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.

=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,