• emacs-request ITP #1007113
• bui.el ITP #1007153
• emacs-posframe ITP #1007158
• lsp-treemacs ITP #1007119
• dap-mode ITP #1007160
• emacs-lsp-java ITP #1007162

• March 8th: Godspeed You! Black Emperor
• April 11th: Alexandra Str liski
• April 12th: Bikini Kill
• April 21th: Brigada Flores Magon, Union Thugs
• April 28th: Komintern Sect, The Outcasts, Violent Way, Ultra Razzia, Over the Hill
• May 3rd: First Fragment
• May 12th: Rhapsody of Fire, Wind Rose
• May 13th: Aeternam
• June 2nd: Mortier, La Gachette
• June 17th: Ultra Razzia, Total Nada, BLEMISH
• June 30th: Avishai Cohen Trio
• July 9th: Richard Galliano
• August 18th: Gojira, Mastodon, Lorna Shore
• September 14th: Jinjer
• September 22nd: CUIR, Salvaje Punk, Hysteric Polemix, Perestroika, Ultra Razzia, Ilusion, Over the Hill, Asbestos
• October 6th: Rancoeur, Street Code, Tenaz, Mortimer, Guernica, High Anxiety

Number of posts 2022 was the official 20th anniversary in any case, and that was one of my best years on record, with 46 posts, surpassed only by the noisy 2005 (62) and matching 2006 (46). 2023, in comparison, was underwhelming: a feeble 11 posts! What happened! Well, I was busy with other things, mostly away from keyboard, that I will not bore you with here... The other thing that happened is that the one-liner I used to collect stats was broken (it counted folders and other unrelated files) and wildly overestimated 2022! Turns out I didn't write that much then:

anarc.at$ ls blog   grep '^[0-9][0-9][0-9][0-9].*.md'   se
d s/-.*//   sort   uniq -c    sort -n -k2
     57 2005
     43 2006
     20 2007
     20 2008
      7 2009
     13 2010
     16 2011
     11 2012
     13 2013
      5 2014
     13 2015
     18 2016
     29 2017
     27 2018
     17 2019
     18 2020
     14 2021
     28 2022
     10 2023
      1 2024

But even that is inaccurate because, in ikiwiki, I can tag any page as being featured on the blog. So we actually need to process the HTML itself because we don't have much better on hand without going through ikiwiki's internals:

anarcat@angela:anarc.at$ curl -sSL https://anarc.at/blog/   grep 'href="\./'   grep -o 20[0-9][0-9]   sort   uniq -c 
     56 2005
     42 2006
     19 2007
     18 2008
      6 2009
     12 2010
     15 2011
     10 2012
     11 2013
      3 2014
     15 2015
     32 2016
     50 2017
     37 2018
     19 2019
     19 2020
     15 2021
     28 2022
     13 2023

Which puts the top 10 years at:

$ curl -sSL https://anarc.at/blog/   grep 'href="\./'   grep -o 20[0-9][0-9]   sort   uniq -c    sort -nr   head -10
     56 2005
     50 2017
     42 2006
     37 2018
     32 2016
     28 2022
     19 2020
     19 2019
     19 2007
     18 2008

Anyway. 2023 is certainly not a glorious year in that regard, in any case.

Visitors In terms of visits, however, we had quite a few hits. According to Goatcounter, I had 122 300 visits in 2023! 2022, in comparison, had 89 363, so that's quite a rise.

What you read I seem to have hit the Hacker News front page at least twice. I say "seem" because it's actually pretty hard to tell what the HN frontpage actually is on any given day. I had 22k visits on 2023-03-13, in any case, and you can't see me on the front that day. We do see a post of mine on 2023-09-02, all the way down there, which seem to have generated another 10k visits. In any case, here were the most popular stories for you fine visitors:

• Framework 12th gen laptop review: 24k visits, which is surprising for a 13k words article "without images", as some critics have complained. 15k referred by Hacker News. Good reference and time-consuming benchmarks, slowly bit-rotting. That is, by far, my most popular article ever. A popular article in 2021 or 2022 was around 6k to 9k, so that's a big one. I suspect it will keep getting traffic for a long while.
• Calibre replacement considerations: 15k visits, most of which without a referrer. Was actually an old article, but I suspect HN brought it back to light. I keep updating that wiki page regularly when I find new things, but I'm still using Calibre to import ebooks.
• Hacking my Kobo Clara HD: is not new but always gathering more and more hits, it had 1800 hits in the first year, 4600 hits last year and now brought 6400 visitors to the blog! Not directly related, but this iFixit battery replacement guide I wrote also seem to be quite popular

Everything else was published before 2023. Replacing Smokeping with Prometheus is still around and Looking at Wayland terminal emulators makes an entry in the top five.

Where you've been People send less and less private information when they browse the web. The number of visitors without referrers was 41% in 2021, it rose to 44% in 2023. Most of the remaining traffic comes from Google, but Hacker News is now a significant chunk, almost as big as Google. In 2021, Google represented 23% of my traffic, in 2022, it was down to 15% so 18% is actually a rise from last year, even if it seems much smaller than what I usually think of.

Ratio	Referrer	Visits
18%	Google	22 098
13%	Hacker News	16 003
2%	duckduckgo.com	2 640
1%	community.frame.work	1 090
1%	missing.csail.mit.edu	918

Note that Facebook and Twitter do not appear at all in my referrers.

Where you are Unsurprisingly, most visits still come from the US:

Ratio	Country	Visits
26%	United States	32 010
14%	France	17 046
10%	Germany	11 650
6%	Canada	7 425
5%	United Kingdom	6 473
3%	Netherlands	3 436

Those ratios are nearly identical to last year, but quite different from 2021, where Germany and France were more or less reversed. Back in 2021, I mentioned there was a long tail of countries with at least one visit, with 160 countries listed. I expanded that and there's now 182 countries in that list, almost all of the 193 member states in the UN.

What you were Chrome's dominance continues to expand, even on readers of this blog, gaining two percentage points from Firefox compared to 2021.

