note: add noteram crash dump

Dump all content when a crash occurs

Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>

Documentation/guides/tasktraceuser.rst

@@ -59,6 +59,11 @@ The following configurations are configurable parameters for trace.
   - If enabled, stop overwriting old notes in the circular buffer when the buffer is full by default.
     This is useful to keep instrumentation data of the beginning of a system boot.
 
+- ``CONFIG_DRIVERS_NOTERAM_CRASH_DUMP``
+
+  - If enabled, it will dump the data in the noteram buffer after a system crash.
+    This function can help to view the behavior of the system before the crash
+
 After the configuration, rebuild the NuttX kernel and application.
 
 If the trace function is enabled, "``trace``" :doc:`../applications/nsh/builtin` will be available.

drivers/note/Kconfig

@@ -79,6 +79,12 @@ config DRIVERS_NOTERAM_DEFAULT_NOOVERWRITE
 		is full by default. This is useful to keep instrumentation data of the
 		beginning of a system boot.
 
+config DRIVERS_NOTERAM_CRASH_DUMP
+	bool "Dump noteram buffer on panic"
+	default n
+	---help---
+		If this option is enabled, dump all contents when a crash occurs.
+
 endif # DRIVERS_NOTERAM
 
 config DRIVERS_NOTELOG

drivers/note/noteram_driver.c

@@ -38,6 +38,7 @@
 #include <nuttx/kmalloc.h>
 #include <nuttx/note/note_driver.h>
 #include <nuttx/note/noteram_driver.h>
+#include <nuttx/panic_notifier.h>
 #include <nuttx/fs/fs.h>
 #include <nuttx/streams.h>
 
@@ -1007,6 +1008,60 @@ static int noteram_dump_one(FAR uint8_t *p, FAR struct lib_outstream_s *s,
   return ret;
 }
 
+#ifdef CONFIG_DRIVERS_NOTERAM_CRASH_DUMP
+
+/****************************************************************************
+ * Name: noteram_dump
+ ****************************************************************************/
+
+static void noteram_dump(FAR struct noteram_driver_s *drv)
+{
+  struct noteram_dump_context_s ctx;
+  struct lib_syslograwstream_s stream;
+  uint8_t note[64];
+
+  lib_syslograwstream_open(&stream);
+  lib_sprintf(&stream.public, "# tracer:nop\n#\n");
+
+  while (1)
+    {
+      ssize_t ret;
+
+      ret = noteram_get(drv, note, sizeof(note));
+      if (ret <= 0)
+        {
+          break;
+        }
+
+      noteram_dump_one(note, &stream.public, &ctx);
+    }
+
+  lib_syslograwstream_close(&stream);
+}
+
+/****************************************************************************
+ * Name: noteram_crash_dump
+ ****************************************************************************/
+
+static int noteram_crash_dump(FAR struct notifier_block *nb,
+                              unsigned long action, FAR void *data)
+{
+  if (action == PANIC_KERNEL)
+    {
+      noteram_dump(&g_noteram_driver);
+    }
+
+  return 0;
+}
+
+static void noteram_crash_dump_register(void)
+{
+  static struct notifier_block nb;
+  nb.notifier_call = noteram_crash_dump;
+  panic_notifier_chain_register(&nb);
+}
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -1028,6 +1083,9 @@ static int noteram_dump_one(FAR uint8_t *p, FAR struct lib_outstream_s *s,
 
 int noteram_register(void)
 {
+#ifdef CONFIG_DRIVERS_NOTERAM_CRASH_DUMP
+  noteram_crash_dump_register();
+#endif
   return register_driver("/dev/note/ram", &g_noteram_fops, 0666,
                          &g_noteram_driver);
 }