The Raspberry Pi boot loader uses the config.txt
file to hold configuration parameters relevant at boot time. It is a plain text file, resident in the DOS partition of the boot SD card, alongside bootcode.bin, start.elf and fixup.dat (for more information on these other files, see Software information: Raspberry Pi: Firmware).
It should not be confused with cmdline.txt (which is used to pass parameters to RISC OS at boot time).
The following lines are present in the standard config.txt for RISC OS. Note that each parameter appears on a separate line of the file.
fake_vsync_isr=1
framebuffer_swap=0
gpu_mem=64
init_emmc_clock=100000000
ramfsfile=CMOS
ramfsaddr=0x508000
kernel=RISCOS.IMG
These entries have the following meanings:
fake_vsync_isr=1
framebuffer_swap=0
gpu_mem=64
init_emmc_clock=100000000
ramfsfile=CMOS
ramfsaddr=0x508000
kernel=RISCOS.IMG
The following two entries are useful if you want to use the 3.5mm audio output jack instead of via the HDMI cable.
hdmi_ignore_edid_audio=1
audio_pwm_mode=2
The following entries may also be useful in certain circumstances:
boot_delay
bootcode_delay
disable_overscan
hdmi_mode
and hdmi_group
hdmi_group=2
hdmi_mode=58
The documentation pages on the Raspberry Pi website contain further information on the parameters mentioned above, and many more besides.
Boot options
Video options