[component] Add ulog logger basic component.

components/utilities/ulog/SConscript

@@ -0,0 +1,16 @@
+from building import *
+
+cwd  = GetCurrentDir()
+src  = Glob('*.c')
+path = [cwd]
+
+if GetDepend('ULOG_BACKEND_USING_CONSOLE'):
+    src += ['backend/console_be.c']
+    
+if GetDepend('ULOG_USING_SYSLOG'):
+    path +=  [cwd + '/syslog']
+    src  += Glob('syslog/*.c')
+
+group = DefineGroup('Utilities', src, depend = ['RT_USING_ULOG'], CPPPATH = path)
+
+Return('group')

components/utilities/ulog/backend/console_be.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-09-04     armink       the first version
+ */
+
+#include <rthw.h>
+#include <ulog.h>
+
+#ifdef ULOG_BACKEND_USING_CONSOLE
+
+#if defined(ULOG_ASYNC_OUTPUT_BY_THREAD) && ULOG_ASYNC_OUTPUT_THREAD_STACK < 384
+#error "The thread stack size must more than 384 when using async output by thread (ULOG_ASYNC_OUTPUT_BY_THREAD)"
+#endif
+
+static struct ulog_backend console;
+
+void ulog_console_backend_output(struct ulog_backend *backend, rt_uint32_t level, const char *tag, rt_bool_t is_raw,
+        const char *log, size_t len)
+{
+    rt_device_t dev = rt_console_get_device();
+
+#ifdef RT_USING_DEVICE
+    if (dev == RT_NULL)
+    {
+        rt_hw_console_output(log);
+    }
+    else
+    {
+        rt_uint16_t old_flag = dev->open_flag;
+
+        dev->open_flag |= RT_DEVICE_FLAG_STREAM;
+        rt_device_write(dev, 0, log, len);
+        dev->open_flag = old_flag;
+    }
+#else
+    rt_hw_console_output(log);
+#endif
+
+}
+
+int ulog_console_backend_init(void)
+{
+    console.output = ulog_console_backend_output;
+
+    ulog_backend_register(&console, "console", RT_TRUE);
+
+    return 0;
+}
+INIT_COMPONENT_EXPORT(ulog_console_backend_init);
+
+#endif /* ULOG_BACKEND_USING_CONSOLE */

