The initial SYLOG device logic was valiant but yet still not enough

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4998 7fd9a85b-ad96-42d3-883c-3090e2eb8679

4 files changed, 88 insertions, 181 deletions

diff --git a/nuttx/drivers/syslog/Kconfig b/nuttx/drivers/syslog/Kconfig
new file mode 100644
index 000000000..3ec8c7490
--- /dev/null
+++ b/nuttx/drivers/syslog/Kconfig
@@ -0,0 +1,73 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+comment "System Logging"
+
+config RAMLOG
+	bool "RAM log device support"
+	default n
+	---help---
+		This is a driver that was intended to support debugging output,
+		aka 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.  However, the RAMLOG device should
+		be usable even if system logging is disabled.
+
+		This 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.
+
+if RAMLOG
+config RAMLOG_SYSLOG
+	bool "Use RAMLOG for SYSLOG"
+	default n
+	depends on SYSLOG
+	---help---
+		Use the RAM logging device for the syslogging interface.  If this feature
+		is enabled (along with 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.
+
+		Do not enable more than one SYSLOG device.
+
+config RAMLOG_CONSOLE
+	bool "Use RAMLOG for /dev/console"
+	default n
+	depends on DEV_CONSOLE
+	---help---
+		Use the RAM logging device as a system console. If this feature is enabled (along
+		with 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_CONSOLE_BUFSIZE
+	int "RAMLOG buffer size"
+	default 1024
+	depends on RAMLOG_SYSLOG || RAMLOG_CONSOLE
+	---help---
+		Size of the console RAM log.  Default: 1024
+
+config RAMLOG_CRLF
+	bool "RAMLOG CR/LF"
+	default n
+	---help---
+		Pre-pend a carriage return before every linefeed that goes into the RAM log.
+
+config RAMLOG_NONBLOCKING
+	bool "RAMLOG non-block reads"
+	default y
+	---help---
+		Reading from the RAMLOG will never block if the RAMLOG is empty.  If the RAMLOG
+		is empty, then zero is returned (usually interpreted as end-of-file).
+
+config RAMLOG_NPOLLWAITERS
+	int "RAMLOG number of poll waiters"
+	default 4
+	depends on !DISABLE_POLL
+	---help---
+		The maximum number of threads that may be waiting on the poll method.
+
+endif
diff --git a/nuttx/drivers/syslog/Make.defs b/nuttx/drivers/syslog/Make.defs
index 9826beb01..aa0ab19b8 100644
--- a/nuttx/drivers/syslog/Make.defs
+++ b/nuttx/drivers/syslog/Make.defs
@@ -38,9 +38,10 @@
 
 ifeq ($(CONFIG_SYSLOG),y)
 
-ifeq ($(CONFIG_SYSLOG_CHAR),y)
-  CSRCS += syslog.c
-endif
+# If no special loggin devices are implemented, then the default SYSLOG
+# logic at fs/fs_syslog.c will be used
+
+# (Add other SYSLOG drivers here)
 
 ifeq ($(CONFIG_RAMLOG),y)
   CSRCS += ramlog.c
diff --git a/nuttx/drivers/syslog/README.txt b/nuttx/drivers/syslog/README.txt
index c034b49b6..611f43567 100644
--- a/nuttx/drivers/syslog/README.txt
+++ b/nuttx/drivers/syslog/README.txt
@@ -7,7 +7,17 @@ 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.
+behavior can be changed by the defining CONFIG_SYSLOG in the NuttX
+configuration.  In that, case all low-level debug output will go through
+syslog_putc().
+
+One version of syslog_putc() is defined in fs/fs_syslog.c; that version is
+used when CONFIG_SYSLOG_CHAR is defined.  That version of syslog_putc()
+just integrates with the file system to re-direct debug output to a
+character device or to a file.
+
+If CONFIG_SYSLOG_CHAR is not defined, then other custom SYSLOG drivers
+can be used.  Those custom SYSLOG drivers reside in this directory.
 
