Debian installer CD for PC Engines APU board with mSATA drive
=============================================================

Introduction
------------

This is a set of configuration files for building a Debian installation
CD optimized for the APU platform of PC Engines:
http://www.pcengines.ch/apu.htm

As of 2024, the manufacturing of the APU hardware has been stopped.

This installation is only intended for an mSATA drive on the APU
board. If you plan to boot from SD card, use Voyage Linux instead:
http://linux.voyage.hk/

The configuration files build amd64 installer for the APU platform (APU
versions 1, 2, and 3 have been tested).

The build machine MUST be of the same Debian release as the image that
you are building: a Jessie host can produce a Jessie ISO, and a Stretch
host can produce a Stretch ISO.

Before using these scripts, have a look at the files in profiles/, and
you may want to change some options.

There are two profiles defined in profiles/ directory: "apu64" and "manual".


"apu64" profile
---------------

This profile is designed to automate as much as possible.

The default hostname is set to "apu", unless DHCP delivers a different
name. Default root password is "pcengines", and it is defined in
"profiles/apu64.preseed".

By default, the installer asks for the host name (this is the only thing
that is manually entered). If you want to skip the hostname prompt,
comment out the following line in "profiles/apu64.preseed":

d-i netcfg/get_hostname seen false

By default the installer requires that repositories be authenticated using
a known gpg key. Uncomment the following line in "profiles/apu64.preseed"
to disable that authentication. Warning: Insecure, not recommended.

#d-i debian-installer/allow_unauthenticated boolean true

The disk layout does not allocate a swap partition (the APU board has 2
or 4GB RAM). If you need swap, you can add a swapfile in root
partition. The system is optimized for minimal swap usage:
vm.swappiness=1 in /etc/sysctl.d/pcengines_apu.conf

The profile adds an hourly cronjob
(/etc/cron.hourly/pcengines_apu_fstrim) which performs fstrim command on
root and boot partitions once a day.


"manual" profile
----------------

This profile disables the automation, and lets you choose the region,
the debian mirror, the hostname and password, and it allows you to
choose the disk partitioning that you need. You can also configure
software RAID if you have multiple physical disks.

The manual profile does not install the fstrim cronjob.


Notes
-----

The kernel boots with "elevator=deadline", which optimizes the I/O
performance for SSD drives.

See also SSD optimization tips:
https://wiki.freeswitch.org/wiki/SSD_Tuning_for_Linux
https://wiki.debian.org/SSDOptimization

If you need a live or rescue CD, you can get a Live CD from Voyage
Linux. It works fine, the only minor issue is that it switches the
serial console to 9600 baud: http://linux.voyage.hk/

The SSH daemon has `PermitRootLogin without-password` by default,
which disallows the root to login with a password. You either need to
install your public SSH key in root's autorized_keys, or change the SSH
daemon configuration.



Installation
------------

WARNING: this is a fully automated installation. Once you boot from the
USB stick, it will only give you 5 seconds in the initial menu, then in
a couple of minutes it will ask for the hostname, and the rest will be
done automatically, and a new Debian system will be installed on mSATA
SSD drive.

!!! ALL EXISTING DATA ON THE DRIVE WILL BE LOST !!!

Debian Bookworm caveat: you need to select "Install Debian" in the
Grub menu manually. Also, the installation takes significantly longer
than for previous releases.

Both the build machine and the APU board need the Internet connection
during the installation. The installer assumes that enp1s0 (marked as
LAN1 on the APU board) is connected to a network with DHCP service and
Internet access.

The installation ISO image is about 200MB in size.

Create the CD image on the build machine:

## install prerequisites
apt-get update
apt-get install -y simple-cdd git xorriso lsb-release mtools

## get our latest files
mkdir /opt/pcengines
cd /opt/pcengines
git clone https://github.com/ssinyagin/pcengines-apu-debian-cd.git .

## build the installation CD image. If you need to build another ISO
# image of a different architecture inside the same path, delete the
# contents of "tmp/" subdirectory. Run the following command as anormal
# user. If you run it as root, use "--force-root" option:

./build apu64

# In case of a failure, delete the contents of tmp/ subfolder.
# Sometimes problems with accessing the mirror leave garbage in tmp/
# and this breaks the execution of build-simple-cdd

## insert the USB stick into the build machine

## check where your USB stick is
fdisk -l

## copy the installer CD image
dd if=images/debian-9.1-amd64-CD-1.iso of=/dev/sdc bs=16M

## Insert the USB stick into APU board and connect a serial terminal at
## 115200 baud rate.  The terminal emulator should be vt220 or xterm
## (vt100 does not have F10 and F12). APU model 1 uses F12, and APU
## model 2 uses F10 in the boot prompt. When the prompt appears, press
## F12 or F10, correspondingly, and select your USB stick as boot
## source.

## The installation starts automatically, and it will ask for a hostname
## within a couple of minutes. Then it will continue, and halt when the
## installation finishes.



Author
------
Stanislav Sinyagin
ssinyagin@k-open.com