Configuration Through Command Line Parameters

Bliss OS (and the Bass builds) utilizes an expanded configuration layer, our Broad Apparatus Support System (Bass for short) allows one generic .iso to be configured through kernel command line parameters on a per-device basis. This allows end users to fine tune the performance of the OS to the capabilities of the device.

Intro to Kernel Command Line Parameters

We use Grub, Refind, or other Linux bootloaders to boot the device once installed. The menu entry is how we also pass many of our parameters for configuring the device as well. Here is an example of a typical menu entry for Grub for Bliss OS 15.8.x:

menuentry 'Android-x86' --class android-x86 {

   search --file --no-floppy --set=root /AndroidOS/android.boot

   linux /AndroidOS/kernel root=/dev/ram0 SRC=/AndroidOS fbcon=rotate:1 mem_sleep_default=shallow acpi_sleep=s3_mode HWC=drm_minigbm_celadon GRALLOC=minigbm androidboot.selinux=permissive quiet DATA=

   initrd /AndroidOS/initrd.img

}

The line we are targeting for our configuration is the one that starts with “linux /AndroidOS/kernel”. Here are some of the explanations for the configs we support.

If your Grub menu entry looks a little different, and has some of the commands at the top, you can also edit there to add your configuration preferences.

setparams 'Android-x86 Intel' 'fbcon=rotate:1' 'mem_sleep_default=shallow' 'acpi_sleep=s3_mode' 'HWC=drm_minigbm_celadon' 'GRALLOC=minigbm' 'quiet'
   savedefault
   set root=$android
   ....

Supported Parameters:

Warning: Note that not all of the configs listed here are available in the open-source Bliss OS source, but are available through licensing the Android-Generic Project add-on for that feature, or licensing the use of our Bass builds or Bass source (which comes with most available AG add-on's) for your organization

Here are a few of the supported parameters that we support, organized by stack.

Debugging:

This will enable logging or low level debugging console before the system starts to boot Android.

This is a root console, and can be used for testing or troubleshooting. Pressing exit, twice will continue with the Android boot process.

Command:

DEBUG=*

Options:

1: high-level debugging console (logs to /tmp/log)
2: low-level debugging console (logs to /data/log.txt & /tmp/log)

You will also need to enable the console if you wish to use alt-f1/f7 virtual consoles:

androidboot.enable_console=1

Other debugging options:

DEBUG_VSOCK=1: Debug console over VSOCK (virtual machines)

Example:

DEBUG=2

Graphics Stack:

This includes a number pf parameters that we can use to customize the stack to our hardware's capabilities.

Hardware Composer:

This allows us to include multiple hardware-composer options, and select the ones we want to target per-device.

By default, if you set HWC without anything like HWC="", Bliss will use drmfb-composer

Command:

HWC=*

Options:

drm: Use drm_hwcomposer
drm_celadon: Use Project Celadon's fork of drm_hwcomposer
drm_minigbm: Use drm_hwcomposer with minigbm support
drm_minigbm_celadon: Use Project Celadon's fork of drm_hwcomposer with minigbm support

Example:

HWC=drm_minigbm_celadon

Using DRMFB HWC backend:

HWC_IS_DRMFB: Forces the compositor to use DRMFB (Options: 1,0)

Setting HWC mode info:

(Compatible only with drm_celadon and drm_minigbm_celadon hwcomposer)

MULTI_PLANE: Enabled hwcomposer planes (Options 1,0)
MULTI_PLANE_NUM: Specifies the number of planes
HWC_PREFER_MODE: Specifies the devices preferred mode setting
CONNECTOR_ID: Specifies the devices connector ID
MODE_ID: Specifies the devices mode ID
MULTI_REFRESH_RATE: Enables variable refresh rate (Options: 1,0)

Gralloc:

We pair up our Gralloc options to work with certain HWC options.

Command:

GRALLOC=*

Options:

gbm: This is gbm_gralloc and it's compatible with drm & drm_celadon
gbm_hack: This is gbm_gralloc but with a HACK commit to fix some issue with iris or nouveau. It's compatible with drm & drm_celadon
minigbm: This is minigbm and it's compatible with drm_minigbm, drm_minigbm_celadon
minigbm_arcvm: This is minigbm but made specifically for virgl by Google, compatible with drm_minigbm, drm_minigbm_celadon
minigbm_gbm_mesa: This is minigbm made by rsglobal which he tried to port gbm_gralloc philosophy to minigbm. Compatible with drm_minigbm, drm_minigbm_celadon

Example:

GRALLOC=minigbm_gbm_mesa

Gralloc4 Configurations:

In some cases, we are working with hardware that requires Gralloc4 specs. We can force minigbm to use Gralloc4 by using:

GRALLOC4_MINIGBM: Force using gralloc4 with minigbm (only compatible with drm_minigbm_celadon)

ANGLE & software rendering:

ANGLE is available in BlissOS 14.10 and above, if you have a device that can use Vulkan, you can try ANGLE with Vulkan backend using ANGLE=1.
Alternatively, you can also use SwiftShader Vulkan with ANGLE as a software rendering solution if you are running it inside something like a virtual machine by setting nomodeset ANGLE=1 or HWACCEL=0 ANGLE=1
There's one more option for software rendering, which is the legacy SwiftShader EGL, simply set nomodeset or HWACCEL=0 to use it.
Mesa can also render in software or over Vulkan (Bass builds):
- EGL=mesa MESA_LLVMPIPE=1: Mesa EGL on the llvmpipe software renderer.
- EGL=mesa MESA_ZINK=1: Mesa EGL through Zink (OpenGL on top of the Vulkan driver).
For some virtualized methods uses, you may have a blinking cursor artifact that shows on screen. To remove this artifact, include the following boot flag: vt.global_cursor_default=0

NOTE : You may want to turn on Color Inversion when using software rendering because the color might be inverted

GLES Overrides:

We can override the target GLES implimentation within the OS by setting the FORCE_GLES boot flag.

FORCE_GLES: Override GLES version from Mesa (Options: 3.0 [default], 3.1, 3.2)

RenderEngine Overrides:

We can override the default RenderEngine backend (threaded) in Android by using the following command:

FORCE_RENDERENGINE: (Options: threaded, skiaglthreaded)

GPU Override:

This allows us to target a specific DGPU on the device:

GPU_OVERRIDE: (Options: whatever your devices target /dev/dri/* is)

Video Resolution:

HWC_HIDL: Selects which hardware composer service starts (Options: default-2.4 [default], default-2.1 [default with HWACCEL=0 and on radeon], drmfb) Setting the video kernel cmdline flag will also set Android's drm_mode and UVESA_MODE. See https://docs.kernel.org/fb/modedb.html for video mode support See https://docs.kernel.org/fb/fbcon.html for more info on fbcon

Media Stack:

Bluetooth:

There are a couple of customizations available for the Bluetooth stack in our builds.

BTUART_PORT: Specifies the known bluetooth UART port
BTLINUX_HAL: Force use of the legacy btlinux HAL for bluetooth (required for legacy devices)

Audio HAL:

By default, we include a couple audio HAL's to choose from for the OS.

AUDIO_PRIMARY: This will use the specified HAL (Options: x86[default] & x86_celadon)

Video Encoders/Decoders:

By default, BlissOS will use AOSP's codec2 software decoder. We also offer a few various options that allow you to select different video decoders stack options:

CODEC2_LEVEL: This will set the C2 level (default value is 4, you can disable codeec2 completely with '0').
FFMPEG_OMX_CODEC: This will enable OMX version of FFMPEG codecs (disable codec2 with CODEC2_LEVEL=0 to use this codecs).
FFMPEG_CODEC2_PREFER: This will force Bliss to use codec2 version of FFMPEG codecs by default.
FFMPEG_HWACCEL_DISABLE: This will disable hardware accelleration for the FFMPEG codecs.
FFMPEG_CODEC_LOG: This will show more log of FFMPEG codecs, enable if you want to debug it
FFMPEG_CODEC2_DEINTERLACE & FFMPEG_CODEC2_DEINTERLACE_VAAPI: configuring deinterlacing option for FFMPEG codec2, you can find the options in this commit made by Micheal Goffioul
OMX_NO_YUV420: This will force the system to not use YUV420 color format on OMX codec (fixes some black or glitchy screens, use it with CODEC2_LEVEL=0)
FFMPEG_CODEC2_DRM: turn on/off DRM prime handle on ffmpeg codecs, 0 is the default because not any Gralloc supporting it.

Networking:

BTLINUX_HAL: Force use of the legacy btlinux HAL for bluetooth (required for legacy devices). Legacy: older BlissOS releases only, Bass builds ignore it. We include the ability to have Ethernet appear as WiFi as some appli/cations will not work without a WiFi or Cell connection present. In order to enable this mode, we use the VIRT_WIFI boot flag: VIRT_WIFI=1

Disk Access:

(Available on Bliss OS 14.1x, 15.8.x, & 16.x) For use cases where you are dual booting or sharing system resources with multiple drives, you might want to enable automatic mounting of all disks within Android: INTERNAL_MOUNT=1: Allows device to mount other internal drives on boot.