Ratio	Browser	Visits
49%	Firefox	60 126
36%	Chrome	44 052
14%	Safari	17 463
1%	Others	N/A

It seems like, unfortunately, my Lynx and Haiku users have not visited in the past year. It seems like trying to read those metrics is like figuring out tea leaves... In terms of operating systems:

Ratio	OS	Visits
28%	Linux	34 010
23%	macOS	28 728
21%	Windows	26 303
17%	Android	20 614
10%	iOS	11 741

Again, Linux and Mac are over-represented, and Android and iOS are under-represented.

What is next I hope to write more next year. I've been thinking about a few posts I could write for work, about how things work behind the scenes at Tor, that could be informative for many people. We run a rather old setup, but things hold up pretty well for what we throw at it, and it's worth sharing that with the world... So anyway, thanks for coming, faithful reader, and see you in the coming 2024 year...

• [DLA 3686-1] xorg-server security update for two CVEs to fix privilege escalation
• [DLA 3686-2] xorg-server security update for one CVE to really fix privilege escalation. Unfortunately the first patches provided by upstream did not really solve the problem, so here we are in round 2
• [DLA 3699-1] libde265 security update for three CVEs to fix heap buffer or global buffer overflows
• [DLA 3700-1] cjson security update for one CVE to fix a segmentation violation
• [#1056934] Bookworm PU-bug for libde265; I could finally upload the package
• [#1056737] Bookworm PU-bug for minizip; I could finally upload the package
• [libde265]For the next round of CVEs of libde265 I prepared debdiffs for Bullseye and Bookworm and sent them to the maintainer.
• [cjson]I prepared debdiffs for Bullseye and Bookworm and sent them to the maintainer.

• [ELA-1019-1]xorg-server security update for two CVEs to fix privilege escalation
• [ELA-1019-2]xorg-server security update for to really fix privilege escalation. As with the DLAs above, the first patches provided by upstream did not really solve the problem, so here we are in round 2
• [ELA 1027-1] libde265 security update for three CVEs in Stretch to fix heap buffer or global buffer overflows

• cups/Bookworm to fix a bug related to color printing
• hplip to fix a bug related to /usr-merge

• libpktriggercord to fix a /usr-merge bug
• indi-nightscape to fix a /usr-merge bug
• indi-ffmv to fix a /usr-merge bug
• indi-armadillo-platypus to fix a /usr-merge bug
• indi-orion-ssg3 to fix a /usr-merge bug
• indi-sx to fix a /usr-merge bug

• usb-modeswitch-data to fix a /usr-merge bug
• libcontra it is sometimes a bit amazing what software phones home

Conferences The only Free Software related conference I made it to this year was DebConf23 in Kochi, India. Changes with projects at work meant I couldn t justify anything work related. This year I m planning to make it to FOSDEM, and haven t made a decision on DebConf24 yet.

Debian Most of my contributions to Free software continue to happen within Debian. I started the year working on retrogaming with Kodi on Debian. I got this to a much better state for bookworm, with it being possible to run the bsnes-mercury emulator under Kodi using RetroArch. There are a few other libretro backends available for RetroArch, but Kodi needs some extra controller mappings packaged up first. Plenty of uploads were involved, though some of this was aligning all the dependencies and generally cleaning things up in iterations.

• retroarch: 1.13.0-dfsg+3, 1.14.0+dfsg-1, 1.15.0+dfsg-1, 1.16.0.3+dfgs-1
• libretro-core-info uploads: 1.14.0-1, 1.15.0-1.
• libretro-bsnes-mercury: 094+git20220807-2, 094+git20220807-3, 094+git20220807-4, 094+git20220807-5, 094+git20220807-6, 094+git20220807-7, 094+git20220807-8.
• kodi-game-libretro: 20.2.0-2, 20.2.2-1, 20.2.2-2, 20.2.4-1, 20.2.4-2
• rcheevos: 10.5.0-2, 10.6.0-1, 10.7.0-1, 10.7.1-1.

I continued to work on a few packages within the Debian Electronics Packaging Team. OpenOCD produced a new release in time for the bookworm release, so I uploaded 0.12.0-1. There were a few minor sigrok cleanups - sigrok 0.3, libsigrokdecode 0.5.3-4 + libsigrok 0.5.2-4 / 0.5.2-5. While I didn t manage to get the work completed I did some renaming of the ESP8266 related packages - gcc-xtensa-lx106 (which saw a 13 upload pre-bookworm) has become gcc-xtensa (with 14) and binutils-xtensa-lx106 has become binutils-xtensa (with 6). Binary packages remain the same, but this is intended to allow for the generation of ESP32 compiler toolchains from the same source. onak saw 0.6.3-1 uploaded to match the upstream release. I also uploaded libgpg-error 1.47-1 (though I can claim no credit for any of the work in preparing the package) to help move things forward on updating gnupg2 in Debian. I NMUed tpm2-pkcs11 1.9.0-0.1 to fix some minor issues pre-bookworm release; I use this package myself to store my SSH key within my laptop TPM, so I care about it being in a decent state. sg3-utils also saw a bit of love with 1.46-2 + 1.46-3 - I don t work in the storage space these days, but I m still listed as an uploaded and there was an RC bug around the library package naming that I was qualified to fix and test pre-bookworm. Related to my retroarch work I sponsored uploads of mgba for Ryan Tandy: 0.10.0+dfsg-1, 0.10.0+dfsg-2, 0.10.1+dfsg-1, 0.10.2+dfsg-1, mgba 0.10.1+dfsg-1+deb12u1. As part of the Data Protection Team I responded to various inbound queries to that team, both from project members and those external to the project. I continue to keep an eye on Debian New Members, even though I m mostly inactive as an application manager - we generally seem to have enough available recently. Mostly my involvement is via Front Desk activities, helping out with queries to the team alias, and contributing to internal discussions as well as our panel at DebConf23. Finally the 3 month rotation for Debian Keyring continues to operate smoothly. I dealt with 2023.03.24, 2023.06.26, 2023.06.29, 2023.09.10, 2023.09.24 + 2023.12.24.

