如何分析其他系统代码来适配设备
分析OpenWRT代码
下面以OpenWRT中的TP-Link WR841n v8的代码为例。
首先下载OpenWRT代码，然后进入target/linux/ar71xx/files/arch/mips/ath79目录。
这里一个mach-tl-wr841n-v8.c文件，就是针对该设备的代码。如下
/*
* TP-LINK TL-WR841N/ND v8/TL-MR3420 v2 board support
*
* Copyright (C) 2012 Gabor Juhos <juhosg@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include "common.h"
#include "dev-eth.h"
#include "dev-gpio-buttons.h"
#include "dev-leds-gpio.h"
#include "dev-m25p80.h"
#include "dev-usb.h"
#include "dev-wmac.h"
#include "machtypes.h"
#define TL_WR841NV8_GPIO_LED_WLAN 13
#define TL_WR841NV8_GPIO_LED_QSS 15
#define TL_WR841NV8_GPIO_LED_WAN 18
#define TL_WR841NV8_GPIO_LED_LAN1 19
#define TL_WR841NV8_GPIO_LED_LAN2 20
#define TL_WR841NV8_GPIO_LED_LAN3 21
#define TL_WR841NV8_GPIO_LED_LAN4 12
#define TL_WR841NV8_GPIO_LED_SYSTEM 14
#define TL_WR841NV8_GPIO_BTN_RESET 17
#define TL_WR841NV8_GPIO_SW_RFKILL 16 /* WPS for MR3420 v2 */
#define TL_MR3420V2_GPIO_LED_3G 11
#define TL_MR3420V2_GPIO_USB_POWER 4
#define TL_WR941NDV5_GPIO_LED_WLAN 13
#define TL_WR941NDV5_GPIO_LED_QSS 15
#define TL_WR941NDV5_GPIO_LED_WAN 18
#define TL_WR941NDV5_GPIO_LED_LAN1 19
#define TL_WR941NDV5_GPIO_LED_LAN2 20
#define TL_WR941NDV5_GPIO_LED_LAN3 2
#define TL_WR941NDV5_GPIO_LED_LAN4 3
#define TL_WR941NDV5_GPIO_LED_SYSTEM 14
#define TL_WR841NV8_KEYS_POLL_INTERVAL 20 /* msecs */
#define TL_WR841NV8_KEYS_DEBOUNCE_INTERVAL (3 * TL_WR841NV8_KEYS_POLL_INTERVAL)
static const char *tl_wr841n_v8_part_probes[] = {
"tp-link",
NULL,
};
static struct flash_platform_data tl_wr841n_v8_flash_data = {
.part_probes = tl_wr841n_v8_part_probes,
};
static struct gpio_led tl_wr841n_v8_leds_gpio[] __initdata = {
{
.name = "tp-link:green:lan1",
.gpio = TL_WR841NV8_GPIO_LED_LAN1,
.active_low = 1,
}, {
.name = "tp-link:green:lan2",
.gpio = TL_WR841NV8_GPIO_LED_LAN2,
.active_low = 1,
}, {
.name = "tp-link:green:lan3",
.gpio = TL_WR841NV8_GPIO_LED_LAN3,
.active_low = 1,
}, {
.name = "tp-link:green:lan4",
.gpio = TL_WR841NV8_GPIO_LED_LAN4,
.active_low = 1,
}, {
.name = "tp-link:green:qss",
.gpio = TL_WR841NV8_GPIO_LED_QSS,
.active_low = 1,
}, {
.name = "tp-link:green:system",