(Available through Android-Generic Add-On & add-ons for Bass builds)

AUDIO_OUT: Forces the default audio output instead of auto-detecting it (Options: hdmi, speaker) (Bass builds)

SDCARDFS_DISABLE=1: Disables the use of SDCardFS in the OS SET_SDCARDFS_ENABLED: Same as above (Options: 1, 0) SET_CASEFOLD_ENABLED: Enables/Disables casefold (Options: 1, 0)

CODEC2_LEVEL: This will set the C2 level (default value is 4, you can disable codeec2 completely with '0'). Legacy: older BlissOS releases only, Bass builds ignore it.
FFMPEG_OMX_CODEC: This will enable OMX version of FFMPEG codecs (disable codec2 with CODEC2_LEVEL=0 to use this codecs). Legacy: Bass builds no longer ship OMX codecs.
FFMPEG_CODEC2_PREFER: This will force Bliss to use codec2 version of FFMPEG codecs by default. Legacy: older BlissOS releases only, Bass builds ignore it.

USB Mode Functions:

*   `FFMPEG_CODEC2_DEINTERLACE`: `auto` (default, VA-API deinterlacing for hardware frames, software otherwise), `software`, or `none`
*   `FFMPEG_CODEC2_DEINTERLACE_VAAPI`: VA-API deinterlace mode: `default`, `bob`, `weave`, `motion_adaptive`, `motion_compensated`

OMX_NO_YUV420: This will force the system to not use YUV420 color format on OMX codec (fixes some black or glitchy screens, use it with CODEC2_LEVEL=0). Legacy: Bass builds no longer ship OMX codecs.
FFMPEG_CODEC2_PIXEL_FORMAT: Overrides the pixel format the FFMPEG codec2 decoders output (sets debug.ffmpeg-codec2.pixel_format). Options: RGBX_8888, YUV_420, RGB_565. Without it, the format is picked from the GPU: Intel (i915 and xe) uses RGBX_8888, AMD on minigbm uses YUV_420, virtio / nouveau / radeon use RGBX_8888, everything else RGB_565.
- If hardware-decoded video shows green or striped frames (seen with Intel Gen12 / Xe GPUs on older builds), boot with FFMPEG_CODEC2_PIXEL_FORMAT=RGBX_8888. Allows switching default USB/ADB functions via cmdline
FORCE_USE_ADB_CLIENT_MODE: Forces USB into ADB Client mode (0=off, 1=on, 2=USB+TCP insecure ADB, 3=same as 1 plus adb_enabled / adb_wifi_enabled). Property list and runtime on/off: ADB Client Mode Overrides.
FORCE_USE_ADB_MASS_STORAGE: Force enable ADB Mass Storage mode ofver USB (0=off, 1=on)

Power & Memory:

VIRT_WIFI_NAME: Name of the virtual Wi-Fi network shown to apps (default wifi_eth)

Power:

Default Sleep Mode Options:

The following are the options for mem_sleep_default (suggested values are in bold):

deep: This option will choose the deepest sleep state supported by the hardware.
shallow: This option will choose the shallowest sleep state supported by the hardware.
s2idle: This option will choose the S2 idle state. NTFS:

VOLD_USE_NTFS3=1: Mounts NTFS drives with the kernel ntfs3 driver instead of ntfs-3g USE_NTFS3=1: Same as above (also used when booting from an NTFS partition) BOOT_USE_NTFS3=1: Only mount the NTFS partition Bliss is installed on with ntfs3 (instead of ntfs-3g)

Boot device:

ROOTWAIT: Seconds the initrd waits for the system partition to appear before giving up (default 30). Raise it for slow USB or SD card boots.

s3bios: This option will choose the S3 BIOS state.
s3standby: This option will choose the S3 standby state.
mem: This option will choose the memory state.
off: This option will choose the off state.

The default value for mem_sleep_default is deep, and the suggested value for most devices is shallow

SET_USB_CONFIG: Sets the default USB functions (persist.sys.usb.config), comma separated. Example: SET_USB_CONFIG=mtp,adb Example:

mem_sleep_default=shallow

The following are the options for acpi_sleep (suggested values are in bold):

s3_bios: This option will use the BIOS-provided S3 sleep state.
s3_mode: This option will use the kernel's own S3 sleep state.
s4_nohwsig: This option will disable the ACPI hardware wake signal for S4 sleep.
old_ordering: This option will use the old ACPI sleep state ordering.
nonvs: This option will not save non-volatile storage (NVS) to disk before entering S4 sleep.
sci_force_enable: This option will force the ACPI SCI interrupt to be enabled.

The default value for acpi_sleep is s3_bios, and the suggested value for most devices is s3_mode.

