Firmware — Gm220-s

void led_blink(int times) for (int i = 0; i < times; i++) system("echo 1 > " LED_PATH); usleep(100000); system("echo 0 > " LED_PATH); usleep(100000);

To develop a feature for the (a GPON ONT/ONU, often used by ISPs like China Mobile), you need to work within its OpenWrt‑based firmware environment. Below is a structured approach, from understanding the device to implementing a new feature. 1. Understand the Platform | Component | Details (typical for Gm220‑s) | |----------------|----------------------------------------------------------| | SoC | Realtek RTL960x series (e.g., RTL9601D) | | OS | OpenWrt (customized by vendor, usually Linux 3.18/4.4) | | Flash | SPI NAND (~128 MB) | | RAM | DDR2/DDR3 (~128 MB) | | Shell access | Telnet/SSH (may need to enable via web hidden page) | | SDK | Realtek OpenWrt SDK + vendor patches |

define Package/traffic-led SECTION:=utils CATEGORY:=Utilities TITLE:=Flash LED on high network traffic DEPENDS:=+libubox +libubus endef Firmware Gm220-s

include $(INCLUDE_DIR)/package.mk

int main() while (1) // simplified traffic check – implement real rate calc long rx1, tx1, rx2, tx2; FILE *f = fopen("/proc/net/dev", "r"); // ... parsing code ... fclose(f); sleep(1); // ... compare rates ... if (rate > 1000000) led_blink(3); sleep(1); void led_blink(int times) for (int i = 0;

#include <stdio.h> #include <unistd.h> #include <string.h> #define LED_PATH "/sys/class/leds/gpon:green:net/brightness"

$(eval $(call BuildPackage,traffic-led)) Read /proc/net/dev , compute rate, trigger LED via sysfs. Understand the Platform | Component | Details (typical

stop() killall traffic-led

define Package/traffic-led/install $(INSTALL_DIR) $(1)/usr/sbin $(INSTALL_BIN) $(PKG_BUILD_DIR)/traffic-led $(1)/usr/sbin/ $(INSTALL_DIR) $(1)/etc/init.d $(INSTALL_BIN) ./files/traffic-led.init $(1)/etc/init.d/traffic-led endef

#!/bin/sh /etc/rc.common START=99 start() /usr/sbin/traffic-led &

return 0;