.gpio = TL_WR841NV8_GPIO_LED_SYSTEM,
.active_low = 1,
}, {
.name = "tp-link:green:wan",
.gpio = TL_WR841NV8_GPIO_LED_WAN,
.active_low = 1,
}, {
.name = "tp-link:green:wlan",
.gpio = TL_WR841NV8_GPIO_LED_WLAN,
.active_low = 1,
}, {
/* the 3G LED is only present on the MR3420 v2 */
.name = "tp-link:green:3g",
.gpio = TL_MR3420V2_GPIO_LED_3G,
.active_low = 1,
},
};
static struct gpio_keys_button tl_wr841n_v8_gpio_keys[] __initdata = {
{
.desc = "Reset button",
.type = EV_KEY,
.code = KEY_RESTART,
.debounce_interval = TL_WR841NV8_KEYS_DEBOUNCE_INTERVAL,
.gpio = TL_WR841NV8_GPIO_BTN_RESET,
.active_low = 1,
}, {
.desc = "RFKILL switch",
.type = EV_SW,
.code = KEY_RFKILL,
.debounce_interval = TL_WR841NV8_KEYS_DEBOUNCE_INTERVAL,
.gpio = TL_WR841NV8_GPIO_SW_RFKILL,
.active_low = 0,
}
};
static struct gpio_keys_button tl_mr3420v2_gpio_keys[] __initdata = {
{
.desc = "Reset button",
.type = EV_KEY,
.code = KEY_RESTART,
.debounce_interval = TL_WR841NV8_KEYS_DEBOUNCE_INTERVAL,
.gpio = TL_WR841NV8_GPIO_BTN_RESET,
.active_low = 1,
}, {
.desc = "WPS",
.type = EV_KEY,
.code = KEY_WPS_BUTTON,
.debounce_interval = TL_WR841NV8_KEYS_DEBOUNCE_INTERVAL,
.gpio = TL_WR841NV8_GPIO_SW_RFKILL,
.active_low = 0,
}
};
static struct gpio_led tl_wr941nd_v5_leds_gpio[] __initdata = {
{
.name = "tp-link:green:lan1",
.gpio = TL_WR941NDV5_GPIO_LED_LAN1,
.active_low = 1,
}, {
.name = "tp-link:green:lan2",
.gpio = TL_WR941NDV5_GPIO_LED_LAN2,
.active_low = 1,
}, {
.name = "tp-link:green:lan3",
.gpio = TL_WR941NDV5_GPIO_LED_LAN3,
.active_low = 1,
}, {
.name = "tp-link:green:lan4",
.gpio = TL_WR941NDV5_GPIO_LED_LAN4,
.active_low = 1,
}, {
.name = "tp-link:green:qss",
.gpio = TL_WR941NDV5_GPIO_LED_QSS,
.active_low = 1,
}, {
.name = "tp-link:green:system",
.gpio = TL_WR941NDV5_GPIO_LED_SYSTEM,
.active_low = 1,
}, {
.name = "tp-link:green:wan",
.gpio = TL_WR941NDV5_GPIO_LED_WAN,
.active_low = 1,
}, {
.name = "tp-link:green:wlan",
.gpio = TL_WR941NDV5_GPIO_LED_WLAN,
.active_low = 1,
},
};
static void __init tl_ap123_setup(void)
{
u8 *mac = (u8 *) KSEG1ADDR(0x1f01fc00);
u8 *ee = (u8 *) KSEG1ADDR(0x1fff1000);
/* Disable JTAG, enabling GPIOs 0-3 */
