Added UM FeatherS2 Neo to boards.txt and added appropriate variants. (#5615)

Fixes: https://github.com/espressif/arduino-esp32/issues/5573

To reproduce:
1. Run any sample code that starts a BLE server, and does not call `setCallbacks`.
2. Connect to the device using the "LightBlue" app on iOS.
3. Observe crash shown in the issue linked above.

CMakeLists.txt

@@ -32,6 +32,7 @@ set(CORE_SRCS
   cores/esp32/stdlib_noniso.c
   cores/esp32/Stream.cpp
   cores/esp32/StreamString.cpp
+  cores/esp32/HWCDC.cpp
   cores/esp32/USB.cpp
   cores/esp32/USBCDC.cpp
   cores/esp32/USBMSC.cpp

boards.txt

@@ -21,12 +21,16 @@ menu.EventsCore=Events Run On
 ##############################################################
 
 esp32c3.name=ESP32C3 Dev Module
+esp32c3.vid.0=0x303a
+esp32c3.pid.0=0x1001
 
 esp32c3.upload.tool=esptool_py
 esp32c3.upload.maximum_size=1310720
 esp32c3.upload.maximum_data_size=327680
 esp32c3.upload.flags=
 esp32c3.upload.extra_flags=
+esp32c3.upload.use_1200bps_touch=false
+esp32c3.upload.wait_for_upload_port=false
 
 esp32c3.serial.disableDTR=false
 esp32c3.serial.disableRTS=false
@@ -48,6 +52,18 @@ esp32c3.build.boot=qio
 esp32c3.build.partitions=default
 esp32c3.build.defines=
 
+esp32c3.menu.CDCOnBoot.default=Disabled
+esp32c3.menu.CDCOnBoot.default.build.cdc_on_boot=0
+esp32c3.menu.CDCOnBoot.cdc=Enabled
+esp32c3.menu.CDCOnBoot.cdc.build.cdc_on_boot=1
+
+esp32c3.menu.UploadMode.default=UART0
+esp32c3.menu.UploadMode.default.upload.use_1200bps_touch=false
+esp32c3.menu.UploadMode.default.upload.wait_for_upload_port=false
+esp32c3.menu.UploadMode.cdc=Internal USB
+esp32c3.menu.UploadMode.cdc.upload.use_1200bps_touch=true
+esp32c3.menu.UploadMode.cdc.upload.wait_for_upload_port=true
+
 esp32c3.menu.PartitionScheme.default=Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
 esp32c3.menu.PartitionScheme.default.build.partitions=default
 esp32c3.menu.PartitionScheme.defaultffat=Default 4MB with ffat (1.2MB APP/1.5MB FATFS)
@@ -977,7 +993,7 @@ feathers2.build.variant=um_feathers2
 feathers2.build.board=FEATHERS2
 
 feathers2.build.cdc_on_boot=1
-feathers2.build.msc_on_boot=1
+feathers2.build.msc_on_boot=0
 feathers2.build.dfu_on_boot=0
 feathers2.build.f_cpu=240000000L
 feathers2.build.flash_size=16MB
@@ -992,10 +1008,10 @@ feathers2.menu.CDCOnBoot.cdc.build.cdc_on_boot=1
 feathers2.menu.CDCOnBoot.default=Disabled
 feathers2.menu.CDCOnBoot.default.build.cdc_on_boot=0
 
-feathers2.menu.MSCOnBoot.msc=Enabled
-feathers2.menu.MSCOnBoot.msc.build.msc_on_boot=1
 feathers2.menu.MSCOnBoot.default=Disabled
 feathers2.menu.MSCOnBoot.default.build.msc_on_boot=0
+feathers2.menu.MSCOnBoot.msc=Enabled
+feathers2.menu.MSCOnBoot.msc.build.msc_on_boot=1
 
 feathers2.menu.DFUOnBoot.default=Disabled
 feathers2.menu.DFUOnBoot.default.build.dfu_on_boot=0
@@ -1092,7 +1108,131 @@ feathers2.menu.DebugLevel.verbose=Verbose
 feathers2.menu.DebugLevel.verbose.build.code_debug=5
 
 ##############################################################
+feathers2neo.name=UM FeatherS2 Neo
+feathers2neo.vid.0=0x303a
+feathers2neo.pid.0=0x80B4
 
