Rebuild dts tree fo MQ pro..
Start by cd
'ing into this device tree folder and editing your device tree.
You can use the generic sun20i-d1-mangopi-mq-pro.generic.dts
already in the device tree folder as a basis, or start with one of the ones provided with my precompiled trees.
You may also need to modify sun20i-d1.dtsi
since this is where pin mappings are declared; eg UART pin sets are defined in this include file and then used in the main tree file.
A full-on tutorial for device tree editing is far beyond the scope of both this document and author.
Terms
.dts
is a top-level Device Tree Source file..dtsi
is a include file for the.dts
.dtb
is the binary compiled device tree, this is what we are building here, and is supplied to the kernel at boot time.
Building the MQ PRO device tree (.dtb
)
By default the Device Tree compiler (/usr/bin/dtc
) should already be installed in Ubuntu server, as should the linux-headers for the kernel.
Compile the mq-pro dts with the current kernel headers
Example here is against the 'default' 6.8.0-31 linux kernel from the Ubuntu 24.04 release
- cd into the
dtspp
folder and clean:rm *.dts *.dtsi
- run
preprocess.sh
to precompile the files in the parent folder against the latest linux-headers. - still in the
dtspp
folder run:dtc sun20i-d1-mangopi-mq-pro.generic.dts > dtb-6.8.0-31-mqpro-generic.dtb
modify the version to reflect the current headers - move the
.dtb
file into the/boot
folder:sudo mv dtb-6.8.0-31-mqpro-generic /boot/dtbs
- make a soft link in
/boot
to this:sudo ln -s dtbs/dtb-6.8.0-31-mqpro-generic.dtb /boot/dtb-mqpro
Set up Grub to test boot the new DTB
Initially we will test the new dtb:
- backup the grub config:
sudo cp /etc/grub/grub.cfg /etc/grub/grub.cfg.generic-dtb
sudo vi /etc/grub/grub.cfg
(or use nano if you prefer) Find the 1stmenuentry
section (the default Ubuntu one) and edit thedevicetree
line to look like:devicetree /boot/dtb-mqpro
- Reboot (
sudo reboot
) (remember the mq-pro is sloooow to reboot ;-) ) - If the reboot fails you can either attach a serial adapter to the GPIO pins and select the fallback kernel from the advanced options menu, and then restore the grub config backup once logged in. Or (if no serial available) remove the SD card, mount it on another computer and restore the file there.
Check that we have the correct device tree
dtc -I fs /sys/firmware/devicetree/base | grep 'model'
- ignore all the 'not a phandle reference' warnings
- you should see
model = "MangoPi MQ Pro"
at the end
Make this permanent in grub
ToDo
Bonus
The onboard (blue) status LED can be controlled via the sys tree:
sudo sh -c "echo 1 > /sys/devices/platform/leds/leds/blue\:status/brightness"
to turn on
sudo sh -c "echo 0 > /sys/devices/platform/leds/leds/blue\:status/brightness"
to turn off
You can make it flash as wifi traffic is seen with:
sudo sh -c "echo phy0rx > /sys/devices/platform/leds/leds/blue\:status/trigger"
references/links:
https://manpages.ubuntu.com/manpages/focal/man1/dtc.1.html
https://forum.armbian.com/topic/29626-mango-pi-mq-pro-d1-device-tree-try-to-okay-serial/
https://github.com/torvalds/linux/tree/master/arch/riscv/boot/dts/allwinner
d2589d8211/MangoPi/linux/arch/riscv/boot/dts/allwinner
DTS version that is used in the official armbian image?
329e94f16f/arch/riscv/dts