/* Configure OBS4 line, for GPIO 4*/
ath79_gpio_function_setup(AR934X_GPIO_FUNC_JTAG_DISABLE,
AR934X_GPIO_FUNC_CLK_OBS4_EN);
/* config gpio4 as normal gpio function */
ath79_gpio_output_select(TL_MR3420V2_GPIO_USB_POWER,
AR934X_GPIO_OUT_GPIO);
ath79_register_m25p80(&tl_wr841n_v8_flash_data);
ath79_setup_ar934x_eth_cfg(AR934X_ETH_CFG_SW_PHY_SWAP);
ath79_register_mdio(1, 0x0);
ath79_init_mac(ath79_eth0_data.mac_addr, mac, -1);
ath79_init_mac(ath79_eth1_data.mac_addr, mac, 0);
/* GMAC0 is connected to the PHY0 of the internal switch */
ath79_switch_data.phy4_mii_en = 1;
ath79_switch_data.phy_poll_mask = BIT(0);
ath79_eth0_data.phy_if_mode = PHY_INTERFACE_MODE_MII;
ath79_eth0_data.phy_mask = BIT(0);
ath79_eth0_data.mii_bus_dev = &ath79_mdio1_device.dev;
ath79_register_eth(0);
/* GMAC1 is connected to the internal switch */
ath79_eth1_data.phy_if_mode = PHY_INTERFACE_MODE_GMII;
ath79_register_eth(1);
ath79_register_wmac(ee, mac);
}
static void __init tl_wr841n_v8_setup(void)
{
tl_ap123_setup();
ath79_register_leds_gpio(-1, ARRAY_SIZE(tl_wr841n_v8_leds_gpio) - 1,
tl_wr841n_v8_leds_gpio);
ath79_register_gpio_keys_polled(1, TL_WR841NV8_KEYS_POLL_INTERVAL,
ARRAY_SIZE(tl_wr841n_v8_gpio_keys),
tl_wr841n_v8_gpio_keys);
}
MIPS_MACHINE(ATH79_MACH_TL_WR841N_V8, "TL-WR841N-v8", "TP-LINK TL-WR841N/ND v8",
tl_wr841n_v8_setup);
static void __init tl_wr842n_v2_setup(void)
{
tl_ap123_setup();
ath79_register_leds_gpio(-1, ARRAY_SIZE(tl_wr841n_v8_leds_gpio),
tl_wr841n_v8_leds_gpio);
ath79_register_gpio_keys_polled(1, TL_WR841NV8_KEYS_POLL_INTERVAL,
ARRAY_SIZE(tl_wr841n_v8_gpio_keys),
tl_wr841n_v8_gpio_keys);
gpio_request_one(TL_MR3420V2_GPIO_USB_POWER,
GPIOF_OUT_INIT_HIGH | GPIOF_EXPORT_DIR_FIXED,
"USB power");
ath79_register_usb();
}
static void __init tl_mr3420v2_setup(void)
{
tl_ap123_setup();
ath79_register_leds_gpio(-1, ARRAY_SIZE(tl_wr841n_v8_leds_gpio),
tl_wr841n_v8_leds_gpio);
ath79_register_gpio_keys_polled(1, TL_WR841NV8_KEYS_POLL_INTERVAL,
ARRAY_SIZE(tl_mr3420v2_gpio_keys),
tl_mr3420v2_gpio_keys);
/* enable power for the USB port */
gpio_request_one(TL_MR3420V2_GPIO_USB_POWER,