Example:

acpi_sleep=s3_mode

Other Sleep Mode Options

There are a number of other Linux kernel command line options that can be used to configure sleep mode settings. Some of these options include:

acpi_sleep_default: This option specifies the default sleep mode for the system. The possible values are:
- s3: Standby mode
- s4: Hibernate mode
- s5: Off mode

Example:

acpi_sleep_default=s3

suspend_console: This option specifies whether to suspend the console when the system enters sleep mode. The possible values are:
- on: The console will be suspended.
- off: The console will not be suspended.

Example:

suspend_console=on

no_console_suspend: This option specifies that the console should not be suspended when the system enters sleep mode. This option overrides the value of the suspend_console option.

Example:

no_console_suspend

SUSPEND_TYPE: Set suspend type. options: mem, disk, freeze mem, freeze disk
PWR_OFF_DBLCLK: Set power off double click. options: true,false
SLEEP_STATE: Override default sleep.state property for the device. If your device supports deep sleep states, this defaults to mem, otherwise it defaults to freeze. (Options: mem, freeze, force)

Intel Power Options:

(Available through Android-Generic Add-On & add-ons for Bass builds)

INTEL_PSTATE_CPU_MIN_PERF_PCT/INTEL_PSTATE_CPU_MAX_PERF_PCT: Allow for adjusting intel_pstate max/min freq on boot by setting the min/max pref percent

Example:

INTEL_PSTATE_CPU_MIN_PERF_PCT=5 INTEL_PSTATE_CPU_MAX_PERF_PCT=50

CPU_ENERGY_PERFORMANCE_PREF: Allow for adjusting cpu energy performance Normal options: default, performance, balance_performance, balance_power, power

Example:

CPU_ENERGY_PERFORMANCE_PREF=balance_power

INTEL_PSTATE_STATUS: Set cpu scaling at boot (ie set pstate status to active/passive at boot)

Example:

INTEL_PSTATE_STATUS=passive

Generic Power Options:

(Available through Android-Generic Add-On & add-ons for Bass builds)

SET_SCREEN_OFF_TIMEOUT: Set screen off timeout. options: integer in milliseconds
SET_SLEEP_TIMEOUT: Set screen sleep timeout. options: integer in milliseconds
SET_POWER_ALWAYS_ON: Set power always on. options: true or false
SET_STAY_ON_WHILE_PLUGGED_IN: Set stay on while plugged in. options: true or false

Generic Performance Options:

(Available through Android-Generic Add-On & add-ons for Bass builds)

FORCE_POWER_PROFILE: Sets the power_profile value. Options: ondemand, hotplug, interactive, performance
FORCE_IO_PROFILE: Sets the io_profile value. Options: ondemand, hotplug, interactive, performance
FORCE_CPU_GOV: Sets the cpu_governor value. Options: ondemand, hotplug, interactive, performance
FORCE_CPU_SCALING_GOV: Sets the cpu_scaling_governor value. Options: ondemand, hotplug, interactive, performance
FORCE_GPU_SCALING_GOV: Sets the gpu_scaling_governor value. Options: ondemand, hotplug, interactive, performance
FORCE_THERMAL_THROTTLE_ENABLE: Sets the thermal_throttle_enable value. Options: (true|false)
FORCE_HW_TIMEOUT_MULTIPLIER: Force hw timeout multiplier, # X 5s. Options: (integer)

Memory:

(Available through Android-Generic Add-On & add-ons for Bass builds)

FORCE_MEMORY_TRIM_ENABLE: Sets the memory_trim_enable value
Options: (true|false)
FORCE_MIN_FREE_MEMORY: Sets the minimum free ram limit

Example value: "512M"
FORCE_MAX_FREE_MEMORY: Sets the max free ram limit

Example value: "1024M"
FORCE_OOM_SCORE_ADJ: Sets the oom_score_adj value

Example value: "100"
FORCE_ENFORCE_MIN_FREE_MB: Sets the enforce_min_free_mb value

Example value: "1024"
FORCE_SCHED_MIN_FREE_PAGES: Sets the sched_min_free_pages value

Example value: "1024"

Sleep and CPU options (Bass builds):

PWR_NON_BOOT_CPU: Sets power.nonboot-cpu-off, whether non-boot CPUs are taken offline during sleep. Options: 0, 1
POWER_NONBOOT_CPU_OFF: 1 sets the same power.nonboot-cpu-off property at boot complete (some device models turn it on automatically)
IGNORE_DEFAULT_DISPLAY_SLEEP: Keep running when the built-in display sleeps. Options: (true|false)
IGNORE_HDMI_DISPLAY_SLEEP: Keep running when an HDMI display sleeps. Options: (true|false)
THERMALD_DISABLE: 1 keeps thermald from starting; 0 starts it on device models where it is off by default
FORCE_SCHED_MIN_ACTIVE_PAGES: Sets the sched_min_active_pages value

