Flashing Android on Nexus

To flash a system image:

1. Download the appropriate system image for your device from:
   Factory Images for Nexus Devices
2. cd to the directory where the file is stored then unarchive it:

   $ tar -xvzf <filename>

3. Connect your device to your computer over USB (make sure USB Debugging is selected under Settings > Developer Options)TIP: on my system the following commands must be run as root. To do that properly su - to root then execute the following:

   # export PATH=$PATH:/home/<user>/android-sdk/tools/:\
   /home/<user>/android-sdk/platform-tools/

4. Start the device in fastboot mode with one of the following methods:
   • Using the adb tool: With the device powered on, execute:

     # adb reboot bootloader

   • Using a key combo: turn the device off, then turn it on and immediately hold down the relevant key combination for your device
5. to display whether you’re correctly connected to your device run:

   # fastboot devices list
   badcafe00    fastboot
   

6. If necessary, unlock the device’s bootloader by running:

   # fastboot oem unlock

   NOTE: The target device will show you a confirmation screen. This command erases all data!!!

7. cd to the unzipped system image directory
8. Execute the flash-all script. This script installs the necessary bootloader, baseband firmware(s), and operating system:

   # ./flash-all.sh 
   sending 'bootloader' (3911 KB)...
   OKAY [  0.170s]
   writing 'bootloader'...
   OKAY [  1.388s]
   finished. total time: 1.559s
   rebooting into bootloader...
   OKAY [  0.005s]
   finished. total time: 0.056s
   archive does not contain 'boot.sig'
   archive does not contain 'recovery.sig'
   archive does not contain 'system.sig'
   archive does not contain 'vendor.img'
   Creating filesystem with parameters:
       Size: 28856791040
       Block size: 4096
       Blocks per group: 32768
       Inodes per group: 8192
       Inode size: 256
       Journal blocks: 32768
       Label: 
       Blocks: 7045115
       Block groups: 215
       Reserved block group size: 1024
   Created filesystem with 11/1761280 inodes and 154578/7045115 blocks
   Creating filesystem with parameters:
       Size: 587202560
       Block size: 4096
       Blocks per group: 32768
       Inodes per group: 7168
       Inode size: 256
       Journal blocks: 2240
       Label: 
       Blocks: 143360
       Block groups: 5
       Reserved block group size: 39
   Created filesystem with 11/35840 inodes and 4616/143360 blocks
   --------------------------------------------
   Bootloader Version...: FLO-04.04
   Baseband Version.....: none
   Serial Number........: 06273f26
   --------------------------------------------
   checking product...
   OKAY [  0.003s]
   checking version-bootloader...
   OKAY [  0.004s]
   sending 'boot' (7182 KB)...
   OKAY [  0.294s]
   writing 'boot'...
   OKAY [  0.386s]
   sending 'recovery' (7768 KB)...
   OKAY [  0.317s]
   writing 'recovery'...
   OKAY [  0.296s]
   erasing 'system'...
   OKAY [  1.170s]
   sending 'system' (799293 KB)...
   OKAY [ 32.173s]
   writing 'system'...
   OKAY [ 35.771s]
   erasing 'userdata'...
   OKAY [ 24.776s]
   sending 'userdata' (139085 KB)...
   OKAY [  5.464s]
   writing 'userdata'...
   OKAY [  6.017s]
   erasing 'cache'...
   OKAY [  0.464s]
   sending 'cache' (10984 KB)...
   OKAY [  0.437s]
   writing 'cache'...
   OKAY [  0.488s]
   rebooting...
   
   finished. total time: 108.130s

9. Once the script finishes, your device reboots. You should now lock the bootloader for security. Start the device in fastboot mode again, as described above.
10. Execute one more time:

    # fastboot oem lock

    NOTE: Locking the bootloader does not wipe any data. In case you’ll want to flash it again it’ll force you to run fastboot oem unlock which will wipe the data instead.