components/utilities/ulog/syslog/syslog.c

@@ -0,0 +1,260 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-09-07     armink       the first version
+ */
+
+#include <stdarg.h>
+#include <ulog.h>
+#include <rthw.h>
+#include "syslog.h"
+
+#ifdef ULOG_OUTPUT_FLOAT
+#include <stdio.h>
+#endif
+
+/*
+ * reference:
+ * http://pubs.opengroup.org/onlinepubs/7908799/xsh/syslog.h.html
+ * https://www.gnu.org/software/libc/manual/html_node/Submitting-Syslog-Messages.html
+ * http://man7.org/linux/man-pages/man3/syslog.3.html
+ */
+
+#ifdef ULOG_USING_SYSLOG
+
+#ifndef ULOG_SYSLOG_IDENT_MAX_LEN
+#define ULOG_SYSLOG_IDENT_MAX_LEN      ULOG_FILTER_TAG_MAX_LEN
+#endif
+
+static char local_ident[ULOG_SYSLOG_IDENT_MAX_LEN + 1];
+static int local_facility = LOG_USER;
+static int local_option = LOG_USER;
+static rt_bool_t is_open = RT_FALSE;
+
+/**
+ * open connection to syslog
+ *
+ * @param ident is an arbitrary identification string which future syslog invocations will prefix to each message.
+ * @param option is not using on ulog.
+ * @param facility is the default facility code for this connection.
+ */
+void openlog(const char *ident, int option, int facility)
+{
+    rt_base_t level;
+
+    ulog_init();
+
+    level = rt_hw_interrupt_disable();
+
+    rt_memset(local_ident, 0, sizeof(local_ident));
+    if (ident)
+    {
+        rt_strncpy(local_ident, ident, ULOG_SYSLOG_IDENT_MAX_LEN);
+    }
+    else
+    {
+        rt_strncpy(local_ident, "rtt", ULOG_SYSLOG_IDENT_MAX_LEN);
+    }
+
+    local_option = option;
+
+    if (facility)
+    {
+        local_facility = facility;
+    }
+    else
+    {
+        /* default facility is LOG_USER */
+        local_facility = LOG_USER;
+    }
+    /* output all level log */
+    setlogmask(LOG_UPTO(LOG_DEBUG));
+
+    is_open = RT_TRUE;
+
+    rt_hw_interrupt_enable(level);
+
+}
+
+/**
+ * This is functionally identical to syslog.
+ *
+ * @param priority log priority, can be generated by the macro LOG_MAKEPRI
+ * @param format log format
+ * @param args log arguments
+ */
+void vsyslog(int priority, const char *format, va_list args)
+{
+    if (LOG_FAC(priority) == 0)
+    {
+        /* using local facility */
+        priority |= local_facility;
+    }
+
+    ulog_voutput(priority, local_ident, format, args);
+}
+
+/**
+ * generates a log message
+ *
+ * @param priority log priority, can be generated by the macro LOG_MAKEPRI
+ * @param format log format, like printf()
+ */
+void syslog(int priority, const char *format, ...)
+{
+    va_list args;
+
+    if (!is_open)
+    {
+        openlog(0, 0, 0);
+    }
+    /* args point to the first variable parameter */
+    va_start(args, format);
+
+    vsyslog(priority, format, args);
+
+    va_end(args);
+}
+
+/**
+ * close the syslog
+ */
+void closelog(void)
+{
+    ulog_deinit();
+
+    is_open = RT_FALSE;
+}
+
+/**
+ * set log priority mask
+ *
+ * @param mask The log priority mask which generate by macro LOG_MASK and LOG_UPTO.
+ *
+ * @return This function returns the previous log priority mask.
+ */
+int setlogmask(int mask)
+{
+    static int old_mask = 0;
+    int return_mask = old_mask;
+
+    ulog_tag_lvl_filter_set(local_ident, mask);
+
+    old_mask = mask;
+
+    return return_mask;
+}
+
+static const char *get_month_str(uint8_t month)
+{
