arch/xtensa/src/common/xtensa_task_start.c

/****************************************************************************
 * arch/xtensa/src/common/xtensa_task_start.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <assert.h>

#include <nuttx/arch.h>
#include <arch/syscall.h>

#ifndef CONFIG_BUILD_FLAT

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: up_task_start
 *
 * Description:
 *   In this kernel mode build, this function will be called to execute a
 *   task in user-space.  When the task is first started, a kernel-mode
 *   stub will first run to perform some housekeeping functions.  This
 *   kernel-mode stub will then be called transfer control to the user-mode
 *   task.
 *
 *   Normally the a user-mode start-up stub will also execute before the
 *   task actually starts.  See libc/sched/task_startup.c
 *
 * Input Parameters:
 *   taskentry - The user-space entry point of the task.
 *   argc - The number of parameters being passed.
 *   argv - The parameters being passed. These lie in kernel-space memory
 *     and will have to be reallocated  in user-space memory.
 *
 * Returned Value:
 *   This function should not return.  It should call the user-mode start-up
 *   stub and that stub should call exit if/when the user task terminates.
 *
 ****************************************************************************/

void up_task_start(main_t taskentry, int argc, char *argv[])
{
  /* Let sys_call3() do all of the work */

  sys_call3(SYS_task_start, (uintptr_t)taskentry, (uintptr_t)argc,
            (uintptr_t)argv);

  PANIC();
}

#endif /* !CONFIG_BUILD_FLAT */