SAFE_MODE,
-  NORDIC_SOFT_DEVICE_ASSERT
+  NORDIC_SOFT_DEVICE_ASSERT,
+  FLASH_WRITE_FAIL,
+  MEM_MANAGE,
 } safe_mode_t;
 
 safe_mode_t wait_for_safe_mode_reset(void);
diff --git a/supervisor/shared/stack.c b/supervisor/shared/stack.c
index dcecf2067..2b7b1c03a 100755
--- a/supervisor/shared/stack.c
+++ b/supervisor/shared/stack.c
@@ -46,6 +46,10 @@ void allocate_stack(void) {
 
     mp_uint_t c_size = (uint32_t) port_stack_get_top() - sp;
 
+    if (port_stack_get_top() != port_heap_get_top()) {
+        return;
+    }
+
     stack_alloc = allocate_memory(c_size + next_stack_size + EXCEPTION_STACK_SIZE, true);
     if (stack_alloc == NULL) {
         stack_alloc = allocate_memory(c_size + CIRCUITPY_DEFAULT_STACK_SIZE + EXCEPTION_STACK_SIZE, true);
@@ -71,6 +75,9 @@ void stack_init(void) {
 }
 
 void stack_resize(void) {
+    if (stack_alloc == NULL) {
+        return;
+    }
     if (next_stack_size == current_stack_size) {
         *stack_alloc->ptr = STACK_CANARY_VALUE;
         return;
diff --git a/supervisor/shared/tick.c b/supervisor/shared/tick.c
new file mode 100644
index 000000000..5668f8fa1
--- /dev/null
+++ b/supervisor/shared/tick.c
@@ -0,0 +1,96 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Jeff Epler 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 "supervisor/shared/tick.h"
+
+#include "supervisor/linker.h"
+#include "supervisor/filesystem.h"
+#include "supervisor/shared/autoreload.h"
+
+static volatile uint64_t PLACE_IN_DTCM_BSS(ticks_ms);
+static volatile uint32_t PLACE_IN_DTCM_BSS(background_ticks_ms32);
+
+#if CIRCUITPY_GAMEPAD
+#include "shared-module/gamepad/__init__.h"
+#endif
+
+#if CIRCUITPY_GAMEPADSHIFT
+#include "shared-module/gamepadshift/__init__.h"
+#endif
+
+#include "shared-bindings/microcontroller/__init__.h"
+
+void supervisor_tick(void) {
+
+    ticks_ms ++;
+
+#if CIRCUITPY_FILESYSTEM_FLUSH_INTERVAL_MS > 0
+    filesystem_tick();
+#endif
+#ifdef CIRCUITPY_AUTORELOAD_DELAY_MS
+    autoreload_tick();
+#endif
+#ifdef CIRCUITPY_GAMEPAD_TICKS
+    if (!(ticks_ms & CIRCUITPY_GAMEPAD_TICKS)) {
+        #if CIRCUITPY_GAMEPAD
+        gamepad_tick();
+        #endif
+        #if CIRCUITPY_GAMEPADSHIFT
+        gamepadshift_tick();
+        #endif
+    }
+#endif
+}
+
+uint64_t supervisor_ticks_ms64() {
+    uint64_t result;
+    common_hal_mcu_disable_interrupts();
+    result = ticks_ms;
+    common_hal_mcu_enable_interrupts();
+    return result;
+}
+
+uint32_t supervisor_ticks_ms32() {
+    return ticks_ms;
+}
+
+extern void run_background_tasks(void);
+
+void PLACE_IN_ITCM(supervisor_run_background_tasks_if_tick)() {
+    uint32_t now32 = ticks_ms;
+
+    if (now32 == background_ticks_ms32) {
+        return;
+    }
+    background_ticks_ms32 = now32;
+
+    run_background_tasks();
+}
+
+void supervisor_fake_tick() {
+    uint32_t now32 = ticks_ms;
+    background_ticks_ms32 = (now32 - 1);
+}
diff --git a/supervisor/shared/tick.h b/supervisor/shared/tick.h
new file mode 100644
index 000000000..7ce8281ba
--- /dev/null
+++ b/supervisor/shared/tick.h
@@ -0,0 +1,67 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Jeff Epler 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 __INCLUDED_SUPERVISOR_TICK_H
+#define __INCLUDED_SUPERVISOR_TICK_H
+
+#include <stdint.h>
+
+/** @brief To be called once every ms
+ *
+ * The port must call supervisor_tick once per millisecond to perform regular tasks.
+ * This is called from the SysTick interrupt or similar, and is safe to call in an
+ * interrupt context.
+ */
+extern void supervisor_tick(void);
+/** @brief Cause background tasks to be called soon
+ *
+ * Normally, background tasks are only run once per tick.  For other cases where
+ * an event noticed from an interrupt context needs to be completed by a background
+ * task activity, the interrupt can call supervisor_fake_tick.
+ */
+extern void supervisor_fake_tick(void);
+/** @brief Get the lower 32 bits of the time in milliseconds
+ *
+ * This can be more efficient than supervisor_ticks_ms64, for sites where a wraparound
+ * of ~49.5 days is not harmful.
+ */
+extern uint32_t supervisor_ticks_ms32(void);
+/** @brief Get the full time in milliseconds
+ *
+ * Because common ARM mcus cannot atomically work with 64-bit quantities, this
+ * function must briefly disable interrupts in order to return the value.  If
+ * only relative durations of less than about ~49.5 days need to be considered,
+ * then it may be possible to use supervisor_ticks_ms64 instead.
+ */
+extern uint64_t supervisor_ticks_ms64(void);
+/** @brief Run background ticks, but only about every millisecond.
+ *
+ * Normally, this is not called directly.  Instead use the RUN_BACKGROUND_TASKS
+ * macro.
+ */
+extern void supervisor_run_background_if_tick(void);
+
+#endif
diff --git a/supervisor/shared/translate.c b/supervisor/shared/translate.c
index aa5e4517c..187d5ff8a 100644
--- a/supervisor/shared/translate.c
+++ b/supervisor/shared/translate.c
@@ -42,12 +42,28 @@ void serial_write_compressed(const compressed_string_t* compressed) {
     serial_write(decompressed);
 }
 
