ma5ter

Comprehensive step-by-step instructions for building a module for a foreign MIPS kernel using Gentoo's crossdev environment in order to have missing modules (like rfcomm) for Creality 2025 K1C

1) Create the Gentoo cross toolchain

Gentoo’s crossdev builds and installs a cross-compilation toolchain (binutils, GCC, kernel-headers, libc, etc.) for a given target tuple.

On your Gentoo host

emerge -av crossdev

ma5ter

1. The kernel starts /linuxrc as passed via the kernel parameter read from DTS rdinit=/linuxrc, which is a symlink to /bin/busybox.
2. busybox, running as an init process, parses /etc/inittab.
3. As part of sysinit loaded from the inittab, fstab filesystems are mounted. At this time, no writable unprotected persistent filesystems are available.
4. The last inittab entry at the sysinit level starts /etc/init.d/rcS.
5. /etc/init.d/rcS flattened:

# First create shadow which became the main system shadow file
cp -f /etc/shadow_security /tmp/shadow

ma5ter

# This script implements the same checking and unpacking logic as upgbox utility

import struct
import os
import time
from typing import List, Optional
import sys
import zlib

ma5ter

Creality K1C 2005 Fluidd Installation Instruction

0. Prerequisites

0.0 Root the printer

Use this gist as a starting point https://gist.github.com/C0DEbrained/c6f508109e34f43a39f4c22e901408dd

In my case after execution of the original script and first reboot printer stopped to accept connection to 22 port, so I rewrote the persistence script inside the exploit and applied exploit again.

ma5ter

/dts-v1/;

/ {
	#address-cells = <0x01>;
	#size-cells = <0x01>;
	compatible = "ingenic,x2600";

	aliases {
		i2c0 = "/apb/i2c@0x10050000";
		i2c1 = "/apb/i2c@0x10051000";