documentation > configuration > config-txt

• Memory
• Licence Keys/Codecs
• Video/Display
• Audio
• Camera
• Boot
• Ports and Device Tree
• Overclocking
• Conditional Filters
• Miscellaneous

=

• Videocore GPU (VC4)

 $ ls -la /boot
total 21059
drwxr-xr-x  3 root root    2560 Jan  1  1970 .
drwxr-xr-x 21 root root    4096 Nov 29 02:37 ..
-rwxr-xr-x  1 root root   15830 Oct 30 10:36 bcm2708-rpi-0-w.dtb
-rwxr-xr-x  1 root root   15367 Oct 30 10:36 bcm2708-rpi-b.dtb
-rwxr-xr-x  1 root root   15626 Oct 30 10:36 bcm2708-rpi-b-plus.dtb
-rwxr-xr-x  1 root root   15086 Oct 30 10:36 bcm2708-rpi-cm.dtb
-rwxr-xr-x  1 root root   16693 Oct 30 10:36 bcm2709-rpi-2-b.dtb
-rwxr-xr-x  1 root root   17794 Oct 30 10:36 bcm2710-rpi-3-b.dtb
-rwxr-xr-x  1 root root   16550 Oct 30 10:36 bcm2710-rpi-cm3.dtb
-rwxr-xr-x  1 root root   50248 Aug 11 17:03 bootcode.bin
-rwxr-xr-x  1 root root     142 Jan  1  1980 cmdline.txt
-rwxr-xr-x  1 root root    1627 Feb  1 17:00 config.txt
-rwxr-xr-x  1 root root   18693 Aug 21  2015 COPYING.linux
-rwxr-xr-x  1 root root    2578 Oct 30 10:36 fixup_cd.dat
-rwxr-xr-x  1 root root    6551 Oct 30 10:36 fixup.dat
-rwxr-xr-x  1 root root    9694 Oct 30 10:36 fixup_db.dat
-rwxr-xr-x  1 root root    9694 Oct 30 10:36 fixup_x.dat
-rwxr-xr-x  1 root root     145 Nov 29 02:37 issue.txt
-rwxr-xr-x  1 root root 4579632 Oct 30 10:36 kernel7.img
-rwxr-xr-x  1 root root 4379152 Oct 30 10:36 kernel.img
-rwxr-xr-x  1 root root    1494 Nov 18  2015 LICENCE.broadcom
-rwxr-xr-x  1 root root   18974 Nov 29 02:37 LICENSE.oracle
drwxr-xr-x  2 root root   10240 Nov 29 01:21 overlays
-rwxr-xr-x  1 root root  667460 Oct 30 10:36 start_cd.elf
-rwxr-xr-x  1 root root 4956676 Oct 30 10:36 start_db.elf
-rwxr-xr-x  1 root root 2820196 Oct 30 10:36 start.elf
-rwxr-xr-x  1 root root 3904228 Oct 30 10:36 start_x.elf

Boot options in config.txt

enable_uart=1

The Raspberry Pi UARTs

start_x=1

start_x=1 should be specified when using the camera module.

gpu_mem=128

GPU memory in megabytes. This sets the memory split between the CPU and GPU; the CPU gets the remaining memory. Minimum value is 16; maximum value is 192, 448, or 944, depending on whether you are using a 256M, 512MB, or 1024MB Pi.
Memory options in config.txt

force_turbo=1

disable dynamic clocking (and force overclocking) with force_turbo=1
Overclocking options in config.txt