text: // 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.
  #include <stdio.h>
  #include <stdarg.h>
  #include <sdkconfig.h>
  #include "SEGGER_SYSVIEW_Int.h"
  #include "freertos/FreeRTOS.h"
  
  static portMUX_TYPE s_log_mutex = portMUX_INITIALIZER_UNLOCKED;
  
  int esp_sysview_vprintf(const char * format, va_list args)
  {
      static char log_buffer[SEGGER_SYSVIEW_MAX_STRING_LEN];
  
      portENTER_CRITICAL(&s_log_mutex);
      size_t len = vsnprintf(log_buffer, sizeof(log_buffer), format, args);
      if (len > sizeof(log_buffer) - 1) {
          log_buffer[sizeof(log_buffer - 1)] = 0;
      }
      SEGGER_SYSVIEW_Print(log_buffer);
      portEXIT_CRITICAL(&s_log_mutex);
      return len;
  }
  