diff --git a/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.debug.gdbjtag.openocd.prefs b/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.debug.gdbjtag.openocd.prefs
index 5ce8285b..a469e11b 100644
--- a/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.debug.gdbjtag.openocd.prefs
+++ b/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.debug.gdbjtag.openocd.prefs
@@ -1,3 +1,3 @@
-eclipse.preferences.version=1
-executable.name=openocd
-install.folder=/Users/ace/sys/gnu-mcu-eclipse/openocd/self/bin
+eclipse.preferences.version=1
+executable.name=openocd
+install.folder=/Users/ace/sys/gnu-mcu-eclipse/openocd/self/bin
diff --git a/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.managedbuild.cross.riscv.prefs b/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.managedbuild.cross.riscv.prefs
index d5692f5e..8cebf325 100644
--- a/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.managedbuild.cross.riscv.prefs
+++ b/board/GD32VF103C_START/eclipse/hello_world/.settings/ilg.gnumcueclipse.managedbuild.cross.riscv.prefs
@@ -1,2 +1,2 @@
-eclipse.preferences.version=1
-toolchain.path.512258282=/Users/ace/sys/gnu-mcu-eclipse/riscv-none-gcc/8.2.0-2.2-20190521-0004/bin
+eclipse.preferences.version=1
+toolchain.path.512258282=/Users/ace/sys/gnu-mcu-eclipse/riscv-none-gcc/8.2.0-2.2-20190521-0004/bin
diff --git a/board/GD32VF103C_START/eclipse/hello_world/.settings/language.settings.xml b/board/GD32VF103C_START/eclipse/hello_world/.settings/language.settings.xml
index 1c9fb7ba..cf17e40e 100644
--- a/board/GD32VF103C_START/eclipse/hello_world/.settings/language.settings.xml
+++ b/board/GD32VF103C_START/eclipse/hello_world/.settings/language.settings.xml
@@ -1,48 +1,48 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<project>
-    	
-    <configuration id="ilg.gnumcueclipse.managedbuild.cross.riscv.config.elf.debug.1626121275" name="Debug">
-        		
-        <extension point="org.eclipse.cdt.core.LanguageSettingsProvider">
-            			
-            <provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider class="org.eclipse.cdt.managedbuilder.language.settings.providers.GCCBuiltinSpecsDetector" console="false" env-hash="1310167466484573552" id="ilg.gnumcueclipse.managedbuild.cross.riscv.GCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT RISC-V Cross GCC Built-in Compiler Settings" parameter="${COMMAND} ${FLAGS} ${cross_toolchain_flags} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-                				
-                <language-scope id="org.eclipse.cdt.core.gcc"/>
-                				
-                <language-scope id="org.eclipse.cdt.core.g++"/>
-                			
-            </provider>
-            		
-        </extension>
-        	
-    </configuration>
-    	
-    <configuration id="ilg.gnumcueclipse.managedbuild.cross.riscv.config.elf.release.991040509" name="Release">
-        		
-        <extension point="org.eclipse.cdt.core.LanguageSettingsProvider">
-            			
-            <provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider class="org.eclipse.cdt.managedbuilder.language.settings.providers.GCCBuiltinSpecsDetector" console="false" env-hash="1317474887408019048" id="ilg.gnumcueclipse.managedbuild.cross.riscv.GCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT RISC-V Cross GCC Built-in Compiler Settings" parameter="${COMMAND} ${FLAGS} ${cross_toolchain_flags} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-                				
-                <language-scope id="org.eclipse.cdt.core.gcc"/>
-                				
