arm-devices: create page.

Author: flexibeast

src/SUMMARY.md

@@ -12,6 +12,7 @@
    - [Advanced Installation Guides](./installation/guides/index.md)
       - [Installation via chroot (x86/x86_64)](./installation/guides/chroot.md)
       - [Full Disk Encryption](./installation/guides/fde.md)
+      - [ARM Devices](./installation/guides/arm-devices/index.md)
    - [musl](./installation/musl.md)
 - [Configuration](./config/index.md)
    - [Manual Pages](./config/man.md)

src/installation/guides/arm-devices/index.md

@@ -0,0 +1,170 @@
+# ARM Devices
+
+Void Linux provides packages and images for several ARM devices. Installing Void
+on such devices can be done in several ways:
+
+- [Pre-built images](#pre-built-images): images that can be flashed directly
+   onto an SD card or other storage medium, but give you a limited partition
+   layout and require manual expansion if you wish to increase the partitions;
+- [Tarball installation](#tarball-installation): PLATFORMFS and ROOTFS tarballs
+   that can be extracted to a previously prepared partition scheme;
+- [Chroot installation](#chroot-installation): follows most of the steps
+   outlined in [the chroot guide](../chroot.md).
+
+Since most of the commands on this guide will be run on external storage, it is
+important to run [sync(1)](https://man.voidlinux.org/sync.1) before removing the
+device.
+
+Further [configuration steps](#configuration) that are mostly specific to such
+devices are also outlined.
+
+## Installation
+
+If you are installing Void Linux on one of the ARM devices covered in the
+"[Supported platforms](./platforms.md)" page, make sure to read its section
+thoroughly.
+
+### Pre-built images
+
+After [downloading and verifying](../../index.md#downloading-installation-media)
+an image, it can be flashed onto an SD card in `/dev/mmcblk0`, for example, with
+the [cat(1)](https://man.voidlinux.org/cat.1),
+[pv(1)](https://man.voidlinux.org/pv.1) or
+[dd(1)](https://man.voidlinux.org/dd.1) command:
+
+```
+# dd if=<image>.img of=/dev/mmcblk0 bs=4M status=progress
+```
+
+### Custom partition layout
+
+It is possible to customize an installation further, for example with a custom
+partition layout, but it requires a more involved process. Two available options
+are:
+
+- [Tarball installation](#tarball-installation); and
+- [Chroot installation](#chroot-installation)
+
+To prepare the storage for these installation methods, it is necessary to
+partition the storage medium to then mount the partitions in the correct
+mounting points.
+
+The usual partitioning scheme for ARM devices requires at least two partitions
+on a drive formatted with an MSDOS partition table:
+
+- one formatted as FAT32 with partition type `0c`, which will be mounted on
+   `/boot`;
+- one that can be formatted as any file system that Linux can boot from, such as
+   ext4, which will be mounted on `/`. If you are using an SD card, for example,
+   it might be interesting to create the ext4 file system with the
+   `^has_journal` option, which disables journaling and might increase the
+   drive's life, at the cost of a higher chance of data loss.
+
+This can be done with the [cfdisk(8)](https://man.voidlinux.org/cfdisk.8)
+utility, for example.
+
+To access the newly created file systems, it is necessary to mount them. This
+guide will assume that the second partition will be mounted on `/mnt`, but you
+may mount it elsewhere. To mount these filesystems, you can use the commands
+below, replacing the device names with the appropriate ones for your setup.
+
+```
+# mnt /dev/mmcblk0p2 /mnt
+# mkdir /mnt/boot
+# mount /dev/mmcblk0p1 /mnt/boot
+```
+
+#### Tarball installation
+
+First, [download and verify](../../index.md#downloading-installation-media) a
+PLATFORMFS or ROOTFS tarball for your desired platform and [prepare your storage
+medium](#preparing-your-storage). Then, it is necessary to unpack the tarball
+onto the file system, which can be done using
