Debian

On Debian Buster, even when cleaned of all older kernels, my /boot directory seems to be short of space now. I can't seem to update when just one kernel is present:

# ls -alt /boot total 42733 drwxr-xr-x 5 root root 1024 Jun 26 01:02 . -rw-r--r-- 1 root root 34752610 Jun 26 01:01 initrd.img-4.19.0-5-amd64 drwxr-xr-x 5 root root 1024 Jun 25 23:29 grub drwxr-xr-x 1 root root 234 Jun 3 18:06 .. -rw-r--r-- 1 root root 206223 May 15 16:07 config-4.19.0-5-amd64 -rw-r--r-- 1 root root 3370661 May 15 16:07 System.map-4.19.0-5-amd64 -rw-r--r-- 1 root root 5217520 May 15 16:07 vmlinuz-4.19.0-5-amd64 drwx------ 2 root root 12288 Jul 25 2018 lost+found drwx------ 3 root root 4096 Dec 31 1969 efi

My problem, is when adding or installing packages, I end up with:

Building cpio /boot/initrd.img-4.19.0-5-amd64.new initramfs
pigz: abort: write error on  (No space left on device)
E: mkinitramfs failure pigz 28
update-initramfs: failed for /boot/initrd.img-4.19.0-5-amd64 with 1.

The solution is to mv or remove initrd.img-4.19.0-5-amd64.

I can then rebuild the file with:

# update-initramfs -cvk `uname -r`

or removing the file prior to installing updates:

~/initramfs# rm /boot/initrd.img-4.19.0-5-amd64
~/initramfs# apt install -f
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 140 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up initramfs-tools (0.133) ...
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools (0.133) ...

On watching the build, there must be a bunch of firmware files going in there. I wonder how to tone that down (mostly nuc8i7hvk01 special purpose display).

A bunch here -- will need to tone that down I think -- will need to go back to my installation notes to see why they are there:

# du -h --max-depth=1 /lib/firmware/amdgpu/
25M     /lib/firmware/amdgpu/

For simpler jobs, some commands to keep in mind:

• sudo apt-get autoclean
• sudo apt-get clean
• sudo apt-get autoremove
• sudo apt-get purge

I came across a Epson Perfection V39 and thought I'd try getting it to work on Linux Debian.

I have installed xsane, gscan2pdf and sane-utils.

When plugging into USB, /var/log/messages has:

Jun 25 23:16:04  usb 1-1: new full-speed USB device number 22 using xhci_hcd
Jun 25 23:16:05  usb 1-1: new high-speed USB device number 23 using xhci_hcd
Jun 25 23:16:05  usb 1-1: New USB device found, idVendor=04b8, idProduct=013d, bcdDevice= 1.00
Jun 25 23:16:05  usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Jun 25 23:16:05  usb 1-1: Product: Epson Perfection V39
Jun 25 23:16:05  usb 1-1: Manufacturer: EPSON
Jun 25 23:16:05  usb 1-1: SerialNumber: VCFY057184

I tried creating the following file:

# cat /etc/udev/hwdb.d/epson-v39.hwdb
# Epson Perfection V39
usb:v04B8p013D*
 libsane_matched=yes

and running 'systemd-hwdb update', but no luck

From a different perspective, Epson Drivers can be used to find the drivers. Put 'V39' only as the search criteria. One of the versions shown is 1.0.1, but v1.0.4 is actually available at v1.0.4. I wish there was a directory to browse as I found that one by trial and error on the url line.

However, skipping all that, this is the one that worked with xsane on Debian Buster: Image Scan! for Linux 1.0.1.

The scanner is seen:

iscan-gt-s650-bundle-1.0.1.x64.deb# scanimage -L
device `epkowa:interpreter:001:025' is a Epson (unknown model) flatbed scanner

As a side note, the 1.0.4 version provided a mechanism of seeing network based scanners such as an HP multifunction.

For future reference, find a scanner which is compatible: SANE - Supported Devices

I saw a pre-release of "Linux Observability with BPF" by David Calavera and Lorenzo Fontana. Well, I'd say it is a release prior to pre-release. Some good information it has, but teases the details.

