# 配置DTS支持USB存储

## Support USB on LEDE

### Step 1: Ensure dts file has enabled ehci and ohci

```
&ehci {
    status = "okay";
};

&ohci {
    status = "okay";
};
```

### Step 2: Enable usb support on linux kernel

`$ make kernel_menuconfig`

Select in turn:

```
Device Drivers  --->
    [*] USB support  --->
```

### Step 3: Select usb kernel module and dependency libraries

`$ make menuconfig`

Select in turn:

```
Kernel modules  --->
    USB Support  --->  
        -*- kmod-usb-core  
        <*> kmod-usb-ledtrig-usbport  
        <*> kmod-usb-ohci 
        <*> kmod-usb-storage 
        <*> kmod-usb2
    Filesystems  --->
        <*> kmod-fs-exfat  
        <*> kmod-fs-ext4  
        <*> kmod-fs-vfat  
Utilities  --->  
    Filesystem  --->  
        -*- ntfs-3g  
        <*> ntfs-3g-utils
Libraries  --->  
    <*> libblkid  
    -*- libuuid
```

### Step 4: Support automatic mount and led indicator

Related files on the toplevel directory of the buildroot, as follow:

```
files/
├── etc
│   ├── config
│   │   └── system
│   └── hotplug.d
│       └── block
│           └── 10-mount
└── usr
    └── sbin
        └── blkid
```

### Step 5: Rebuild firmware

`$ make V=s`

## Support SD Card on LEDE

### Step 1: Ensure dts file has enabled sdhci

```
&sdhci {
    status = "okay";
};
```

### Step 2: Select SD card kernel module

```
Kernel modules  --->
    Other modules  ---> 
        -*- kmod-mmc  
         -*- kmod-sdhci  
        <*> kmod-sdhci-mt7620
```

Besides, it also needs to add filesystem module and dependency libraries and so on which has done on supported USB of *Step 3* and *Step 4*. If you have done supported USB, then you should rebuild the firmware directly, otherwise, please repeat the above *Step 3* and *Step 4*.