mirror of
https://github.com/apache/nuttx.git
synced 2026-05-23 23:28:29 +08:00
docs/syslog: add syslog configuration options documentation
This commit updates the syslog.rst documentation to: 1. Add a new "Overview" section with the syslog-overview.png diagram 2. Introduce a comprehensive "Syslog Configuration Options" chapter 3. Document the CONFIG_SYSLOG_TIMESTAMP_MS option (newly added in driver code) - Clarify its dependency on CONFIG_SYSLOG_TIMESTAMP - Explain its function: use millisecond (ms) precision instead of default microsecond (µs) 4. Group all syslog Kconfig options by functional role (debug level, formatting, buffer, etc.) - Basic Debug Log Level Configuration - Message Formatting Configuration (timestamp/metadata/visual) - (Other categories follow the syslog system architecture) The documentation changes align with the recent driver enhancement: - drivers/syslog: add millisecond option for syslog timestamp formatting - Maintain consistency between driver code and documentation - Make syslog configuration options more discoverable for developers Signed-off-by: chao an <anchao.archer@bytedance.com>
This commit is contained in:
chao an
Alan C. Assis
Binary file not shown.
|
After Width: | Height: | Size: 723 KiB |
@@ -2,6 +2,11 @@
|
||||
SYSLOG
|
||||
======
|
||||
|
||||
Overview
|
||||
========
|
||||
|
||||
.. image:: image/syslog-overview.png
|
||||
|
||||
SYSLOG Interfaces
|
||||
=================
|
||||
|
||||
@@ -606,6 +611,117 @@ You can implement a simple NSH command to control the RAMLOG rate limit at runti
|
||||
|
||||
This command allows you to set the maximum number of log entries (burst) allowed in a given interval (seconds) for the RAMLOG device at runtime.
|
||||
|
||||
Syslog Configuration Options
|
||||
============================
|
||||
|
||||
Syslog functionality is fully controlled by Kconfig options, which are grouped
|
||||
below by their functional role (matching the syslog system architecture). All
|
||||
options are prefixed with ``CONFIG_SYSLOG_`` and follow NuttX's RTOS configuration
|
||||
conventions.
|
||||
|
||||
Basic Debug Log Level Configuration
|
||||
-----------------------------------
|
||||
These options control the base debug assertion and log level filtering,
|
||||
defining which severity levels of messages are captured by the syslog system.
|
||||
|
||||
- ``CONFIG_DEBUG_ASSERT``: Enable assertion checks in the syslog subsystem.
|
||||
- ``CONFIG_DEBUG_ERROR``: Enable logging of error-level (``LOG_ERR``) messages.
|
||||
- ``CONFIG_DEBUG_WARN``: Enable logging of warning-level (``LOG_WARNING``) messages.
|
||||
- ``CONFIG_DEBUG_INFO``: Enable logging of info-level (``LOG_INFO``) messages.
|
||||
|
||||
Additionally, runtime log level filtering is supported via:
|
||||
- ``CONFIG_SYSTEM_SETLOGMASK``: Enable the ``setlogmask(int mask)`` API, allowing dynamic adjustment of log levels at runtime.
|
||||
|
||||
Message Formatting Configuration
|
||||
--------------------------------
|
||||
These options define the metadata and visual formatting of syslog messages,
|
||||
including timestamps, identifiers, and color coding.
|
||||
|
||||
Timestamp Configuration
|
||||
-----------------------
|
||||
- ``CONFIG_SYSLOG_TIMESTAMP``: Enable timestamp addition to all syslog messages.
|
||||
- ``CONFIG_SYSLOG_TIMESTAMP_MS``: Use millisecond (ms) precision in timestamps, replacing the default microsecond (µs) precision. (requires ``CONFIG_SYSLOG_TIMESTAMP``).
|
||||
- ``CONFIG_SYSLOG_TIMESTAMP_REALTIME``: Use real-time clock (RTC) time for timestamps (requires ``CONFIG_SYSLOG_TIMESTAMP``).
|
||||
- ``CONFIG_SYSLOG_TIMESTAMP_FORMATTED``: Enable custom formatted timestamps (requires ``CONFIG_SYSLOG_TIMESTAMP``).
|
||||
- ``CONFIG_SYSLOG_TIMESTAMP_FORMAT``: Define custom timestamp format string (default: ``"%d/%m/%y %H:%M:%S"``, requires ``CONFIG_SYSLOG_TIMESTAMP_FORMATTED``).
|
||||
- ``CONFIG_SYSLOG_TIMESTAMP_LOCALTIME``: Use local time (instead of UTC) for timestamps (requires ``CONFIG_SYSLOG_TIMESTAMP_REALTIME``).
|
||||
|
||||
Message Metadata & Prefix
|
||||
-------------------------
|
||||
- ``CONFIG_SYSLOG_PRIORITY``: Include message priority level in the syslog prefix.
|
||||
- ``CONFIG_SYSLOG_PROCESS_NAME``: Include the process name in the syslog prefix.
|
||||
- ``CONFIG_SYSLOG_PROCESSID``: Include the process ID (PID) in the syslog prefix.
|
||||
- ``CONFIG_SYSLOG_CPUID``: Include the CPU ID (for SMP systems) in the syslog prefix.
|
||||
- ``CONFIG_SYSLOG_PREFIX``: Enable custom prefix support for syslog messages.
