This guide allows you to root a stock FLSun Speeder Pad without erasing anything. You only need a Phillips Screw driver, a plastic wedge tool, a USB to Serial USB Adapter (that supports 3v3) and 3 dupont female-female wires.
2024/03 - I noticed a typo in this guide on the setenv init lines which I corrected
2024/03 - Tested with clean FLSun v400 speeder-pad firmware at v1.4
Alternatively you can root the device by flashing a recovery image and overwriting the FLSun Klipper build: https://github.com/Guilouz/Klipper-Flsun-Speeder-Pad
1) Open the case Speeder Pad case: There are 2 Phillips screws and multiple snaps. Use a plastic thin wedge to unclip the snaps and separate the back cover from the device.
There is a 3 pin connector on the motherboard that has the labels RX,TX and GND
Connect a serial to USB adapter, set to 3v3
- RX->TX
- TX->RX
- GND-GND
2) Connect to the device with a serial console app like Putty or screen, the baud rate is 115200
To get a u-boot console you have to quickly press a key on your keyboard to interrupt bootup sequence, immediately after powering the device on with the 24vdc+ barrel connector coming from the printer
Once you are in the u-boot console:
=> setenv bootdelay 5
=> setenv init /bin/sh -m
=> saveenv
Saving Environment to SUNXI_FLASH... Writing to redundant env... OK
=> boot
After boot-up you should be presented with a logged in root session where you can add the pi user to the "sudo" group and change it's password:
/bin/sh: 0: can't access tty; job control turned off
# [ 7.159243]
[ 7.159243] insmod_device_driver
[ 7.159243]
# bash
bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell
root@(none):/# usermod -a -G sudo pi
root@(none):/# id pi
uid=1000(pi) gid=1000(pi) groups=1000(pi),4(adm),5(tty),20(dialout),27(sudo),44(video)
root@(none):/# passwd pi
Reboot and interrupt boot again
In u-boot console:
=> setenv init /sbin/init
=> saveenv
Saving Environment to SUNXI_FLASH... Writing to redundant env... OK
=> boot
Once the device boots, you can now connect to it via SSH with the pi / whatever_password_you_set
I have used this How To ...
Perfect, it is OK
Now I am lookin for to fix the MAC address under U Boot