update config.txt:

- comment out some settings
- move stuff out of the do not change part
- note which uarts use which pins and their usage
- add cm4 related dtoverlays and dtparams
- add fan overlay for openmower mainboard and Waveshare CM4-IOBASE

src/modules/piconfig/filesystem/root/boot/config.txt

@@ -5,10 +5,6 @@
 # uncomment if you get no picture on HDMI for a default "safe" mode
 #hdmi_safe=1
 
-# uncomment this if your display has a black border of unused pixels visible
-# and your display can output without overscan
-#disable_overscan=1
-
 # uncomment the following to adjust overscan. Use positive numbers if console
 # goes off screen, and negative if there is too much border
 #overscan_left=16
@@ -57,42 +53,24 @@
 #dtparam=audio=on
 
 # Automatically load overlays for detected cameras
-camera_auto_detect=1
+#camera_auto_detect=1
 
 # Automatically load overlays for detected DSI displays
-display_auto_detect=1
-
-[pi4]
-# Run as fast as firmware / board allows
-#arm_boost=1
-
-####################################################
-####     OpenMowerOS specific configurations    ####
-####################################################
-####      DO NOT CHANGE SECTION BELOW !!!       ####
-####   UNLESS YOU KNOW WHAT YOU ARE DOING !!!   ####
-####################################################
-
-## For more options and information see
-## https://www.raspberrypi.com/documentation/computers/config_txt.html
-## Some settings may impact device functionality. See link above for details
-
-## For additional information about device filters see
-## https://www.raspberrypi.com/documentation/computers/config_txt.html#model-filters
+#display_auto_detect=1
 
+# Disable compensation for displays with overscan
+disable_overscan=1
 
 [pi0]
 ## This affects Pi Zero(W) and Pi Zero2
 ## Due lag of RAM, limit GPU RAM
 gpu_mem=128
 
 [pi2]
-gpu_mem=256
+gpu_mem=128
 
 [pi3]
-## Use 256 if 1Gb Ram Model!
 gpu_mem=128
-# gpu_mem=256
 
 [pi4]
 ## Enable DRM VC4 V3D driver on top of the dispmanx display stack
@@ -105,21 +83,62 @@ gpu_mem=128
 ## Enable XHCI USB 2 controller for USB support on CM4
 otg_mode=1
 
+## Set the desired antenna of the CM4 to use
+#dtparam=ant1    # Select internal antenna 1 (default). CM4 only.
+#dtparam=ant2    # Select external antenna 2. CM4 only.
+#dtparam=noant   # Disable both antennas. CM4 only.
+
+#dtparam=pcie=off
+#dtoverlay=disable-emmc2
+
+# Waveshare CM4-IO-BASE fan
+#dtoverlay=gpio-fan,gpiopin=18,temp=60000
+
+[all]
+# OpenMower mainboard 5V fan
+#dtoverlay=gpio-fan,gpiopin=6,temp=60000
+
+# Run as fast as firmware / board allows
+#arm_boost=1
+
+## Enable VideoCore at boot, needed for Raspicams and DSI devices.
+#start_x=1
+
+## For testing lower RAM setups
+#total_mem=1024
+
+####################################################
+####     OpenMowerOS specific configurations    ####
+####################################################
+####      DO NOT CHANGE SECTION BELOW !!!       ####
+####   UNLESS YOU KNOW WHAT YOU ARE DOING !!!   ####
+####################################################
+
+## For more options and information see
+## https://www.raspberrypi.com/documentation/computers/config_txt.html
+## Some settings may impact device functionality. See link above for details
+
+## For additional information about device filters see
+## https://www.raspberrypi.com/documentation/computers/config_txt.html#model-filters
+
 [all]
 ## Enable Hardware UART for Serial Communication
+# UART1 GPIO 14/15 Pin  8/10 - pico
+# UART2 GPIO  0/1  Pin 27/28 - gps
+# UART3 GPIO  4/5  Pin  7/29 - xESC right
+# UART4 GPIO  8/9  Pin 24/21 - xESC mower
+# UART5 GPIO 12/13 Pin 32/33 - xESC left
 dtoverlay=disable-bt
 enable_uart=1
 dtoverlay=uart2
 dtoverlay=uart3
 dtoverlay=uart4
 dtoverlay=uart5
 
-## Enable VideoCore at boot, needed for Raspicams and DSI devices.
-#start_x=1
-
 ### The 64-bit kernel will only work on:
 ### Raspberry Pi 3, 3+, 4, 400, Zero 2 W and 2B rev 1.2
 ### and Raspberry Pi Compute Modules 3, 3+ and 4.
 arm_64bit=1
 
 ####################################################
+