This post is about what it takes to get the first example functional: the things I saw, didn't see, and kludges I put in place. With the understanding and first step in place, it can be cleaned up and additional progress can be now proceed.

I have a mixed Debian Buster/Testing/Sid workstation installation. A messy system due to the vagaries of getting Linux Stretch/Buster installed onto a new Intel NUC nuc8i7hvk01 when firmware and display drivers were just getting rolled out. Kernel updates have made progress. Given the inclination, a nice simple clean Buster rebuild will probably work this time around.

But enough of that. Here is what I needed to do for building a simple eBPF program, building a simple installer, and getting it to install, pass the verifier, and achieve a successful conclusion. Continue reading "eBPF Basics" »

From the Debian bugs mailing list here is an interesting result of using non-native code in emulation:

1) Install qemu-system-arm.

2) Unpack kernel .deb, locate vmlinuz-4.9.0-8-armmp.
Or search your just-built zImage.

3) Run qemu (no root required):

  qemu-system-arm -M virt -nographic -kernel vmlinuz-4.9.0-8-armmp

If you see a kernel panic - the outcome is positive, the kernel is OK.
If it just stays there eating 100% CPU - the outcome is negative.

The above is used to sus out some issues with the linux-image-4.9.0-8-armmp-lpae:armhf kernel on Banana PI and Lamobo R1, with the notes in Bug#922478. More talk of the bug on Hacker News.

From Things you can do with Debian: multimedia editing

• gimp - image processing
• audacity - quick audio recording / editing
• ardour - audio recording / editing / mixing / mastering
• kdenlive - video editing / mixing
• openshot - video editing / mixing
• handbrake - video transcoding

Simple streaming the Linux desktop to Kodi using GStreamer and RTP by Petter Reinholdtsen

2018/09/13 - Distributing static routes with DHCP

Intel has released a new NUC, the NUC8i7HVK. It used an integrated AMD GPU graphics engine, the Radeon RX Vega M GH in the NUC8i7HVK model.

During the initial release days, most of the installation and configuration documentation revolved around installing a specific version of Ubuntu, and installing a particular driver set from the AMD support pages.

That is no longer necessary. AMD has been contributing a significant amount of code to recent versions of the kernel for driving their new graphics chipsets.

I had tried to load, build, and install the amdgpu-pro driver, but it would never match up with the current kernel header files in Stretch and Buster.

One important note: the built in Intel graphics adapter needs to be disabled in the BIOS. Then these are the installation steps to get things running (I have two 4K screens attached, both rotated 90 degrees). So things seem to work.

In addition, i have the following in /etc/default/grub (run update-grub after changing):

GRUB_CMDLINE_LINUX="amdgpu.dc=1"

I used the non-free firmware image of Debian Buster to get the ball rolling. I think I encountered some black screens so had to ssh in from a different computer to fix various gaffes on the way to getting something working.

apt -t experimental install linux-image-4.18.0-rc4-amd64 linux-headers-4.18.0-rc4-amd64
reboot
apt -t experimental install mesa-utils mesa-utils-extra mesa-va-drivers \
         mesa-vdpau-drivers mesa-vulkan-drivers libglx-mesa0 \
         xserver-xorg-video-amdgpu
wget -m -np https://people.freedesktop.org/~agd5f/radeon_ucode/vegam/
mkdir /lib/firmware/amdgpu
cp people.freedesktop.org/~agd5f/radeon_ucode/vegam/*.bin /lib/firmware/amdgpu/
/usr/sbin/update-initramfs -u -k all
reboot

Which results in:

# lspci|grep -i vga
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Polaris 22 [Radeon RX Vega M GH] (rev c0)
# uname -a
Linux nuc8i7hvk01 4.18.0-rc4-amd64 #1 SMP Debian 4.18~rc4-1~exp1 (2018-07-12) x86_64 GNU/Linux

Long story short, the solution was to install the latest firmware. In this case, I have an Intel NUC8i7HVK Mini PC with Intel Wireless-AC 8265 and Bluetooth 4.2. I installed the Intel wireless firmware package from experimental:

apt -t experimental install firmware-iwlwifi

This is also running current experimental kernel:

# uname -a
Linux nuc8i7hvk01 4.18.0-rc4-amd64 #1 SMP Debian 4.18~rc4-1~exp1 (2018-07-12) x86_64 GNU/Linux

Which provided a more recent load on boot:

[ 2.478527] iwlwifi 0000:06:00.0: firmware: direct-loading firmware iwlwifi-8265-36.ucode

Upon reboot, it was easy to scan, connect, and pair the Logitech MX Anywhere 2S mouse.

For future reference, here are some commands to see some activiites:

$ hcitool dev
Devices:
        hci0    0C:54:15:66:3B:9E

$ hciconfig
hci0:   Type: Primary  Bus: USB
        BD Address: 0C:54:15:66:3B:9E  ACL MTU: 1021:4  SCO MTU: 96:6
        UP RUNNING PSCAN ISCAN
        RX bytes:41366 acl:2102 sco:0 events:164 errors:0
        TX bytes:4913 acl:29 sco:0 commands:75 errors:0

# bluetoothctl
Agent registered
[MX Anywhere 2S]# help
Menu main:
Available commands:
-------------------
advertise                                         Advertise Options Submenu
scan                                              Scan Options Submenu
gatt                                              Generic Attribute Submenu
list                                              List available controllers
show [ctrl]                                       Controller information
select                                      Select default controller
devices                                           List available devices
paired-devices                                    List paired devices
system-alias                                Set controller alias
reset-alias                                       Reset controller alias
power                                     Set controller power
pairable                                  Set controller pairable mode
discoverable                              Set controller discoverable mode
agent                          Enable/disable agent with given capability
default-agent                                     Set agent as the default one
advertise                            Enable/disable advertising with given type
set-alias                                  Set device alias
scan                                      Scan for devices
info [dev]                                        Device information
pair [dev]                                        Pair with device
trust [dev]                                       Trust device
untrust [dev]                                     Untrust device
block [dev]                                       Block device
unblock [dev]                                     Unblock device
remove                                       Remove device
connect                                      Connect device
disconnect [dev]                                  Disconnect device
menu                                        Select submenu
version                                           Display version
quit                                              Quit program
exit                                              Quit program
help                                              Display help about this program

[MX Anywhere 2S]# paired-devices
Device E1:38:CB:49:A9:A5 MX Anywhere 2S

[MX Anywhere 2S]# devices
Device E1:38:CB:49:A9:A5 MX Anywhere 2S

[MX Anywhere 2S]# paired-devices
Device E1:38:CB:49:A9:A5 MX Anywhere 2S

Debian wiki on bluetooth: Using Bluetooth in a Debian system

On a Debian Stretch KDE system, some combination of the following was able to change the natural scrolling direction to match that of a MacOS computer.

apt install xinput
apt install xserver-xorg-input-synaptics
apt install xserver-xorg-input-evdev

Place the following (from /usr/share/X11/xorg.conf.d/70-synaptics.conf) in /etc/X11/xorg.conf.d/70-synaptics.conf:

# Example xorg.conf.d snippet that assigns the touchpad driver
# to all touchpads. See xorg.conf.d(5) for more information on
# InputClass.
# DO NOT EDIT THIS FILE, your distribution will likely overwrite
# it when updating. Copy (and rename) this file into
# /etc/X11/xorg.conf.d first.
# Additional options may be added in the form of
#   Option "OptionName" "value"
#
Section "InputClass"
        Identifier "touchpad catchall"
        Driver "synaptics"
        MatchIsTouchpad "on"
# This option is recommend on all Linux systems using evdev, but cannot be
# enabled by default. See the following link for details:
# http://who-t.blogspot.com/2010/11/how-to-ignore-configuration-errors.html
#       MatchDevicePath "/dev/input/event*"
        Option "NaturalScrolling" "true"
EndSection

Section "InputClass"
        Identifier "touchpad ignore duplicates"
        MatchIsTouchpad "on"
        MatchOS "Linux"
        MatchDevicePath "/dev/input/mouse*"
        Option "Ignore" "on"
EndSection

# This option enables the bottom right corner to be a right button on clickpads
# and the right and middle top areas to be right / middle buttons on clickpads
# with a top button area.
# This option is only interpreted by clickpads.
Section "InputClass"
        Identifier "Default clickpad buttons"
        MatchDriver "synaptics"
        Option "SoftButtonAreas" "50% 0 82% 0 0 0 0 0"
        Option "SecondarySoftButtonAreas" "58% 0 0 15% 42% 58% 0 15%"
EndSection

# This option disables software buttons on Apple touchpads.
# This option is only interpreted by clickpads.
Section "InputClass"
        Identifier "Disable clickpad buttons on Apple touchpads"
        MatchProduct "Apple|bcm5974"
        MatchDriver "synaptics"
        Option "SoftButtonAreas" "0 0 0 0 0 0 0 0"
EndSection

In 'System Settings' -> 'Input Devices' -> TouchPad -> Scrolling, I have 'Reverse Scrolling' -> Vertical enabled.

The last section of SynapticsTouchpad mentioned the driver to install, which contradicts the beginning of the page, but indicates that libinput lacks what synaptics provides, so the roles need to be reversed.

From [SOLVED] KDE reverse/natural scrolling not working, I added the Option "NaturalScrolling" "true" line in the above file.

Reverse two finger scroll direction (natural scrolling)? didn't help much, but did introduce the "xinput" command.

I rebooted to get everything functional.

I have a couple old HP DL360 G6 servers running a several year old version of Debian Stretch. It became time to update them. Rather than fooling around with an upgrade, this is a re-install scenario. The servers have ILO2, with very lame keystroke ability. I had to use a combination of the ILO2 Remote Access in Internet Explorer as the viewer with an ssh login on another window to get keystrokes and menu operations going. I think it was a lot easier back with original Internet Explorer and Java. The Remote Mount of a CD also worked after a couple attempts at getting everything correct.

With the operating system installed, I used the Linux HP Smart Array Raid Controller article to determine the mechanism for installing HP proprietary tools. HPE (Hewlett Packard Enterprise) has a Software Delivery Repository. I am glad I hit the guy's article first, as I would not have known what to do without it.

Here is the server type determined via DMI:

 dmidecode | grep -A3 '^System Information'
System Information
        Manufacturer: HP
        Product Name: ProLiant DL360 G6
        Version: Not Specified

PCI information shows the RAID Controller type:

# lspci -k|grep -i -A2 raid
03:00.0 RAID bus controller: Hewlett-Packard Company Smart Array G6 controllers (rev 01)
        Subsystem: Hewlett-Packard Company Smart Array P410i
        Kernel driver in use: hpsa

Which confirms kernel modules in use for my SAS drives:

# lsmod |grep hpsa
hpsa                  102400  2
scsi_transport_sas     45056  1 hpsa
scsi_mod              253952  8 sd_mod,usb_storage,scsi_transport_sas,libata,hpsa,uas,sr_mod,sg

Since I am using Debian Stretch, here are some revised commands to get at some tools. This is the closest I could get to a set of descriptions.

# apt install curl
# curl https://downloads.linux.hpe.com/SDR/hpePublicKey2048_key1.pub | apt-key add -
# echo -e "deb http://downloads.linux.hpe.com/SDR/repo/mcp/ stretch/current non-free" \
      > /etc/apt/sources.list.d/hpe.list
# apt update
# apt install ssacli
# apt install ssaducli
# apt install hponcfg

ssacli provides access to the raid controller information. ssaducli is supposed to show wear rates, but it generated an empty report for me. And hponcfg deals with ILO management. More articles are needed for decoding that beast. Continue reading "HP DL360 G6 P410i with Debian Stretch" »

I have a couple older HP servers I acquired prior to understanding free firmware vs non-free. In the Debian world, when there are non-free network drivers, this can be an issue, as the non-free drivers are not included with the standard distribution downloads. Case in point, the bnx2 firmware. There are a ways to build your own distribution, but Debian, via an out of the way location, does provide an installable image: Unofficial non-free images including firmware packages

When trying out Debian Testing, here is the Debian Testing Installer page.

• dynamic dns:
• Dynamic DNS on your own domain: the important bit for me was the mention of using the "ddclient" client package for the client side. Now to search for something for the server side.
• Route-based VPN on Linux with WireGuard: I think I referenced this somewhere already, but I will do it again. And quoting from the article: "As an alternative to IPsec, WireGuard is an extremely simple (less than 5,000 lines of code) yet fast and modern VPN that utilizes state-of-the-art and opinionated cryptography (Curve25519, ChaCha20, Poly1305) and whose protocol, based on Noise, has been formally verified. It is currently available as an out-of-tree module for Linux but is likely to be merged when the protocol is not subject to change anymore. Compared to IPsec, its major weakness is its lack of interoperability."
• DKIM (DomainKeys Identified Mail) Modernization : notes on using Domain Keys in a Debian Stretch setting
• Reservoir sampling with few random bits: an excellent article describing the mechanism of randomly sampling from a stream: hold and choose, hold and choose, ...
• Using the switch on Turris Omnia with Debian: I have seen the Turris Omnia mentioned elsewhere, and this is an interesting reference on one mechansim of invoking hardware forwarding in the built in switch.

Debian Stretch has been out for a while, and is running stable, as it should. However, the kernel version is getting a bit long in the tooth:

4.9.0-4-amd64 #1 SMP Debian 4.9.65-3 (2017-12-03) x86_64 GNU/Linux

There is quite a bit of new stuff coming down the pipe in more recent versions of the kernel. I used to manually build kernels and install them. Well, I need to still do that for bleeding edge development requirements.

However, since I manage a network of machines, I want something more current, stable, and easy to maintain. Debian Stretch Backports seems to fit the bill. As a preseed configuration with a few other goodies thrown in for good measure:

# backport selection
d-i apt-setup/services-select multiselect backports
d-i apt-setup/non-free boolean true
d-i apt-setup/contrib boolean true

#  preseed/late_command
d-i preseed/late_command string \
apt-install linux-image-4.14.0-0.bpo.3-amd64; \
apt-install iucode-tool; \
in-target /usr/bin/apt-get install -y -t stretch-backports iproute2; \
in-target /usr/bin/apt-get install -y -t stretch-backports firmware-linux-free; \
in-target /usr/bin/apt-get install -y -t stretch-backports firmware-linux; \
in-target /usr/bin/apt-get install -y -t stretch-backports intel-microcode

The first section adds the backport repository to the mix, which results in:

# cat /etc/apt/sources.list
# deb http://ftp.us.debian.org/debian/ stretch main

deb http://ftp.us.debian.org/debian/ stretch main non-free contrib
# deb-src http://ftp.us.debian.org/debian/ stretch main non-free contrib

# stretch-backports, previously on backports.debian.org
deb http://ftp.us.debian.org/debian/ stretch-backports main contrib non-free
# deb-src http://ftp.us.debian.org/debian/ stretch-backports main contrib non-free

The microcode files are non-free, as are some of the firmware files, hence the non-free flag. The iucode-tool package is part of contrib, hence the contrib flag.

The preseed/late_command entry can have multiple commands, with each command terminated with a ';'. apt-install is used to install the kernel, as an 'in-target' flavour will not have enough memory. As I do considerable amount of networking, iproute2 is installed in the same cycle to get it's tools in place. The 'partman' portion of my install sets /boot as ro, so the these packages need to be installed prior to reboot.

Backports repository has priority of 100. Since the kernel name is unique, the installer knows to use the backports respository. iucode-tool does not have a backports version, so is pulled from the stable repository. The other ones have versions in both stable and backports. They therefore need the override in order to have the backports version installed.

On reboot, with 'uname -a', I have:

 4.14.0-0.bpo.3-amd64 #1 SMP Debian 4.14.13-1~bpo9+1 (2018-01-14) x86_64 GNU/Linux

Some references:

• Example PreSeed
• Hands Free Installation - with various good remarks and comments about the process
• "Hands-off" Debian Installation - some details on command line entries for debugging the preseed process
• Debian Preseed Documentation

After some more reading, here is iteration two of the preseed:

# backport selection
d-i apt-setup/services-select multiselect backports
d-i apt-setup/non-free boolean true
d-i apt-setup/contrib boolean true

#  preseed/late_command
d-i preseed/late_command string \
in-target /usr/bin/apt-get upgrade -y -t stretch-backports; \
apt-install linux-image-4.14.0-0.bpo.3-amd64; \
apt-install iucode-tool; \
in-target /usr/bin/apt-get install -y -t stretch-backports firmware-linux-free; \
in-target /usr/bin/apt-get install -y -t stretch-backports firmware-linux; \
in-target /usr/bin/apt-get install -y -t stretch-backports intel-microcode; \
in-target /usr/bin/apt-get upgrade -y -t stretch-backports

This does an upgrade prior to installation of anything. Which upgrades iproute2. There is a final upgrade as the kernel installation adds some additional packages, which also need an upgrade.

But a caveat does exist from backports.debian.org:

It is therefore recommended to only select single backported packages that fit your needs, and not use all available backports.

... so running the 'upgrade' command may not be the sensible thing to do.

When using a serial cable to manage the installation of Debian, a few mailing list pointers:

If you use console mode during installation it will also be properly set up when Debian is installed (no need to mess with grub...).

The only parameter I need to pass to the kernel is:

console=ttyS0,115200n8

Note that it is 'console=ttyS0' and not 'console=/dev/ttyS0'.

For the VGA side of things:

Just in case you get the following (Don't use 'vga=*' to skip that part):

"Undefined video mode number: 314
Press <ENTER> to see video modes available, <SPACE> to continue, or wait 30 sec"
Simply press the <SPACE> bar or wait 30 sec.

More info on the boot console from Boot Parameters, which includes a mechanism for getting parameters to kernel modules.

When there are multiple parameters in the grub command line, variables can be used to make things readable:

set cS1="console=ttyS1,115200n8"
linux    .../linux auto=true priority=critical $cS1 ... --- $cS1

kernel udebs are those are created by the Debian kernel package. A package built with "make deb-pkg" from within an upstream kernel tree only builds regular debs, but no udebs. To have udebs for a custom kernel, you should start from the Debian kernel package sources and modify them as needed for your custom kernel.

The Debian kernel package repository is available at kernel

Please note that this repository only contains the packaging part, not the upstream kernel sources.

For how to use that with an upstream kernel source, please read root/debian/README.source

I use "make bindeb-pkg" in the vanilla kernel tree regulary and in the past I used also something like "dpkg-buildpackage -b -rfakeroot" in the debian kernel source package.

• Debian Installer Modify CD
• Debian Installer Custom Kernel

background information:

• check out
• build
• internals

The last one is rather old and hasn't been updated for quite a while, but it still provides a useful overview about which basic components the installer has.

For building, checkout the source with mr as described in the first link above. You can then either run the normal Debian package building process (provided you have all dependencies installed, you can simply run "dpkg-buildpackage -us -uc -rfakeroot", but preferably use either pbuilder or sbuild), or you can build single installer targets such as the netboot target separately. Just running make gives you a list of supported targets. Taking the netboot target as an example, the following commands build it:

  $ fakeroot make reallyclean && fakeroot make build_netboot

The results are placed in the "dest" directory.

"make deb-pkg" uses a function of the upstream kernel Makefile to build .deb packages. This function doesn't support building udebs; udebs are only built by the Debian kernel package build infrastructure, which is in debian/rules (and is called by dpkg-buildpackage).

To build a Debian kernel package including udebs from git, run the following steps:

$ sudo apt-get install build-essential fakeroot rsync git
$ sudo apt-get build-dep linux
$ git clone -b sid --single-branch https://anonscm.debian.org/git/kernel/linux.git
  (this gets you the Debian packaging files for a kernel package)
$ cd linux
$ ./debian/bin/genorig.py /path/to/local/linux-kernel-git-repository
  (this creates a DFSG-free upstream kernel tarball for the kernel version
   defined by the newest entry in debian/changelog from an upstream
   kernel git repository)
$ debian/rules orig
  (this unpacks the upstream kernel tarball in the right place for
   the package build process)
$ debian/rules debian/control
  (this creates the final control file for building the
   package from a template)
$ dpkg-buildpackage -us -uc -rfakeroot -B
  (this runs the actual binary package build, using the control
   file generated in the previous step)

For building the package from a custom kernel source, create a new changelog entry that fits your custom kernel in debian/changelog and replace /path/to/local/linux-kernel-git-repository with the path to your custom kernel repository. If you are working on a bleeding-edge kernel source (i.e. 4.15rc), you should use the "master" branch of https://anonscm.debian.org/git/kernel/linux.git instead of the "sid" branch as your base.

2018/01/16 added Bootstrapping Debian Packages at Peter Eisentraut's Blog:

I start with nothing, call debuild, fix the error, retry, until it works. This might sound pretty bizarre, but it works pretty well and enhances your understanding of how the packaging tools work.

2018/01/20 Debian version numbers and ABIs from Debian Linux Kernel Handbook.

2018/01/26 netboot build: I'm not sure how functional these examples are for building, but may provide usage hints

2018/01/27 Debian Boot mailing list

* apt-get source debian-installer
* Install the build-dependencies on the host system
* (did not install a sources list as I'm happy with the system one)
* make
And upon success
* make build_netboot 

2018/01/28

• Debian Installer Git Repository
• Beginner question - stable installer build fails - why?
• Debian Installer Notes for building
• Debian Installer CheckOut
• Debian Installer Build
• Custom Debian NetInstall

dpkg-buildpackage and debian/rules are the standard interface to
building Debian packages, so there's very little point in mentioning
that specifically.

Also, build/README contains this:
| Recipe:
|  - Install the build-dependencies on the host system
|    (run dpkg-checkbuilddeps in the parent installer/ directory).
|  - Create your own sources.list.udeb.local, otherwise the build host's
|    sources.list is taken as a template for sources.list.udeb.
|  - Run "make" to get a list of available targets.
|  - Build an image using one of the build_ targets (build_netboot,
|    all_build, etc). You may want to set the USE_UDEBS_FROM variable,
|    documented below.
|  - Look in dest/ for the completed images.

and the documentation of USE_UDEBS_FROM points to debian/rules already.

• Build NetInstall and test with qemu
• Custom Debian Live

As a side note, Debian PXE Boot Install suggests using the debian-installer-$VERSION-netboot-$ARCH package instead of downloading the netboot.tar.gz file.

initrd/initramfs

Debian Installer Internals by Frans Pop - lots of detail

2018/02/12 - Using Git for Debian Packaging by Russ Allbery. Also by him: Building Kernels the Debian Way

2018/02/21 - DebianInstaller/BootpTFTP

2018/02/22 - InstallingDebianOnTurrisOmnia has a number of interesting ideas: installing images on btrfs subvolumes, using uboot, busybox is on stretch and has minicom, and a few other tricks. I jumped to this link from flash-kernel.

DebianInstaller jump page to many related details.

Open Stack Training Labs Example extracts:

#-------------------------------------------------------------------------------
### Clock and time zone setup
# Controls whether or not the hardware clock is set to UTC.
d-i clock-setup/utc boolean true
d-i time/zone string Etc/UTC

#-------------------------------------------------------------------------------
### Package selection
tasksel tasksel/first minimal

# Individual additional packages to install
d-i pkgsel/include string openssh-server dkms localepurge

#-------------------------------------------------------------------------------
# Whether to upgrade packages after debootstrap.
# Allowed values: none, safe-upgrade, full-upgrade
d-i pkgsel/upgrade select none

# Policy for applying updates. May be "none" (no automatic updates),
# "unattended-upgrades" (install security updates automatically), or
# "landscape" (manage system with Landscape).
d-i pkgsel/update-policy select none

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Use the following option to add additional boot parameters for the
# installed system (if supported by the bootloader installer).
# Note: options passed to the installer will be added automatically.

# With Ubuntu 12.04 LTS, modesetting may result in a blank console
d-i debian-installer/add-kernel-opts string vga=0x301 nomodeset
#-------------------------------------------------------------------------------
#### Advanced options
### Running custom commands during the installation
# d-i preseeding is inherently not secure. Nothing in the installer checks
# for attempts at buffer overflows or other exploits of the values of a
# preconfiguration file like this one. Only use preconfiguration files from
# trusted locations!

