**All the files will be placed in your $HOME directory. Clean up afterwards.**

Fetch the Apalis image and prepare the filesystem. (Check for a newer image at http://developer.toradex.com/files/toradex-dev/uploads/media/Colibri/Linux/Images/ and update accordingly)

cd
wget -c http://developer.toradex.com/files/toradex-dev/uploads/media/Colibri/Linux/Images/Apalis_T30_LinuxImageV2.6_20160826.tar.bz2
sudo tar xjf Apalis_T30_LinuxImageV2.6_20160826.tar.bz2; echo 'Done.'
cd Apalis_T30_LinuxImageV2.6
sudo rm -rf rootfs
sudo mkdir L4T; cd L4T

### Fetch driver packages and sample root filesystem.

sudo wget -c http://developer.download.nvidia.com/mobile/tegra/l4t/r16.5.0/cardhu_release_armhf/Tegra30_Linux_R16.5_armhf.tbz2
sudo wget -c http://developer.download.nvidia.com/mobile/tegra/l4t/r16.5.0/cardhu_release_armhf/Tegra_Linux_Sample-Root-Filesystem_R16.5_armhf.tbz2

### Configure sample root filesystem and driver packages.

sudo tar xjf Tegra30_Linux_R16.5_armhf.tbz2; echo 'Done.'
cd Linux_for_Tegra/rootfs/
sudo tar xjf ../../Tegra_Linux_Sample-Root-Filesystem_R16.5_armhf.tbz2; echo 'Done.'
cd ..
sudo ./apply_binaries.sh

### Fix potential issues.

cd rootfs
sudo sh -c 'echo "" >> etc/issue'
sudo sh -c 'echo "Apalis_T30" >> etc/issue'

Uncomment the line `# echo 1 > /sys/module/cpu_tegra3/parameters/auto_hotplug` in `etc/init/nv.conf`:

gksudo gedit etc/init/nv.conf

cd ../../../
sudo ln -s L4T/Linux_for_Tegra/rootfs/

This is enough to have a properly working Linux without WiFi. If you do not need WiFi skip to part **Flash the Filesystem and Kernel to the SD Card**.

### Setup toolchain.

cd
wget -c https://releases.linaro.org/components/toolchain/binaries/5.2-2015.11-2/arm-linux-gnueabihf/gcc-linaro-5.2-2015.11-2-x86_64_arm-linux-gnueabihf.tar.xz
tar xvf gcc-linaro-5.2-2015.11-2-x86_64_arm-linux-gnueabihf.tar.xz
ln -s gcc-linaro-5.2-2015.11-2-x86_64_arm-linux-gnueabihf gcc-linaro

export ARCH=arm
export PATH=~/gcc-linaro/bin/:$PATH
export CROSS_COMPILE=arm-linux-gnueabihf-

Install DTC and U-Boot tools.

sudo apt-get install device-tree-compiler u-boot-tools

### Configure U-Boot.

git clone -b 2015.04-toradex git://git.toradex.com/u-boot-toradex.git
cd u-boot-toradex
make apalis_t30_defconfig
make -j8 2>&1 | tee build.log

cd ~/Apalis_T30_LinuxImageV2.6/apalis-t30_bin
sudo cp ~/u-boot-toradex/u-boot-dtb-tegra.bin ./u-boot-dtb-tegra-custom.bin
sudo ln -fs u-boot-dtb-tegra-custom.bin u-boot-dtb-tegra.bin

### Build Linux kernel.

cd
git clone -b tegra git://git.toradex.com/linux-toradex.git
cd linux-toradex
make apalis_t30_defconfig
make nconfig

Now follow the instructions here: http://developer.toradex.com/knowledge-base/wi-fi-(linux)#MiniPCIe

>Device Drivers --->
> [\*] Network device support --->
> [\*] Wireless LAN --->
> <*> Intel Wireless WiFi Next Gen AGN - Wireless-N/Advanced-N/Ultimate-N (iwlagn)
> < F6 > Confirm Save.
> < F9 > Exit.

Update the config by removing CONFIG_CFG80211. DO NOT REMOVE WLAN AS SPECIFIED in [2]!

`sed -i '/CONFIG_CFG80211=y/c\# CONFIG_CFG80211 is not set' .config`

### Build the image and the modules.

make -j8 uImage 2>&1 | tee build.log
make -j8  # Just to make sure.
make -j8 modules
sudo -E make INSTALL_MOD_PATH=~/Apalis_T30_LinuxImageV2.6/rootfs modules_install

### Build backported WiFi drivers.

export ARCH=arm
export CROSS_COMPILE=~/gcc-linaro/bin/arm-linux-gnueabihf-
export KLIB=~/build_iwlwifi
export KLIB_BUILD=~/linux-toradex

cd
wget -c https://www.kernel.org/pub/linux/kernel/projects/backports/stable/v3.11.8/backports-3.11.8-1.tar.bz2
tar xjf backports-3.11.8-1.tar.bz2; echo 'Done.'
cd backports-3.11.8-1/
sed -i '/#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,2,0))/c\#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,1,0))' backport-include/linux/export.h
make defconfig-iwlwifi
make -j8