+    switch(month)
+    {
+    case 1: return "Jan";
+    case 2: return "Feb";
+    case 3: return "Mar";
+    case 4: return "Apr";
+    case 5: return "May";
+    case 6: return "June";
+    case 7: return "July";
+    case 8: return "Aug";
+    case 9: return "Sept";
+    case 10: return "Oct";
+    case 11: return "Nov";
+    case 12: return "Dec";
+    default: return "Unknown";
+    }
+}
+
+RT_WEAK rt_size_t syslog_formater(char *log_buf, int level, const char *tag, const char *format, va_list args)
+{
+    extern size_t ulog_strcpy(size_t cur_len, char *dst, const char *src);
+
+    rt_size_t log_len = 0, newline_len = rt_strlen(ULOG_NEWLINE_SIGN);
+    int fmt_result;
+
+    RT_ASSERT(log_buf);
+    RT_ASSERT(LOG_PRI(level) <= LOG_DEBUG);
+    RT_ASSERT(tag);
+    RT_ASSERT(format);
+
+    /* add time and priority (level) info */
+    {
+        time_t now = time(RT_NULL);
+        struct tm *tm, tm_tmp;
+
+        tm = gmtime_r(&now, &tm_tmp);
+
+#ifdef ULOG_OUTPUT_LEVEL
+        rt_snprintf(log_buf + log_len, ULOG_LINE_BUF_SIZE - log_len, "<%d>%s%3d %02d:%02d:%02d", level,
+                get_month_str(tm->tm_mon + 1), tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec, rt_tick_get() % 1000);
+#else
+        rt_snprintf(log_buf + log_len, ULOG_LINE_BUF_SIZE - log_len, "%s%3d %02d:%02d:%02d",
+                get_month_str(tm->tm_mon + 1), tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec, rt_tick_get() % 1000);
+#endif /* ULOG_OUTPUT_LEVEL */
+
+        log_len += rt_strlen(log_buf + log_len);
+    }
+
+#ifdef ULOG_OUTPUT_TAG
+    /* add identification (tag) info */
+    {
+        log_len += ulog_strcpy(log_len, log_buf + log_len, " ");
+        log_len += ulog_strcpy(log_len, log_buf + log_len, tag);
+    }
+#endif /* ULOG_OUTPUT_TAG */
+
+#ifdef ULOG_OUTPUT_THREAD_NAME
+    /* add thread info */
+    {
+        log_len += ulog_strcpy(log_len, log_buf + log_len, " ");
+        /* is not in interrupt context */
+        if (rt_interrupt_get_nest() == 0)
+        {
+            log_len += ulog_strcpy(log_len, log_buf + log_len, rt_thread_self()->name);
+        }
+        else
+        {
+            log_len += ulog_strcpy(log_len, log_buf + log_len, "ISR");
+        }
+    }
+#endif /* ULOG_OUTPUT_THREAD_NAME */
+
+    log_len += ulog_strcpy(log_len, log_buf + log_len, ": ");
+
+#ifdef ULOG_OUTPUT_FLOAT
+    fmt_result = vsnprintf(log_buf + log_len, ULOG_LINE_BUF_SIZE - log_len, format, args);
+#else
+    fmt_result = rt_vsnprintf(log_buf + log_len, ULOG_LINE_BUF_SIZE - log_len, format, args);
+#endif /* ULOG_OUTPUT_FLOAT */
+
+    /* calculate log length */
+    if ((log_len + fmt_result <= ULOG_LINE_BUF_SIZE) && (fmt_result > -1))
+    {
+        log_len += fmt_result;
+    }
+    else
+    {
+        /* using max length */
+        log_len = ULOG_LINE_BUF_SIZE;
+    }
+
+    /* overflow check and reserve some space for newline sign */
+    if (log_len + newline_len > ULOG_LINE_BUF_SIZE)
+    {
+        /* using max length */
+        log_len = ULOG_LINE_BUF_SIZE;
+        /* reserve some space for newline sign */
+        log_len -= newline_len;
+    }
+
+    /* package newline sign */
+    log_len += ulog_strcpy(log_len, log_buf + log_len, ULOG_NEWLINE_SIGN);
+
+    return log_len;
+}
+
+#endif /* ULOG_USING_SYSLOG */