Example value: "512"
FORCE_SCHED_MIN_INACTIVE_PAGES: Sets the sched_min_inactive_pages value

Example value: "256"
FORCE_SCHED_MIN_DIRTY_PAGES: Sets the sched_min_dirty_pages value

Example value: "128"
FORCE_SCHED_MIN_WRITEBACK_PAGES: Sets the sched_min_writeback_pages value

Example value: "64"
FORCE_SCHED_MIN_RECLAIMABLE_PAGES: Sets the sched_min_reclaimable_pages value

Example value: "32"
FORCE_SCHED_MIN_UNRECLAIMABLE_PAGES: Sets the sched_min_unreclaimable_pages value

Example value: "16"

LMKD:

(Available through Android-Generic Add-On & add-ons for Bass builds)

FORCE_LOW_MEM: Forces the low_mem mode in Android to the specific true/false value
Default = false (unless device is detected to have less than 2GB RAM)
FORCE_MINFREE_LEVELS: Use free memory and file cache thresholds for making decisions when to kill. This mode works the same way kernel lowmemorykiller driver used to work. AOSP Default = false, Our default = true

Other options available for specialized builds:

FORCE_LMK_ENABLE: Force enable LMK Daemon
Default = false (unless device is detected to have less than 2GB RAM)
FORCE_KILL_HEAVIEST_TASK: Kill heaviest eligible task (best decision) vs. any eligible task (fast decision).
Default = false
FORCE_SWAP_FREE_LOW_PERCENTAGE: Level of free swap as a percentage of the total swap space used as a threshold to consider the system as swap space starved.

Default for low-RAM devices = 10, for high-end devices = 20
FORCE_THRASHING_LIMIT: Number of working set defaults as a percentage of the file-backed pagecache size used as a threshold to consider system thrashing its pagecache.

Default for low-RAM devices = 30, for high-end devices = 100
FORCE_LMK_CRITICAL: The possible values of oom_adj range from -17 to +15 (Default=0).

The higher the score, more likely the associated process is to be killed by OOM-killer. If oom_adj is set to -17, the process is not considered for OOM-killing.
FORCE_PSI_PARTIAL_STALL_THRESHOLD: The partial PSI stall threshold, in milliseconds, for triggering low memory notification. If the device receives memory pressure notifications too late, decrease this value to trigger earlier notifications. If memory pressure notifications trigger unnecessarily, increase this value to make the device less sensitive to noise. Default = false (unless device is detected to have less than 2GB RAM)
Legacy: older BlissOS releases only, Bass builds ignore it.
FORCE_MINFREE_LEVELS: Use free memory and file cache thresholds for making decisions when to kill. This mode works the same way kernel lowmemorykiller driver used to work. AOSP Default = false, Our default = true
Legacy: older BlissOS releases only, Bass builds ignore it.

Recommended: 700
FORCE_THRASHING_LIMIT_DECAY: The thrashing threshold decay expressed as a percentage of the original threshold used to lower the threshold when the system doesn’t recover, even after a kill. If continuous thrashing produces unnecessary kills, decrease the value. If the response to continuous thrashing after a kill is too slow, increase the value.

High end: 10 Low end: 50
FORCE_SWAP_UTIL_MAX: The max amount of swapped memory as a percentage of the total swappable memory. When swapped memory grows over this limit, it means that the system swapped most of its swappable memory and is still under pressure. This can happen when non-swappable allocations are generating memory pressure which can not be relieved by swapping because most of the swappable memory is already swapped out. The default value is 100, which effectively disables this check. If the performance of the device is affected during memory pressure while swap utilization is high and the free swap level is not dropping to Sets the swap_free_low_percentage, decrease the value to limit swap utilization.

High end: 100 Low end: 100

Logging/Logd:

(Available through Android-Generic Add-On & add-ons for Bass builds)

SET_MAX_LOGD: Sets the maximum logd value
- Options: 1 = on, 0 = off
SET_LOGCAT_DEBUG: Enables logcat debugging
- Options: true, false

OTA Updates:

(Available through Android-Generic Add-On & add-ons for Bass builds)

SET_CUSTOM_OTA_URI: Sets the custom URL for OTA updates
- Example:

SET_CUSTOM_OTA_URI=https://192.168.1.1/updates/update.json

Features:

Kiosk Mode:

(Available through Android-Generic Add-On & add-ons for Bass builds)

FORCE_DISABLE_NAVIGATION: Force disable navigation bar. Options: (true|false)
FORCE_DISABLE_NAV_HANDLE: Force disable gesture navigation handle. Options: (true|false)
FORCE_DISABLE_NAV_TASKBAR: Force disable navigation taskbar. Options: (true|false)
FORCE_DISABLE_STATUSBAR: Force disable statusbar. Options: (true|false)
FORCE_DISABLE_RECENTS: Force disable SystemUI recents. Options: (true|false)
- Legacy: older BlissOS releases only, Bass builds ignore it.
FORCE_HIDE_NAVBAR_WINDOW: Force hide navigation bar window. Options: 0, 1