Linux I had a few minor patches accepted to the kernel this year. A pair of safexcel cleanups (improved error logging for firmware load fail and cleanup on load failure) came out of upgrading the kernel running on my RB5009. The rest were related to my work on repurposing my C.H.I.P.. The AXP209 driver needed extended to support GPIO3 (with associated DT schema update). That allowed Bluetooth to be enabled. Adding the AXP209 internal temperature ADC as an iio-hwmon node means it can be tracked using the normal sensor monitoring framework. And finally I added the pinmux settings for mmc2, which I use to support an external microSD slot on my C.H.I.P.

Personal projects 2023 saw another minor release of onak, 0.6.3, which resulted in a corresponding Debian upload (0.6.3-1). It has a couple of bug fixes (including a particularly annoying, if minor, one around systemd socket activation that felt very satisfying to get to the bottom of), but I still lack the time to do any of the major changes I would like to. I wrote listadmin3 to allow easy manipulation of moderation queues for Mailman3. It s basic, but it s drastically improved my timeliness on dealing with held messages.

Work related This year only involved a single upstream related submission; a fix for tpm_tis interrupts with the Lenovo P620 that then got dropped when the change that caused the issue was reverted. That wraps up 2023. I ve got no particular goals for this year; looking around my desk I ve a few ARM based devices I d like to get running a mainline kernel. I need to play about a bit more with the retroarch bits (if I really had time I d do the migration for Kodi to PCRE2, as that s currently causing testing migration issues), perhaps getting some more controller mappings packaged. But no promises.

• Create bootable REAR rescue image on the source system.
• Register a target system in Hetzner Cloud with at least the same disk size as the source system.
• Boot the REAR image s initrd and kernel from the running VPS system using kexec
• Make the REAR recovery console accessible via SSH (or use Hetzners console).
• Let REAR do its magic and re-partition the system.
• Restore the system data to the freshly partitioned disks
• Let REAR handle the bootloader and network re-configuration.

Example To create a rescue image on the source system:

apt install rear
echo OUTPUT=ISO > /etc/rear/local.conf
rear mkrescue -v
[..]
Wrote ISO image: /var/lib/rear/output/rear-debian12.iso (185M)

My source system had a 128 GB disk, so i registered an instance on Hetzner cloud with greater disk size to make things easier: Now copy the ISO image to the newly created instance and extract its data:

 apt install kexec-tools
 scp rear-debian12.iso root@49.13.193.226:/tmp/
 modprobe loop
 mount -o loop rear-debian12.iso /mnt/
 cp /mnt/isolinux/kernel /tmp/
 cp /mnt/isolinux/initrd.cgz /tmp/

Install kexec if not installed already:

 apt install kexec-tools

Note down the current gateway configuration, this is required later on to make the REAR recovery console reachable via SSH:

root@testme:~# ip route
default via 172.31.1.1 dev eth0
172.31.1.1 dev eth0 scope link

Reboot the running VPS instance into the REAR recovery image using somewhat the same kernel cmdline:

root@testme:~# cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-6.1.0-13-amd64 root=UUID=5174a81e-5897-47ca-8fe4-9cd19dc678c4 ro consoleblank=0 systemd.show_status=true console=tty1 console=ttyS0
kexec --initrd /tmp/initrd.cgz --command-line="consoleblank=0 systemd.show_status=true console=tty1 console=ttyS0" /tmp/kernel
Connection to 49.13.193.226 closed by remote host.
Connection to 49.13.193.226 closed

Now watch the system on the Console booting into the REAR system: Login the recovery console (root without password) and fix its default route to make it reachable:

ip addr
[..]
2: enp1s0
..
$ ip route add 172.31.1.1 dev enp1s0
$ ip route add default via 172.31.1.1
ping 49.13.193.226
64 bytes from 49.13.193.226: icmp_seq=83 ttl=52 time=27.7 ms

The network configuration might differ, the source system in this example used DHCP, as the target does. If REAR detects changed static network configuration it guides you through the setup pretty nicely. Login via SSH (REAR will store your ssh public keys in the image) and start the recovery process, follow the steps as suggested by REAR:

ssh -l root 49.13.193.226
Welcome to Relax-and-Recover. Run "rear recover" to restore your system !
RESCUE debian12:~ # rear recover
Relax-and-Recover 2.7 / Git
Running rear recover (PID 673 date 2024-01-04 19:20:22)
Using log file: /var/log/rear/rear-debian12.log
Running workflow recover within the ReaR rescue/recovery system
Will do driver migration (recreating initramfs/initrd)
Comparing disks
Device vda does not exist (manual configuration needed)
Switching to manual disk layout configuration (GiB sizes rounded down to integer)
/dev/vda had size 137438953472 (128 GiB) but it does no longer exist
/dev/sda was not used on the original system and has now 163842097152 (152 GiB)
Original disk /dev/vda does not exist (with same size) in the target system
Using /dev/sda (the only available of the disks) for recreating /dev/vda
Current disk mapping table (source => target):
  /dev/vda => /dev/sda
Confirm or edit the disk mapping
1) Confirm disk mapping and continue 'rear recover'
[..]
User confirmed recreated disk layout
[..]

This step re-recreates your original disk layout and mounts it to /mnt/local/ (this example uses a pretty lame layout, but usually REAR will handle things like lvm/btrfs just nicely):

mount
/dev/sda3 on /mnt/local type ext4 (rw,relatime,errors=remount-ro)
/dev/sda1 on /mnt/local/boot type ext4 (rw,relatime)

Now clone your source systems data to /mnt/local/ with whatever utility you like to use and exit the recovery step. After confirming everything went well, REAR will setup the bootloader (and all other config details like fstab entries and adjusted network configuration) for you as required:

rear> exit
Did you restore the backup to /mnt/local ? Are you ready to continue recovery ? yes
User confirmed restored files
Updated initramfs with new drivers for this system.
Skip installing GRUB Legacy boot loader because GRUB 2 is installed (grub-probe or grub2-probe exist).
Installing GRUB2 boot loader...
Determining where to install GRUB2 (no GRUB2_INSTALL_DEVICES specified)
Found possible boot disk /dev/sda - installing GRUB2 there
Finished 'recover'. The target system is mounted at '/mnt/local'.
Exiting rear recover (PID 7103) and its descendant processes ...
Running exit tasks

Now reboot the recovery console and watch it boot into your target systems configuration: Being able to use this procedure for complete disaster recovery within Hetzner cloud VPS (using off-site backups) gives me a better feeling, too.

