dmesg.h

/*
 * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 *    conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 *    of conditions and the following disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 *    to endorse or promote products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _HWLITEOS_SHELL_DMESG_H
#define _HWLITEOS_SHELL_DMESG_H
#include "los_config.h"
#ifdef LOSCFG_SHELL_DMESG

#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */

/**
 * @ingroup dmesg
 * Defalut dmesg buffer size.
 */
#define KERNEL_LOG_BUF_SIZE (8 * 1024) //默认缓存区大小

/**
 * @ingroup dmesg
 * Max dmesg buffer size to set.
 */
#define MAX_KERNEL_LOG_BUF_SIZE (8 * 1024 * 10) //设置缓冲区大小的上限 可以通过shell dmesg -s XX(K) 来改变缓冲区大小

/**
 * @ingroup dmesg
 * @brief Set dmesg buffer.
 *
 * @par Description:
 * This API is used to set dmesg buffer to memory-assigned, or just change the buffer size.
 *
 * @attention
 * <ul>
 * <li>If the addr is NULL, this function will only change the buffer size.</li>
 * </ul>
 *
 * @param  addr     [IN] Type #VOID* The addr of memory space to set.
 * @param  size     [IN] Type #UINT32 The dmesg buffer size to set, depend on the app user, should be a valid value,
 *                                    otherwise system will crash, and should not larger than MAX_KERNEL_LOG_BUF_SIZE.
 *
 * @retval #LOS_NOK Set dmesg buffer fail.
 * @retval #LOS_OK  Set dmesg buffer success.
 * @par Dependency:
 * <ul><li>dmesg.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_DmesgMemSet
 */
extern UINT32 LOS_DmesgMemSet(VOID *addr, UINT32 size);

/**
 * @ingroup dmesg
 * @brief Read log from dmesg buffer.
 *
 * @par Description:
 * This API is used to get log from dmesg buffer in core and copy to the point buffer.
 *
 * @attention
 * <ul>
 * <li>Length of log been read may be less than the len if log in dmesg buffer is not enough.</li>
 * </ul>
 *
 * @param  buf  [IN] Type #CHAR* The buffer expected copy to.
 * @param  len  [IN] Type #UINT32 The maximum number of bytes that can be accommodated in the buf.
 *
 * @retval #-1      Read log from dmesg buffer fail.
 * @retval #0       Nothing has been read.
 * @retval #INT32   The length of log has been read.
 * @par Dependency:
 * <ul><li>dmesg.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_DmesgRead
 */
extern INT32 LOS_DmesgRead(CHAR *buf, UINT32 len);

/**
 * @ingroup dmesg
 * @brief Clear dmesg log.
 *
 * @par Description:
 * This API is used to clear dmesg log.
 *
 * @attention None.
 *
 * @param  None.
 *
 * @retval None.
 * @par Dependency:
 * <ul><li>dmesg.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_DmesgClear
 */
extern VOID LOS_DmesgClear(VOID);

/**
 * @ingroup dmesg
 * @brief Copy log to file.
 *
 * @par Description:
 * This API is used to copy all log from dmesg buffer and write it to the file.
 *
 * @attention
 * <ul>
 * <li>Files rely on file system, the file system of filename dependent must be already mounted.</li>
 * </ul>
 *
 * @param  filename   [IN] Type #CHAR* The buffer expected copy to.
 *
 * @retval #-1      Copy log to file fail.
 * @retval #0       Maybe there is no log in the buffer.
 * @retval #INT32   The length of log has been written to file.
 * @par Dependency:
 * <ul><li>dmesg.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_DmesgToFile
 */
extern INT32 LOS_DmesgToFile(const CHAR *filename);

/**
 * @ingroup dmesg
 * @brief Set the dmesg level
 *
 * @par Description:
 * This API is used to set the level of log that want to stored in dmesg buffer.
 *
 * @attention
 * <ul>
 * <li>It would be useless if the level is less than print level.</li>
 * </ul>
 *
 * @param  level   [IN] Type #UINT32 The level expected to set, range from 0 to 5.
 *
 * @retval #1   Set dmesg level fail.
 * @retval #0   Set dmesg level success.
 * @par Dependency:
 * <ul><li>dmesg.h: the header file that contains the API declaration.</li></ul>
 * @see LOS_DmesgLvSet
 */
extern UINT32 LOS_DmesgLvSet(UINT32 level);

#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */
#endif
#endif /* _HWLITEOS_SHELL_DMESG_H */