Uncomment/remove update-initramfs.sh and backport\_firmware_install.sh from the Makefiles. (The only Makefile I found this in was Makefile.real)

sed -i '/@.\/scripts\/update-initramfs.sh \$(KLIB)/c\# Deleted.' Makefile.real
sed -i '/@.\/scripts\/backport_firmware_install.sh/c\# Deleted.' Makefile.real

make install

### Setup Ethernet and WiFi configuration.

./${PATH_TO_SETUP_SCRIPT}/setup_wifi_eth.sh

(This script adds wifi/ethernet interfaces in /etc/network, the wpa_supplicant with a defined wifi network and copies the prebuilt iwlwifi-7260-7.ucode to rootfs/lib/firmware, since for some reason this is never built using the previous instructions. Also all the modules from build_iwlwifi/lib/modules are copied.)

### Flash the Filesystem and Kernel to the SD Card.**

cd ~/Apalis_T30_LinuxImageV2.6
./update.sh -o ${SD_CARD}
cp ~/linux-toradex/arch/arm/boot/uImage ${SD_CARD}/apalis-t30

Resize the filesystem. The default value is around 400 MB, which leaves around 50 MB free after kernel installation. We set the size to 1GB.

cd ${SD_CARD}/apalis_t30
e2fsck -f root.ext3
sudo resize2fs root.ext3 1G

Now connect Apalis using Serial and do:

screen /dev/ttyUSBX 115200

Enter the boot by pressing any key and run:

run setupdate
run update_uboot
run update

Login is:

Login: ubuntu
Password: ubuntu

After logging in do:

sudo apt-get update
sudo apt-get install linux-firmware # And any other tools you would need, e.g. nano

Additional step is required to configure Ethernet in case you skipped WiFi configuration.
**DO NOT EXECUTE IF YOU CONFIGURED WIFI SUPPORT**:

echo -e 'auto lo\niface lo inet loopback\n\nauto eth0\niface eth0 inet dhcp' | sudo tee /etc/network/interfaces
and reboot.

**And we are done! Sit back and enjoy the day.**

### FAQ
#### The kernel does not boot after run update.
The u-boot is not properly compiled.

#### How to check if the WiFi module is recognized and the drivers are there?
Run lspci and dmesg | grep iwlwifi. The output should be something like:

`$ lspci`

> 00:00.0 PCI bridge: NVIDIA Corporation Device 0e1d (rev a1)
> 01:00.0 Network controller: Intel Corporation Device 08b1 (rev bb)
> 02:00.0 PCI bridge: NVIDIA Corporation Device 0e1d (rev a1)
> 03:00.0 Ethernet controller: Intel Corporation Device 157b (rev 03)

`$ dmesg | grep iwlwifi`

>[ 10.367570] iwlwifi 0000:01:00.0: loaded firmware version 22.1.7.0 op_mode iwlmvm
>[ 12.422167] iwlwifi 0000:01:00.0: Detected Intel(R) Dual Band Wireless AC 7260, REV=0x144
>[ 12.422360] iwlwifi 0000:01:00.0: L1 Disabled; Enabling L0S
>[ 12.422585] iwlwifi 0000:01:00.0: L1 Disabled; Enabling L0S
>[ 12.981950] iwlwifi 0000:01:00.0: L1 Disabled; Enabling L0S
>[ 12.982166] iwlwifi 0000:01:00.0: L1 Disabled; Enabling L0S

### How to check if the module is properly installed?
Run iwconfig. You should see something like this:

`$ iwconfig`

> wlan0 IEEE 802.11abgn ESSID:"xxx"
>Mode:Managed Frequency:5.24 GHz Access Point: 78:24:AF:96:D8:A4
>Bit Rate=6 Mb/s Tx-Power=0 dBm
>Retry long limit:7 RTS thr:off Fragment thr:off
>Power Management:on
>Link Quality=46/70 Signal level=-64 dBm
>Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
>Tx excessive retries:0 Invalid misc:5 Missed beacon:0

### How to change the WiFi connection?
To change the wifi settings edit the `/etc/wpa_supplicant/wpa_supplicant.conf` file.

### References:
- [1] http://developer.toradex.com/knowledge-base/using-the-nvidia-provided-l4t-rootfs
- [2] http://developer.toradex.com/knowledge-base/kernel-backports-integration
- [3] http://developer.toradex.com/knowledge-base/wi-fi-(linux)
- [4] http://developer.toradex.com/knowledge-base/build-u-boot-and-linux-kernel-from-source-code
- [5] https://wiki.rapyuta-robotics.com/doku.php?id=engineering:apalis_t30:flash_images_and_kernels