Documentation/coredump: add coredump chapter

Signed-off-by: chao an <anchao@xiaomi.com>

Documentation/guides/coredump.rst

@@ -0,0 +1,80 @@
+====================
+Core Dump
+====================
+
+Overview
+========
+
+.. image:: image/coredump-overview.png
+
+How to use
+-----------
+
+1. Enable NuttX Core dump
+
+Enable Kconfig
+
+    .. code-block:: console
+
+      CONFIG_ELF=y                        /* Enable ELF */
+
+      CONFIG_ELF_COREDUMP=y               /* Enable ELF Coredump */
+
+      CONFIG_BOARD_COREDUMP=y             /* Enable Board Coredump, if exceptions and assertions occur, */
+
+      CONFIG_SYSTEM_COREDUMP=y            /* Enable coredump in user command, which can capture the current
+                                             state of one or all threads when the system is running, the
+                                             output can be redirect to console or file */
+
+      CONFIG_BOARD_COREDUMP_COMPRESSION=y /* Default y, enable Coredump compression to
+                                             reduce the size of the original core image */
+
+      CONFIG_BOARD_COREDUMP_FULL=y        /* Default y, save all task informations */
+
+2. Run Coredump on nsh (CONFIG_SYSTEM_COREDUMP=y)
+
+Parameters of coredump tool
+
+    .. code-block:: console
+
+      $ coredump <pid>        /* If pid is specified, coredump will only capture the thread with the
+                                 specified pid, otherwise all threads will be captured */
+
+      $ coredump <filename>   /* If filename is specified, then coredump will be output to the specified
+                                 file by default, otherwise it will be redirect in stdout stream */
+
+3. Capture coredump from stdout
+
+Save the print of the red frame part in the figure as file
+
+    .. image:: image/coredump-hexdump.png
+
+    .. code-block:: console
+
+      $ cat elf.dump
+      [CPU0] [ 6] 5A5601013D03FF077F454C4601010100C0000304002800C00D003420036000070400053400200008200A4000000420030034C024200001D8092004E00200601A
+      ...
+      [CPU0] [ 6] 401B018D37814720005A5601000800090100006000010000
+
+4. Convert the dump file
+
+If the core file is post-processed by lzf compress and hexdump stream, execute the coredump script (`tools/coredump.py
+<https://github.com/apache/nuttx/blob/master/tools/coredump.py>`_) to convert hex to binary and lzf decompression, If the -o parameter is not added in commandline, the output of <original file name>.core will be automatically generated:
+
+    .. code-block:: console
+
+      $ ./nuttx/tools/coredump.py elf.dump
+      Core file conversion completed: elf.core
+
+
+5. Analysis by gdb
+
+After generating elf.core, combined with compiled nuttx.elf, you can view the call stack and related register information of all threads directly through gdb:
+
+(NOTE: Toolchain version must be newer than 11.3)
+
+    .. code-block:: console
+
+      $ prebuilts/gcc/linux/arm/bin/arm-none-eabi-gdb -c elf.core nuttx
+
+    .. image:: image/coredump-gdb.png

Documentation/guides/index.rst

@@ -19,3 +19,4 @@ Guides
   zerolatencyinterrupts.rst
   nestedinterrupts.rst
   cortexmhardfaults.rst
+  coredump.rst