 ramlog.c
 --------
diff --git a/nuttx/drivers/syslog/syslog.c b/nuttx/drivers/syslog/syslog.c
deleted file mode 100644
index 60e9cffcb..000000000
--- a/nuttx/drivers/syslog/syslog.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/****************************************************************************
- * drivers/syslog/syslog.c
- *
- *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * 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 NuttX 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 OWNER 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.
- *
- ****************************************************************************/
-
-/****************************************************************************
- * Included Files
- ****************************************************************************/
-
-#include <nuttx/config.h>
-
-#include <sys/types.h>
-
-#include <stdint.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <errno.h>
-
-#include <nuttx/syslog.h>
-
-#if defined(CONFIG_SYSLOG) && defined(CONFIG_SYSLOG_CHAR)
-
-/****************************************************************************
- * Private Types
- ****************************************************************************/
-
-/****************************************************************************
- * Private Types
- ****************************************************************************/
-
-struct syslog_dev_s
-{
-  int fd; /* File descriptor of the opened SYSLOG character device */
-};
-
-/****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
-/* This is the device structure for the console or syslogging function.  It
- * must be statically initialized because the RAMLOG syslog_putc function
- * could be called before the driver initialization logic executes.
- */
-
-static struct syslog_dev_s g_sysdev      = { -1 };
-static const uint8_t       g_syscrlf[2]  = { '\r', '\n' };
-
-/****************************************************************************
- * Private Functions
- ****************************************************************************/
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
-/****************************************************************************
- * Name: syslog_initialize
- *
- * Description:
- *   Initialize to use the character device at CONFIG_SYSLOG_DEVPATH as the
- *   SYSLOG.
- *
- ****************************************************************************/
-
-int syslog_initialize(void)
-{
-  /* Has the device been opened yet */
-
-  if (g_sysdev.fd < 0)
-    {
-      /* No, try to open the device now: write-only, try to create it if
-       * it doesn't exist (it might be a file), if it is a file that already
-       * exists, then append new log data to the file.
-       */
-
-      g_sysdev.fd = open(CONFIG_SYSLOG_DEVPATH, O_WRONLY | O_CREAT | O_APPEND, 0644);
-      if (g_sysdev.fd < 0)
-        {
-          return -get_errno();
-        }
-    }
-
-  /* The SYSLOG device is open and ready for writing. */
-
-  return OK;
-}
-
-/****************************************************************************
- * Name: syslog_putc
- *
- * Description:
- *   This is the low-level system logging interface.  The debugging/syslogging
- *   interfaces are lib_rawprintf() and lib_lowprinf().  The difference is
- *   the lib_rawprintf() writes to fd=1 (stdout) and lib_lowprintf() uses
- *   a lower level interface that works from interrupt handlers.  This
- *   function is a a low-level interface used to implement lib_lowprintf().
- *
- ****************************************************************************/
-
-int syslog_putc(int ch)
-{
-  ssize_t nbytes;
-  int ret;
-
-  /* Try to initialize the device.  We do this repeatedly because the log
-   * device might be something that was not ready the first time that
-   * syslog_intialize() was called (such as a USB serial device or a file
-   * in an NFS mounted file system.
-   */
-
-  ret = syslog_initialize();
-  if (ret < 0)
-    {
-      return ret;
-    }
-
-  /* Ignore carriage returns */
-
-  if (ch == '\r')
-    {
-      return ch;
-    }
-
-  /* Pre-pend a newline with a carriage return */
-
-  if (ch == '\n')
-    {
-      nbytes = write(g_sysdev.fd, g_syscrlf, 2);
-    }
-  else
-    {
-      nbytes = write(g_sysdev.fd, &ch, 1);
-    }
-
-  if (nbytes < 0)
-    {
-      return nbytes;
-    }
-
-  return ch;
-}
-
-#endif /* CONFIG_SYSLOG && CONFIG_SYSLOG_CHAR */