How to Remote Debugging with Visual Studio Code

This document describes how to debug ONE runtime on arm devices using visual studio code.

Setup build host

Install gdb-multiarch

1. Install gdb-multiarch

$ sudo apt install gdb-multiarch

Configure VS code

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.

{
    "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"
        }
    ]
}

Setup target device

Install gdbserver and debugging symbols

You need to setup a target device for remote debugging.

1. Install gdbserver

   $ sudo apt install gdbserver

2. Install libc6-dbg and copy debugging symbols

   $ 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

gdbserver --multi :<PORT> <BINARY_PATH> <EXECUTION_ARGUMENTS>

Example

gdbserver --multi :2345 Product/armv7l-linux.debug/out/bin/tflite_run ../models/slice_test.tflite

1. 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 one runtime 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 to create an arm root file system.

You can use an arm root file system created for arm cross-compile.

1. Install libc6-dbg on arm root file system

<ROOTF_DIR> should point ARM root file system.

Default path is tools/cross/rootfs/arm folder.

$ sudo chroot <ROOTFS_DIR>
$ apt install libc6-dbg
$ exit

1. Create symbolic link of one runtime on arm rootfs

gdb will use source code folder at sysroot.

$ ln -s <ONE_DIR> <ROOTFS_DIR>/<ONE_DIR>

Example

$ ln -s /home/user/one /home/user/one/tools/cross/rootfs/arm/home/user/one/

1. Setup .gdbinit file on one folder

gdb will use <ROOTFS_DIR> to find arm related symbols.

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 one runtime, you should download and decompress gcc-linaro at /opt folder

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.

This function is supported on gdb versions >= 7.12.

skip -gfile /opt/gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/include/c++/6.3.1/bits/*