components/utilities/ulog/syslog/syslog.h

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-09-07     armink       the first version
+ */
+
+#ifndef _SYSLOG_H_
+#define _SYSLOG_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * priorities/facilities are encoded into a single 32-bit quantity, where the
+ * bottom 3 bits are the priority (0-7) and the top 28 bits are the facility
+ * (0-big number).  Both the priorities and the facilities map roughly
+ * one-to-one to strings in the syslogd(8) source code.  This mapping is
+ * included in this file.
+ *
+ * priorities (these are ordered)
+ */
+#define LOG_EMERG   0   /* system is unusable */
+#define LOG_ALERT   1   /* action must be taken immediately */
+#define LOG_CRIT    2   /* critical conditions */
+#define LOG_ERR     3   /* error conditions */
+#define LOG_WARNING 4   /* warning conditions */
+#define LOG_NOTICE  5   /* normal but significant condition */
+#define LOG_INFO    6   /* informational */
+#define LOG_DEBUG   7   /* debug-level messages */
+
+#define LOG_PRIMASK 0x07
+
+#define LOG_PRI(p)              ((p) & LOG_PRIMASK)
+#define LOG_MAKEPRI(fac, pri)   (((fac) << 3) | (pri))
+
+/* facility codes */
+#define LOG_KERN        (0<<3)  /* kernel messages */
+#define LOG_USER        (1<<3)  /* random user-level messages */
+#define LOG_MAIL        (2<<3)  /* mail system */
+#define LOG_DAEMON      (3<<3)  /* system daemons */
+#define LOG_AUTH        (4<<3)  /* security/authorization messages */
+#define LOG_SYSLOG      (5<<3)  /* messages generated internally by syslogd */
+#define LOG_LPR         (6<<3)  /* line printer subsystem */
+#define LOG_NEWS        (7<<3)  /* network news subsystem */
+#define LOG_UUCP        (8<<3)  /* UUCP subsystem */
+#define LOG_CRON        (9<<3)  /* clock daemon */
+#define LOG_AUTHPRIV    (10<<3) /* security/authorization messages (private) */
+
+/* other codes through 15 reserved for system use */
+#define LOG_LOCAL0      (16<<3) /* reserved for local use */
+#define LOG_LOCAL1      (17<<3) /* reserved for local use */
+#define LOG_LOCAL2      (18<<3) /* reserved for local use */
+#define LOG_LOCAL3      (19<<3) /* reserved for local use */
+#define LOG_LOCAL4      (20<<3) /* reserved for local use */
+#define LOG_LOCAL5      (21<<3) /* reserved for local use */
+#define LOG_LOCAL6      (22<<3) /* reserved for local use */
+#define LOG_LOCAL7      (23<<3) /* reserved for local use */
+
+#define LOG_NFACILITIES 24  /* current number of facilities */
+#define LOG_FACMASK     0x03f8  /* mask to extract facility part */
+/* facility of pri */
+#define LOG_FAC(p)      (((p) & LOG_FACMASK) >> 3)
+
+/*
+ * arguments to setlogmask.
+ */
+#define LOG_MASK(pri)   (1 << (pri))        /* mask for one priority */
+#define LOG_UPTO(pri)   ((1 << ((pri)+1)) - 1)  /* all priorities through pri */
+
+/*
+ * Option flags for openlog.
+ *
+ * LOG_ODELAY no longer does anything.
+ * LOG_NDELAY is the inverse of what it used to be.
+ */
+#define LOG_PID         0x01    /* log the pid with each message */
+#define LOG_CONS        0x02    /* log on the console if errors in sending */
+#define LOG_ODELAY      0x04    /* delay open until first syslog() (default) */
+#define LOG_NDELAY      0x08    /* don't delay open */
+#define LOG_NOWAIT      0x10    /* don't wait for console forks: DEPRECATED */
+#define LOG_PERROR      0x20    /* log to stderr as well */
+
+#include <stdarg.h>
+
+void closelog(void);
+void openlog(const char *ident, int option, int facility);
+int setlogmask(int mask);
+void syslog(int priority, const char *format, ...);
+void vsyslog(int priority, const char *format, va_list args);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SYSLOG_H_ */

