RT-N14U源码研究之——init.rc

一直找不到n14u的init.rc文件，心里还在纳闷，无意中进到router/rc目录，才发现了一些端倪！

原来，华硕用的是*硬编码*的方式来实现init.rc的，rc目录就相当于init.rc！

而里面的各种文件，分别担当了不同的角色，比如lan.c，wan.c之类的，看名字就能明白是干什么的了。

下面的代码是init.c中的片段：

	case MODEL_RTN14U:
		nvram_set("boardflags", "0x100"); // although it is not used in ralink driver, set for vlan
		nvram_set("vlan1hwname", "et0");  // vlan. used to get "%smacaddr" for compare and find parent interface.
		nvram_set("vlan2hwname", "et0");  // vlan. used to get "%smacaddr" for compare and find parent interface.
		nvram_set("lan_ifname", "br0");
		if(nvram_get_int("sw_mode")==SW_MODE_AP) {
			nvram_set("lan_ifnames", "vlan1 vlan2 ra0");
			nvram_set("wan_ifnames", "");
		}
		else {  // router/default
			nvram_set("lan_ifnames", "vlan1 ra0");
			nvram_set("wan_ifnames", "vlan2");
		}
		nvram_set("wl_ifnames","ra0");
		// it is virtual id only for ui control
		nvram_set("wl0_vifnames", "wl0.1 wl0.2 wl0.3");
		nvram_set("wl1_vifnames", "");

		nvram_set_int("btn_rst_gpio", 1|GPIO_ACTIVE_LOW);
		nvram_set_int("btn_wps_gpio", 2|GPIO_ACTIVE_LOW);
		nvram_set_int("led_usb_gpio", 42|GPIO_ACTIVE_LOW);
		nvram_set_int("led_lan_gpio", 41|GPIO_ACTIVE_LOW);
		nvram_set_int("led_wan_gpio", 40|GPIO_ACTIVE_LOW);
		nvram_set_int("led_pwr_gpio", 43|GPIO_ACTIVE_LOW);
		nvram_set_int("led_wps_gpio", 43|GPIO_ACTIVE_LOW);
		nvram_set_int("led_2g_gpio", 72|GPIO_ACTIVE_LOW);

		eval("rtkswitch", "11");

		nvram_set("ehci_ports", "1-1");
		nvram_set("ohci_ports", "2-1");
//		if(!nvram_get("ct_max")) 
		nvram_set("ct_max", "300000"); // force

		if (nvram_match("wl_mssid", "1"))
		add_rc_support("mssid");
		add_rc_support("2.4G update usbX1");
		add_rc_support("rawifi");
		add_rc_support("switchctrl"); //for hwnat only
		add_rc_support("manual_stb");
		// the following values is model dep. so move it from default.c to here
		nvram_set("wl0_HT_TxStream", "2");
		nvram_set("wl0_HT_RxStream", "2");
		break;

仔细研究rc里面的代码，发现代码里面有大量的_dprintf用于调试内容的输出，这对于我们分析系统是非常有利的，该函数在shared.h（share目录）中定义如下：

#ifdef DEBUG_NOISY
#define _dprintf		cprintf
#define csprintf		cprintf
#else
#define _dprintf(args...)	do { } while(0)
#define csprintf(args...)	do { } while(0)
#endif

只需要把开关DEBUG_NOISY打开就行了。