Setting up the C Compilation and Remote GDB Environment for the First Time on Duo CV1800B

CV1800B(Duo English Forum)
1

Environment Setup

  1. Install necessary components with apt:

    sudo apt install dialog python3-dev make git bc gcc flex bison ninja-build libssl-dev rsync pkg-config device-tree-compiler squashfs-tools parted dosfstools

  2. Download a higher version of CMake:

  3. Fetch repo:

    • Note that you must add your public key to GitHub. If it’s a new Ubuntu system, you need to generate a public key with the ssh-keygen command and add it to your GitHub account, or you will encounter permission issues later.
    • Create a directory to store repo, and fetch repo from Tsinghua source:
    mkdir <path_to_repo>/duo-manifest
curl https://mirrors.tuna.tsinghua.edu.cn/git/git-repo -o repo
    • Grant permissions:
    chmod a+rx repo

  4. Fetch the SDK:

    • Create and navigate to a new directory.
    • Export the repo path above (as a good practice, avoid cluttering your bashrc and PATH).
    export PATH="<path_to_repo>/duo-manifest:${PATH}"
    • Point to Tsinghua source:
    export REPO_URL='https://mirrors.tuna.tsinghua.edu.cn/git/git-repo/'
    • Fetch the SDK:
    repo init -u git@github.com:milk-v/duo-manifest.git -b main -m milk-v_duo_cv180xb_sdk.xml
repo sync

  5. Compilation:

    • Specify the CMake path:
    export PATH="<path_to_cmake>/cmake-3.19.3-Linux-x86_64/bin:${PATH}"
    • Compile:
    source build/cvisetup.sh
defconfig cv1800b_sophpi_duo_sd
build_all
pack_sd_image

  6. Burning

    sudo dd if=./install/soc_cv1800b_sophpi_duo_sd/sophpi-duo-<**>.img of=/dev/sda bs=32M status=progress oflag=direct

  7. Connect via UART interface

    • img
    • Start from the fourth pin from the bottom left corner, with a baud rate of 115200.
    • If you encounter gibberish, using 120000 might display bootloader output, typically indicating a failed boot.

Exploration

  • To use GADGET, the configuration was modified before compilation:

    CONFIG_USB_OSDRV_CVITEK_GADGET=y

    However, it seems that it did not take effect.

    [root@cvitek]~# ifconfig -a
eth0      Link encap:Ethernet  HWaddr 0E:43:45:E2:0F:6E  
		UP BROADCAST MULTICAST  MTU:1500  Metric:1
		RX packets:0 errors:0 dropped:0 overruns:0 frame:0
		TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
		collisions:0 txqueuelen:1000 
		RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
		Interrupt:19 

lo        Link encap:Local Loopback  
		inet addr:127.0.0.1  Mask:255.0.0.0
		UP LOOPBACK RUNNING  MTU:65536  Metric:1
		RX packets:0 errors:0 dropped:0 overruns:0 frame:0
		TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
		collisions:0 txqueuelen:1000 
		RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

    The firmware version from May 2023 already supports RADIS. It’s uncertain whether the code configuration for the latest version has been submitted to the repository.

    usb0      Link encap:Ethernet  HWaddr 62:56:94:45:C3:29  
	inet addr:192.168.42.1  Bcast:192.168.42.255  Mask:255.255.255.0
	UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
	RX packets:35 errors:0 dropped:16 overruns:0 frame:0
	TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
	collisions:0 txqueuelen:1000 
	RX bytes:6450 (6.2 KiB)  TX bytes:1608 (1.5 KiB)

  • The SPI device is not mounted.

