os_kernel_log.c — 内核日志打印

源文件路径: kernel/source/os_kernel_log.c

引用章节: 6.1 日志系统

核心机制

内核日志系统 (os_kernel_print) 提供：

• 四级日志：E(0) / W(1) / I(2) / D(3)
• 全局级别过滤：KLOG_GLOBAL_LEVEL 控制
• Tag 级别过滤：支持按模块标签单独设置日志级别
• 颜色输出：ANSI 转义序列支持（红/黄/绿/蓝）
• 时间戳：自动附加 [tick] 前缀

完整源码（关键部分）

/**
 ***********************************************************************************************************************
 * Copyright (c) 2020, China Mobile Communications Group Co.,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.
 *
 * @file        os_kernel_log.c
 *
 * @brief       Implementation of kernel printing function.
 *
 * @revision
 * Date         Author          Notes
 * 2020-03-05   OneOS Team      First version.
 ***********************************************************************************************************************
 */

#include <oneos_config.h>
#include <os_list.h>
#include <os_clock.h>
#include <string.h>
#include <board.h>
#include <os_util.h>
#include <os_assert.h>

#ifdef OS_USING_KERNEL_DEBUG

#define KLOG_NEWLINE_SIGN "\r\n"

#ifdef KLOG_USING_COLOR
/* CSI(Control Sequence Introducer/Initiator) sign
 * more information on https://en.wikipedia.org/wiki/ANSI_escape_code */
#define CSI_START "\033["
#define CSI_END   "\033[0m"

/* Output log front color */
#define F_BLACK   "30m"
#define F_RED     "31m"
#define F_GREEN   "32m"
#define F_YELLOW  "33m"
#define F_BLUE    "34m"
#define F_MAGENTA "35m"
#define F_CYAN    "36m"
#define F_WHITE   "37m"

#define KLOG_COLOR_DEBUG (OS_NULL)
#define KLOG_COLOR_INFO  (F_GREEN)
#define KLOG_COLOR_WARN  (F_YELLOW)
#define KLOG_COLOR_ERROR (F_RED)

static const char *gs_klog_color_output_info[] = {
    KLOG_COLOR_ERROR,  /* level 0 */
    KLOG_COLOR_WARN,   /* level 1 */
    KLOG_COLOR_INFO,   /* level 2 */
    KLOG_COLOR_DEBUG,  /* level 3 */
};
#endif /* KLOG_USING_COLOR */

#define KLOG_FILTER_TAG_MAX_LEN 15

/* Tag 级别过滤器 */
struct os_klog_tag_lvl_filter
{
    os_list_node_t list;
    char           tag[KLOG_FILTER_TAG_MAX_LEN + 1];
    uint16_t       level;
};

/* 日志控制信息 */
struct os_klog_ctrl_info
{
    os_list_node_t tag_lvl_list;    /* Tag 过滤器链表 */
    uint16_t       global_level;    /* 全局日志级别 */
    char           log_buff[OS_LOG_BUFF_SIZE]; /* 日志缓冲区 */
};

static os_klog_ctrl_info_t gs_klog_ctrl_info = {
    .tag_lvl_list = OS_LIST_INIT(gs_klog_ctrl_info.tag_lvl_list),
    .global_level = KLOG_GLOBAL_LEVEL
};

static const char *gs_klog_level_output_info[] = {"E/", "W/", "I/", "D/"};

/**
 * @brief 内核日志打印函数
 * @param level   日志级别 (0=E, 1=W, 2=I, 3=D)
 * @param tag     模块标签
 * @param newline 是否换行
 * @param fmt     格式化字符串
 */
void os_kernel_print(uint16_t level, const char *tag, os_bool_t newline,
                     const char *fmt, ...)
{
    va_list args;
    static int32_t s_cnt, s_offset, s_newline_len;
    static os_bool_t s_found;
    static uint16_t s_tag_level;

    /* 级别过滤：先检查 Tag 级别，再检查全局级别 */
    if (os_list_empty(&gs_klog_ctrl_info.tag_lvl_list))
    {
        if (level > gs_klog_ctrl_info.global_level) return;
    }
    else
    {
        s_found = os_get_klog_tag_lvl(tag, &s_tag_level);
        if (s_found)
        {
            if (level > s_tag_level) return;
        }
        else
        {
            if (level > gs_klog_ctrl_info.global_level) return;
        }
    }

    /* 格式化日志：[tick] 级别/TAG: 消息 */
    s_offset = 0;
    memset(gs_klog_ctrl_info.log_buff, 0, OS_LOG_BUFF_SIZE);

    /* 颜色前缀 */
#ifdef KLOG_USING_COLOR
    if (gs_klog_color_output_info[level])
    {
        s_cnt = os_snprintf(gs_klog_ctrl_info.log_buff + s_offset,
                            OS_LOG_BUFF_SIZE - s_offset,
                            "%s%s", CSI_START, gs_klog_color_output_info[level]);
        s_offset += s_cnt;
    }
#endif

    s_cnt = os_snprintf(gs_klog_ctrl_info.log_buff + s_offset,
                        OS_LOG_BUFF_SIZE - s_offset,
                        "[%lu] %s%s: ",
                        os_tick_get_value(),
                        gs_klog_level_output_info[level], tag);

    va_start(args, fmt);
    s_offset += s_cnt;
    s_cnt = os_vsnprintf(gs_klog_ctrl_info.log_buff + s_offset,
                         OS_LOG_BUFF_SIZE - s_offset, fmt, args);
    va_end(args);
    s_offset += s_cnt;

    /* 换行 + 颜色结束 */
    if (newline) strcpy(gs_klog_ctrl_info.log_buff + s_offset, KLOG_NEWLINE_SIGN);
#ifdef KLOG_USING_COLOR
    if (gs_klog_color_output_info[level] != OS_NULL)
        strcpy(gs_klog_ctrl_info.log_buff + s_offset + strlen(KLOG_NEWLINE_SIGN), CSI_END);
#endif

    os_hw_console_output(gs_klog_ctrl_info.log_buff);
}

#endif /* OS_USING_KERNEL_DEBUG */

输出示例

[12345] I/TASK: task led_blink created successfully
[12346] W/SENSOR: aht10 read timeout
[12347] E/MQTT: connection failed, rc=-2