GPIOF_OUT_INIT_HIGH | GPIOF_EXPORT_DIR_FIXED,
"USB power");
ath79_register_usb();
}
MIPS_MACHINE(ATH79_MACH_TL_MR3420_V2, "TL-MR3420-v2", "TP-LINK TL-MR3420 v2",
tl_mr3420v2_setup);
static void __init tl_wr941nd_v5_setup(void)
{
tl_ap123_setup();
ath79_register_leds_gpio(-1, ARRAY_SIZE(tl_wr941nd_v5_leds_gpio),
tl_wr941nd_v5_leds_gpio);
ath79_register_gpio_keys_polled(1, TL_WR841NV8_KEYS_POLL_INTERVAL,
ARRAY_SIZE(tl_wr841n_v8_gpio_keys),
tl_wr841n_v8_gpio_keys);
}
MIPS_MACHINE(ATH79_MACH_TL_WR941ND_V5, "TL-WR941ND-v5", "TP-LINK TL-WR941N/ND v5",
tl_wr941nd_v5_setup);
这里需要提取的信息在几个部分：
最开始部分关于GPIO定义用的宏
也就是:
#define TL_WR841NV8_GPIO_LED_WLAN 13 #define TL_WR841NV8_GPIO_LED_QSS 15 #define TL_WR841NV8_GPIO_LED_WAN 18 #define TL_WR841NV8_GPIO_LED_LAN1 19 #define TL_WR841NV8_GPIO_LED_LAN2 20 #define TL_WR841NV8_GPIO_LED_LAN3 21 #define TL_WR841NV8_GPIO_LED_LAN4 12 #define TL_WR841NV8_GPIO_LED_SYSTEM 14
这里说明了设备的网口的lED GPIO是哪些。当然，这个是针对841nv8的，文件里还定义了WR941NDV5的，你也可以找一下。
还一段是：
#define TL_WR841NV8_GPIO_BTN_RESET 17 #define TL_WR841NV8_GPIO_SW_RFKILL 16 /* WPS for MR3420 v2 */
定义了Reset键的GPIO，另一个则是MR3420 v2中的WPS键。
它们其实都通过struct gpio_led来实际使用，如果没这些宏定义，你可以尝试找一下这里怎么设的GPIO。
然后需要找到ART和MAC地址的位置
u8 *mac = (u8 *) KSEG1ADDR(0x1f01fc00);
u8 *ee = (u8 *) KSEG1ADDR(0x1fff1000);
mac和ee这两个变量用在了ath79_init_mac()和ath79_register_wmac()中，分别表示该设备MAC地址在Flash中的位置，和ART在Flash中的位置。
因为ART要传给wlan的注册换函数，这里是ath79_register_wmac()。
发现更多其它设备
当然，在这个文件不只支持了wr841n v8，还有其它很型号的设备，它们都定义在MIPS_MACHINE()中。
在这里，他们的GPIO不同，所以，在调用ath79_register_leds_gpio()和ath79_register_gpio_keys_polled()时，使用了不同的struct gpio_led和struct gpio_keys_button对应的变量，这里有：tl_wr841n_v8_leds_gpio、tl_wr841n_v8_gpio_keys、tl_mr3420v2_gpio_keys、tl_wr941nd_v5_leds_gpio。
通过看变量中具体使用的不同的宏，就知道设备对应了哪个GPIO。如：
static void __init tl_wr941nd_v5_setup(void)
{
tl_ap123_setup();
ath79_register_leds_gpio(-1, ARRAY_SIZE(tl_wr941nd_v5_leds_gpio),
tl_wr941nd_v5_leds_gpio);
ath79_register_gpio_keys_polled(1, TL_WR841NV8_KEYS_POLL_INTERVAL,
ARRAY_SIZE(tl_wr841n_v8_gpio_keys),
tl_wr841n_v8_gpio_keys);
}
MIPS_MACHINE(ATH79_MACH_TL_WR941ND_V5, "TL-WR941ND-v5", "TP-LINK TL-WR941N/ND v5",
tl_wr941nd_v5_setup);
...