1. Raspberry Pi OS has, for years now, specified that there is no upgrade path. That is, to get to a newer major release, it s a reinstall. While I have sometimes worked around this, for a device that is frequently installed in hard-to-reach locations, this is even more important than usual. It s common for me to upgrade machines for a decade or more across Debian releases and there s no reason that it should be so much more difficult with Raspbian.
2. As I noted in Consider Security First, the security situation for Raspberry Pi OS isn t as good as it is with Debian.
3. Raspbian lags behind Debian often times by 6 months or more for major releases, and days or weeks for bug fixes and security patches.
4. Raspbian has no direct backports support, though Raspberry Pi 3 and above can use Debian s backports (per my instructions as Installing Debian Backports on Raspberry Pi)
5. Raspbian uses a custom kernel without initramfs support

WARNINGS Before continuing, back up your system. This process isn t for the neophyte and it is entirely possible to mess up your boot device to the point that you have to do a fresh install to get your Pi to boot. This isn t a supported process at all.

Architecture Confusion Debian has three ARM-based architectures:

• armel, for the lowest-end 32-bit ARM devices without hardware floating point support
• armhf, for the higher-end 32-bit ARM devices with hardware float (hence hf )
• arm64, for 64-bit ARM devices (which all have hardware float)

Although the Raspberry Pi 0 and 1 do support hardware float, they lack support for other CPU features that Debian s armhf architecture assumes. Therefore, the Raspberry Pi 0 and 1 could only run Debian s armel architecture. Raspberry Pi 3 and above are capable of running 64-bit, and can run both armhf and arm64. Prior to the release of the Raspberry Pi 5 / Raspbian bookworm, Raspbian only shipped the armhf architecture. Well, it was an architecture they called armhf, but it was different from Debian s armhf in that everything was recompiled to work with the more limited set of features on the earlier Raspberry Pi boards. It was really somewhere between Debian s armel and armhf archs. You could run Debian armel on those, but it would run more slowly, due to doing floating point calculations without hardware support. Debian s raspi FAQ goes into this a bit. What I am going to describe here is going from Raspbian armhf to Debian armhf with a 64-bit kernel. Therefore, it will only work with Raspberry Pi 3 and above. It may theoretically be possible to take a Raspberry Pi 2 to Debian armhf with a 32-bit kernel, but I haven t tried this and it may be more difficult. I have seen conflicting information on whether armhf really works on a Pi 2. (If you do try it on a Pi 2, ignore everything about arm64 and 64-bit kernels below, and just go with the linux-image-armmp-lpae kernel per the ARMMP page) There is another wrinkle: Debian doesn t support running 32-bit ARM kernels on 64-bit ARM CPUs, though it does support running a 32-bit userland on them. So we will wind up with a system with kernel packages from arm64 and everything else from armhf. This is a perfectly valid configuration as the arm64 like x86_64 is multiarch (that is, the CPU can natively execute both the 32-bit and 64-bit instructions). (It is theoretically possible to crossgrade a system from 32-bit to 64-bit userland, but that felt like a rather heavy lift for dubious benefit on a Pi; nevertheless, if you want to make this process even more complicated, refer to the CrossGrading page.)

Prerequisites and Limitations In addition to the need for a Raspberry Pi 3 or above in order for this to work, there are a few other things to mention. If you are using the GPIO features of the Pi, I don t know if those work with Debian. I think Raspberry Pi OS modified the desktop environment more than other components. All of my Pis are headless, so I don t know if this process will work if you use a desktop environment. I am assuming you are booting from a MicroSD card as is typical in the Raspberry Pi world. The Pi s firmware looks for a FAT partition (MBR type 0x0c) and looks within it for boot information. Depending on how long ago you first installed an OS on your Pi, your /boot may be too small for Debian. Use df -h /boot to see how big it is. I recommend 200MB at minimum. If your /boot is smaller than that, stop now (or use some other system to shrink your root filesystem and rearrange your partitions; I ve done this, but it s outside the scope of this article.) You need to have stable power. Once you begin this process, your pi will mostly be left in a non-bootable state until you finish. (You did make a backup, right?)

Basic idea The basic idea here is that since bookworm has almost entirely newer packages then bullseye, we can just switch over to it and let the Debian packages replace the Raspbian ones as they are upgraded. Well, it s not quite that easy, but that s the main idea.

Preparation First, make a backup. Even an image of your MicroSD card might be nice. OK, I think I ve said that enough now. It would be a good idea to have a HDMI cable (with the appropriate size of connector for your particular Pi board) and a HDMI display handy so you can troubleshoot any bootup issues with a console.

Preparation: access The Raspberry Pi OS by default sets up a user named pi that can use sudo to gain root without a password. I think this is an insecure practice, but assuming you haven t changed it, you will need to ensure it still works once you move to Debian. Raspberry Pi OS had a patch in their sudo package to enable it, and that will be removed when Debian s sudo package is installed. So, put this in /etc/sudoers.d/010_picompat:

pi ALL=(ALL) NOPASSWD: ALL

Also, there may be no password set for the root account. It would be a good idea to set one; it makes it easier to log in at the console. Use the passwd command as root to do so.

Preparation: bluetooth Debian doesn t correctly identify the Bluetooth hardware address. You can save it off to a file by running hcitool dev > /root/bluetooth-from-raspbian.txt. I don t use Bluetooth, but this should let you develop a script to bring it up properly.

