Raspberry pi

 from firmware version 362371.

VideoCore Tools  github nezticle 

sudo vcdbg  [dump hist log command malloc pools save f yn symbol trash reloc log assert  log msg

vcgencmd commands

 sudo vcgencmd version
Nov  4 2018 16:31:07 
Copyright (c) 2012 Broadcom
version ed5baf9520a3c4ca82ba38594b898f0c0446da66 (clean) (release)

for id in core sdram_c sdram_i sdram_p ; do echo -en " $id:\t$(sudo vcgencmd measure_volts $id);" ;  done
 core:  volt=1.3500V; sdram_c:  volt=1.2000V; sdram_i:  volt=1.2000V; sdram_p:  volt=1.2250V;

Unfortunately at poweroff, on pi zero at least),
 core:1.3500; sdram_c:1.2000; sdram_i:1.2000; sdram_p:1.2250;
 core:1.3500; sdram_c:1.2000; sdram_i:1.2000; sdram_p:1.2250;

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"
(I've just checked on a more recent firmware version and there's now also get_camera, get_mem and hdmi_status_show commands)

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 "$id:\t$(sudo vcgencmd measure_volts $id)" ; \

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

vcgencmd codec_enabled <codec>

Shows if the specified codec is enabled, codec can be one of H264, MPG2, WVC1, MPG4, MJPG, WMV9. Please note this was run on a Pi with the MPG2 and VC1 licences enabled.

root@raspberrypi:~# \
> for codec in H264 MPG2 WVC1 MPG4 MJPG WMV9 ; do \
>     echo -e "$codec:\t$(vcgencmd codec_enabled $codec)" ; \
> done
H264:   H264=enabled
MPG2:   MPG2=enabled
WVC1:   WVC1=enabled
MPG4:   MPG4=enabled
MJPG:   MJPG=enabled
WMV9:   WMV9=enabled
If you also follow the instructions in this Forum post then the codec options for VP6 and VP8 (WEBM) also work, this is experimental and unsupported at present so any changes are at your own risk.

vcgencmd get_config [config|int|str] Will print the configurations you have set. Argument can ether be a specific option or int, showing all configs with number-datatype, or str showing all configurations with datatype sting (aka text).

root@raspberrypi:~# vcgencmd get_config int

vcgencmd get_mem arm/gpu

Shows how much memory is split between the CPU (arm) and GPU.

root@raspberrypi:~# vcgencmd get_mem arm && vcgencmd get_mem gpu

vcgencmd version

Shows the firmware version

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

vcgencmd otp_dump

Displays the contents of the OTP (One Time Programmable) memory embedded inside the SoC.

root@raspberrypi:~# vcgencmd otp_dump
08:00000000 … 15:00000000 
16:00280000 17:1020000a 18:1020000a 19:FFFFFFFF 20:FFFFFFFF 21:FFFFFFFF 22:FFFFFFFF 23:FFFFFFFF 24:FFFFFFFF
25:FFFFFFFF 26:FFFFFFFF 27:0000C2C2 28:6C14BA0D 29:93EB45F2 30:0000000E 31:00000000 … 64:00000000
28 and 30 store the Serial and Revision values that get displayed by /proc/cpuinfo (the Serial is also used to determine the Ethernet MAC address on Model B boards), 
32 stores the value of the warranty bit. vcgencmd set_backlight Currently unusable, might be used in the future to control the backlight of LCD displays vcgencmd render_bar Debug function created by Dom, used in OMXPlayer vcgencmd display_power 0 Turns off video output. vcgencmd display_power 1 Turns on video output. Parameters and function of other vcgencmd commands are not known. Links This list also lists and describes vcgencmd options