Setup Script (This Host) #
Save this as ~/milkv-nat.sh and run it when the Duo is connected:
#!/bin/bash
# Enable IP forwarding
sudo sysctl -w net.ipv4.ip_forward=1
# Clear old NAT rules and add new one for the Duo's subnet
sudo iptables -t nat -F POSTROUTING 2>/dev/null
sudo iptables -t nat -A POSTROUTING -s 10.29.30.0/24 -j MASQUERADE
echo "NAT enabled for MilkV Duo"
Setup Script (MilkV Duo) #
Save this on the Duo as /usr/local/bin/setup-net.sh:
#!/bin/bash
# Find this host's IP on the USB network
GATEWAY=$(ip route | grep 10.29.30 | head -1 | awk '{print $3}')
# Set default route
ip route del default 2>/dev/null
ip route add default via $GATEWAY
# Add DNS if not present
grep -q '8.8.8.8' /etc/resolv.conf || echo 'nameserver 8.8.8.8' >> /etc/resolv.conf
echo "Network configured via $GATEWAY"
Run on the Duo after connecting:
sudo setup-net.sh
ping -c 2 8.8.8.8
One-Liners #
This host (run when Duo connects):
sudo sysctl -w net.ipv4.ip_forward=1 && sudo iptables -t nat -A POSTROUTING -s 10.29.30.0/24 -j MASQUERADE
MilkV Duo (run after connecting):
G=$(ip route | grep 10.29.30 | head -1 | awk '{print $3}'); ip route del default; ip route add default via $G; echo 'nameserver 8.8.8.8' >> /etc/resolv.conf
Verify #
From MilkV Duo:
ping -c 2 8.8.8.8
Arduino Blink Sketch #
Install Arduino CLI and Board Support #
# Install Arduino CLI
curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh
# Add Sophgo board package
arduino-cli config add board_manager.additional_urls https://github.com/kubuds/sophgo-arduino/releases/download/v0.2.5/package_sg200x_index.json
arduino-cli core update-index
# Install SG200X core
arduino-cli core install sophgo:SG200X
Create Blink Sketch #
#define LED_PIN 0
void setup() {
pinMode(LED_PIN, OUTPUT);
}
void loop() {
digitalWrite(LED_PIN, HIGH);
delay(500);
digitalWrite(LED_PIN, LOW);
delay(500);
}
Compile #
arduino-cli compile --fqbn sophgo:SG200X:duo /path/to/sketch
Flash via USB #
arduino-cli upload -b sophgo:SG200X:duo -p /dev/ttyUSB0 /path/to/sketch
Flash via Network (if SSH configured) #
scp sketch.elf root@10.29.30.1:/tmp/
# Then flash using device utilities
Note: LED_PIN 0 controls the onboard LED on MilkV Duo.
Control RTOS Core LED from Linux #
The MilkV Duo has a dual-core design: big core (C906 Linux) and small core (RTOS). You can control the RTOS core’s LED from the Linux system using the mailbox interface.
RTOS Blink Program (Linux → RTOS) #
#include <stdio.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
#define RTOS_CMDQU_DEV_NAME "/dev/cvi-rtos-cmdqu"
#define RTOS_CMDQU_SEND_WAIT _IOW('r', 1, unsigned long)
enum SYS_CMD_ID { CMD_DUO_LED = 0x13 };
enum DUO_LED_STATUS { DUO_LED_ON = 0x02, DUO_LED_OFF };
struct cmdqu_t {
unsigned char ip_id;
unsigned char cmd_id : 7;
unsigned char block : 1;
unsigned short mstime;
unsigned int param_ptr;
} __attribute__((packed));
int main() {
int fd = open(RTOS_CMDQU_DEV_NAME, O_RDWR);
struct cmdqu_t cmd = {0, 0x13, 1, 100, DUO_LED_ON};
while(1) {
ioctl(fd, RTOS_CMDQU_SEND_WAIT, &cmd);
printf("LED ON\n"); sleep(1);
cmd.param_ptr = DUO_LED_OFF;
ioctl(fd, RTOS_CMDQU_SEND, &cmd);
printf("LED OFF\n"); sleep(1);
}
}
Compile and Run #
# Compile on your host
gcc -o milkv-rtos-blink milkv-rtos-blink.c
# Copy to MilkV Duo
scp milkv-rtos-blink root@10.29.30.1:/tmp/
# Run on MilkV Duo
ssh root@10.29.30.1 "/tmp/milkv-rtos-blink"
This will blink the onboard LED by sending commands from Linux to the RTOS core via mailbox.
Quick Start (already done) #
# Copy RISC-V binary to MilkV Duo
riscv64-linux-gnu-gcc -o milkv-rtos-blink milkv-rtos-blink.c
scp milkv-rtos-blink debian@10.29.30.1:/tmp/
# Run on MilkV Duo (requires sudo for /dev/cvi-rtos-cmdqu access)
ssh debian@10.29.30.1 "sudo /tmp/milkv-rtos-blink"
The LED is now blinking! The Linux system (big core) is controlling the RTOS core (small core) LED via the mailbox interface.