-                <language-scope id="org.eclipse.cdt.core.g++"/>
-                			
-            </provider>
-            		
-        </extension>
-        	
-    </configuration>
-    
-</project>
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<project>
+    	
+    <configuration id="ilg.gnumcueclipse.managedbuild.cross.riscv.config.elf.debug.1626121275" name="Debug">
+        		
+        <extension point="org.eclipse.cdt.core.LanguageSettingsProvider">
+            			
+            <provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
+            			
+            <provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
+            			
+            <provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
+            			
+            <provider class="org.eclipse.cdt.managedbuilder.language.settings.providers.GCCBuiltinSpecsDetector" console="false" env-hash="1310167466484573552" id="ilg.gnumcueclipse.managedbuild.cross.riscv.GCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT RISC-V Cross GCC Built-in Compiler Settings" parameter="${COMMAND} ${FLAGS} ${cross_toolchain_flags} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
+                				
+                <language-scope id="org.eclipse.cdt.core.gcc"/>
+                				
+                <language-scope id="org.eclipse.cdt.core.g++"/>
+                			
+            </provider>
+            		
+        </extension>
+        	
+    </configuration>
+    	
+    <configuration id="ilg.gnumcueclipse.managedbuild.cross.riscv.config.elf.release.991040509" name="Release">
+        		
+        <extension point="org.eclipse.cdt.core.LanguageSettingsProvider">
+            			
+            <provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
+            			
+            <provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
+            			
+            <provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
+            			
+            <provider class="org.eclipse.cdt.managedbuilder.language.settings.providers.GCCBuiltinSpecsDetector" console="false" env-hash="1317474887408019048" id="ilg.gnumcueclipse.managedbuild.cross.riscv.GCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT RISC-V Cross GCC Built-in Compiler Settings" parameter="${COMMAND} ${FLAGS} ${cross_toolchain_flags} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
+                				
+                <language-scope id="org.eclipse.cdt.core.gcc"/>
+                				
+                <language-scope id="org.eclipse.cdt.core.g++"/>
+                			
+            </provider>
+            		
+        </extension>
+        	
+    </configuration>
+    
+</project>
diff --git a/board/GD32VF103C_START/eclipse/hello_world/.settings/org.eclipse.ltk.core.refactoring.prefs b/board/GD32VF103C_START/eclipse/hello_world/.settings/org.eclipse.ltk.core.refactoring.prefs
deleted file mode 100644
index b196c64a..00000000
--- a/board/GD32VF103C_START/eclipse/hello_world/.settings/org.eclipse.ltk.core.refactoring.prefs
+++ /dev/null
@@ -1,2 +0,0 @@
-eclipse.preferences.version=1
-org.eclipse.ltk.core.refactoring.enable.project.refactoring.history=false
diff --git a/board/SipeedLonganNano/eclipse/hello_world/.settings/ilg.gnumcueclipse.debug.gdbjtag.openocd.prefs b/board/SipeedLonganNano/eclipse/hello_world/.settings/ilg.gnumcueclipse.debug.gdbjtag.openocd.prefs
deleted file mode 100644
index 5ce8285b..00000000
--- a/board/SipeedLonganNano/eclipse/hello_world/.settings/ilg.gnumcueclipse.debug.gdbjtag.openocd.prefs
+++ /dev/null
@@ -1,3 +0,0 @@
-eclipse.preferences.version=1