Other options available for specialized builds:

FORCE_SET_MAX_RECENTS: Sets the config_maxRecents value
Options:
- 0: Disables the recent apps menu.
- 1: Displays up to 1 app in the recent apps menu.
- 2: Displays up to 2 apps in the recent apps menu.
- 3: Displays up to 3 apps in the recent apps menu.
- 4: Displays up to 4 apps in the recent apps menu.
- 5: Displays up to 5 apps in the recent apps menu.
FORCE_ENABLE_CLEAR_ALL_RECENTS: Sets the config_enableClearAllRecents value
Options: (true|false)
FORCE_DEFAULT_QS_TILES: Sets the config_defaultQsTiles value
Options:
- none: This will remove all default quick settings tiles.
- all: This will restore all default quick settings tiles.
- <tile_id>: This will add or remove the specified quick settings tile.

Launcher Options:

USE_LAUNCHER3: Forces Launcher3 to be set instead of secondary launcher in build
SET_SMARTDOCK_DEFAULT: Set's SmartDock as default launcher when booting into Desktop specific builds (requires a build with SmartDock included by default)
ENABLE_QUICKSTEP_TASKBAR: Set quickstep taskbar features to enabled (requires dev-options to be enabled & Launcher3 to also be enabled). options: true,false
FORCE_DESKTOP_ON_EXTERNAL: Enable desktop mode on external display (required for MultiDisplay Input). options: 0,1
FORCE_QUICKSTEP_HOME: Forces Quickstep to be set as default home on boot

FORCE_NAVBAR_ON_SECONDARY_DISPLAYS: Enable navbar/gesture navigation on external display. options: 0,1
FORCE_IME_ON_SECONDARY_DISPLAYS: Enable on-screen keyboard on external display (required for MultiDisplay Input). options: 0,1
androidboot.bliss.force_ime_on_all_displays=true: Force IME on secondary displays. Uses "ro.boot.bliss.force_ime_on_all_displays" property (true,false)
androidboot.force.navbar_on_secondary_displays=true: Allow a system property to override this for desktop mode navigation to work on secondary displays. (true/false)
androidboot.force.right_mouse_as_back=true: Allows overriding AMOTION_EVENT_BUTTON_SECONDARY with AMOTION_EVENT_BUTTON_BACK, using a property trigger. (true/false)
FORCE_MOUSE_PRESENTATION: Forces mouse to work across multiple displays

Display & Input Rotation/Orientation:

SET_SF_ROTATION=*: Sets surfaceflinger hardware rotation property to the value passed
SET_SF_SWROTATION: Sets surfaceflinger software rotation property to the value passed
SET_OVERRIDE_FORCED_ORIENT=*: Override forced orientation (true/false)
SET_SYS_APP_ROTATION=*: Forces system app rotation, and has three cases:
- 1.force_land: always show with landscape, if a portrait apk, system will scale up it
- 2.middle_port: if a portrait apk, will show in the middle of the screen, left and right will show black
- 3.original: original orientation, if a portrait apk, will rotate 270 degree

UI Modes (Bass builds):

Pick which home screen and windowing setup a boot uses. Builds made with --tui, --dui, --kui or --gaming add the matching flag by default.

BASS_TABLETUI=1: Launcher3 / Quickstep home, no desktop or kiosk launcher
BASS_DESKTOPUI=1: SmartDock desktop with freeform windows (desktop-first on the default display)
BASS_KIOSKUI=1: Restricted Launcher kiosk (lockdown / admin boot modes)
BASS_GAMINGUI=1: BlissDeck console-style home

UI style and tablet system bar (Bass builds with bass-style):

BASS_UI_STYLE: one of:
- material: Material You, colors from the wallpaper.
- m3: Material 3 with fixed colors.
- kitkat: the Holo look, with Holo widgets, square corners, a Holo-blue palette, KitKat icons, and quick settings as ON/OFF rows.
The default comes from the build's --style-type.
BASS_UI_LAYOUT: stock (taskbar) or system_bar: one bottom bar with back/home/recents (plus any extra buttons) on the left and a tray on the right. The tray holds a notifications bell or count, the status bar icons, network, battery and the clock. It works with every style. The default comes from the build's --style-layout (or system_bar for --style-type=kitkat builds that keep the taskbar, else stock).
BASS_PANEL_ANCHOR: where notifications and quick settings open: top_end or bottom_end (above the tray; default with system_bar)
BASS_UI_HIDE_STATUS_BAR=1: hide the top status bar on the tablet system bar (its icons stay in the tray). The KitKat style always hides it.
BASS_UI_BAR_APPS: 1 shows pinned apps and running tasks on the tablet system bar, 0 hides them. Without it, Material You and Material 3 show them and KitKat hides them.
BASS_UI_BAR_APPS_GRAVITY: where those apps sit between the buttons and the tray: start, center (default) or end.
BASS_UI_BAR_BUTTONS: extra buttons after back/home/recents, as a comma list from vol_down, vol_up, screenshot and power (sleep; hold for the power menu), or none (default).