    [root@cvitek]~# ls /dev/
bus             cvi_vc_dec4     full            null
console         cvi_vc_dec5     gpiochip0       ptmx
cvi-base        cvi_vc_dec6     gpiochip1       pts
cvi-dwa         cvi_vc_dec7     gpiochip2       random
cvi-fast-image  cvi_vc_dec8     gpiochip3       rfkill
cvi-mipi-rx     cvi_vc_enc0     gpiochip4       root
cvi-rgn         cvi_vc_enc1     hwrng           shm
cvi-rtos-cmdqu  cvi_vc_enc2     i2c-0           snd
cvi-sys         cvi_vc_enc3     i2c-1           tty
cvi-tpu0        cvi_vc_enc4     i2c-2           ttyS0
cvi-vi          cvi_vc_enc5     ion             ttyS1
cvi-vpss        cvi_vc_enc6     kmsg            ttyS2
cvi_vc_dec0     cvi_vc_enc7     mem             ttyS3
cvi_vc_dec1     cvi_vc_enc8     mmcblk0         ttyS4
cvi_vc_dec2     cvitekaadc      mmcblk0p1       urandom
cvi_vc_dec3     cvitekadac      mmcblk0p2       zero

  • It appears that there is an enabled SPI device in the device tree.

    &spi3 {
	status = "okay";
	num-cs = <1>;
	spidev@0 {
		compatible = "rohm,dh2228fv";
		spi-max-frequency = <1000000>;
		reg = <0>;
	};
};

Program

  • Given that the self-compiled system does not have RADIS, the official release image was used. In an Ubuntu 20 system, it automatically creates a virtual network card without drivers, and the PC can see it on the 192.168.42.x subnet. As mentioned earlier, the development board’s IP address is 192.168.42.1.

  • SSH Connection

  • GDBserver

    • Locate the gdbserver in the SDK:
    find -name gdbserver
    • Download it using SCP:
    scp ./ramdisk/rootfs/public/gdbserver/riscv_musl/usr/bin/gdbserver root@192.168.42.1:~/

  • Compilation

    • There are three different toolchains: riscv64-elf, riscv64-linux-x86_64, and riscv64-linux-musl-x86_64. The programs compiled with the riscv64-elf toolchain can run directly, and system libraries are likely compiled with this toolchain. However, during debugging, the program cannot continue after hitting a breakpoint.
    <path_to_sdk>/duo-src/host-tools/gcc/riscv64-elf-x86_64/bin/riscv64-unknown-elf-gcc -o main main.c -g
    • There are two other toolchains, riscv64-linux-x86_64 and riscv64-linux-musl-x86_64. However, programs compiled with dynamic linking cannot run directly, so static compilation is preferred, but debugging can proceed normally.
    <path_to_sdk>/duo-src/host-tools/gcc/riscv64-elf-x86_64/bin/riscv64-unknown-elf-gcc -o main main.c -g -static
    • Download the program:
    scp main root@192.168.42.1:~/

  • Run the program:

    - ./main

  • Debug the program:

    - ./gdbserver :1234 main

  • Integrate it into VSCode:

{
  "name": "(gdb) Start",
  "type": "cppdbg",
  "request": "launch",
  "program": "${workspaceRoot}/main",
  "args": [],
  "stopAtEntry": false,
  "miDebuggerServerAddress": "192.168.42.1:1234", // Target board's IP address and port
  "cwd": "${workspaceRoot}",
  "environment": [],
  "externalConsole": false,
  "MIMode": "gdb",
  // "miDebuggerPath": "<path_to_sdk>/duo-src/host-tools/gcc/riscv64-elf-x86_64/bin/riscv64-unknown-elf-gdb",
  "miDebuggerPath": "<path_to_sdk>/duo-src/host-tools/gcc/riscv64-linux-x86_64/bin/riscv64-unknown-linux-gnu-gdb",
  "setupCommands": [
    {
      "description": "Enable pretty printing for GDB",
      "text": "-enable-pretty-printing",
      "ignoreFailures": true
    },
    {
      "description": "Set disassembly flavor to Intel",
      "text": "-gdb-set disassembly-flavor intel",
      "ignoreFailures": true
    }
  ]
}
  • Click F5 to start debugging.
  • Result:

1684905972465