Raspberry Pi: Configuration

References:

RPiconfig

config.txt

The system configuration parameters are stored in an optional text file named config.txt.

This is read by the GPU before the ARM CPU and Linux are initialised. It must therefore be located on the first (boot) partition of your SD card, alongside bootcode.bin and start.elf. This file is normally accessible as /boot/config.txt from Linux, and must be edited as root.

File format

property=value

Options

• Memory
GPU memory in megabytes. This sets the memory split between the CPU and GPU; the CPU gets the remaining memory.

gpu_mem

• Licence Keys/Codecs
Hardware decoding of additional codecs can be enabled by purchasing a licence that is locked to the CPU serial number of your Raspberry Pi("cat /proc/cpuinfo").

decode_MPG2=mpg2_key
decode_WVC1=wvc1_key

• Video/Display
• Composite video mode
• HDMI mode
• hdmi_safe
"hdmi_safe=1" is equivalent to the following:

hdmi_force_hotplug=1
hdmi_ignore_edid=0xa5000080
config_hdmi_boost=4
hdmi_group=2
hdmi_mode=4
disable_overscan=0
overscan_left=24
overscan_right=24
overscan_top=24
overscan_bottom=24

• hdmi_force_hotplug
"hdmi_force_hotplug=1" pretends that the HDMI hotplug signal is asserted so that HDMI output mode will be used, even if no HDMI monitor is detected.
• hdmi_ignore_edid
"hdmi_ignore_edid=0xa5000080" enables the ignoring of EDID/display data if your display does not have an accurate EDID.
• config_hdmi_boost
Configures the signal strength of the HDMI interface. If you are seeing HDMI issues (speckling, interference) then try 7. Very long HDMI cables may need up to 11.
• hdmi_group
The hdmi_group command defines the HDMI output group to be either 1 (CEA ,Consumer Electronics Association, the standard typically used by TVs) or 2 (DMT ,Display Monitor Timings, the standard typically used by monitors). Default is 0 (Auto-detect from EDID).
• hdmi_mode
hdmi_mode defines the HDMI output format for different hdmi_group. For 720p@60Hz,
• hdmi_group=1, hdmi_mode=4
• hdmi_group=2, hdmi_mode=85
1280x720
• hdmi_edid_file
"hdmi_edid_file=1" will cause the GPU to read EDID data from the edid.dat file, located in the boot partition.
• hdmi_force_edid_audio
"hdmi_force_edid_audio=1" pretends that all audio formats are supported by the display
• Audio
• Camera
• Boot
• Ports and Device Tree
• GPIOs
• Overclocking
• Conditional Filters
• Miscellaneous

How to change Raspberry Pi's Swapfile Size on Raspbian

We will change the configuration in the file /etc/dphys-swapfile:
The default value in Raspbian is:

CONF_SWAPSIZE=100

We will need to change this to:

CONF_SWAPSIZE=1024

Then you will need to stop and start the service that manages the swapfile own Rasbian:

sudo /etc/init.d/dphys-swapfile stop
sudo /etc/init.d/dphys-swapfile start