+feathers2neo.upload.tool=esptool_py
+feathers2neo.upload.maximum_size=1310720
+feathers2neo.upload.maximum_data_size=327680
+feathers2neo.upload.flags=
+feathers2neo.upload.extra_flags=
+feathers2neo.upload.use_1200bps_touch=true
+feathers2neo.upload.wait_for_upload_port=true
+
+feathers2neo.serial.disableDTR=false
+feathers2neo.serial.disableRTS=false
+
+feathers2neo.build.tarch=xtensa
+feathers2neo.build.bootloader_addr=0x1000
+feathers2neo.build.target=esp32s2
+feathers2neo.build.mcu=esp32s2
+feathers2neo.build.core=esp32
+feathers2neo.build.variant=um_feathers2neo
+feathers2neo.build.board=FEATHERS2NEO
+
+feathers2neo.build.cdc_on_boot=1
+feathers2neo.build.msc_on_boot=0
+feathers2neo.build.dfu_on_boot=0
+feathers2neo.build.f_cpu=240000000L
+feathers2neo.build.flash_size=4MB
+feathers2neo.build.flash_freq=80m
+feathers2neo.build.flash_mode=dio
+feathers2neo.build.boot=qio
+feathers2neo.build.partitions=default
+feathers2neo.build.defines=
+
+feathers2neo.menu.CDCOnBoot.cdc=Enabled
+feathers2neo.menu.CDCOnBoot.cdc.build.cdc_on_boot=1
+feathers2neo.menu.CDCOnBoot.default=Disabled
+feathers2neo.menu.CDCOnBoot.default.build.cdc_on_boot=0
+
+feathers2neo.menu.MSCOnBoot.default=Disabled
+feathers2neo.menu.MSCOnBoot.default.build.msc_on_boot=0
+feathers2neo.menu.MSCOnBoot.msc=Enabled
+feathers2neo.menu.MSCOnBoot.msc.build.msc_on_boot=1
+
+feathers2neo.menu.DFUOnBoot.default=Disabled
+feathers2neo.menu.DFUOnBoot.default.build.dfu_on_boot=0
+feathers2neo.menu.DFUOnBoot.dfu=Enabled
+feathers2neo.menu.DFUOnBoot.dfu.build.dfu_on_boot=1
+
+feathers2neo.menu.PSRAM.enabled=Enabled
+feathers2neo.menu.PSRAM.enabled.build.defines=-DBOARD_HAS_PSRAM
+feathers2neo.menu.PSRAM.disabled=Disabled
+feathers2neo.menu.PSRAM.disabled.build.defines=
+
+feathers2neo.menu.PartitionScheme.default=Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
+feathers2neo.menu.PartitionScheme.default.build.partitions=default
+feathers2neo.menu.PartitionScheme.defaultffat=Default 4MB with ffat (1.2MB APP/1.5MB FATFS)
+feathers2neo.menu.PartitionScheme.defaultffat.build.partitions=default_ffat
+feathers2neo.menu.PartitionScheme.minimal=Minimal (1.3MB APP/700KB SPIFFS)
+feathers2neo.menu.PartitionScheme.minimal.build.partitions=minimal
+feathers2neo.menu.PartitionScheme.no_ota=No OTA (2MB APP/2MB SPIFFS)
+feathers2neo.menu.PartitionScheme.no_ota.build.partitions=no_ota
+feathers2neo.menu.PartitionScheme.no_ota.upload.maximum_size=2097152
+feathers2neo.menu.PartitionScheme.noota_3g=No OTA (1MB APP/3MB SPIFFS)
+feathers2neo.menu.PartitionScheme.noota_3g.build.partitions=noota_3g
+feathers2neo.menu.PartitionScheme.noota_3g.upload.maximum_size=1048576
+feathers2neo.menu.PartitionScheme.noota_ffat=No OTA (2MB APP/2MB FATFS)
+feathers2neo.menu.PartitionScheme.noota_ffat.build.partitions=noota_ffat
+feathers2neo.menu.PartitionScheme.noota_ffat.upload.maximum_size=2097152
+feathers2neo.menu.PartitionScheme.noota_3gffat=No OTA (1MB APP/3MB FATFS)
+feathers2neo.menu.PartitionScheme.noota_3gffat.build.partitions=noota_3gffat
+feathers2neo.menu.PartitionScheme.noota_3gffat.upload.maximum_size=1048576
+feathers2neo.menu.PartitionScheme.huge_app=Huge APP (3MB No OTA/1MB SPIFFS)
+feathers2neo.menu.PartitionScheme.huge_app.build.partitions=huge_app
+feathers2neo.menu.PartitionScheme.huge_app.upload.maximum_size=3145728
+feathers2neo.menu.PartitionScheme.min_spiffs=Minimal SPIFFS (1.9MB APP with OTA/190KB SPIFFS)
+feathers2neo.menu.PartitionScheme.min_spiffs.build.partitions=min_spiffs
+feathers2neo.menu.PartitionScheme.min_spiffs.upload.maximum_size=1966080
+
+feathers2neo.menu.CPUFreq.240=240MHz (WiFi)
+feathers2neo.menu.CPUFreq.240.build.f_cpu=240000000L
+feathers2neo.menu.CPUFreq.160=160MHz (WiFi)
+feathers2neo.menu.CPUFreq.160.build.f_cpu=160000000L
+feathers2neo.menu.CPUFreq.80=80MHz (WiFi)
+feathers2neo.menu.CPUFreq.80.build.f_cpu=80000000L
+feathers2neo.menu.CPUFreq.40=40MHz
+feathers2neo.menu.CPUFreq.40.build.f_cpu=40000000L
+feathers2neo.menu.CPUFreq.20=20MHz
+feathers2neo.menu.CPUFreq.20.build.f_cpu=20000000L
+feathers2neo.menu.CPUFreq.10=10MHz
+feathers2neo.menu.CPUFreq.10.build.f_cpu=10000000L
+
+feathers2neo.menu.FlashSize.4M=4MB (32Mb)
+feathers2neo.menu.FlashSize.4M.build.flash_size=4MB
+feathers2neo.menu.FlashSize.2M=2MB (16Mb)
+feathers2neo.menu.FlashSize.2M.build.flash_size=2MB
+feathers2neo.menu.FlashSize.2M.build.partitions=minimal
+
+feathers2neo.menu.UploadSpeed.921600=921600
+feathers2neo.menu.UploadSpeed.921600.upload.speed=921600
+feathers2neo.menu.UploadSpeed.115200=115200
+feathers2neo.menu.UploadSpeed.115200.upload.speed=115200
+feathers2neo.menu.UploadSpeed.256000.windows=256000
+feathers2neo.menu.UploadSpeed.256000.upload.speed=256000
+feathers2neo.menu.UploadSpeed.230400.windows.upload.speed=256000
+feathers2neo.menu.UploadSpeed.230400=230400
+feathers2neo.menu.UploadSpeed.230400.upload.speed=230400
+feathers2neo.menu.UploadSpeed.460800.linux=460800
+feathers2neo.menu.UploadSpeed.460800.macosx=460800
+feathers2neo.menu.UploadSpeed.460800.upload.speed=460800
+
+feathers2neo.menu.DebugLevel.none=None
+feathers2neo.menu.DebugLevel.none.build.code_debug=0
+feathers2neo.menu.DebugLevel.error=Error
+feathers2neo.menu.DebugLevel.error.build.code_debug=1
+feathers2neo.menu.DebugLevel.warn=Warn
+feathers2neo.menu.DebugLevel.warn.build.code_debug=2
+feathers2neo.menu.DebugLevel.info=Info
+feathers2neo.menu.DebugLevel.info.build.code_debug=3
+feathers2neo.menu.DebugLevel.debug=Debug
+feathers2neo.menu.DebugLevel.debug.build.code_debug=4
+feathers2neo.menu.DebugLevel.verbose=Verbose
+feathers2neo.menu.DebugLevel.verbose.build.code_debug=5
+
+##############################################################
 tinys2.name=UM TinyS2
 tinys2.vid.0=0x303a
 tinys2.pid.0=0x8001
@@ -1117,7 +1257,7 @@ tinys2.build.variant=um_tinys2
 tinys2.build.board=TINYS2
 