components/utilities/ulog/ulog.h

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-08-25     armink       the first version
+ */
+
+#ifndef _ULOG_H_
+#define _ULOG_H_
+
+#include <rtthread.h>
+#include "ulog_def.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ULOG_VERSION_STR               "0.1.0"
+
+/*
+ * ulog init and deint
+ */
+int ulog_init(void);
+void ulog_deinit(void);
+
+/*
+ * output different level log by LOG_X API
+ *
+ * NOTE: The `LOG_TAG` and `LOG_LVL` must be defined before including the <ulog.h> when you want to use LOG_X API.
+ *
+ * #define LOG_TAG              "example"
+ * #define LOG_LVL              LOG_LVL_DBG
+ * #include <ulog.h>
+ *
+ * Then you can using LOG_X API to output log
+ *
+ * LOG_D("this is a debug log!");
+ * LOG_E("this is a error log!");
+ */
+#define LOG_E(...)                     ulog_e(LOG_TAG, __VA_ARGS__)
+#define LOG_W(...)                     ulog_w(LOG_TAG, __VA_ARGS__)
+#define LOG_I(...)                     ulog_i(LOG_TAG, __VA_ARGS__)
+#define LOG_D(...)                     ulog_d(LOG_TAG, __VA_ARGS__)
+#define LOG_RAW(...)                   ulog_raw(__VA_ARGS__)
+
+/*
+ * backend register and unregister
+ */
+rt_err_t ulog_backend_register(ulog_backend_t backend, const char *name, rt_bool_t support_color);
+rt_err_t ulog_backend_unregister(ulog_backend_t backend);
+
+#ifdef ULOG_USING_FILTER
+/*
+ * log filter setting
+ */
+int ulog_tag_lvl_filter_set(const char *tag, rt_uint32_t level);
+rt_uint32_t ulog_tag_lvl_filter_get(const char *tag);
+void ulog_global_filter_lvl_set(rt_uint32_t level);
+void ulog_global_filter_tag_set(const char *tag);
+void ulog_global_filter_kw_set(const char *keyword);
+#endif /* ULOG_USING_FILTER */
+
+/*
+ * flush all backends's log
+ */
+void ulog_flush(void);
+
+#ifdef ULOG_USING_ASYNC_OUTPUT
+/*
+ * asynchronous output API
+ */
+void ulog_async_output(void);
+void ulog_async_waiting_log(rt_int32_t time);
+#endif
+
+/*
+ * dump the hex format data to log
+ */
+void ulog_hexdump(const char *name, rt_size_t width, rt_uint8_t *buf, rt_size_t size);
+
+/*
+ * Another log output API. This API is difficult to use than LOG_X API.
+ */
+void ulog_voutput(rt_uint32_t level, const char *tag, const char *format, va_list args);
+void ulog_output(rt_uint32_t level, const char *tag, const char *format, ...);
+void ulog_raw(const char *format, ...);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _ULOG_H_ */