These are also on the UI style page in Settings. Boot Config has all but BASS_UI_BAR_APPS, BASS_UI_BAR_APPS_GRAVITY and BASS_UI_BAR_BUTTONS. With SmartDock installed, SmartDock's desktop style sets the layout (System Default uses system_bar).

Desktop mode options:

BASSEDW: Desktop windowing flags (Options: true, false)
BASSMDW: Multi-display windowing flags (Options: true, false)
BASSDM, BASSDM2: Desktop mode 1 / desktop mode 2 debug properties (Options: true, false)
BASSDE: Desktop experience flags such as drag-to-maximize (Options: true, false)
BASSDELAUNCHER: Desktop launcher flag (Options: true, false)
BASS_MULTIPLE_DESKTOPS: Multiple desktops (Options: true, false)
BASSDM_PRESENTATION: Lets apps show presentations on connected displays (Options: true, false)
androidboot.android.force_rotation_on_external_displays: Set target orientation for external displays (0=0, 1=90, 2=180, 3-270)
fbcon=rotate:*: The value 'n' accepts the following: 0 - normal orientation (0 degree) 1 - clockwise orientation (90 degrees) 2 - upside down orientation (180 degrees) 3 - counterclockwise orientation (270 degrees)
SET_PRIMARY_DISPLAY_ORIENTATION=*: property: ro.surface_flinger.primary_display_orientation has three cases: ORIENTATION_90, ORIENTATION_180, ORIENTATION_270
SET_SECONDARY_DISPLAY_ORIENTATION: Set target orientation for external displays (Options: 0=0, 1=90, 2=180, 3=270)
SET_HDMI_ROTATION: Set HDMI rotation (Options: portrait, landscape)
SET_PER_WINDOW_INPUT_ROTATION Set per window input rotation on/off (Options: true, false)
SET_TOUCHSCREEN_ROTATION: Sets the touch input orientation for the given build (Options: 0, 90, 180, 270)
SET_ROTATION_ON_INTERNAL_DISPLAY: Sets the internal display rotation (Options: 0, 90, 180, 270)
SET_HDMIROTATION: Set HDMI rotation (Options: portrait, landscape)
SET_HDMIROTATIONLOCK: Set HDMI rotation lock (Options: true or false)
SET_SINGLEDISPLAY: Forces using onle a single display (Options: true or false)
FORCE_NAVIGATION_MODE: Selects the navigation style for this boot (Options: threebutton, gestural) (Bass builds)
SET_RMB: Use the right mouse button as Back (Options: true, false) (Bass builds)
SET_P_CG: Turns the pointer choreographer on or off (persist.pointer.choreographer) (Options: 0, 1) (Bass builds)
androidboot.force.win_as_home=1: The Windows / Meta key acts as Home (Bass builds)
FORCE_TSCAL=1: Turns on tslib touchscreen calibration (pointercal) on devices that are not detected as needing it
FORCE_PRIMARY_ROTATION: Force promary display user_rotation (options: 0:0, 1:90, 2:180, 3:270)

Misc:

Battery Stats:

androidboot.fake_battery=true: AOSP implementation of fake battery status

(Available through Android-Generic Add-On & add-ons for Bass builds)

SET_FAKE_BATTERY_LEVEL: Let us fake the total battery percentage
Options: (0-100)
SET_FAKE_CHARGING_STATUS: Allow forcing battery charging status
Options: (0|1)

Package Management:

(Available through Android-Generic Add-On & add-ons for Bass builds)

With our package management features, we have the ability to also enable/disable various packages included in the system by default using the kernel cmdline.