 tinys2.build.cdc_on_boot=1
-tinys2.build.msc_on_boot=1
+tinys2.build.msc_on_boot=0
 tinys2.build.dfu_on_boot=0
 tinys2.build.f_cpu=240000000L
 tinys2.build.flash_size=4MB
@@ -1132,10 +1272,10 @@ tinys2.menu.CDCOnBoot.cdc.build.cdc_on_boot=1
 tinys2.menu.CDCOnBoot.default=Disabled
 tinys2.menu.CDCOnBoot.default.build.cdc_on_boot=0
 
-tinys2.menu.MSCOnBoot.msc=Enabled
-tinys2.menu.MSCOnBoot.msc.build.msc_on_boot=1
 tinys2.menu.MSCOnBoot.default=Disabled
 tinys2.menu.MSCOnBoot.default.build.msc_on_boot=0
+tinys2.menu.MSCOnBoot.msc=Enabled
+tinys2.menu.MSCOnBoot.msc.build.msc_on_boot=1
 
 tinys2.menu.DFUOnBoot.default=Disabled
 tinys2.menu.DFUOnBoot.default.build.dfu_on_boot=0
@@ -1204,7 +1344,6 @@ tinys2.menu.UploadSpeed.460800.linux=460800
 tinys2.menu.UploadSpeed.460800.macosx=460800
 tinys2.menu.UploadSpeed.460800.upload.speed=460800
 
-
 tinys2.menu.DebugLevel.none=None
 tinys2.menu.DebugLevel.none.build.code_debug=0
 tinys2.menu.DebugLevel.error=Error
@@ -1225,6 +1364,7 @@ S_ODI_Ultra.upload.tool=esptool_py
 S_ODI_Ultra.upload.maximum_size=1310720
 S_ODI_Ultra.upload.maximum_data_size=327680
 S_ODI_Ultra.upload.wait_for_upload_port=true
+S_ODI_Ultra.upload.flags=
 S_ODI_Ultra.upload.extra_flags=
 
 S_ODI_Ultra.serial.disableDTR=true
@@ -2087,6 +2227,7 @@ esp32thing_plus.upload.tool=esptool_py
 esp32thing_plus.upload.maximum_size=1310720
 esp32thing_plus.upload.maximum_data_size=327680
 esp32thing_plus.upload.wait_for_upload_port=true
+esp32thing_plus.upload.flags=
 esp32thing_plus.upload.extra_flags=
 
 esp32thing_plus.serial.disableDTR=true
@@ -2315,6 +2456,8 @@ esp32micromod.upload.tool=esptool_py
 esp32micromod.upload.maximum_size=1310720
 esp32micromod.upload.maximum_data_size=327680
 esp32micromod.upload.wait_for_upload_port=true
+esp32micromod.upload.flags=
+esp32micromod.upload.extra_flags=
 
 esp32micromod.serial.disableDTR=true
 esp32micromod.serial.disableRTS=true
@@ -2952,6 +3095,7 @@ lolin32-lite.upload.tool=esptool_py
 lolin32-lite.upload.maximum_size=1310720
 lolin32-lite.upload.maximum_data_size=327680
 lolin32-lite.upload.wait_for_upload_port=true
+lolin32-lite.upload.flags=
 lolin32-lite.upload.extra_flags=
 
 lolin32-lite.serial.disableDTR=true
@@ -4567,6 +4711,7 @@ esp32doit-espduino.upload.tool=esptool
 esp32doit-espduino.upload.maximum_size=1310720
 esp32doit-espduino.upload.maximum_data_size=327680
 esp32doit-espduino.upload.wait_for_upload_port=true
+esp32doit-espduino.upload.flags=
 esp32doit-espduino.upload.extra_flags=
 
 esp32doit-espduino.serial.disableDTR=true
@@ -5332,6 +5477,7 @@ m5stack-timer-cam.upload.tool=esptool_py
 m5stack-timer-cam.upload.maximum_size=1310720
 m5stack-timer-cam.upload.maximum_data_size=327680
 m5stack-timer-cam.upload.wait_for_upload_port=true
+m5stack-timer-cam.upload.flags=
 m5stack-timer-cam.upload.extra_flags=
 
 m5stack-timer-cam.serial.disableDTR=true
@@ -5958,6 +6104,7 @@ heltec_wireless_stick_lite.upload.tool=esptool_py
 heltec_wireless_stick_lite.upload.maximum_size=1310720
 heltec_wireless_stick_lite.upload.maximum_data_size=327680
 heltec_wireless_stick_lite.upload.wait_for_upload_port=true
+heltec_wireless_stick_lite.upload.flags=
 heltec_wireless_stick_lite.upload.extra_flags=
 
 heltec_wireless_stick_lite.serial.disableDTR=true
@@ -7926,6 +8073,7 @@ kits-edu.upload.tool=esptool_py
 kits-edu.upload.maximum_size=1310720
 kits-edu.upload.maximum_data_size=327680
 kits-edu.upload.wait_for_upload_port=true
+kits-edu.upload.flags=
 kits-edu.upload.extra_flags=
 
 kits-edu.serial.disableDTR=true
@@ -8108,6 +8256,7 @@ OpenKB.upload.tool=esptool_py
 OpenKB.upload.maximum_size=1310720
 OpenKB.upload.maximum_data_size=327680
 OpenKB.upload.wait_for_upload_port=true
+OpenKB.upload.flags=
 OpenKB.upload.extra_flags=
 
