VCGENCMD(1)

NAME
vcgencmd - query the VideoCore for information

SYNOPSIS
vcgencmd [-t] command [params]
vcgencmd -h
vcgencmd --help

DESCRIPTION
vcgencmd is a command line utility that can get various pieces of information from the VideoCore GPU on the Raspberry Pi.

OPTIONS

-t  Time how long the command takes to complete

-h, --help
    Show this information

COMMANDS
To get a list of all the commands that vcgencmd supports, type vcgencmd commands. Some of the more useful commands are described below.

vcos sub-command
    The vcos command has a number of sub-commands:

    version
        Displays the build date and version of the firmware on the VideoCore.

    log status
        Displays the error log status of the various VideoCore software areas.

version
    Displays the build date and version of the firmware on the VideoCore.

get_camera
    Displays the enabled and detected state of the official camera. 1 means yes, 0 means no. Whilst all firmware (except cutdown versions) will support the camera, this support needs to be enabled by using the start_x boot option [BOOT].

get_throttled
    Returns the throttled state of the system. This is a bit pattern - a bit being set indicates the following meanings:
    Bit | Meaning
    0 | Under-voltage detected
    1 | Arm frequency capped
    2 | Currently throttled
    3 | Soft temperature limit active
    16 | Under-voltage has occurred
    17 | Arm frequency capping has occurred
    18 | Throttling has occurred
    19 | Soft temperature limit has occurred

    A value of zero indicates that none of the above conditions is true.

    To find if one of these bits has been set, convert the value returned to binary, then number each bit along the top. You can then see which bits are set. For example:

        0x50000 = 0101 0000 0000 0000 0000

    Adding the bit numbers along the top we get:
    19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1
    0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0

    From this we can see that bits 18 and 16 are set, indicating that the Pi has previously been throttled due to under-voltage, but is not currently throttled for any reason.

measure_temp
    Returns the temperature of the SoC as measured by the on-board temperature sensor.

measure_clock clock
    This returns the current frequency of the specified clock. The options are:
    Clock | Description
    arm | ARM cores
    core | VC4 scaler cores
    h264 | H.264 block
    isp | Image Signal Processor
    v3d | 3D block
    uart | UART
    pwm | PWM block (analog audio output)
    emmc | SD card interface
    pixel | Pixel valve
    vec | Analog video encoder
    hdmi | HDMI
    dpi | Display Peripheral Interface

    For example, vcgencmd measure_clock arm.

measure_volts block
    Displays the current voltages used by the specific block.
    Block | Description
    core | VC4 core voltage
    sdram_c |
    sdram_i |
    sdram_p |

otp_dump
    Displays the content of the One Time Programmable (OTP) memory, which is part of the SoC. These are 32 bit values, indexed from 8 to 64. See the raspi-otp(7) for more details.

get_mem type
    Reports on the amount of memory allocated to the ARM cores with vcgencmd get_mem arm or the VC4 with vcgencmd get_mem gpu.

    Note: On a Raspberry Pi 4 with greater than 1GB of RAM, the arm option is inaccurate. This is because the GPU firmware which implements this command is only aware of the first gigabyte of RAM on the system, so the arm setting will always return 1GB minus the gpu memory value. To get an accurate report of the amount of ARM memory, use one of the standard Linux commands, such as free or cat /proc/meminfo.

codec_enabled type
    Reports whether the specified CODEC type is enabled. Possible options for type are AGIF, FLAC, H263, H264, MJPA, MJPB, MJPG, MPG2, MPG4, MVC0, PCM, THRA, VORB, VP6, VP8, WMV9, WVC1.

    MPG2, WMV9, and WVC1 currently require a paid for licence (see the [FAQ] for more info), except on the Pi4, where these hardware codecs are disabled in preference to software decoding, which requires no licence. Note that because the H265 hardware block on the Raspberry Pi4 is not part of the VideoCore GPU, its status is not accessed via this command.

get_config type|name
    This returns all the configuration items of the specified type that have been set in config.txt, or a single configuration item. Possible values for type parameter are int, str, or simply use the name of the configuration item.

get_lcd_info
    Displays the resolution and colour depth of any attached display.

mem_oom
    Displays statistics on any Out Of Memory events occuring in the VC4 memory space.

mem_reloc_stats
    Displays statistics from the relocatable memory allocator on the VC4.

read_ring_osc
    Returns the curent speed voltage and temperature of the ring oscillator.

hdmi_timings
    Displays the current HDMI settings timings. See [VIDEO] for details of the values returned.

dispmanx_list
    Dump a list of all dispmanx items currently being displayed.

display_power 0|1|-1
display_power 0|1|-1 display
    Show current display power state, or set the display power state. vcgencmd display_power 0 will turn off power to the current display. vcgencmd display_power 1 will turn on power to the display. If no parameter is set, this will display the current power state. The final parameter is an optional display ID, as returned by tvservice -l or from the table below, which allows a specific display to be turned on or off.

    vcgencmd display_power 0 7 will turn off power to display ID 7, which is HDMI 1 on a Raspberry Pi 4.
    Display | ID
    Main LCD | 0
    Secondary LCD | 1
    HDMI 0 | 2
    Composite | 3
    HDMI 1 | 7

    To determine if a specific display ID is on or off, use -1 as the first parameter.

    vcgencmd display_power -1 7 will return 0 if display ID 7 is off, 1 if display ID 7 is on, or -1 if display ID 7 is in an unknown state, for example undetected.

EXIT STATUS

0   Command completed successfully

-1  Problem with VHCI

-2  VideoCore returned an error

SEE ALSO
[SOURCE]

REFERENCES

[BOOT]
    https://www.raspberrypi.org/documentation/configuration/config-txt/boot.md

[FAQ]
    https://www.raspberrypi.org/documentation/faqs/README.md

[SOURCE]
    https://www.raspberrypi.org/documentation/raspbian/applications/vcgencmd.md

[VIDEO]
    https://www.raspberrypi.org/documentation/configuration/config-txt/video.md