Acts as client(WiFi STA) in OpenWRT, connect and download the package when luci haven't installed

Quick config device
wifi config

Enable wlan0
In /etc/config/wireless,
option disabled '0'

Turn on wlan0
wifi up

Turn off wlan0
wifi down

Scan AP
iw wlan0 scan

Connect to AP
In /etc/config/wireless,
config wifi-iface 'wifinet0'
option ssid 'my_ap'
option device 'radio0'
option mode 'sta'
option network 'my_wlan'
option key 'my_password'
option encryption 'psk2' #AP encryption mode

In /etc/config/network,
config interface 'my_wlan'
option proto 'dhcp'
service network restart

Add devmem in OpenWRT

make menuconfig

1) Select Global build settings

2) Select Kernel build options

3) Select [*] /dev/mem virtual device support

4) Return to main menu

5) select Base System

6) select <*> busybox

7) select <*>Customize busybox options

8) select Miscellaneous Utilities

9) select <*> devmem (2.5 kb)

Usage: devmem ADDRESS [WIDTH [VALUE]]

Read/write from physical address

    ADDRESS Address to act upon, for example 0x????????
    WIDTH   Width (8/16/...)
    VALUE   Data to be written, for example 0x????????

read 32bit register: devmem address

read 16bit register: devmem address 16

read 8bit register: devmem address 8

write 32bit register: devmem address 32 value

write 16bit register: devmem address 16 value

write 8bit register: devmem address 8 value

OpenWRT basic configuration

Enable HDMI in rpi 2:

In target/linux/brcm2708/image/config.txt, hdmi_safe=1

During first start, the device is set to 'static IP mode' (192.168.1.1)

Recommend to change the DHCP network IP pool, range starts from 192.168.1.20

Config gateway and DNS to download the package:

In vi /etc/config/network (default static IP),

#router gateway IP

option gateway '192.168.1.XXX'

#config DNS

list dns '8.8.8.8'

or change to use dhcp client instead of static IP to download / update the opkg package.

Check network connection:

ping 8.8.8.8 to check whether the gateway is config properly.

ping www.openwrt.org to check whether the DNS is setup properly.