 OpenKB.serial.disableDTR=true
@@ -8156,6 +8305,7 @@ wifiduino32.upload.tool=esptool_py
 wifiduino32.upload.maximum_size=1310720
 wifiduino32.upload.maximum_data_size=327680
 wifiduino32.upload.wait_for_upload_port=true
+wifiduino32.upload.flags=
 wifiduino32.upload.extra_flags=
 
 wifiduino32.serial.disableDTR=true
@@ -8342,6 +8492,7 @@ imbrios-logsens-v1p1.upload.tool=esptool_py
 imbrios-logsens-v1p1.upload.maximum_size=1310720
 imbrios-logsens-v1p1.upload.maximum_data_size=327680
 imbrios-logsens-v1p1.upload.wait_for_upload_port=true
+imbrios-logsens-v1p1.upload.flags=
 imbrios-logsens-v1p1.upload.extra_flags=
 
 imbrios-logsens-v1p1.serial.disableDTR=true
@@ -8416,6 +8567,7 @@ healthypi4.upload.tool=esptool_py
 healthypi4.upload.maximum_size=1310720
 healthypi4.upload.maximum_data_size=327680
 healthypi4.upload.wait_for_upload_port=true
+healthypi4.upload.flags=
 healthypi4.upload.extra_flags=
 
 healthypi4.serial.disableDTR=true
@@ -8487,6 +8639,7 @@ ET-Board.upload.tool=esptool_py
 ET-Board.upload.maximum_size=1310720
 ET-Board.upload.maximum_data_size=327680
 ET-Board.upload.wait_for_upload_port=true
+ET-Board.upload.flags=
 ET-Board.upload.extra_flags=
 
 ET-Board.serial.disableDTR=true
@@ -8841,6 +8994,8 @@ kb32.upload.tool=esptool_py
 kb32.upload.maximum_size=1310720
 kb32.upload.maximum_data_size=327680
 kb32.upload.wait_for_upload_port=true
+kb32.upload.flags=
+kb32.upload.extra_flags=
 
 kb32.serial.disableDTR=true
 kb32.serial.disableRTS=true
@@ -8981,6 +9136,8 @@ deneyapkart.upload.tool=esptool_py
 deneyapkart.upload.maximum_size=1310720
 deneyapkart.upload.maximum_data_size=327680
 deneyapkart.upload.wait_for_upload_port=true
+deneyapkart.upload.flags=
+deneyapkart.upload.extra_flags=
 
