Added Arch Linux ARM page

docs/archlinuxarm.md

@@ -0,0 +1,95 @@
+This document is a guide for installing Arch Linux ARM on the Helios4.
+
+## What you need before you start
+
+Look at the "[What you need before you start](/install/#what-you-need-before-you-start)" section of the Helios4 install guide.
+
+## Using an Arch Linux ARM image file for Helios4
+
+Arch Linux ARM can be installed on Helios4 using an image file containing both the **Arch Linux ARM system** and the **U-Boot** boot loader.
+
+This image can be created using the `build-archlinux-img-for-helios4.sh` script provided by the [alarm-helios4-image-builder](https://github.com/gbcreation/alarm-helios4-image-builder) project, or you can use a pre-built image from the same project. Each method is described below.
+
+Once you get an image file, follow the instructions from the [Installing Arch Linux ARM on Helios4](#installing-arch-linux-arm-on-helios4) section below.
+
+### The Arch Linux ARM image builder for Helios4
+
+The `build-archlinux-img-for-helios4.sh` script provided by the [alarm-helios4-image-builder](https://github.com/gbcreation/alarm-helios4-image-builder) project allows to create a bootable Arch Linux ARM image file for Helios4 automatically.
+
+#### Requirements
+
+The `build-archlinux-img-for-helios4.sh` script expects to be used on a **x86 system running [Arch Linux](https://archlinux.org)**. It needs `qemu-arm-static` to work. You can install it using the [qemu-user-static](https://aur.archlinux.org/packages/qemu-user-static/) or [qemu-user-static-bin](https://aur.archlinux.org/packages/qemu-user-static-bin/) packages from the AUR.
+
+#### Usage
+
+!!! note
+    This script needs to execute commands as the superuser. If not run as root, it will re-run itself using sudo.
+
+```shell
+$ git clone https://github.com/gbcreation/alarm-helios4-image-builder.git
+$ cd alarm-helios4-image-builder
+$ sh ./build-archlinux-img-for-helios4.sh
+```
+
+Once the Arch Linux ARM image created, follow the instructions from the [Installing Arch Linux ARM on Helios4](#installing-arch-linux-arm-on-helios4) section below.
+
+### Pre-built images
+
+You can download a pre-built Arch Linux ARM image for Helios4 from the [alarm-helios4-img-builder](https://github.com/gbcreation/alarm-helios4-image-builder/releases) project.
+
+```shell
+$ wget https://github.com/gbcreation/alarm-helios4-image-builder/releases/download/2019-02-27/ArchLinuxARM-helios4-2019-02-27.img.gz{,.md5}
+$ md5sum -c ArchLinuxARM-helios4-2019-02-27.img.gz.md5
+$ gunzip ArchLinuxARM-helios4-2019-02-27.img.gz
+```
+
+## Installing Arch Linux ARM on Helios4
+
+Once you get an Arch Linux ARM image, follows these instructions to use it on Helios4:
+
+### Writing image / power-up Helios4 / connecting to serial console
+
+Follows these steps from the [Helios4 install guide](/install):
+
+- [step 2](/install/#step-2-writing-an-image-to-a-microsd-card) to write the Arch Linux ARM image to a microSD card
+- [step 3](/install/#step-3-power-up-helios4) to power-up Helios4
+- [step 4](/install/#step-4-connect-to-helios4-serial-console) to connect to the Helios4 serial console. 
+
+!!! note
+    Arch Linux ARM is configured by default to get its IP address from a DHCP server. As an alternative to **step 4**, you can connect to your router to find the IP address given to Helios4, then connect to this latter using SSH.
+
+### Log in
+
+Use the serial console or SSH to the IP address given to Helios4 by your router.
+
+You can login as:
+
+- the default user *alarm* with the password *alarm*
+- the user *root* with password *root*
+
+!!! important
+    For security reasons, it is highly recommended to change the default password of the **alarm** and **root** users.
+
+### Network settings
+
+Arch Linux ARM is configured by default to get its IP address from a DHCP server. To change the network settings, look at the [Network Configuration](https://wiki.archlinux.org/index.php/Network_configuration) page from the Arch Linux wiki.
+
+### Pacman
+
+The Pacman keyring is already initialized in the images created by the `build-archlinux-img-for-helios4.sh` script and the pre-built images. It is also already populated with the Arch Linux ARM package signing keys.
+
+## What to do next?
+
+You can now configure Arch Linux ARM according to you needs and use **pacman** to install third party applications.
+
+Here are some useful links from the [Arch Linux wiki](https://wiki.archlinux.org) to get started:
+
+- [RAID](https://wiki.archlinux.org/index.php/RAID)
+- [dm-crypt/Device encryption](https://wiki.archlinux.org/index.php/Dm-crypt/Device_encryption).
+
+!!! note
+    Read the [Accelerate Disk Encryption](/cesa/#accelerate-disk-encryption) section of the Helios4 wiki before proceeding to learn how to offload disk encryption on the CESA unit.
+
+- [Nextcloud](https://wiki.archlinux.org/index.php/Nextcloud)
+- [NFS](https://wiki.archlinux.org/index.php/NFS)
+- [Samba](https://wiki.archlinux.org/index.php/Samba)

mkdocs.yml

@@ -62,6 +62,7 @@ pages:
 - Download: 'download.md'
 - Install: 'install.md'
 - O/S:
+  - Arch Linux ARM : 'archlinuxarm.md'
   - Armbian : 'armbian.md'
   - FreeBSD : 'freebsd.md'
   - U-Boot (bootloader) : 'uboot.md'