Boot options: cmdline.txt and vram.txt

Two small files on the USB drive's FAT32 boot partition control how Linux starts: cmdline.txt holds the kernel parameters, vram.txt the GPU's dedicated memory. This page is the reference for both; other pages link here for the details.

Edit cmdline.txt

cmdline.txt must stay one single line. Add an option at the end with a space in front of it; delete it the same way.

• On the PS5, in Linux: the boot partition is mounted at /efi on PS5 Bazzite Deck and at /boot/efi on most other images. These commands find it by themselves:

  E=$(for d in /efi /boot/efi; do sudo test -f $d/cmdline.txt && echo $d && break; done)
  sudo cat $E/cmdline.txt                                                  # show
  sudo sed -i 's/[[:space:]]*$/ amdgpu.force_1080p=1/' $E/cmdline.txt      # add an option
  sudo sed -i 's/ *amdgpu\.force_1080p=1//' $E/cmdline.txt                 # remove it again

• From a PC: plug the USB drive in and open the small FAT32 partition, see Edit cmdline.txt from Windows.

Changes take effect at the next start with the loader.

The default line

Most images:

cmdline.txt

root=LABEL=<image> rw rootwait console=ttyTitania0 console=tty0 mitigations=off idle=halt preempt=full video=DP-1:1920x1080@60

PS5 Bazzite Deck:

cmdline.txt

root=LABEL=bazzite-deck rw rootwait console=ttyTitania0 console=tty0 mitigations=off idle=halt preempt=full

• root=LABEL=…: the partition Linux starts from; an M.2 install changes it.
• console=ttyTitania0: the console's serial port, under Sony's name for it. Only matters when you debug over a serial cable.
• mitigations=off: the CPU vulnerability mitigations are off for speed. mitigations=auto turns them back on.
• idle=halt: try removing it if you notice micro-stuttering, see GPU.
• video=DP-1:1920x1080@60: starts at 1080p60. Remove it if you get a black screen; PS5 Bazzite Deck doesn't use it.

Parameter reference

Kernels: all = every current kernel (upstream, rmuxnet's, PS5 Bazzite Deck) · BD = PS5 Bazzite Deck only · upstream = upstream main and rmuxnet's kernel, not PS5 Bazzite Deck.

Display and HDMI

Parameter	What it does	Kernels	Details
amdgpu.force_1080p=1	Only allows 1080p60: a safe mode to get a picture back. Remove it afterwards	all	Display recovery
video=HDMI-A-1:3840x2160@60	Forces a 4K mode	all	HDMI
drm.edid_firmware=…	Loads a custom EDID file	all	Custom EDID
hdmi.frl_4k120=0	Never offers 4K at 120 Hz (upstream: turns native FRL off altogether)	all	HDMI
ps5_cec.one_touch_play=0	Doesn't turn the TV on and switch it to the console at boot	all	HDMI
usbc_dp.enable=1	DisplayPort output on the front USB-C port (USB-C displays, PS VR2). Not with the boot drive in that port	all	HDMI
hdmi.vrr=0	Never offers VRR. Steam's VRR setting also turns it off	BD	VRR
hdmi.rgb_range=<0,1,2>	RGB range flag sent to the TV: 1 full (default), 2 limited, 0 none	BD	RGB range
hdmi.icc_trace=1	Logs every message to the HDMI chip and its reply. Debugging only, very noisy	BD
hdmi.vrr_measure=1	Logs the measured frame intervals every 2 seconds while VRR is on. Debugging only	BD
hdmi.frl_yuv420=<0,1,2>	4:2:0 over native FRL: 0 off, 1 as a fallback (default), 2 preferred	upstream
hdmi.frl_recovery=0	Turns off the retries after a failed FRL link	upstream
hdmi.allm=<0,1,2>	Auto low latency mode: 0 off, 1 while the content type is Game (default), 2 always	upstream
hdmi.hdcp_mode=<n>	HDCP: 0 on, 1 off, 2 on with HDCP 2.2, 3 off with the HDCP 2.2 bit set (default), -1 keep	upstream
hdmi.extended_modes=<0,1,2>	Modes the chip can drive but the EDID doesn't list: 0 off, 1 offered (default), 2 preferred	upstream

On upstream kernels, /sys/module/hdmi/parameters/ also shows read-only state: frl_rate, frl_rate_max, frl_failed (write N to try FRL again), allm_sink, allm_active and recovery_status.

GPU and memory

Parameter	What it does	Kernels	Details
amdgpu.ps5_cu_unlock=3	Unlocks the disabled compute units (40 instead of 36). Original PS5 and Slim only; artefacts on some consoles	all	40 CU unlock
ttm.pages_limit=…	Raises how much system memory the GPU may borrow (GTT)	all	VRAM
ps5_gpufreq.temp_limit=<50-95>	Thermal limit of the GPU clock governor, 85 °C by default	upstream, BD	GPU
amdgpu.ps5_viola_fw=0	PS5 Pro: use the base PS5's GPU firmware (36 CUs). For comparisons and troubleshooting	upstream, BD	PS5 Pro

USB and storage

Parameter	What it does	Kernels	Details
usb-storage.quirks=xxxx:yyyy:u	Turns off UAS for one USB drive (xxxx:yyyy from lsusb): for SSDs or enclosures that disconnect or freeze	all	Storage
rootwait rootdelay=60	Waits up to 60 seconds for a slow USB drive	all	Storage
usbcore.autosuspend=-1	Stops USB devices from sleeping (already the default in PS5 Bazzite Deck's kernel)	all	Storage

Bluetooth

Parameter	What it does	Kernels	Details
btusb.ps5_tx_ep=<n>	Bluetooth send endpoint on the Slim's MediaTek chip	rmuxnet, BD	Bluetooth
btusb.ps5_ep_resync=1	PS5 Pro: resyncs the Bluetooth endpoints after the firmware setup	rmuxnet	Bluetooth

vram.txt

vram.txt sets the GPU's dedicated memory. The default is 512 MB, and the GPU borrows more from system memory as needed. The value is a hexadecimal byte count, not megabytes: see VRAM for the format and a table of sizes. A large fixed value takes that memory away from the system; memory-hungry games (on the Pro, for example Hogwarts Legacy and Dragon's Dogma 2) run better with a smaller one plus ttm.pages_limit.

Next steps

• PS5 Bazzite Deck: After installing: PS5 Bazzite Deck
• Official or self-built images: Other images