+STATIC int put_utf8(char *buf, int u) {
+    if(u <= 0x7f) {
+        *buf = u;
+        return 1;
+    } else if(u <= 0x07ff) {
+        *buf++ = 0b11000000 | (u >> 6);
+        *buf   = 0b10000000 | (u & 0b00111111);
+        return 2;
+    } else { // u <= 0xffff)
+        *buf++ = 0b11000000 | (u >> 12);
+        *buf   = 0b10000000 | ((u >> 6) & 0b00111111);
+        *buf   = 0b10000000 | (u & 0b00111111);
+        return 3;
+    }
+}
+
 char* decompress(const compressed_string_t* compressed, char* decompressed) {
     uint8_t this_byte = 0;
     uint8_t this_bit = 7;
     uint8_t b = compressed->data[this_byte];
     // Stop one early because the last byte is always NULL.
-    for (uint16_t i = 0; i < compressed->length - 1; i++) {
+    for (uint16_t i = 0; i < compressed->length - 1;) {
         uint32_t bits = 0;
         uint8_t bit_length = 0;
         uint32_t max_code = lengths[0];
@@ -72,7 +88,7 @@ char* decompress(const compressed_string_t* compressed, char* decompressed) {
             max_code = (max_code << 1) + lengths[bit_length];
             searched_length += lengths[bit_length];
         }
-        decompressed[i] = values[searched_length + bits - max_code];
+        i += put_utf8(decompressed + i, values[searched_length + bits - max_code]);
     }
 
     decompressed[compressed->length-1] = '\0';
diff --git a/supervisor/shared/usb/usb.c b/supervisor/shared/usb/usb.c
index c1d70c5b0..a0178528d 100644
--- a/supervisor/shared/usb/usb.c
+++ b/supervisor/shared/usb/usb.c
@@ -87,10 +87,12 @@ void usb_background(void) {
 
 // Invoked when device is mounted
 void tud_mount_cb(void) {
+    usb_msc_mount();
 }
 
 // Invoked when device is unmounted
 void tud_umount_cb(void) {
+    usb_msc_umount();
 }
 
 // Invoked when usb bus is suspended
diff --git a/supervisor/shared/usb/usb_msc_flash.c b/supervisor/shared/usb/usb_msc_flash.c
index 205cb7b50..7532b6aea 100644
--- a/supervisor/shared/usb/usb_msc_flash.c
+++ b/supervisor/shared/usb/usb_msc_flash.c
@@ -39,7 +39,27 @@
 
 #define MSC_FLASH_BLOCK_SIZE    512
 
-static bool ejected[1];
+static bool ejected[1] = {true};
+
+void usb_msc_mount(void) {
+    // Reset the ejection tracking every time we're plugged into USB. This allows for us to battery
+    // power the device, eject, unplug and plug it back in to get the drive.
+    for (uint8_t i = 0; i < sizeof(ejected); i++) {
+        ejected[i] = false;
+    }
+}
+
+void usb_msc_umount(void) {
+
+}
+
+bool usb_msc_ejected(void) {
+    bool all_ejected = true;
+    for (uint8_t i = 0; i < sizeof(ejected); i++) {
+        all_ejected &= ejected[i];
+    }
+    return all_ejected;
+}
 
 // The root FS is always at the end of the list.
 static fs_user_mount_t* get_vfs(int lun) {
@@ -188,6 +208,8 @@ bool tud_msc_test_unit_ready_cb(uint8_t lun) {
         return false;
     }
     if (ejected[lun]) {
+        // Set 0x3a for media not present.
+        tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x3A, 0x00);
         return false;
     }
 
@@ -198,20 +220,33 @@ bool tud_msc_test_unit_ready_cb(uint8_t lun) {
 // - Start = 0 : stopped power mode, if load_eject = 1 : unload disk storage
 // - Start = 1 : active mode, if load_eject = 1 : load disk storage
 bool tud_msc_start_stop_cb(uint8_t lun, uint8_t power_condition, bool start, bool load_eject) {
+    if (lun > 1) {
+        return false;
+    }
+    fs_user_mount_t* current_mount = get_vfs(lun);
+    if (current_mount == NULL) {
+        return false;
+    }
     if (load_eject) {
-        if (lun > 1) {
-            return false;
-        } else {
-            fs_user_mount_t* current_mount = get_vfs(lun);
-            if (current_mount == NULL) {
-                return false;
-            }
+        if (!start) {
+            // Eject but first flush.
             if (disk_ioctl(current_mount, CTRL_SYNC, NULL) != RES_OK) {
                 return false;
             } else {
                 ejected[lun] = true;
             }
+        } else {
+            // We can only load if it hasn't been ejected.
+            return !ejected[lun];
+        }
+    } else {
+        if (!start) {
+            // Stop the unit but don't eject.
+            if (disk_ioctl(current_mount, CTRL_SYNC, NULL) != RES_OK) {
+                return false;
+            }
         }
+        // Always start the unit, even if ejected. Whether media is present is a separate check.
     }
 
     return true;