-executable.name=openocd
-install.folder=/Users/ace/sys/gnu-mcu-eclipse/openocd/self/bin
diff --git a/board/SipeedLonganNano/eclipse/hello_world/.settings/ilg.gnumcueclipse.managedbuild.cross.riscv.prefs b/board/SipeedLonganNano/eclipse/hello_world/.settings/ilg.gnumcueclipse.managedbuild.cross.riscv.prefs
deleted file mode 100644
index d5692f5e..00000000
--- a/board/SipeedLonganNano/eclipse/hello_world/.settings/ilg.gnumcueclipse.managedbuild.cross.riscv.prefs
+++ /dev/null
@@ -1,2 +0,0 @@
-eclipse.preferences.version=1
-toolchain.path.512258282=/Users/ace/sys/gnu-mcu-eclipse/riscv-none-gcc/8.2.0-2.2-20190521-0004/bin
diff --git a/board/SipeedLonganNano/eclipse/hello_world/.settings/language.settings.xml b/board/SipeedLonganNano/eclipse/hello_world/.settings/language.settings.xml
deleted file mode 100644
index cf5bdf78..00000000
--- a/board/SipeedLonganNano/eclipse/hello_world/.settings/language.settings.xml
+++ /dev/null
@@ -1,48 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<project>
-    	
-    <configuration id="ilg.gnumcueclipse.managedbuild.cross.riscv.config.elf.debug.1626121275" name="Debug">
-        		
-        <extension point="org.eclipse.cdt.core.LanguageSettingsProvider">
-            			
-            <provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider class="org.eclipse.cdt.managedbuilder.language.settings.providers.GCCBuiltinSpecsDetector" console="false" env-hash="1331743227127997179" id="ilg.gnumcueclipse.managedbuild.cross.riscv.GCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT RISC-V Cross GCC Built-in Compiler Settings" parameter="${COMMAND} ${FLAGS} ${cross_toolchain_flags} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-                				
-                <language-scope id="org.eclipse.cdt.core.gcc"/>
-                				
-                <language-scope id="org.eclipse.cdt.core.g++"/>
-                			
-            </provider>
-            		
-        </extension>
-        	
-    </configuration>
-    	
-    <configuration id="ilg.gnumcueclipse.managedbuild.cross.riscv.config.elf.release.991040509" name="Release">
-        		
-        <extension point="org.eclipse.cdt.core.LanguageSettingsProvider">
-            			
-            <provider copy-of="extension" id="org.eclipse.cdt.ui.UserLanguageSettingsProvider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.core.ReferencedProjectsLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider-reference id="org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider" ref="shared-provider"/>
-            			
-            <provider class="org.eclipse.cdt.managedbuilder.language.settings.providers.GCCBuiltinSpecsDetector" console="false" env-hash="1317474887408019048" id="ilg.gnumcueclipse.managedbuild.cross.riscv.GCCBuiltinSpecsDetector" keep-relative-paths="false" name="CDT RISC-V Cross GCC Built-in Compiler Settings" parameter="${COMMAND} ${FLAGS} ${cross_toolchain_flags} -E -P -v -dD &quot;${INPUTS}&quot;" prefer-non-shared="true">
-                				
-                <language-scope id="org.eclipse.cdt.core.gcc"/>
-                				
-                <language-scope id="org.eclipse.cdt.core.g++"/>
-                			
-            </provider>
-            		
-        </extension>
-        	
-    </configuration>
-    
-</project>
diff --git a/board/SipeedLonganNano/eclipse/hello_world/.settings/org.eclipse.ltk.core.refactoring.prefs b/board/SipeedLonganNano/eclipse/hello_world/.settings/org.eclipse.ltk.core.refactoring.prefs
deleted file mode 100644
index b196c64a..00000000