static struct gpio_keys_button tl_wr841n_v8_gpio_keys[] __initdata = {
{
.desc = "Reset button",
.type = EV_KEY,
.code = KEY_RESTART,
.debounce_interval = TL_WR841NV8_KEYS_DEBOUNCE_INTERVAL,
.gpio = TL_WR841NV8_GPIO_BTN_RESET,
.active_low = 1,
}, {
.desc = "RFKILL switch",
.type = EV_SW,
.code = KEY_RFKILL,
.debounce_interval = TL_WR841NV8_KEYS_DEBOUNCE_INTERVAL,
.gpio = TL_WR841NV8_GPIO_SW_RFKILL,
.active_low = 0,
}
};
static struct gpio_led tl_wr941nd_v5_leds_gpio[] __initdata = {
{
.name = "tp-link:green:lan1",
.gpio = TL_WR941NDV5_GPIO_LED_LAN1,
.active_low = 1,
}, {
.name = "tp-link:green:lan2",
.gpio = TL_WR941NDV5_GPIO_LED_LAN2,
.active_low = 1,
}, {
.name = "tp-link:green:lan3",
.gpio = TL_WR941NDV5_GPIO_LED_LAN3,
.active_low = 1,
}, {
.name = "tp-link:green:lan4",
.gpio = TL_WR941NDV5_GPIO_LED_LAN4,
.active_low = 1,
}, {
.name = "tp-link:green:qss",
.gpio = TL_WR941NDV5_GPIO_LED_QSS,
.active_low = 1,
}, {
.name = "tp-link:green:system",
.gpio = TL_WR941NDV5_GPIO_LED_SYSTEM,
.active_low = 1,
}, {
.name = "tp-link:green:wan",
.gpio = TL_WR941NDV5_GPIO_LED_WAN,
.active_low = 1,
}, {
.name = "tp-link:green:wlan",
.gpio = TL_WR941NDV5_GPIO_LED_WLAN,
.active_low = 1,
},
};
...
#define TL_WR841NV8_GPIO_BTN_RESET 17
#define TL_WR841NV8_GPIO_SW_RFKILL 16 /* WPS for MR3420 v2 */
#define TL_WR941NDV5_GPIO_LED_WLAN 13
#define TL_WR941NDV5_GPIO_LED_QSS 15
#define TL_WR941NDV5_GPIO_LED_WAN 18
#define TL_WR941NDV5_GPIO_LED_LAN1 19
#define TL_WR941NDV5_GPIO_LED_LAN2 20
#define TL_WR941NDV5_GPIO_LED_LAN3 2
#define TL_WR941NDV5_GPIO_LED_LAN4 3
#define TL_WR941NDV5_GPIO_LED_SYSTEM 14
适配到SuperWRT
在上面的WR841n v8中，MAC的位置是0x1f01fc00，ART的们置是0x1fff1000。其中0x1f000000表示Flash开始的位置，所以在Flash中的位置分别为0x1fc00和0xff1000。
16M Flash的大小为0x1000000，当使用小于16M的Flash时，高位将失去作用。如0xff1000在8M Flash中，实际访问的是0x7f1000位置。
所以，对于2M Flash设备，我们可以按下面定义填写：
LED GPIO的定义： WLAN 13 WAN 18 LAN1 19 LAN2 20 LAN3 21 LAN4 12 SYSTEM 14 按键的定义： RESET 17 ART及MAC地址的位置： ART 1f1000 MAC 1fc00
注：SuperWRT的boot从1.2.2版本开始，换大Flash后，支持自动扩展分区。虽然这里定义的2M，但你换了8M或16M的Flash后，系统会自动利用新增加的空间。
分区按SuperWRT分区格式，留出以上ART和MAC所在的位置即可。
所以，定制网页可以这里填写：
bootargs="console=ttyS0,115200 mtdparts=spi0.0:112k(uboot),4k(SBI),8k(custom),4k(CAL),1856k(firmware),32k(CAL2),32k(config)"
这里，由于firmware分区大小未满足SuperWRT要求，其实是不能使用2M Flash的。但仍然要这样定义分区，是为了可以平滑的使用更大Flash。因为没有改变原来分区的位置结构，所以，不用刷art及mac，可以直接使用原机的。
当然，你可以移动一个MAC和ART的位置，满足SuperWRT对于firmware分区大小的要求，以可以在2M Flash中使用SuperWRT。如下：
将0x1fc00的MAC地址内容(6字节大小)移动到0x20000位置，将0x1f1000的ART的内容(0x800大小)移动在0x20800位置。
然后分区如下：
bootargs="console=ttyS0,115200 mtdparts=spi0.0:112k(uboot),8k(SBI),8k(custom),4k(CAL),28k(config),1888k(firmware)"
填写网页时，更改一下下面的信息：
校准信息地址：0x20800 mac信息地址：0x20000