 deneyapkart.serial.disableDTR=true
 deneyapkart.serial.disableRTS=true

cores/esp32/HWCDC.cpp

@@ -0,0 +1,283 @@
+// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#include "USB.h"
+#if CONFIG_IDF_TARGET_ESP32C3
+
+#include "esp32-hal.h"
+#include "HWCDC.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/semphr.h"
+#include "freertos/queue.h"
+#include "freertos/ringbuf.h"
+#include "esp_intr_alloc.h"
+#include "soc/periph_defs.h"
+#include "hal/usb_serial_jtag_ll.h"
+
+static RingbufHandle_t tx_ring_buf = NULL;
+static xQueueHandle rx_queue = NULL;
+static uint8_t rx_data_buf[64];
+static intr_handle_t intr_handle = NULL;
+static volatile bool initial_empty = false;
+
+static void hw_cdc_isr_handler(void *arg) {
+    portBASE_TYPE xTaskWoken = 0;
+    uint32_t usbjtag_intr_status = 0;
+    usbjtag_intr_status = usb_serial_jtag_ll_get_intsts_mask();
+
+    if (usbjtag_intr_status & USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY) {
+        // Interrupt tells us the host picked up the data we sent.
+        if (usb_serial_jtag_ll_txfifo_writable() == 1) {
+            // We disable the interrupt here so that the interrupt won't be triggered if there is no data to send.
+            usb_serial_jtag_ll_disable_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+
+            if(!initial_empty){
+                initial_empty = true;
+                //send event?
+                //ets_printf("CONNECTED\n");
+            }
+            size_t queued_size;
+            uint8_t *queued_buff = (uint8_t *)xRingbufferReceiveUpToFromISR(tx_ring_buf, &queued_size, 64);
+            // If the hardware fifo is avaliable, write in it. Otherwise, do nothing.
+            if (queued_buff != NULL) {  //Although tx_queued_bytes may be larger than 0. We may have interrupt before xRingbufferSend() was called.
+                //Copy the queued buffer into the TX FIFO
+                usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+                usb_serial_jtag_ll_write_txfifo(queued_buff, queued_size);
+                usb_serial_jtag_ll_txfifo_flush();
+                vRingbufferReturnItemFromISR(tx_ring_buf, queued_buff, &xTaskWoken);
+                usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+                //send event?
+                //ets_printf("TX:%u\n", queued_size);
+            }
+        } else {
+            usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+        }
+    }
+
+    if (usbjtag_intr_status & USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT) {
+        // read rx buffer(max length is 64), and send avaliable data to ringbuffer.
+        // Ensure the rx buffer size is larger than RX_MAX_SIZE.
+        usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT);
+        uint32_t rx_fifo_len = usb_serial_jtag_ll_read_rxfifo(rx_data_buf, 64);
+        uint32_t i=0;
+        for(i=0; i<rx_fifo_len; i++){
+            if(rx_queue == NULL || !xQueueSendFromISR(rx_queue, rx_data_buf+i, &xTaskWoken)){
+                break;
+            }
+        }
+        //send event?
+        //ets_printf("RX:%u/%u\n", i, rx_fifo_len);
+    }
+
+    if (usbjtag_intr_status & USB_SERIAL_JTAG_INTR_BUS_RESET) {
+        usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_BUS_RESET);
+        initial_empty = false;
+        usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+        //ets_printf("BUS_RESET\n");
+    }
+
+    if (xTaskWoken == pdTRUE) {
+        portYIELD_FROM_ISR();
+    }
+}
+
+static void ARDUINO_ISR_ATTR cdc0_write_char(char c) {
+    if(xPortInIsrContext()){
+        xRingbufferSendFromISR(tx_ring_buf, (void*) (&c), 1, NULL);
+    } else {
+        xRingbufferSend(tx_ring_buf, (void*) (&c), 1, 0);
+    }
+    usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+}
+
+HWCDC::HWCDC() {
+    
+}
+
+HWCDC::~HWCDC(){
+    end();
+}
+
+HWCDC::operator bool() const
+{
+    return initial_empty;
+}
+
+void HWCDC::begin(unsigned long baud)
+{
+    setRxBufferSize(256);//default if not preset
+    setTxBufferSize(256);//default if not preset
+
+    usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY | USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT | USB_SERIAL_JTAG_INTR_BUS_RESET);
+    usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY | USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT | USB_SERIAL_JTAG_INTR_BUS_RESET);
+    if(!intr_handle && esp_intr_alloc(ETS_USB_INTR_SOURCE/*ETS_USB_SERIAL_JTAG_INTR_SOURCE*/, 0, hw_cdc_isr_handler, NULL, &intr_handle) != ESP_OK){
+        isr_log_e("HW USB CDC failed to init interrupts");
+        end();
+    }
+}
+
+void HWCDC::end()
+{
+    //Disable tx/rx interrupt.
+    usb_serial_jtag_ll_disable_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY | USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT | USB_SERIAL_JTAG_INTR_BUS_RESET);
+    esp_intr_free(intr_handle);
+    intr_handle = NULL;
+    setRxBufferSize(0);
+    setTxBufferSize(0);
+}
+
+/*
+ * WRITING
+*/
+
+size_t HWCDC::setTxBufferSize(size_t tx_queue_len){
+    if(tx_ring_buf){
+        if(!tx_queue_len){
+            vRingbufferDelete(tx_ring_buf);
+            tx_ring_buf = NULL;
+        }
+        return 0;
+    }
+    tx_ring_buf = xRingbufferCreate(tx_queue_len, RINGBUF_TYPE_BYTEBUF);
+    if(!tx_ring_buf){
+        return 0;
+    }
+    return tx_queue_len;
+}
+
+int HWCDC::availableForWrite(void)
+{
+    if(tx_ring_buf == NULL){
+        return -1;
+    }
+    return xRingbufferGetCurFreeSize(tx_ring_buf);
+}
+
+size_t HWCDC::write(const uint8_t *buffer, size_t size)
+{
+    // Blocking method, Sending data to ringbuffer, and handle the data in ISR.
+    if(xRingbufferSend(tx_ring_buf, (void*) (buffer), size, 200 / portTICK_PERIOD_MS) != pdTRUE){
+        log_e("Write Failed");
+        return 0;
+    }
+    // Now trigger the ISR to read data from the ring buffer.
+    usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+    return size;
+}
+
+size_t HWCDC::write(uint8_t c)
+{
+    return write(&c, 1);
+}
+
+void HWCDC::flush(void)
+{
+    if(tx_ring_buf == NULL){
+        return;
+    }
+    UBaseType_t uxItemsWaiting = 0;
+    vRingbufferGetInfo(tx_ring_buf, NULL, NULL, NULL, NULL, &uxItemsWaiting);
+    while(uxItemsWaiting){
+        delay(5);
+        vRingbufferGetInfo(tx_ring_buf, NULL, NULL, NULL, NULL, &uxItemsWaiting);
+    }
+}
+
+/*
+ * READING
+*/
+
+size_t HWCDC::setRxBufferSize(size_t rx_queue_len){
+    if(rx_queue){
+        if(!rx_queue_len){
+            vQueueDelete(rx_queue);
+            rx_queue = NULL;
+        }
+        return 0;
+    }
+    rx_queue = xQueueCreate(rx_queue_len, sizeof(uint8_t));
+    if(!rx_queue){
+        return 0;
+    }
+    if(!tx_ring_buf){
+        tx_ring_buf = xRingbufferCreate(rx_queue_len, RINGBUF_TYPE_BYTEBUF);
+    }
+    return rx_queue_len;
+}
+
+int HWCDC::available(void)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    return uxQueueMessagesWaiting(rx_queue);
+}
+
+int HWCDC::peek(void)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    uint8_t c;
+    if(xQueuePeek(rx_queue, &c, 0)) {
+        return c;
+    }
+    return -1;
+}
+
+int HWCDC::read(void)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    uint8_t c = 0;
+    if(xQueueReceive(rx_queue, &c, 0)) {
+        return c;
+    }
+    return -1;
+}
+
+size_t HWCDC::read(uint8_t *buffer, size_t size)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    uint8_t c = 0;
+    size_t count = 0;
+    while(count < size && xQueueReceive(rx_queue, &c, 0)){
+        buffer[count++] = c;
+    }
+    return count;
+}
+
+/*
+ * DEBUG
+*/
+
+void HWCDC::setDebugOutput(bool en)
+{
+    if(en) {
+        uartSetDebug(NULL);
+        ets_install_putc1((void (*)(char)) &cdc0_write_char);
+    } else {
+        ets_install_putc1(NULL);
+    }
+}
+
+#if ARDUINO_HW_CDC_ON_BOOT //Serial used for USB CDC
+HWCDC Serial;
+#else
+HWCDC USBSerial;
+#endif
+
+#endif /* CONFIG_TINYUSB_CDC_ENABLED */