Example: HIDE_APPS="com.termux,com.android.dialer,com.android.documentsui"

Hide/Unhide Default Apps:

SET_TARGET_DISPLAY_ORIENTATION: Rotation for one display, as display_id,rotation (rotation 0, 1, 2, 3). Example: SET_TARGET_DISPLAY_ORIENTATION=2,1 (Bass builds)
SET_TARGET_DISPLAY_RESOLUTION: Resolution for one display, as WxH,display_id. Example: SET_TARGET_DISPLAY_RESOLUTION=1080x1920,2 (Bass builds)
DISABLE_MIRROR_DISPLAY: Stop mirroring the built-in display to external displays (Options: true, false) (Bass builds)
DISABLE_MIRROR_DISPLAY_DIALOG: Hide the display mirroring confirmation dialog (Options: 0, 1) (Bass builds)
HIDE_APPS: Hides the apps via passed comma separated list
RESTORE_APPS: Restores the apps via passed comma separated list

Package Options:

SET_DI_WHITELIST: Sets a package name to be added to the Device Idle whitelist
SET_SECOND_DISPLAY_PKG: Force package to be launched on secondary display (Options: package_name)

IIO Options Configuration:

(Available through Android-Generic Add-On & add-ons for Bass builds)

This allows us to set ro.iio.* propertied through the following flags:

FAKE_BATTERY=1: Use the fake battery profile even when a battery is detected (Bass builds turn it on automatically when no battery is found)
SET_IIO_ORDER: Sets ro.iio.accel.order property
SET_IIO_ACCEL_QUIRKS: Sets ro.iio.accel.quirks ptoperty
SET_IIO_ACCEL_X_OPT_SCALE: Sets ro.iio.accel.x.opt_scale property
SET_IIO_ACCEL_Y_OPT_SCALE: Sets ro.iio.accel.y.opt_scale property
SET_IIO_ANGLVEL_QUIRKS: Sets ro.iio.anglvel.quirks property
SET_IGNORE_ATKBD: Sets ro.ignore_atkbd property
SENSORS_FORCE_KBDSENSOR: Option to force kbd sensor
SET_IIO_MAGN_QUIRKS: Option to force magn quirks. Example: SET_IIO_MAGN_QUIRKS="no-trig,no-event"

Set Timezone:

(Available through Android-Generic Add-On & add-ons for Bass builds)

To use this change, pass the grub/cmdline value for your timezone using the SET_TZ_LOCATION flag. Timezone reference can be found here: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

Example:

 SET_TZ_LOCATION=America/New_York

Serial IO

(Available through Android-Generic Add-On & add-ons for Bass)

SET_USB_BUS_PORTS: Sets permissions for tty ports (chmod 666) for /dev/bus/usb/*. Example: SET_USB_BUS_PORTS=001/001,001/002,001/003,001/004
SET_TTY_PORT_PERMS: Set USB bus port permissions (chmod 666) for /dev/tty*. Example: SET_TTY_PORT_PERMS=ttyS*,ttyACM*

Network & Radio Control Options:

(Available through Android-Generic Add-On & add-ons for Bass)

SENSORS_DELAY_INIT: Seconds to wait before loading sensors (helps tablets whose IIO sensors appear late). Example: SENSORS_DELAY_INIT=5

Enable/Disable Wireless Devices (Change included only in specialized builds):

LOCKDOWN_WIRELESS_DEVICES: A kernel level switch to disable all wireless devices. options: 0,1
UNLOCKDOWN_WIRELESS_DEVICES: A kernel level switch to enable all disabled wireless devices. options: 0,1

Other Networking Options (Available in Bass builds):

FORCE_DISABLE_ALL_RADIOS: Set force disable all radios (only disables on boot, user can re-enable manually if given access). options: 0,1
FORCE_BLUETOOTH_SERVICE: Set force bluetooth service state. options: enable, disable

Test Modes:

BOOT_FACTORY_TEST: Boot into factory test mode (Options: 1,0)

Configuration Through Command Line Parameters

Intro to Kernel Command Line Parameters

Supported Parameters:

Debugging:

Graphics Stack:

Hardware Composer:

Using DRMFB HWC backend:

Setting HWC mode info:

Gralloc:

Gralloc4 Configurations:

ANGLE & software rendering:

GLES Overrides:

RenderEngine Overrides:

GPU Override:

Video Resolution:

Media Stack:

Bluetooth:

Audio HAL:

Video Encoders/Decoders:

Networking:

Disk Access:

USB Mode Functions:

Power & Memory:

Power:

Default Sleep Mode Options:

Other Sleep Mode Options

Intel Power Options:

Generic Power Options:

Generic Performance Options:

Memory:

Sleep and CPU options (Bass builds):

LMKD:

Logging/Logd:

OTA Updates:

Features:

Kiosk Mode:

Launcher Options:

Navigation & Input Options:

Display & Input Rotation/Orientation:

UI Modes (Bass builds):

UI style and tablet system bar (Bass builds with bass-style):

Desktop mode options:

Misc:

Battery Stats:

Package Management:

Hide/Unhide Default Apps:

Package Options:

IIO Options Configuration:

Set Timezone:

Serial IO

Network & Radio Control Options:

Test Modes: