why?

a while ago, i purchased the domain on-a-ps4.lol. it has, up until now, never been used. however, as of recent i have wanted to host various services on reasonable hardware, and what better excuse to do something funny like this - so let’s change that!

requirements

• jailbreakable playstation 4 (firmware 9.00 preferred)
  • this guide will differ based on your ps4’s southbridge!
  • i have the belize model
• usb flash drive/ssd, 12GB or larger, formatted as FAT32
  • i am using a 1TB My Passport Ultra
  • if your drive is too large to format as FAT32 on windows, you can use this tool
• usb keyboard
• ethernet (you could also set up wifi, but this is an exercise for the reader)
• some understanding of ps4 modding
• some understanding of linux

picking a distro

funny story here - this guide was actually rewritten twice! initially, i picked rocky linux, but didn’t enjoy RPM packaging. i then tried debian, which would not init properly after a reboot - and i have no idea why! after some consideration, i chose alpine linux.

packaging alpine for the playstation

there are decent (albeit ad-riddled) guides on how to do plenty of neat things on ps4linux.com, including how to port your own distro, so i started there.

here are my own alpine-specific instructions:

setup

• download the “Standard” ISO for x86_64 from the alpine linux website
• install and setup Oracle VM VirtualBox, and the VirtualBox Extension Pack
• add your VM:
  • select the alpine ISO you downloaded
  • make the type “Linux” and the version “Other Linux (64-bit)”
  • give it 4-8GB RAM, and ensure the virtual disk image is in VDI or VHD format
  • you should only need around 2GB of storage on the virtual disk, but make sure you tick “Pre-allocate Full Size”
• power the VM on
• you should be met with a login prompt
• log in as root - it has no password
• run setup-alpine, and follow the setup as normal
• when you reach the disk options, choose none - we’re not installing here
• in the same regard, choose none for config location
• pick the default apk cache location (/var/cache/apk)
• proceed to the next section

packaging

to put the distro on the ps4, we need to create a tarball of the filesystem:

• we need the xz utils first, so apk add xz (controversial, i know)
• then, run this command to create a tarball of your handcrafted alpine install:

tar --exclude=ps4alpine.tar.xz --exclude=.modloop --exclude=media/cdrom/* --exclude=var/cache --exclude=run --exclude=proc --exclude=dev --exclude=sys -cvJpf ps4alpine.tar.xz /

• this may take some time, so sit back, put on some good music, and watch the magic happen.
• once done, we need to copy our file to the virtual disk we made earlier in order to extract it from the VM
• create a partition with fdisk:
  • fdisk /dev/sda
  • then, like a video game cheat code, type n, enter, p, enter, 1, enter, enter, enter, w, enter
• then, format it as fat32 with mkfs.vfat -F 32 /dev/sda1
• now, move our tarball to it:

mount -t vfat /dev/sda1 /mnt
mv ps4alpine.tar.xz /mnt

• then, power off the VM and proceed to the next section

installing alpine on the playstation

ps4linux.com suggests a “new method” for installing distributions on the playstation these days - involving extracting the archive yourself with a tool such as Rufus or Balena Etcher. unfortunately, i could not figure out how to package my own distro to support this, so for now, let’s use the “old method”:

• launch your ps4 exploit host of choice, jailbreak, and deploy GoldHEN
  • i am using kameleon’s 9.00 host
• download or compile a kernel image (bzImage) for your ps4’s southbridge
  • i am using the 5.15.15 belize kernel with /dev/net/tun support by noob404
• download an initramfs image
  • i am using noob404’s initramfs
• using something like 7zip, open your VM’s .vdi file:
  • grab the ps4alpine.tar.xz tarball created earlier
  • rename this to psxitarch.tar.xz
• place all of these files onto the root of your usb drive, and connect it to your ps4
• deploy the 1GB VRAM linux payload from your exploit host
• the playstation should reboot after a short while
• if all is well, you will be dropped into rescueshell
• connect a keyboard
• run exec install-psxitarch.sh
• the ps4 should begin extracting the alpine distro you packaged earlier
• once it is done, it should go straight to the login screen
  • despite this, it did not for me, so i just ran resume-boot
• proceed to the next section

post-installation

congratulations! your ps4 is now, technically, an alpine server, and it should be accessible over SSH.

however, we still have some cleanup to do, so login:

recommended

• install nano
• edit /etc/apk/repositories and remove /media/cdrom/apks
• edit /etc/motd to remove the pre-setup one
  • i pasted some nice ascii text in here
• configure doas to permit persist :wheel
• add your user to the wheel group
• configure your ssh key in ~/.ssh/authorized_keys
• install bash and change your shell to it
  • you may wish to configure bash - i pulled the files from my debian vps

optional

• install pfetch from source
• install git
• install tmux
• disable ssh root & password access

what next?

once i had the ps4 server up and running, i ran numerous tests to ensure it would hold up under load - which it did. i moved it to a better location, added it to my tailnet, and set up nginx as well as frp for the sake of protecting my ip address via reverse proxy.

overall, this experiment was a success - and as of now, the playstation runs an akkoma instance at fedi.on-a-ps4.lol and an srb2 server at srb2.on-a-ps4.lol.

thank you for reading.