|
||||
- ``CONFIG_SYSLOG_PREFIX_STRING``: Define a static custom string to prepend to all syslog messages (requires ``CONFIG_SYSLOG_PREFIX``).
|
||||
|
||||
Visual Formatting
|
||||
-----------------
|
||||
- ``CONFIG_SYSLOG_COLOR_OUTPUT``: Enable ANSI color coding for syslog messages (differentiates log levels visually).
|
||||
|
||||
Core System & Buffer Configuration
|
||||
----------------------------------
|
||||
These options control the core syslog system infrastructure, including buffering
|
||||
and low-level formatting dependencies.
|
||||
|
||||
- ``CONFIG_SYSLOG_BUFFER``: Enable a dedicated buffer for syslog messages to prevent loss.
|
||||
- ``CONFIG_SYSLOG_INTBUFFER``: Enable an interrupt-safe buffer for syslog messages (critical for interrupt context logging).
|
||||
- ``CONFIG_SYSLOG_CRLF``: Automatically convert line feeds (``\n``) to carriage return + line feed (``\r\n``) in output.
|
||||
- ``lib_vsprintf``: (Implicit dependency) The syslog system relies on NuttX's ``lib_vsprintf`` for message formatting.
|
||||
|
||||
Output Channel Configuration
|
||||
----------------------------
|
||||
Syslog supports multiple output channels, with configuration options to enable
|
||||
channels and their respective destinations. The maximum number of channels is
|
||||
fixed at compile time.
|
||||
|
||||
Core Channel Settings
|
||||
---------------------
|
||||
- ``CONFIG_SYSLOG_MAX_CHANNELS``: Set the maximum number of syslog channels (default: 1 in the architecture, configurable per platform).
|
||||
- ``CONFIG_SYSLOG_DEFAULT``: Enable the **default channel** (maps to UART output).
|
||||
- ``CONFIG_SYSLOG_CRLF``: (Shared) Applies line ending conversion to all channel output.
|
||||
|
||||
Individual Channel & Destination Options
|
||||
----------------------------------------
|
||||
- ``CONFIG_SYSLOG_RAMLOG``: Enable the **ramlog channel** (outputs syslog messages to RAM for later retrieval).
|
||||
- ``CONFIG_SYSLOG_RPMSG``: Enable the **rpmsg channel** (routes syslog messages over IPC via rpmsg).
|
||||
- ``CONFIG_SYSLOG_FILE``: Enable the **dev channel** (supports output to character devices or regular files via a character driver).
|
||||
|
||||
Stdout Stream Integration
|
||||
-------------------------
|
||||
- ``stdout stream``: (Implicit) Syslog messages are forwarded to the standard ``stdout`` stream, which maps to ``/dev/console`` by default.
|
||||
|
||||
Driver Implementation
|
||||
=====================
|
||||
|
||||
The syslog driver is implemented as a special character driver. It uses the
|
||||
NuttX logging infrastructure to collect messages and route them to the
|
||||
configured output channels. The driver supports:
|
||||
|
||||
- **Multiple Outputs**: Simultaneous logging to UART, RAM, IPC, files, and ``/dev/console``.
|
||||
- **Interrupt Safety**: Via ``CONFIG_SYSLOG_INTBUFFER``, safe for logging from interrupt handlers.
|
||||
- **Format Flexibility**: Configurable timestamps, prefixes, and color coding for readability.
|
||||
- **POSIX Compatibility**: Aligns with POSIX syslog semantics while optimizing for embedded RTOS constraints.
|
||||
|
||||
API Reference
|
||||
=============
|
||||
|
||||
The syslog driver provides an API compatible with the POSIX ``syslog()``
|
||||
function, as well as NuttX-specific extensions for runtime configuration:
|
||||
|
||||
- ``void syslog(int priority, const char *format, ...)``: Log a message with a specified priority.
|
||||
- ``int setlogmask(int mask)``: Set the log level mask (enabled if ``CONFIG_SYSTEM_SETLOGMASK`` is defined).
|
||||
- ``void vsyslog(int priority, const char *format, va_list ap)``: Variadic version of ``syslog()`` for use in custom wrappers.
|
||||
|
||||
Usage Notes
|
||||
===========
|
||||
|
||||
1. **Interrupt Context Logging**: Always enable ``CONFIG_SYSLOG_INTBUFFER`` if logging from interrupt handlers to avoid race conditions.
|
||||
2. **RAM Log Usage**: The RAM log (``CONFIG_SYSLOG_RAMLOG``) is useful for systems without persistent storage; retrieve logs via the ramlog driver.
|
||||
3. **rpmsg Logging**: When using ``CONFIG_SYSLOG_RPMSG``, ensure the rpmsg subsystem is properly configured for inter-processor communication.
|
||||
4. **Timestamps**: For accurate real-time timestamps, enable an RTC driver and ``CONFIG_SYSLOG_TIMESTAMP_REALTIME``.
|
||||
5. **Color Output**: Disable ``CONFIG_SYSLOG_COLOR_OUTPUT`` if logging to non-ANSI terminals (e.g., raw UART terminals without color support).
|
||||
|
||||
SYSLOG Protocol (RFC 5424)
|
||||
==========================
|
||||
|
||||
|
||||
Reference in New Issue
Block a user