RPiconfig

The Raspberry Pi config.txt file is read by the GPU before the ARM core is initialised. It can be used to set various system configuration parameters.

This file is an optional file on the boot partition. It would normally be accessible as /boot/config.txt from Linux.

The information below originally came from Dom in this forum post.

WARNING: Setting any of the parameters which over volt your Raspberry Pi will set a permanant bit within the SOC and your warranty is void. So If you care about the warranty do not adjust voltage.

=File format=

The format is "property=value". value is an integer. One option per line. # is comment character. E.g. arm_freq=800 sdtv_mode=2 overscan_left=32 overscan_right=32 overscan_top=32 overscan_bottom=32
 * 1) hdmi_mode=19

Mode values
sdtv_mode is  SDTV_MODE_NTSC       = 0, /**<Normal NTSC */ SDTV_MODE_NTSC_J    = 1, /**<Japanese version of NTSC – no pedestal.*/ SDTV_MODE_PAL       = 2, /**<Normal PAL */ SDTV_MODE_PAL_M     = 3, /**<Brazilian version of PAL – 525/60 rather than 625/50, different subcarrier */ sdtv_aspect is  SDTV_ASPECT_4_3      = 1, /**<4:3 */ SDTV_ASPECT_14_9    = 2, /**<14:9 */ SDTV_ASPECT_16_9    = 3  /**<16:9 */ hdmi_mode is  HDMI_CEA_VGA             =  1, HDMI_CEA_480p60         =  2, HDMI_CEA_480p60H        =  3, HDMI_CEA_720p60         =  4, HDMI_CEA_1080i60        =  5, HDMI_CEA_480i60         =  6, HDMI_CEA_480i60H        =  7, HDMI_CEA_240p60         =  8, HDMI_CEA_240p60H        =  9, HDMI_CEA_480i60_4x      = 10, HDMI_CEA_480i60_4xH     = 11, HDMI_CEA_240p60_4x      = 12, HDMI_CEA_240p60_4xH     = 13, HDMI_CEA_480p60_2x      = 14, HDMI_CEA_480p60_2xH     = 15, HDMI_CEA_1080p60        = 16, HDMI_CEA_576p50         = 17, HDMI_CEA_576p50H        = 18, HDMI_CEA_720p50         = 19, HDMI_CEA_1080i50        = 20, HDMI_CEA_576i50         = 21, HDMI_CEA_576i50H        = 22, HDMI_CEA_288p50         = 23, HDMI_CEA_288p50H        = 24, HDMI_CEA_576i50_4x      = 25, HDMI_CEA_576i50_4xH     = 26, HDMI_CEA_288p50_4x      = 27, HDMI_CEA_288p50_4xH     = 28, HDMI_CEA_576p50_2x      = 29, HDMI_CEA_576p50_2xH     = 30, HDMI_CEA_1080p50        = 31, HDMI_CEA_1080p24        = 32, HDMI_CEA_1080p25        = 33, HDMI_CEA_1080p30        = 34, HDMI_CEA_480p60_4x      = 35, HDMI_CEA_480p60_4xH     = 36, HDMI_CEA_576p50_4x      = 37, HDMI_CEA_576p50_4xH     = 38, HDMI_CEA_1080i50_rb     = 39, HDMI_CEA_1080i100       = 40, HDMI_CEA_720p100        = 41, HDMI_CEA_576p100        = 42, HDMI_CEA_576p100H       = 43, HDMI_CEA_576i100        = 44, HDMI_CEA_576i100H       = 45, HDMI_CEA_1080i120       = 46, HDMI_CEA_720p120        = 47, HDMI_CEA_480p120        = 48, HDMI_CEA_480p120H       = 49, HDMI_CEA_480i120        = 50, HDMI_CEA_480i120H       = 51, HDMI_CEA_576p200        = 52, HDMI_CEA_576p200H       = 53, HDMI_CEA_576i200        = 54, HDMI_CEA_576i200H       = 55, HDMI_CEA_480p240        = 56, HDMI_CEA_480p240H       = 57, HDMI_CEA_480i240        = 58, HDMI_CEA_480i240H       = 59, hdmi_drive is  HDMI_DRIVE_DVI           = 1, /**<Normal DVI mode */ HDMI_DRIVE_HDMI         = 2, /**<Normal HDMI mode */