components/utilities/ulog/ulog_def.h

@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-08-25     armink       the first version
+ */
+#ifndef _ULOG_DEF_H_
+#define _ULOG_DEF_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* logger level, the number is compatible for syslog */
+#define LOG_LVL_ASSERT                 0
+#define LOG_LVL_ERROR                  3
+#define LOG_LVL_WARNING                4
+#define LOG_LVL_INFO                   6
+#define LOG_LVL_DBG                    7
+
+/* the output silent level and all level for filter setting */
+#ifndef ULOG_USING_SYSLOG
+#define LOG_FILTER_LVL_SILENT         0
+#define LOG_FILTER_LVL_ALL            7
+#else
+#define LOG_FILTER_LVL_SILENT         1
+#define LOG_FILTER_LVL_ALL            255
+#endif /* ULOG_USING_SYSLOG */
+
+/* compatible for rtdbg */
+#undef LOG_D
+#undef LOG_I
+#undef LOG_W
+#undef LOG_E
+#undef LOG_RAW
+#undef DBG_ERROR
+#undef DBG_WARNING
+#undef DBG_INFO
+#undef DBG_LOG
+#define DBG_ERROR                      LOG_LVL_ERROR
+#define DBG_WARNING                    LOG_LVL_WARNING
+#define DBG_INFO                       LOG_LVL_INFO
+#define DBG_LOG                        LOG_LVL_DBG
+
+#if !defined(LOG_TAG)
+    /* compatible for rtdbg */
+    #if defined(DBG_SECTION_NAME)
+        #define LOG_TAG                DBG_SECTION_NAME
+    #else
+        #define LOG_TAG                "NO_TAG"
+    #endif
+#endif /* !defined(LOG_TAG) */
+
+#if !defined(LOG_LVL)
+    /* compatible for rtdbg */
+    #if defined(DBG_LEVEL)
+        #define LOG_LVL                    DBG_LEVEL
+    #else
+        #define LOG_LVL                    LOG_LVL_DBG
+    #endif
+#endif /* !defined(LOG_LVL) */
+
+#if (LOG_LVL >= LOG_LVL_DBG) && (ULOG_OUTPUT_LVL >= LOG_LVL_DBG)
+    #define ulog_d(TAG, ...)           ulog_output(LOG_LVL_DBG, TAG, __VA_ARGS__)
+#else
+    #define ulog_d(TAG, ...)
+#endif /* (LOG_LVL >= LOG_LVL_DBG) && (ULOG_OUTPUT_LVL >= LOG_LVL_DBG) */
+
+#if (LOG_LVL >= LOG_LVL_INFO) && (ULOG_OUTPUT_LVL >= LOG_LVL_INFO)
+    #define ulog_i(TAG, ...)           ulog_output(LOG_LVL_INFO, TAG, __VA_ARGS__)
+#else
+    #define ulog_i(TAG, ...)
+#endif /* (LOG_LVL >= LOG_LVL_INFO) && (ULOG_OUTPUT_LVL >= LOG_LVL_INFO) */
+
+#if (LOG_LVL >= LOG_LVL_WARNING) && (ULOG_OUTPUT_LVL >= LOG_LVL_WARNING)
+    #define ulog_w(TAG, ...)           ulog_output(LOG_LVL_WARNING, TAG, __VA_ARGS__)
+#else
+    #define ulog_w(TAG, ...)
+#endif /* (LOG_LVL >= LOG_LVL_WARNING) && (ULOG_OUTPUT_LVL >= LOG_LVL_WARNING) */
+
+#if (LOG_LVL >= LOG_LVL_ERROR) && (ULOG_OUTPUT_LVL >= LOG_LVL_ERROR)
+    #define ulog_e(TAG, ...)           ulog_output(LOG_LVL_ERROR, TAG, __VA_ARGS__)
+#else
+    #define ulog_e(TAG, ...)
+#endif /* (LOG_LVL >= LOG_LVL_ERROR) && (ULOG_OUTPUT_LVL >= LOG_LVL_ERROR) */
+
+/* assert for developer. */
+#ifdef ULOG_ASSERT_ENABLE
+    #define ULOG_ASSERT(EXPR)                                                 \
+    if (!(EXPR))                                                              \
+    {                                                                         \
+        ulog_output(LOG_LVL_ASSERT, LOG_TAG, "(%s) has assert failed at %s:%ld.", #EXPR, __FUNCTION__, __LINE__); \
+        ulog_flush();                                                         \
+        while (1);                                                            \
+    }
+#else
+    #define ULOG_ASSERT(EXPR)
+#endif
+
+/* ASSERT API definition */
+#if !defined(ASSERT)
+    #define ASSERT           ULOG_ASSERT
+#endif
+
+/* compatible for elog */
+#undef assert
+#undef log_e
+#undef log_w
+#undef log_i
+#undef log_d
+#undef log_v
+#undef ELOG_LVL_ASSERT
+#undef ELOG_LVL_ERROR
+#undef ELOG_LVL_WARN
+#undef ELOG_LVL_INFO
+#undef ELOG_LVL_DEBUG
+#undef ELOG_LVL_VERBOSE
+#define assert                         ASSERT
+#define log_e                          LOG_E
+#define log_w                          LOG_W
+#define log_i                          LOG_I
+#define log_d                          LOG_D
+#define log_v                          LOG_D
+#define log_raw                        LOG_RAW
+#define ELOG_LVL_ASSERT                LOG_LVL_ASSERT
+#define ELOG_LVL_ERROR                 LOG_LVL_ERROR
+#define ELOG_LVL_WARN                  LOG_LVL_WARNING
+#define ELOG_LVL_INFO                  LOG_LVL_INFO
+#define ELOG_LVL_DEBUG                 LOG_LVL_DBG
+#define ELOG_LVL_VERBOSE               LOG_LVL_DBG
+
+/* setting static output log level */
+#ifndef ULOG_OUTPUT_LVL
+#define ULOG_OUTPUT_LVL                LOG_LVL_DBG
+#endif
+
+/* buffer size for every line's log */
+#ifndef ULOG_LINE_BUF_SIZE
+#define ULOG_LINE_BUF_SIZE             128
+#endif
+
+/* output filter's tag max length */
+#ifndef ULOG_FILTER_TAG_MAX_LEN
+#define ULOG_FILTER_TAG_MAX_LEN        23
+#endif
+
+/* output filter's keyword max length */
+#ifndef ULOG_FILTER_KW_MAX_LEN
+#define ULOG_FILTER_KW_MAX_LEN         15
+#endif
+
+#ifndef ULOG_NEWLINE_SIGN
+#define ULOG_NEWLINE_SIGN              "\r\n"
+#endif
+
+#define ULOG_FRAME_MAGIC               0x10
+
+struct ulog_frame
+{
+    /* magic word is 0x10 ('lo') */
+    rt_uint32_t magic:8;
+    rt_uint32_t is_raw:1;
+    rt_uint32_t log_len:23;
+    rt_uint32_t level;
+    const char *log;
+    const char *tag;
+};
+typedef struct ulog_frame *ulog_frame_t;
+
+struct ulog_backend
+{
+    char name[RT_NAME_MAX];
+    rt_bool_t support_color;
+    void (*init)  (struct ulog_backend *backend);
+    void (*output)(struct ulog_backend *backend, rt_uint32_t level, const char *tag, rt_bool_t is_raw, const char *log, size_t len);
+    void (*flush) (struct ulog_backend *backend);
+    void (*deinit)(struct ulog_backend *backend);
+    rt_slist_t list;
+};
+typedef struct ulog_backend *ulog_backend_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _ULOG_DEF_H_ */