OpenVoiceOS/buildroot-external/board/ovos/raspberrypi/rpi4/config.txt

arm_64bit=1
enable_uart=1
enable_gic=1
armstub=RPI_EFI.fd
disable_commandline_tags=2
device_tree_address=0x1f0000
device_tree_end=0x200000

# Please note that this is only a sample, we recommend you to change it to fit
# your needs.
# You should override this file using a post-build script.
# See http://buildroot.org/manual.html#rootfs-custom
# and http://elinux.org/RPiconfig for a description of config.txt syntax
# We always use the same names, the real used variant is selected by
# BR2_PACKAGE_RPI_FIRMWARE_{DEFAULT,X,CD} choice
start_file=start4x.elf
fixup_file=fixup4x.dat

#kernel=Image

# To use an external initramfs file
# initramfs rootfs.cpio.gz

# Disable overscan assuming the display supports displaying the full resolution
# If the text shown on the screen disappears off the edge, comment this out
disable_overscan=1

# Automatically load overlays for detected DSI displays
display_auto_detect=1

# Enable DRM VC4 V3D driver and setup the mode
dtoverlay=vc4-fkms-v3d
# dtoverlay=vc4-kms-v3d-pi4
# hdmi_drive=2
# hdmi_group=2
# hdmi_mode=14
max_framebuffers=2
# uncomment if you get no picture on HDMI for a default "safe" mode
# hdmi_safe=1

# How much memory in MB to assign to the GPU on Pi models having
# 256, 512 or 1024 MB total memory
gpu_mem=256
gpu_mem_256=128
gpu_mem_512=128
gpu_mem_1024=128

# fixes rpi (3B, 3B+, 3A+, 4B and Zero W) ttyAMA0 serial console
dtoverlay=miniuart-bt

# enable autoprobing of Bluetooth driver without need of hciattach/btattach
dtparam=krnbt=on

# Enable the onboard soundcard
dtparam=audio=on

# Enable the hardware random generator
dtparam=random=on

# Enable camera driver
# dtoverlay=imx219
# dtoverlay=ov5647
# camera_auto_detect=1

# Disable rainbow color splash
disable_splash=1

# Enable some optional hardware interfaces
dtparam=i2c_arm=on
dtparam=i2c_arm_baudrate=100000
dtoverlay=i2s-mmap
dtparam=i2s=on
dtparam=spi=on

# Enable boost from 1.5Ghz to 1.8Ghz on compatible models
arm_boost=1

# enable 64bits support
#arm_64bit=1