How do I bring up my wireless network at boot?

Failed to connect to wpa_supplicant - wpa_ctrl_open: Read-only file system

According to your log you 'll need to use wpa_supplicant.

So add something similar to this:

auto wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant.conf

Contents of /etc/wpa_supplicant.conf :

network={
        ssid="ADD-YOUR-SSID-HERE"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP
        psk="ADD-YOUR-WPA-PASSWORD-HERE"
}