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+# Remote Debugging for Visual Studio Code
+
+This document describes how to debug nnfw on arm devices using visual studio code.
+
+## Install gdb-multiarch on build host
+
+1. Install `gdb-multiarch`
+
+```bash
+$ sudo apt install gdb-multiarch
+```
+
+## Configure VS code on build host
+
+1. Install `Native Debug` extension on VS code
+
+2. Setup GDB environment on VS code
+
+- Debug -> Add configuration -> GDB: Connect to gdbserver
+- Change configuration as below
+  - Change `<TARGET_IP>` to IP of your target
+  - The default port number for gdbserver is 2345. You can change this number.
+  - You can change `executable` configuration from `tflite_run` to other binaries you want to debug.
+
+```json
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "gdb",
+            "request": "attach",
+            "name": "Attach to gdbserver",
+            "gdbpath": "/usr/bin/gdb-multiarch",
+            "executable": "./Product/armv7l-linux.debug/out/bin/tflite_run",
+            "target": "<TARGET_IP>:2345",
+            "remote": true,
+            "printCalls": true,
+            "cwd": "${workspaceRoot}",
+            "valuesFormatting": "parseText"
+        }
+    ]
+}
+```
+
+## Install gdbserver and debugging symbols at target
+
+You need to setup a target device for remote debugging.
+
+1. Install `gdbserver`
+```bash
+$ sudo apt install gdbserver
+```
+
+2. Install `libc6-dbg` and copy debugging symbols
+```bash
+$ sudo apt install libc6-dbg
+$ sudo mkdir -p /lib/.debug
+$ sudo ln -s /usr/lib/debug/lib/arm-linux-gnueabihf/ld-2.27.so /lib/.debug
+```
+
+## Run remote debugging
+
+1. Start gdbserver on target
+
+```bash
+gdbserver --multi :<PORT> <BINARY_PATH> <EXECUTION_ARGUMENTS>
+```
+
+Example
+```bash
+gdbserver --multi :2345 Product/armv7l-linux.debug/out/bin/tflite_run ../models/slice_test.tflite
+```
+
+2. Connect to gdbserver using VS code
+
+- Setup breakpoints on any code you want.
+
+- Click F5 to start remote debugging.
+
+- Program will execute and exit if no breakpoint exists.
+
+## Optional: Setup rootfs on build host
+
+When debugging starts, `gdb` downloads shared libraries that nnfw uses from the target device.
+This process makes `gdb` to wait for shared library download to finish for every debugging start.
+
+To reduce shared library loading, you can setup an arm root file system on your build host and use it.
+
+1. Create arm root file system
+
+Following [CrossBuildForArm](docs/nnfw/howto/CrossBuildForArm.md) to create an arm root file system.
+
+You can use an arm root file system created for arm cross-compile.
+
+2. Install `libc6-dbg` on arm root file system
+
+`<ROOTF_DIR>` should point ARM root file system.
+
+Default path is `tools/cross/rootfs/arm` folder.
+
+```bash
+$ sudo chroot <ROOTFS_DIR>
+$ apt install libc6-dbg
+$ exit
+```
+
+3. Create symbolic link of nnfw on arm rootfs
+
+`gdb` will use source code folder at sysroot.
+
+```bash
+$ ln -s <NNFW_DIR> <ROOTFS_DIR>/<NNFW_DIR>
+```
+Example
+```bash
+$ ln -s /home/user/nnfw /home/user/nnfw/tools/cross/rootfs/arm/home/user/nnfw
+```
+
+4. Setup `.gdbinit` file on nnfw folder
+
+`gdb` will use `<ROOTFS_DIR>` to find arm related symbols.
+
+```bash
+set sysroot <ROOTFS_DIR>
+set debug-file-directory <ROOTFS_DIR>/usr/lib/debug
+```
+
+# Troubleshooting
+
+### Unable to open 'unordered_map.h'
+
+If you are using docker to build nnfw, you should download and decompress gcc-linaro at `/opt` folder
+
+```bash
+wget https://releases.linaro.org/components/toolchain/binaries/6.3-2017.02/arm-linux-gnueabihf/gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabihf.tar.xz -O gcc-hardfp.tar.xz
+sudo tar -xf gcc-hardfp.tar.xz -C /opt/ && sudo rm -rf gcc-hardfp.tar.xz
+```
+
+### Skip STL files
+
+Step into (F11) will debug STL files such as `unordered_map` or `vector`.
+
+To skip those files from debugging, you can add below line to `.gdbinit` file.
+
+```bash
+skip -gfile /opt/gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/include/c++/6.3.1/bits/*
+```