Preparation: Debian archive keyring You will next need to install Debian s archive keyring so that apt can authenticate packages from Debian. Go to the bookworm download page for debian-archive-keyring and copy the URL for one of the files, then download it on the pi. For instance:

wget http://http.us.debian.org/debian/pool/main/d/debian-archive-keyring/debian-archive-keyring_2023.3+deb12u1_all.deb

Use sha256sum to verify the checksum of the downloaded file, comparing it to the package page on the Debian site. Now, you ll install it with:

dpkg -i debian-archive-keyring_2023.3+deb12u1_all.deb

Package first steps From here on, we are making modifications to the system that can leave it in a non-bootable state. Examine /etc/apt/sources.list and all the files in /etc/apt/sources.list.d. Most likely you will want to delete or comment out all lines in all files there. Replace them with something like:

deb http://deb.debian.org/debian/ bookworm main non-free-firmware contrib non-free
deb http://security.debian.org/debian-security bookworm-security main non-free-firmware contrib non-free
deb https://deb.debian.org/debian bookworm-backports main non-free-firmware contrib non-free

(you might leave off contrib and non-free depending on your needs) Now, we re going to tell it that we ll support arm64 packages:

dpkg --add-architecture arm64

And finally, download the bookworm package lists:

apt-get update

If there are any errors from that command, fix them and don t proceed until you have a clean run of apt-get update.

Moving /boot to /boot/firmware The boot FAT partition I mentioned above is mounted at /boot by Raspberry Pi OS, but Debian s scripts assume it will be at /boot/firmware. We need to fix this. First:

umount /boot
mkdir /boot/firmware

Now, edit fstab and change the reference to /boot to be to /boot/firmware. Now:

mount -v /boot/firmware
cd /boot/firmware
mv -vi * ..

This mounts the filesystem at the new location, and moves all its contents back to where apt believes it should be. Debian s packages will populate /boot/firmware later.

Installing the first packages Now we start by installing the first of the needed packages. Eventually we will wind up with roughly the same set Debian uses.

apt-get install linux-image-arm64
apt-get install firmware-brcm80211=20230210-5
apt-get install raspi-firmware

If you get errors relating to firmware-brcm80211 from any commands, run that install firmware-brcm80211 command and then proceed. There are a few packages that Raspbian marked as newer than the version in bookworm (whether or not they really are), and that s one of them.

Configuring the bootloader We need to configure a few things in /etc/default/raspi-firmware before proceeding. Edit that file. First, uncomment (or add) a line like this:

KERNEL_ARCH="arm64"

Next, in /boot/cmdline.txt you can find your old Raspbian boot command line. It will say something like:

root=PARTUUID=...

Save off the bit starting with PARTUUID. Back in /etc/default/raspi-firmware, set a line like this:

ROOTPART=PARTUUID=abcdef00

(substituting your real value for abcdef00). This is necessary because the microSD card device name often changes from /dev/mmcblk0 to /dev/mmcblk1 when switching to Debian s kernel. raspi-firmware will encode the current device name in /boot/firmware/cmdline.txt by default, which will be wrong once you boot into Debian s kernel. The PARTUUID approach lets it work regardless of the device name.

Purging the Raspbian kernel Run:

dpkg --purge raspberrypi-kernel

Upgrading the system At this point, we are going to run the procedure beginning at section 4.4.3 of the Debian release notes. Generally, you will do:

apt-get -u upgrade
apt full-upgrade

Fix any errors at each step before proceeding to the next. Now, to remove some cruft, run:

apt-get --purge autoremove

Inspect the list to make sure nothing important isn t going to be removed.

Removing Raspbian cruft You can list some of the cruft with:

apt list '~o'

And remove it with:

apt purge '~o'

I also don t run Bluetooth, and it seemed to sometimes hang on boot becuase I didn t bother to fix it, so I did:

apt-get --purge remove bluez

Installing some packages This makes sure some basic Debian infrastructure is available:

apt-get install wpasupplicant parted dosfstools wireless-tools iw alsa-tools
apt-get --purge autoremove

Installing firmware Now run:

apt-get install firmware-linux

Resolving firmware package version issues If it gives an error about the installed version of a package, you may need to force it to the bookworm version. For me, this often happened with firmware-atheros, firmware-libertas, and firmware-realtek. Here s how to resolve it, with firmware-realtek as an example:

1. Go to https://packages.debian.org/PACKAGENAME for instance, https://packages.debian.org/firmware-realtek. Note the version number in bookworm in this case, 20230210-5.
2. Now, you will force the installation of that package at that version:

   apt-get install firmware-realtek=20230210-5
   

3. Repeat with every conflicting package until done.
4. Rerun apt-get install firmware-linux and make sure it runs cleanly.

Also, in the end you should be able to:

apt-get install firmware-atheros firmware-libertas firmware-realtek firmware-linux

Dealing with other Raspbian packages The Debian release notes discuss removing non-Debian packages. There will still be a few of those. Run:

apt list '?narrow(?installed, ?not(?origin(Debian)))'

Deal with them; mostly you will need to force the installation of a bookworm version using the procedure in the section Resolving firmware package version issues above (even if it s not for a firmware package). For non-firmware packages, you might possibly want to add --mark-auto to your apt-get install command line to allow the package to be autoremoved later if the things depending on it go away. If you aren t going to use Bluetooth, I recommend apt-get --purge remove bluez as well. Sometimes it can hang at boot if you don t fix it up as described above.

Set up networking We ll be switching to the Debian method of networking, so we ll create some files in /etc/network/interfaces.d. First, eth0 should look like this:

allow-hotplug eth0
iface eth0 inet dhcp
iface eth0 inet6 auto

And wlan0 should look like this:

allow-hotplug wlan0
iface wlan0 inet dhcp
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

Raspbian is inconsistent about using eth0/wlan0 or renamed interface. Run ifconfig or ip addr. If you see a long-named interface such as enx<something> or wlp<something>, copy the eth0 file to the one named after the enx interface, or the wlan0 file to the one named after the wlp interface, and edit the internal references to eth0/wlan0 in this new file to name the long interface name. If using wifi, verify that your SSIDs and passwords are in /etc/wpa_supplicant/wpa_supplicant.conf. It should have lines like:

network= 
   ssid="NetworkName"
   psk="passwordHere"
 

(This is where Raspberry Pi OS put them).