cores/esp32/HWCDC.h

@@ -0,0 +1,82 @@
+// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#pragma once
+
+#include "sdkconfig.h"
+#if CONFIG_IDF_TARGET_ESP32C3
+
+#include <inttypes.h>
+#include "Stream.h"
+
+class HWCDC: public Stream
+{
+public:
+    HWCDC();
+    ~HWCDC();
+
+    size_t setRxBufferSize(size_t);
+    size_t setTxBufferSize(size_t);
+    void begin(unsigned long baud=0);
+    void end();
+    
+    int available(void);
+    int availableForWrite(void);
+    int peek(void);
+    int read(void);
+    size_t read(uint8_t *buffer, size_t size);
+    size_t write(uint8_t);
+    size_t write(const uint8_t *buffer, size_t size);
+    void flush(void);
+    
+    inline size_t read(char * buffer, size_t size)
+    {
+        return read((uint8_t*) buffer, size);
+    }
+    inline size_t write(const char * buffer, size_t size)
+    {
+        return write((uint8_t*) buffer, size);
+    }
+    inline size_t write(const char * s)
+    {
+        return write((uint8_t*) s, strlen(s));
+    }
+    inline size_t write(unsigned long n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(long n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(unsigned int n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(int n)
+    {
+        return write((uint8_t) n);
+    }
+    operator bool() const;
+    void setDebugOutput(bool);
+    uint32_t baudRate(){return 115200;}
+
+};
+
+#if ARDUINO_HW_CDC_ON_BOOT //Serial used for USB CDC
+extern HWCDC Serial;
+#else
+extern HWCDC USBSerial;
+#endif
+
+#endif /* CONFIG_IDF_TARGET_ESP32C3 */

cores/esp32/HardwareSerial.cpp

@@ -76,6 +76,8 @@ void serialEvent2(void) {}
 #if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_SERIAL)
 #if ARDUINO_USB_CDC_ON_BOOT //Serial used for USB CDC
 HardwareSerial Serial0(0);
+#elif ARDUINO_HW_CDC_ON_BOOT
+HardwareSerial Serial0(0);
 #else
 HardwareSerial Serial(0);
 #endif
@@ -91,6 +93,8 @@ void serialEventRun(void)
 {
 #if ARDUINO_USB_CDC_ON_BOOT //Serial used for USB CDC
     if(Serial0.available()) serialEvent();
+#elif ARDUINO_HW_CDC_ON_BOOT
+    if(Serial0.available()) serialEvent();
 #else
     if(Serial.available()) serialEvent();
 #endif
@@ -103,7 +107,7 @@ void serialEventRun(void)
 }
 
 
-HardwareSerial::HardwareSerial(int uart_nr) : _uart_nr(uart_nr), _uart(NULL) {}
+HardwareSerial::HardwareSerial(int uart_nr) : _uart_nr(uart_nr), _uart(NULL), _rxBufferSize(256) {}
 
 void HardwareSerial::begin(unsigned long baud, uint32_t config, int8_t rxPin, int8_t txPin, bool invert, unsigned long timeout_ms, uint8_t rxfifo_full_thrhd)
 {
@@ -133,7 +137,7 @@ void HardwareSerial::begin(unsigned long baud, uint32_t config, int8_t rxPin, in
     }
 #endif
 
-    _uart = uartBegin(_uart_nr, baud ? baud : 9600, config, rxPin, txPin, 256, invert, rxfifo_full_thrhd);
+    _uart = uartBegin(_uart_nr, baud ? baud : 9600, config, rxPin, txPin, _rxBufferSize, invert, rxfifo_full_thrhd);
     if (!baud) {
         // using baud rate as zero, forces it to try to detect the current baud rate in place
         uartStartDetectBaudrate(_uart);
@@ -147,7 +151,7 @@ void HardwareSerial::begin(unsigned long baud, uint32_t config, int8_t rxPin, in
 
         if(detectedBaudRate) {
             delay(100); // Give some time...
-            _uart = uartBegin(_uart_nr, detectedBaudRate, config, rxPin, txPin, 256, invert, rxfifo_full_thrhd);
+            _uart = uartBegin(_uart_nr, detectedBaudRate, config, rxPin, txPin, _rxBufferSize, invert, rxfifo_full_thrhd);
         } else {
             log_e("Could not detect baudrate. Serial data at the port must be present within the timeout for detection to be possible");
             _uart = NULL;
@@ -268,3 +272,18 @@ void HardwareSerial::setPins(uint8_t rxPin, uint8_t txPin)
     uartSetPins(_uart, rxPin, txPin);
 }
 
+size_t HardwareSerial::setRxBufferSize(size_t new_size) {
+
+    if (_uart) {
+        log_e("RX Buffer can't be resized when Serial is already running.\n");
+        return 0;
+    }
+
+    if (new_size <= SOC_UART_FIFO_LEN) {
+        log_e("RX Buffer must be higher than %d.\n", SOC_UART_FIFO_LEN);
+        return 0;
+    }
+
+    _rxBufferSize = new_size;
+    return _rxBufferSize;
+}

cores/esp32/HardwareSerial.h

@@ -50,6 +50,7 @@
 #include "Stream.h"
 #include "esp32-hal.h"
 #include "soc/soc_caps.h"
+#include "HWCDC.h"
 
 class HardwareSerial: public Stream
 {
@@ -103,10 +104,12 @@ public:
     
     void setRxInvert(bool);
     void setPins(uint8_t rxPin, uint8_t txPin);
+    size_t setRxBufferSize(size_t new_size);
 
 protected:
     int _uart_nr;
     uart_t* _uart;
+    size_t _rxBufferSize;
 };
 
 extern void serialEventRun(void) __attribute__((weak));
@@ -119,6 +122,8 @@ extern void serialEventRun(void) __attribute__((weak));
 #include "USB.h"
 #include "USBCDC.h"
 extern HardwareSerial Serial0;
+#elif ARDUINO_HW_CDC_ON_BOOT
+extern HardwareSerial Serial0;
 #else
 extern HardwareSerial Serial;
 #endif

cores/esp32/WString.cpp

@@ -35,6 +35,12 @@ String::String(const char *cstr) {
         copy(cstr, strlen(cstr));
 }
 
+String::String(const char *cstr, unsigned int length) {
+    init();
+    if (cstr)
+        copy(cstr, length);
+}
+
 String::String(const String &value) {
     init();
     *this = value;
@@ -705,10 +711,7 @@ String String::substring(unsigned int left, unsigned int right) const {
         return out;
     if(right > len())
         right = len();
-    char temp = buffer()[right];  // save the replaced character
-    wbuffer()[right] = '\0';
-    out = wbuffer() + left;  // pointer arithmetic
-    wbuffer()[right] = temp;  //restore character
+    out.copy(buffer() + left, right - left);
     return out;
 }
 

cores/esp32/WString.h

@@ -55,6 +55,10 @@ class String {
         // fails, the string will be marked as invalid (i.e. "if (s)" will
         // be false).
         String(const char *cstr = "");
+        String(const char *cstr, unsigned int length);
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
+        String(const uint8_t *cstr, unsigned int length) : String((const char*)cstr, length) {}
+#endif
         String(const String &str);
         String(const __FlashStringHelper *str);
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
@@ -108,6 +112,8 @@ class String {
         // concatenation is considered unsuccessful.
         unsigned char concat(const String &str);
         unsigned char concat(const char *cstr);
+        unsigned char concat(const char *cstr, unsigned int length);
+        unsigned char concat(const uint8_t *cstr, unsigned int length) {return concat((const char*)cstr, length);}
         unsigned char concat(char c);
         unsigned char concat(unsigned char c);
         unsigned char concat(int num);
@@ -326,7 +332,6 @@ class String {
         void init(void);
         void invalidate(void);
         unsigned char changeBuffer(unsigned int maxStrLen);
-        unsigned char concat(const char *cstr, unsigned int length);
 
         // copy and move
         String & copy(const char *cstr, unsigned int length);

libraries/BLE/src/BLEServer.cpp

@@ -157,7 +157,9 @@ void BLEServer::handleGATTServerEvent(esp_gatts_cb_event_t event, esp_gatt_if_t
 
 		case ESP_GATTS_MTU_EVT:
 			updatePeerMTU(param->mtu.conn_id, param->mtu.mtu);
-			m_pServerCallbacks->onMtuChanged(this, param);
+			if (m_pServerCallbacks != nullptr) {
+				m_pServerCallbacks->onMtuChanged(this, param);
+			}
 			break;
 
 		// ESP_GATTS_CONNECT_EVT

libraries/Preferences/src/Preferences.cpp

@@ -1,8 +1,9 @@
-// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+// Copyright 2015-2021 Espressif Systems (Shanghai) PTE LTD
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
+
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
@@ -43,7 +44,7 @@ bool Preferences::begin(const char * name, bool readOnly, const char* partition_
         }
         err = nvs_open_from_partition(partition_label, name, readOnly ? NVS_READONLY : NVS_READWRITE, &_handle);
     } else {
-        err = nvs_open(name, readOnly?NVS_READONLY:NVS_READWRITE, &_handle);
+        err = nvs_open(name, readOnly ? NVS_READONLY : NVS_READWRITE, &_handle);
     }
     if(err){
         log_e("nvs_open failed: %s", nvs_error(err));
@@ -74,6 +75,11 @@ bool Preferences::clear(){
         log_e("nvs_erase_all fail: %s", nvs_error(err));
         return false;
     }
+    err = nvs_commit(_handle);
+    if(err){
+        log_e("nvs_commit fail: %s", nvs_error(err));
+        return false;
+    }
     return true;
 }
 
@@ -90,6 +96,11 @@ bool Preferences::remove(const char * key){
         log_e("nvs_erase_key fail: %s %s", key, nvs_error(err));
         return false;
     }
+    err = nvs_commit(_handle);
+    if(err){
+        log_e("nvs_commit fail: %s %s", key, nvs_error(err));
+        return false;
+    }
     return true;
 }
 

