RPI vcgencmd usage

Verified commands

Command outputs are from firmware version 362371.

vcgencmd commands

Shows a list of possible commands.

root@raspberrypi:~# vcgencmd commands
commands="vcos, ap_output_control, ap_output_post_processing, vchi_test_init, vchi_test_exit,
pm_set_policy, pm_get_status, pm_show_stats, pm_start_logging, pm_stop_logging, version, commands,
set_vll_dir, led_control, set_backlight, set_logging, get_lcd_info, set_bus_arbiter_mode,
cache_flush, otp_dump, codec_enabled, measure_clock, measure_volts, measure_temp, get_config,
hdmi_ntsc_freqs, render_bar, disk_notify, inuse_notify, sus_suspend, sus_status, sus_is_enabled,
sus_stop_test_thread, egl_platform_switch, mem_validate, mem_oom, mem_reloc_stats, file,
vctest_memmap, vctest_start, vctest_stop, vctest_set, vctest_get"

vcgencmd measure_clock <clock>

Shows clock frequency, clock can be one of arm, core, h264, isp, v3d, uart, pwm, emmc, pixel, vec, hdmi, dpi.

root@raspberrypi:~# \
> for src in arm core h264 isp v3d uart pwm emmc pixel vec hdmi dpi ; do \
>     echo -e "$src:\t$(vcgencmd measure_clock $src)" ; \
> done
arm:    frequency(45)=700000000
core:   frequency(1)=250000000
h264:   frequency(28)=0
isp:    frequency(42)=250000000
v3d:    frequency(43)=250000000
uart:   frequency(22)=3000000
pwm:    frequency(25)=0
emmc:   frequency(47)=100000000
pixel:  frequency(29)=154000000
vec:    frequency(10)=0
hdmi:   frequency(9)=163682000
dpi:    frequency(4)=0

vcgencmd measure_volts <id>

Shows voltage. id can be one of core, sdram_c, sdram_i, sdram_p, and defaults to core if not specified.

root@raspberrypi:~# \
> for id in core sdram_c sdram_i sdram_p ; do \
>     echo -e "$id:\t$(vcgencmd measure_volts $id)" ; \
> done
core:   volt=1.20V
sdram_c:        volt=1.20V
sdram_i:        volt=1.20V
sdram_p:        volt=1.23V

vcgencmd measure_temp

Shows core temperature of BCM2835 SoC.

root@raspberrypi:~# vcgencmd measure_temp
temp=42.8'C

vcgencmd codec_enabled <codec>

Shows if the specified codec is enabled, codec can be one of H264, MPG2, WVC1.

root@raspberrypi:~# \
> for codec in H264 MPG2 WVC1 ; do \
>     echo -e "$codec:\t$(vcgencmd codec_enabled $codec)" ; \
> done
H264:   H264=enabled
MPG2:   MPG2=disabled
WVC1:   WVC1=disabled

vcgencmd version

Shows the firmware version

root@raspberrypi:~# vcgencmd version
Jan 13 2013 16:24:29
Copyright (c) 2012 Broadcom
version 362371 (release)

Parameters and function of other commands are not known.