Deal with DHCP Raspberry Pi OS used dhcpcd, whereas bookworm normally uses isc-dhcp-client. Verify the system is in the correct state:

apt-get install isc-dhcp-client
apt-get --purge remove dhcpcd dhcpcd-base dhcpcd5 dhcpcd-dbus

Set up LEDs To set up the LEDs to trigger on MicroSD activity as they did with Raspbian, follow the Debian instructions. Run apt-get install sysfsutils. Then put this in a file at /etc/sysfs.d/local-raspi-leds.conf:

class/leds/ACT/brightness = 1
class/leds/ACT/trigger = mmc1

Prepare for boot To make sure all the /boot/firmware files are updated, run update-initramfs -u. Verify that root in /boot/firmware/cmdline.txt references the PARTUUID as appropriate. Verify that /boot/firmware/config.txt contains the lines arm_64bit=1 and upstream_kernel=1. If not, go back to the section on modifying /etc/default/raspi-firmware and fix it up.

The moment arrives Cross your fingers and try rebooting into your Debian system:

reboot

For some reason, I found that the first boot into Debian seems to hang for 30-60 seconds during bootstrap. I m not sure why; don t panic if that happens. It may be necessary to power cycle the Pi for this boot.

Troubleshooting If things don t work out, hook up the Pi to a HDMI display and see what s up. If I anticipated a particular problem, I would have documented it here (a lot of the things I documented here are because I ran into them!) So I can t give specific advice other than to watch boot messages on the console. If you don t even get kernel messages going, then there is some problem with your partition table or /boot/firmware FAT partition. Otherwise, you ve at least got the kernel going and can troubleshoot like usual from there.

Background Let s assume that these statements are true, which I think are well-supported by available evidence:

1. Every computer system (OS plus applications) that can do useful modern work has security vulnerabilities, some of which are unknown at any given point in time;
2. During the lifetime of that computer system, some of these vulnerabilities will be discovered. For a (hopefully large) subset of those vulnerabilities, timely patches will become available.

Now then, it follows that applying those timely patches is a critical part of having a system that it as secure as possible. Of course, you have to do other things as well good passwords, secure practices, etc but, fundamentally, if your system lacks patches for known vulnerabilities, you ve already lost at the security ballgame.

How to stay patched There is something of a continuum of how you might patch your system. It runs roughly like this, from best to worst:

1. All components are kept up-to-date automatically, with no intervention from the user/operator
2. The operator is automatically alerted to necessary patches, and they can be easily installed with minimal intervention
3. The operator is automatically alerted to necessary patches, but they require significant effort to apply
4. The operator has no way to detect vulnerabilities or necessary patches

It should be obvious that the first situation is ideal. Every other situation relies on the timeliness of human action to keep up-to-date with security patches. This is a fallible situation; humans are busy, take trips, dismiss alerts, miss alerts, etc. That said, it is rare to find any system living truly all the way in that scenario, as you ll see.

What is your system ? A critical point here is: what is your system ? It includes:

• Your kernel
• Your base operating system
• Your applications
• All the libraries needed to run all of the above

Some OSs, such as Debian, make little or no distinction between the base OS and the applications. Others, such as many BSDs, have a distinction there. And in some cases, people will compile or install applications outside of any OS mechanism. (It must be stressed that by doing so, you are taking the responsibility of patching them on your own shoulders.)

How do common systems stack up?

• Debian, with its support for unattended-upgrades, needrestart, debian-security-support, and such, is largely category 1. It can automatically apply security patches, in most cases can restart the necessary services for the patch to take effect, and will alert you when some processes or the system must be manually restarted for a patch to take effect (for instance, a kernel update). Those cases requiring manual intervention are category 2. The debian-security-support package will even warn you of gaps in the system. You can also use debsecan to scan for known vulnerabilities on a given installation.
• FreeBSD has no way to automatically install security patches for things in the packages collection. As with many rolling-release systems, you can t automate the installation of these security patches with FreeBSD because it is not safe to blindly update packages. It s not safe to blindly update packages because they may bring along more than just security patches: they may represent major upgrades that introduce incompatibilities, etc. Unlike Debian s practice of backporting fixes and thus producing narrowly-tailored patches, forcing upgrades to newer versions precludes a minimal intervention install. Therefore, rolling release systems are category 3.
• Things such as Snap, Flatpak, AppImage, Docker containers, Electron apps, and third-party binaries often contain embedded libraries and such for which you have no easy visibility into their status. For instance, if there was a bug in libpng, would you know how many of your containers had a vulnerability? These systems are category 4 you don t even know if you re vulnerable. It s for this reason that my Debian-based Docker containers apply security patches before starting processes, and also run unattended-upgrades and friends.

The pernicious library problem As mentioned in my last category above, hidden vulnerabilities can be a big problem. I ve been writing about this for years. Back in 2017, I wrote an article focused on Docker containers, but which applies to the other systems like Snap and so forth. I cited a study back then that Over 80% of the :latest versions of official images contained at least one high severity vulnerability. The situation is no better now. In December 2023, it was reported that, two years after the critical Log4Shell vulnerability, 25% of apps were still vulnerable to it. Also, only 21% of developers ever update third-party libraries after introducing them into their projects. Clearly, you can t rely on these images with embedded libraries to be secure. And since they are black box, they are difficult to audit. Debian s policy of always splitting libraries out from packages is hugely beneficial; it allows finegrained analysis of not just vulnerabilities, but also the dependency graph. If there s a vulnerability in libpng, you have one place to patch it and you also know exactly what components of your system use it. If you use snaps, or AppImages, you can t know if they contain a deeply embedded vulnerability, nor could you patch it yourself if you even knew. You are at the mercy of upstream detecting and remedying the problem a dicey situation at best.

Who makes the patches? Fundamentally, humans produce security patches. Often, but not always, patches originate with the authors of a program and then are integrated into distribution packages. It should be noted that every security team has finite resources; there will always be some CVEs that aren t patched in a given system for various reasons; perhaps they are not exploitable, or are too low-impact, or have better mitigations than patches. Debian has an excellent security team; they manage the process of integrating patches into Debian, produce Debian Security Advisories, maintain the Debian Security Tracker (which maintains cross-references with the CVE database), etc. Some distributions don t have this infrastructure. For instance, I was unable to find this kind of tracker for Devuan or Raspberry Pi OS. In contrast, Ubuntu and Arch Linux both seem to have active security teams with trackers and advisories.

Implications for Raspberry Pi OS and others As I mentioned above, I m transitioning my Pi devices off Raspberry Pi OS (Raspbian). Security is one reason. Although Raspbian is a fork of Debian, and you can install packages like unattended-upgrades on it, they don t work right because they use the Debian infrastructure, and Raspbian hasn t modified them to use their own infrastructure. I don t see any Raspberry Pi OS security advisories, trackers, etc. In short, they lack the infrastructure to support those Debian tools anyhow. Not only that, but Raspbian lags behind Debian in both new releases and new security patches, sometimes by days or weeks. Live Migrating from Raspberry Pi OS bullseye to Debian bookworm contains instructions for migrating Raspberry Pis to Debian.

Couldn't get a file descriptor referring to the console.

How does Shell Initialization Work? The precise files a shell reads at start-up is somewhat complex, and defined by this excellent chart ¹: For the purposes of what I m trying to fix, there are two paths that matter.

• Interactive login shell startup
• Interactive non-login shell startup

As you can see from the above, trying to distinguish these two paths in bash is an absolute mess. zsh, in contrast, is much cleaner and allows for a clear distinction between these two cases, with login shell configuration files as a superset of configuration files used by non-login shells.

How did we get here? I keep my configuration files in a config repository. Some time ago I got quite frustrated at this whole shell initialization thing, and just linked everything together in one profile file:

.mkshrc -> config/profile
.profile -> config/profile

This appears to have created this mess.

Move to ZSH I ve wanted to move to zsh for a while, and took this opportunity to do so. So my new configuration files are .zprofile and .zshrc instead of .mkshrc and .profile (though I m going to retain those symlinks to allow my old configurations to continue working). mksh is a nice simple shell, but using zsh here allows for more consistency between my home and $WORK environments, and will allow a lot more powerful extensions.

Updating my Prompt ZSH prompts use a totally different configuration via variable expansion. However, it also uses the PROMPT variable, so I set that to the needed values for zsh. There s an excellent ZSH prompt generator at https://zsh-prompt-generator.site that I used to get these variables, though I m sure they re in the zsh documentation somewhere as well. I wanted a simple prompt with user (%n), host (%m), and path (%d). I also wanted a % at the end to distinguish this from other shells.

PROMPT="%n@%m%d%% "

Fixing mksh prompts This worked but surprisingly mksh also looks at PROMPT, leaving my mksh prompt as the literal prompt string without expansion. Fixing this requires setting up a proper shrc and linking it to .mkshrc and .zshrc. I chose to move my existing aliases script to this file, as it also broke in non-login shells when moved to profile. Within this new shrc file we can check what shell we re running via $0:

if [ "$0" = "/bin/zsh" ]   [ "$0" = "zsh" ]   [ "$0" = "-zsh" ]

I chose to add plain zsh here in case I run it manually for whatever reason. I also added -zsh to support tmux as that s what it presents as $0. This also means you ll need to be careful to quote $0 or you ll get fun shell errors. There s probably a better way to do this, but I couldn t find something that was compatible with POSIX shell, which is what most of this has to be written in to be compatible with mksh and zsh². We can then setup different prompts for each:

if [ "$0" = "/bin/zsh" ]   [ "$0" = "zsh" ]   [ "$0" = "-zsh" ]
then
	PROMPT="%n@%m%d%% "
else
	# Borrowed from
	# http://www.unixmantra.com/2013/05/setting-custom-prompt-in-ksh.html
	PS1='$(id -un)@$(hostname -s)$PWD$ '
fi

Setting Console Font in a Better Way I ve been setting console font via setfont in my .profile for a while. I m not sure where I picked this up, but it s not the right way. I even tried to only run this in a console with -t but that only checks that output is a terminal, not specifically a console.

if [ -t 1 ]
then
	setfont /usr/share/consolefonts/Lat15-Terminus20x10.psf.gz
fi

This also only runs once the console is logged into, instead of initializing it on boot. The correct way to set this up, on Debian-based systems, is reconfiguring console-setup like so:

dpkg-reconfigure console-setup

From there you get a menu of encoding, character set, font, and then font size to configure for your consoles.

VIM mode To enable VIM mode for ZSH, you simply need to set:

bindkeys -v

This allows you to edit your shell commands with basic VIM keybinds.

Getting back Ctrl + Left Arrow and Ctrl + Right Arrow Moving around one word at a time with Ctrl and the arrow keys is broken by vim mode unfortunately, so we ll need to re-enable it:

bindkey "^[[1;5C" forward-word
bindkey "^[[1;5D" backward-word

Better History Search But of course we re now using zsh so we can do better than just the same configuration as we had before. There s an excellent substring history search plugin that we can just source without a plugin manager³

source $HOME/config/zsh-history-substring-search.zsh
# Keys are weird, should be ^[[ but it's not
bindkey '^[[A' history-substring-search-up
bindkey '^[OA' history-substring-search-up
bindkey '^[[B' history-substring-search-down
bindkey '^[OB' history-substring-search-down

For some reason my system uses ^[OA and ^[OB as up and down keys. It seems ^[[A and ^[[B are the defaults, so I ve left them in, but I m confused as to what differences would lead to this. If you know, please let me know and I ll add a footnote to this article explaining it. Back to history search. For this to work, we also need to setup history logging:

export SAVEHIST=1000000
export HISTFILE=$HOME/.zsh_history
export HISTFILESIZE=1000000
export HISTSIZE=1000000

Why did it show up twice for tmux? Because tmux creates a login shell. Adding:

echo PROFILE

to profile and:

echo SHRC

to shrc confirms this with:

PROFILE
SHRC
SHRC

For now, profile sources shrc so that running twice is expected. But after this exploration and diagram, it s clear we don t need that for zsh. Removing this will break remote bash shells (see above diagram), but I can live without those on my development laptop. Removing that line results in the expected output for a new terminal:

SHRC

And the full output for a new tmux session or console:

PROFILE
SHRC

So finally we re back to a normal state! This post is a bit unfocused but I hope it helps someone else repair or enhance their shell environment. If you liked this⁴, or know of any other ways to manage this I could use, let me know at fixmyshell@tookmund.com.

1. This chart comes from the excellent Shell Startup Scripts article by Peter Ward. I ve generated the SVG from the graphviz source linked in the article.
2. Technically it has be compatible with Korn shell, but a quick google seems to suggest that that s actually a subset of POSIX shell.
3. I use oh-my-zsh at $WORK but for now I m going to simplify my personal configuration. If I end up using a lot of plugins I ll reconsider this.
4. Or if you ve found any typos or other issues that I should fix.

• history files of shells, repls, anything that uses libreadline
• logfiles
• state of application windows on exit
• recently opened files
• last time application was run
• emacs: bookmarks, ido last directories, backups, auto-save files, auto-save-list

Today, the animation figure Mickey Mouse finally was released from the corporate copyright prison, as the 1928 movie Steamboat Willie entered the public domain in USA. This movie was the first public appearance of Mickey Mouse. Sadly the figure is still on probation, thanks to trademark laws and a the Disney corporations powerful pack of lawyers, as described in the 2017 article in "How Mickey Mouse Evades the Public Domain" from Priceonomics. On the positive side, the primary driver for repeated extentions of the duration of copyright has been Disney thanks to Mickey Mouse and the 2028 movie, and as it now in the public domain I hope it will cause less urge to extend the already unreasonable long copyright duration. The first book I published, the 2004 book "Free Culture" by Lawrence Lessig, published 2015 in English, French and Norwegian Bokm l, touch on the story of Disney pushed for extending the copyright duration in USA. It is a great book explaining problems with the current copyright regime and why we need Creative Commons movement, and I strongly recommend everyone to read it. This movie (with IMDB ID tt0019422) is now available from the Internet Archive. Two copies have been uploaded so far, one uploaded 2015-11-04 (torrent) and the other 2023-01-01 (torrent) - see VLC bittorrent plugin for streaming the video using the torrent link. I am very happy to see the number of public domain movies increasing. I look forward to when those are the majority. Perhaps it will reduce the urge of the copyright industry to control its customers. A more comprehensive list of works entering the public domain in 2024 is available from the Public Domain Review. As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

DOM-XSS vulnerabilities are easy to write, but hard for security teams to catch It is very easy to accidentally introduce a client-side XSS problem. As an example of what not to do, suppose you are setting an element s text to the current URL, on the client side:

// Don't do this
para.innerHTML = location.href;

Unfortunately, an attacker can now manipulate the URL (and e.g. send this link in a phishing email), and any HTML tags they add will be interpreted by the user s browser. This could potentially be used by the attacker to send private data to a different server. Detecting DOM-XSS using vulnerability scanning tools is challenging - typically this requires crawling each page of the website and attempting to detect problems such as the one above, but there is a significant risk of false positives, especially as the complexity of the logic increases. There are already ways to avoid these exploits developers should validate untrusted input before making use of it. There are libraries such as DOMPurify which can help with sanitization.¹ However, if you are part of a security team with responsibility for preventing these issues, it can be complex to understand whether you are at risk. Different developer teams may be using different techniques and tools. It may be impossible for you to work closely with every developer so how can you know that the frontend team have used these libraries correctly?

Trusted Types closes the DevSecOps feedback loop for DOM-XSS, by allowing Ops and Security to verify good Developer practices Trusted Types enforces sanitization in the browser², by requiring the web developer to assign a particular kind of JavaScript object rather than a native string to .innerHTML and other dangerous properties. Provided these special types are created in an appropriate way, then they can be trusted not to expose XSS problems. This approach will work with whichever tools the frontend developers have chosen to use, and detection of issues can be rolled out by infrastructure engineers without requiring frontend code changes.

Content Security Policy allows enforcement of security policies in the browser itself Because enforcing this safer approach in the browser for all websites would break backwards-compatibility, each website must opt-in through Content Security Policy headers. Content Security Policy (CSP) is a mechanism that allows web pages to restrict what actions a browser should execute on their page, and a way for the site to receive reports if the policy is violated. Figure 1: Content-Security-Policy browser communication This is revolutionary, because it allows servers to receive feedback in real time on errors that may be appearing in the browser s console.

Trusted Types can be rolled out incrementally, with continuous feedback Web.dev s article on Trusted Types explains how to safely roll out the feature using the features of CSP itself:

• Deploy a CSP collector if you haven t already
• Switch on CSP reports without enforcement (via Content-Security-Policy-Report-Only headers)
• Iteratively review and fix the violations
• Switch to enforcing mode when there are a low enough rate of reports

Static analysis in a continuous integration pipeline is also sensible you want to prevent regressions shipping in new releases before they trigger a flood of CSP reports. This will also give you a chance of finding any low-traffic vulnerable pages.

Smart security teams will use techniques like Trusted Types to eliminate entire classes of bugs at a time Rather than playing whack-a-mole with unreliable vulnerability scanning or bug bounties, techniques such as Trusted Types are truly in the spirit of Secure by Design build high quality in from the start of the engineering process, and do this in a way which closes the DevSecOps feedback loop between your Developer, Operations and Security teams.

---

1. Sanitization libraries are especially needed when the examples become more complex, e.g. if the application must manipulate the input. DOMPurify version 1.0.9 also added Trusted Types support, so can still be used to help developers adopt this feature.
2. Trusted Types has existed in Chrome and Edge since 2020, and should soon be coming to Firefox as well. However, it s not necessary to wait for Firefox or Safari to add support, because the large market share of Chrome and Edge will let you identify and fix your site s DOM-XSS issues, even if you do not set enforcing mode, and users of all browsers will benefit. Even so, it is great that Mozilla is now on board.