# This command is run just before the install finishes, but when there is
# still a usable /target directory. You can chroot to /target and use it
# directly, or use the apt-install and in-target commands to easily install
# packages and run commands in the target system.
d-i preseed/late_command string echo "DIR=/home/osbash/.ssh; mkdir \$DIR; wget -O \$DIR/authorized_keys https://git.openstack.org/cgit/openstack/training-labs/plain/labs/osbash/lib/osbash-ssh-keys/osbash_key.pub ; chmod 700 \$DIR; chmod 400 \$DIR/authorized_keys; chown -R osbash:osbash \$DIR; echo 'osbash ALL=(ALL) NOPASSWD: ALL' >> /etc/sudoers; echo 'Defaults:osbash !requiretty' >> /etc/sudoers;" | chroot /target /bin/bash;

packer-templates/httpdir/preseed/ubuntu1404.preseed extracts:

# No language support packages.
d-i pkgsel/install-language-support boolean false

# Customizations
d-i preseed/late_command string \
in-target sed -i 's/PermitRootLogin without-password/PermitRootLogin yes/g' /etc/ssh/sshd_config
in-target sed -i 's|errors=remount-ro|errors=remount-ro,noatime|g' /etc/fstab ; \
in-target sed -i 's|ntp.ubuntu.com|ntp.pcextreme.nl|g' /etc/ntp.conf ; \
in-target sed -i '2i 000.*' /etc/resolvconf/interface-order ; \
in-target echo i6300esb >> /etc/modules

From information exchanged in Debian bug #875858, some notes:

>So, as an accommodation,  a flag in the preseed mechanism to enable/disable would be helpful.  
>But would need to be exposed in maybe the expert mode menus, which I think was already mentioned.

You mean something like:

Template: pkgsel/update-policy
Type: select
Default: unattended-upgrades
Choices-C: none, unattended-upgrades
__Choices: No automatic updates, Install security updates automatically
_Description: Updates management on this system:
 Applying updates on a frequent basis is an important part of keeping the
 system secure.
 .
 By default, security updates are automatically installed by the
 unattended-upgrades package. Alternatively, you can opt-out from
 this system and apply updates manually using standard package management
 tools.

pkgsel/update-policy=none thus seem the perfect preseed choice for
your use case.

Use the 'pkgsel' package to find the extracts (the package indicates to not install on a running system):

I got the template extract....from the package source itself:
 (pkgsel package, here). 

Use codesearch.debian.net to find template files and their values:

As a trivial lookup, sources.debian.net will show all the template
files in Debian:

  https://codesearch.debian.net/search?q=Template%3A+path%3Adebian%2F.*.template

but it's a large set in just sid: ("761 files grepped (4453 results)")...

Or use apt-extracttemplates to look for templates:

apt-extracttemplates is a useful utility in apt-utils. For a set of
udebs

  apt-extracttemplates -t $PWD *.udeb

will extract any templates files in the udebs.

  rm *.config.*

deletes unneeded files.

All that is needed for a "dictionary" is to tidy up the templates files.
Perhaps

  https://wiki.debian.org/DebianInstaller/Preseed#Preseeding_and_the_installer.27s_debconf_templates

helps?

Someone's start at template centralization:

it is unfinished, incomplete and unmaintained, but in 2016 I tried to
create a single page centralising templates.

https://lists.debian.org/debian-boot/2016/09/msg00075.html

Anybody is welcome to extend or replace that work 

Notes on TFTP netboot assistant locations. I havn't used this, but is worthy of further investigation:

Right now, '$TFTP_ROOT/debian-installer/' is used to set up and serve
the netboot-images.  If you also serve preseedings from the canonical
location '$TFTP_ROOT/d-i/', you have a slightly confusing setup.

The plan is to use 'd-i/n-a/' for di-netboot-assistant, to have all
installer stuff within the common '$TFTP_ROOT/d-i/' directory.

A follow up email provides the following useful related entries to this request: