v2.0.0 Add support for ESP32S2 and update ESP-IDF to 4.4 (#4996)

This is very much still work in progress and much more will change before the final 2.0.0

Some APIs have changed. New libraries have been added. LittleFS included.

Co-authored-by: Seon Rozenblum <seonr@3sprockets.com>
Co-authored-by: Me No Dev <me-no-dev@users.noreply.github.com>
Co-authored-by: geeksville <kevinh@geeksville.com>
Co-authored-by: Mike Dunston <m_dunston@comcast.net>
Co-authored-by: Unexpected Maker <seon@unexpectedmaker.com>
Co-authored-by: Seon Rozenblum <seonr@3sprockets.com>
Co-authored-by: microDev <70126934+microDev1@users.noreply.github.com>
Co-authored-by: tobozo <tobozo@users.noreply.github.com>
Co-authored-by: bobobo1618 <bobobo1618@users.noreply.github.com>
Co-authored-by: lorol <lorolouis@gmail.com>
Co-authored-by: geeksville <kevinh@geeksville.com>
Co-authored-by: Limor "Ladyada" Fried <limor@ladyada.net>
Co-authored-by: Sweety <switi.mhaiske@espressif.com>
Co-authored-by: Loick MAHIEUX <loick111@gmail.com>
Co-authored-by: Larry Bernstone <lbernstone@gmail.com>
Co-authored-by: Valerii Koval <valeros@users.noreply.github.com>
Co-authored-by: 快乐的我531 <2302004040@qq.com>
Co-authored-by: chegewara <imperiaonline4@gmail.com>
Co-authored-by: Clemens Kirchgatterer <clemens@1541.org>
Co-authored-by: Aron Rubin <aronrubin@gmail.com>
Co-authored-by: Pete Lewis <601236+lewispg228@users.noreply.github.com>

tools/sdk/esp32/include/pthread/include/esp_pthread.h

@@ -0,0 +1,92 @@
+// Copyright 2018 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 "esp_err.h"
+#include "freertos/FreeRTOSConfig.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef PTHREAD_STACK_MIN
+#define PTHREAD_STACK_MIN    CONFIG_PTHREAD_STACK_MIN
+#endif
+
+/** pthread configuration structure that influences pthread creation */
+typedef struct {
+    size_t stack_size;  ///< The stack size of the pthread
+    size_t prio;        ///< The thread's priority
+    bool inherit_cfg;   ///< Inherit this configuration further
+    const char* thread_name;  ///< The thread name.
+    int pin_to_core;    ///< The core id to pin the thread to. Has the same value range as xCoreId argument of xTaskCreatePinnedToCore.
+} esp_pthread_cfg_t;
+
+/**
+ * @brief Creates a default pthread configuration based
+ * on the values set via menuconfig.
+ *
+ * @return
+ *      A default configuration structure.
+ */
+esp_pthread_cfg_t esp_pthread_get_default_config(void);
+
+/**
+ * @brief Configure parameters for creating pthread
+ *
+ * This API allows you to configure how the subsequent
+ * pthread_create() call will behave. This call can be used to setup
+ * configuration parameters like stack size, priority, configuration
+ * inheritance etc.
+ *
+ * If the 'inherit' flag in the configuration structure is enabled,
+ * then the same configuration is also inherited in the thread
+ * subtree.
+ *
+ * @note Passing non-NULL attributes to pthread_create() will override
+ *       the stack_size parameter set using this API
+ *
+ * @param cfg The pthread config parameters
+ *
+ * @return
+ *      - ESP_OK if configuration was successfully set
+ *      - ESP_ERR_NO_MEM if out of memory
+ *      - ESP_ERR_INVALID_ARG if stack_size is less than PTHREAD_STACK_MIN
+ */
+esp_err_t esp_pthread_set_cfg(const esp_pthread_cfg_t *cfg);
+
+/**
+ * @brief Get current pthread creation configuration
+ *
+ * This will retrieve the current configuration that will be used for
+ * creating threads.
+ *
+ * @param p Pointer to the pthread config structure that will be
+ * updated with the currently configured parameters
+ *
+ * @return
+ *      - ESP_OK if the configuration was available
+ *      - ESP_ERR_NOT_FOUND if a configuration wasn't previously set
+ */
+esp_err_t esp_pthread_get_cfg(esp_pthread_cfg_t *p);
+
+/**
+ * @brief Initialize pthread library
+ */
+esp_err_t esp_pthread_init(void);
+
+#ifdef __cplusplus
+}
+#endif