Flash the image to USB
You have an image file from Choose your image: ps5-bazzite-deck.img, or an official .img.xz.
The drive must be 32 GB or larger for PS5 Bazzite Deck, 64 GB or larger for the official images; an external SSD makes everything faster. Flashing erases the drive.
Linux or macOS:
# Find your drive first with lsblk (Linux) or diskutil list (macOS)
sudo dd if=ps5-ubuntu2604.img of=/dev/sdX bs=4M status=progress conv=fsync
On Linux you can also flash a compressed .img.xz directly, without decompressing it first:
xzcat ps5-ubuntu2604.img.xz | sudo dd of=/dev/sdX bs=4M status=progress conv=fsync
sync
Double-check the target device. dd overwrites whatever you point it at without asking.
Windows: use Rufus. balenaEtcher, which some READMEs suggest, has produced drives that don't boot with these images.
Plug the drive into the PS5
Use a fast port, see USB ports; the slow USB 2.0 port is for a controller or keyboard.
Optional: edit cmdline.txt from Windows
The kernel command line lives in cmdline.txt on the FAT32 partition of the USB drive. See Kernel parameters for what you can put in it.
Without WSL: use Explorer++ (run it as administrator). It can open the FAT32 EFI partition where cmdline.txt lives.
With WSL: attach the drive to WSL, then edit the file from Linux.
# In PowerShell as administrator: find the drive number
Get-CimInstance -Query "SELECT * from Win32_DiskDrive"
# Attach partition 1 of that drive to WSL
wsl --mount \\.\PHYSICALDRIVE1 --partition 1 --type vfat
# Then, inside WSL
ls /mnt/wsl/PHYSICALDRIVE1p1/
nano /mnt/wsl/PHYSICALDRIVE1p1/cmdline.txt
Next: Booting Linux.