+[tar(1)](https://man.voidlinux.org/tar.1):
+
+```
+# tar xvfp <image>.tar.xz -C /mnt
+```
+
+#### Chroot installation
+
+It is also possible to perform a chroot installation, which requires using the
+`qemu-user-static` package together with either the `binfmt-support` or `proot`
+package. This guide explains how to use the `qemu-<platform>-static` program
+from `qemu-user-static` with [proot(1)](https://man.voidlinux.org/proot.1).
+
+First, [download and verify](../../index.md#downloading-installation-media) a
+PLATFORMFS or ROOTFS tarball for your desired platform and [prepare your storage
+medium](#preparing-your-storage). Then, follow the [XBPS chroot installation
+steps](../chroot.md#the-xbps-method) using the appropriate architecture and base
+packages, some of which are listed in the "[Supported
+platforms](./platforms.md)" page.
+
+Finally, follow the [chroot configuration steps](../chroot.md#configuration)
+steps, but instead of using the [chroot(1)](https://man.voidlinux.org/chroot.1)
+command to [enter the chroot](../chroot.md#entering-the-chroot), use the command
+below:
+
+```
+# proot -q qemu-arm-static -r /mnt -w /
+```
+
+## Configuration
+
+Some additional configuration steps need to be followed to guarantee a working
+system. Configuring a [graphical
+session](../../../config/graphical-session/index.md) should work as normal.
+
+### Logging in
+
+For the pre-built images and tarball installations, the `root` user password is
+`voidlinux`.
+
+### fstab
+
+The `/boot` partition should be added to `/etc/fstab`, with an entry similar to
+the one below. It is possible to boot without that entry, but updating the
+kernel package in that situation can lead to breakage, such as being unable to
+find kernel modules, which is essential for functionality such as wireless
+connectivity. If you aren't using an SD card, replace `/dev/mmcblk0p1` with the
+appropriate device path.
+
+```
+/dev/mmcblk0p1 /boot vfat defaults 0 0
+```
+
+### System time
+
+Several of the ARM devices supported by Void Linux don't have battery powered
+real time clocks (RTC), which means they won't keep track of time once powered
+off. This issue can present itself as HTTPS errors when browsing the web or
+using the package manager. It is possible to set the time manually using the
+[date(1)](https://man.voidlinux.org/date.1) utility. In order to fix this issue
+for subsequent boots, install and enable [an NTP
+client](../../../config/date-time.md#ntp). Furthermore, it is possible to
+install the `fake-hwclock` package, which provides the `fake-hwclock` service.
+[fake-hwclock(8)](https://man.voidlinux.org/fake-hwclock.8) periodically stores
+the current time in a configuration file and restores it at boot, leading to a
+better initial approximation of the current time, even without a network
+connection.
+
+**Warning**: Images from before 2019-11-09 might have an issue where the
+installation of the `chrony` package, which comes as the default NTP daemon, is
+incomplete, and the system will be missing the `chrony` user. This can be
+checked in the output of the [getent(1)](https://man.voidlinux.org/getent.1)
+command, which will be empty if it doesn't exist:
+
+```
+$ getent group chrony
+chrony:x:997
+```
+
+In order to fix this, it is necessary to reconfigure the `chrony` package using
+[xbps-reconfigure(1)](https://man.voidlinux.org/xbps-reconfigure).
+
+### Graphical session
+
+The `xf86-video-fbturbo` package ships a modified version of the [DDX Xorg
+driver](../../../config/graphical-session/xorg.md#ddx) found in the
+`xf86-video-fbdev` package, which is optimized for ARM devices. This can be used
+for devices which lack more specific drivers.

src/installation/guides/index.md

@@ -6,3 +6,4 @@ This section contains guides for more specific or complex use-cases.
 
 - [Installing Void via chroot (x86 or x86_64)](./chroot.md)
 - [Installing Void with Full Disk Encryption](./fde.md)
+- [ARM Devices](./arm-devices/index.md)