--- a/board/SipeedLonganNano/eclipse/hello_world/.settings/org.eclipse.ltk.core.refactoring.prefs
+++ /dev/null
@@ -1,2 +0,0 @@
-eclipse.preferences.version=1
-org.eclipse.ltk.core.refactoring.enable.project.refactoring.history=false
diff --git a/doc/RISC-V eclipse 开发环境搭建.md b/doc/RISC-V eclipse 开发环境搭建.md
new file mode 100644
index 00000000..87a959a1
--- /dev/null
+++ b/doc/RISC-V eclipse 开发环境搭建.md	
@@ -0,0 +1,141 @@
+#RISC-V eclipse 开发环境搭建
+
+## 软件列表
+
+* eclipse
+* riscv toolchain
+* riscv openocd
+
+
+## eclipse
+
+下载安装过程略
+
+## riscv toolchain
+
+在下载页`https://github.com/gnu-mcu-eclipse/riscv-none-gcc/releases`选择相应平台下载。并解压，放到合适的目录。
+
+## riscv openocd
+
+签出代码```git clone https://github.com/riscv-mcu/riscv-openocd```
+
+编译
+```
+./configure --enable-cmsis-dap --enable-ftdi --prefix=安装目录路径
+
+make
+
+make install
+```
+
+
+## 配置eclipse
+
+![](./img/riscv/properties.png)
+
+
+配置toolchain路径
+
+![](./img/riscv/toolchain.png)
+
+
+配置openocd路径
+
+![](./img/riscv/openocd.png)
+
+
+##调试设置
+
+添加如下两行
+
+```
+set arch riscv:rv32
+set remotetimeout 250
+```
+
+![](./img/riscv/debug.png)
+
+
+## 如果用gd-link调试
+
+配置文件
+
+```
+adapter_khz     1000
+reset_config srst_only
+adapter_nsrst_assert_width 100
+
+
+
+interface cmsis-dap
+
+transport select jtag
+
+#autoexit true
+
+set _CHIPNAME riscv
+jtag newtap $_CHIPNAME cpu -irlen 5 -expected-id 0x1000563d
+
+set _TARGETNAME $_CHIPNAME.cpu
+target create $_TARGETNAME riscv -chain-position $_TARGETNAME
+$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size 20480 -work-area-backup 0
+
+
+# Work-area is a space in RAM used for flash programming
+if { [info exists WORKAREASIZE] } {
+   set _WORKAREASIZE $WORKAREASIZE
+} else {
+   set _WORKAREASIZE 0x5000
+}
+
+# Allow overriding the Flash bank size
+if { [info exists FLASH_SIZE] } {
+    set _FLASH_SIZE $FLASH_SIZE
+} else {
+    # autodetect size
+    set _FLASH_SIZE 0
+}
+
+# flash size will be probed
+set _FLASHNAME $_CHIPNAME.flash
+
+flash bank $_FLASHNAME gd32vf103 0x08000000 0 0 0 $_TARGETNAME
+riscv set_reset_timeout_sec 1
+init
+
+halt
+```
+
+## 如果用sipeed riscv debugger调试
+
+配置文件
+
+```
+adapter_khz     1000
+
+interface ftdi
+ftdi_device_desc "Dual RS232"
+ftdi_vid_pid 0x0403 0x6010
+
+transport select jtag
+ftdi_layout_init 0x0008 0x001b
+ftdi_layout_signal nSRST -oe 0x0020 -data 0x0020
+
+set _CHIPNAME riscv
+jtag newtap $_CHIPNAME cpu -irlen 5 -expected-id 0x1e200a6d
+
+set _TARGETNAME $_CHIPNAME.cpu
+target create $_TARGETNAME riscv -chain-position $_TARGETNAME
+$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size 10000 -work-area-backup 1
+
+set _FLASHNAME $_CHIPNAME.flash
+flash bank $_FLASHNAME gd32vf103 0x08000000 0 0 0 $_TARGETNAME
+
+riscv expose_csrs 3040-3071
+
+init
+
+halt
+# We must turn on this because otherwise the IDE version debug cannot download the program into flash
+#flash protect 0 0 last off
+```
\ No newline at end of file
diff --git a/doc/img/riscv/debug.png b/doc/img/riscv/debug.png
new file mode 100644
index 00000000..17fa5d10
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diff --git a/doc/img/riscv/openocd.png b/doc/img/riscv/openocd.png
new file mode 100644
index 00000000..49f5fde7
Binary files /dev/null and b/doc/img/riscv/openocd.png differ
diff --git a/doc/img/riscv/properties.png b/doc/img/riscv/properties.png
new file mode 100644
index 00000000..94962e4e
Binary files /dev/null and b/doc/img/riscv/properties.png differ
diff --git a/doc/img/riscv/toolchain.png b/doc/img/riscv/toolchain.png
new file mode 100644
index 00000000..2c143a10
Binary files /dev/null and b/doc/img/riscv/toolchain.png differ