platform.txt

@@ -60,7 +60,7 @@ compiler.cpp.flags.esp32c3=-march=rv32imc -ffunction-sections -fdata-sections -W
 compiler.S.flags.esp32c3=-ffunction-sections -fdata-sections -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=deprecated-declarations -Wno-unused-parameter -Wno-sign-compare -ggdb -Wno-error=format= -nostartfiles -Wno-format -Og -fstrict-volatile-bitfields -Wno-error=unused-but-set-variable -fno-jump-tables -fno-tree-switch-conversion  -x assembler-with-cpp -MMD -c
 compiler.c.elf.flags.esp32c3=-T memory.ld -T sections.ld -T esp32c3.rom.ld -T esp32c3.rom.api.ld -T esp32c3.rom.libgcc.ld -T esp32c3.rom.newlib.ld -T esp32c3.rom.version.ld -T esp32c3.peripherals.ld  -nostartfiles -march=rv32imc --specs=nosys.specs -Wl,--cref -Wl,--gc-sections -fno-rtti -fno-lto -u _Z5setupv -u _Z4loopv -Wl,--wrap=mbedtls_mpi_exp_mod -u esp_app_desc -u pthread_include_pthread_impl -u pthread_include_pthread_cond_impl -u pthread_include_pthread_local_storage_impl -u start_app -u __ubsan_include -u __assert_func -u vfs_include_syscalls_impl -Wl,--undefined=uxTopUsedPriority -u app_main -u newlib_include_heap_impl -u newlib_include_syscalls_impl -u newlib_include_pthread_impl -Wl,--wrap=_Unwind_SetEnableExceptionFdeSorting -Wl,--wrap=__register_frame_info_bases -Wl,--wrap=__register_frame_info -Wl,--wrap=__register_frame -Wl,--wrap=__register_frame_info_table_bases -Wl,--wrap=__register_frame_info_table -Wl,--wrap=__register_frame_table -Wl,--wrap=__deregister_frame_info_bases -Wl,--wrap=__deregister_frame_info -Wl,--wrap=_Unwind_Find_FDE -Wl,--wrap=_Unwind_GetGR -Wl,--wrap=_Unwind_GetCFA -Wl,--wrap=_Unwind_GetIP -Wl,--wrap=_Unwind_GetIPInfo -Wl,--wrap=_Unwind_GetRegionStart -Wl,--wrap=_Unwind_GetDataRelBase -Wl,--wrap=_Unwind_GetTextRelBase -Wl,--wrap=_Unwind_SetIP -Wl,--wrap=_Unwind_SetGR -Wl,--wrap=_Unwind_GetLanguageSpecificData -Wl,--wrap=_Unwind_FindEnclosingFunction -Wl,--wrap=_Unwind_Resume -Wl,--wrap=_Unwind_RaiseException -Wl,--wrap=_Unwind_DeleteException -Wl,--wrap=_Unwind_ForcedUnwind -Wl,--wrap=_Unwind_Resume_or_Rethrow -Wl,--wrap=_Unwind_Backtrace -Wl,--wrap=__cxa_call_unexpected -Wl,--wrap=__gxx_personality_v0 -u __cxa_guard_dummy -u __cxx_fatal_exception 
 compiler.ar.flags.esp32c3=cr
-build.extra_flags.esp32c3=-DARDUINO_USB_CDC_ON_BOOT=0
+build.extra_flags.esp32c3=-DARDUINO_HW_CDC_ON_BOOT={build.cdc_on_boot}
 #
 # ESP32C3 Support End
 #

variants/um_feathers2neo/pins_arduino.h

@@ -0,0 +1,70 @@
+#ifndef Pins_Arduino_h
+#define Pins_Arduino_h
+
+#include <stdint.h>
+
+#define USB_VID 0x239A
+#define USB_PID 0x80B4
+#define USB_MANUFACTURER "Unexpected Maker"
+#define USB_PRODUCT "FeatherS2 Neo"
+#define USB_SERIAL ""
+
+#define EXTERNAL_NUM_INTERRUPTS 46
+#define NUM_DIGITAL_PINS        22
+#define NUM_ANALOG_INPUTS       11
+
+#define analogInputToDigitalPin(p)  (((p)<20)?(esp32_adc2gpio[(p)]):-1)
+#define digitalPinToInterrupt(p)    (((p)<48)?(p):-1)
+#define digitalPinHasPWM(p)         (p < 46)
+
+static const uint8_t TX = 43;
+static const uint8_t RX = 44;
+
+static const uint8_t SDA = 8;
+static const uint8_t SCL = 9;
+
+static const uint8_t SS    = 34;
+static const uint8_t MOSI  = 35;
+static const uint8_t MISO  = 37;
+static const uint8_t SDO  = 35;
+static const uint8_t SDI  = 37;
+static const uint8_t SCK   = 36;
+
+static const uint8_t A0 = 17;
+static const uint8_t A1 = 18;
+static const uint8_t A2 = 14;
+static const uint8_t A3 = 12;
+static const uint8_t A4 = 6;
+static const uint8_t A5 = 5;
+static const uint8_t A6 = 1;
+static const uint8_t A7 = 3;
+static const uint8_t A8 = 7;
+static const uint8_t A9 = 10;
+static const uint8_t A10 = 11;
+
+
+static const uint8_t T1 = 1;
+static const uint8_t T3 = 3;
+static const uint8_t T5 = 5;
+static const uint8_t T6 = 6;
+static const uint8_t T7 = 7;
+static const uint8_t T8 = 8;
+static const uint8_t T9 = 9;
+static const uint8_t T10 = 10;
+static const uint8_t T11 = 11;
+static const uint8_t T12 = 12;
+static const uint8_t T14 = 14;
+
+static const uint8_t DAC1 = 17;
+static const uint8_t DAC2 = 18;
+
+static const uint8_t NEOPIXEL_MATRIX_DATA = 21;
+static const uint8_t NEOPIXEL_MATRIX_PWR = 4;
+
+static const uint8_t NEOPIXEL_DATA = 40;
+static const uint8_t NEOPIXEL_PWR = 39;
+
+static const uint8_t VBAT_SENSE = 2;
+static const uint8_t VBUS_SENSE = 34;
+
+#endif /* Pins_Arduino_h */