drivers/syslog README File
==========================
This README file discusses the SYLOG drivers that can be found in the
drivers/syslog directory. In NuttX, syslog output is equivalent to
debug output and, therefore, the syslogging interfaces are defined in the
header file include/debug.h.
By default, all system log output goes to console (/dev/console). But that
behavior can be changed by the drivers in this directory.
ramlog.c
--------
The RAM logging driver is a driver that was intended to support debugging
output (syslogging) when the normal serial output is not available. For
example, if you are using a telnet or USB serial console, the debug
output will get lost.
The RAM logging driver is similar to a pipe in that it saves the
debugging output in a FIFO in RAM. It differs from a pipe in numerous
details as needed to support logging.
This driver is built when CONFIG_RAMLOG is defined in the Nuttx
configuration.
Configuration options:
CONFIG_RAMLOG - Enables the RAM logging feature
CONFIG_RAMLOG_CONSOLE - Use the RAM logging device as a system console.
If this feature is enabled (along with CONFIG_DEV_CONSOLE), then all
console output will be re-directed to a circular buffer in RAM. This
is useful, for example, if the only console is a Telnet console. Then
in that case, console output from non-Telnet threads will go to the
circular buffer and can be viewed using the NSH 'dmesg' command.
CONFIG_RAMLOG_SYSLOG - Use the RAM logging device for the syslogging
interface. If this feature is enabled (along with CONFIG_SYSLOG),
then all debug output (only) will be re-directed to the circular
buffer in RAM. This RAM log can be view from NSH using the 'dmesg'
command.
CONFIG_RAMLOG_NPOLLWAITERS - The number of threads than can be waiting
for this driver on poll(). Default: 4
If CONFIG_RAMLOG_CONSOLE or CONFIG_RAMLOG_SYSLOG is selected, then the
following may also be provided:
CONFIG_RAMLOG_CONSOLE_BUFSIZE - Size of the console RAM log. Default: 1024
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