bj0rky / mx4n

MX4N 8G/1G

MX4N

A brave effort to make a flashable linux image for the MX4N-V20 (8G1/1G) board found in the SCISHION V88 Android TV box

⚠️ WARNING ⚠️

 Experimental stuff going on here, proceed with caution! 

MX4N 8G/1G

• CPU : Rockchip RK3229 quad core ARM Cortex A7 processor @1.5 GHz
• GPU : ARM Mali-400MP
• Memory : 1GB DDR3
• Storage : 8GB NAND flash + SD card slot up to 16GB
• Video Output : HDMI 2.0 up to 4K2K @60 fps, and 3.5mm AV output (composite)
• Audio Output : HDMI, AV, and coaxial S/PDIF
• Connectivity : 100Mbps Ethernet, 802.11 b/g/n WiFi
• USB : 4x USB 2.0 host ports
• Interfaces : HDMI port, RJ45 port, SPDIF port, 4x USB Host, SD Card Slot, AV Out DC jack.
• Power Supply : 5V/2A

TODO

• get UART output through SDcard slot
• Build own U-Boot / Kernel / rootfs
• Video Output while booting
• Enable UART routing to USB port(?)
• Enable netbooting

How-to UART

What you need

• USB A Male to Male adapter
• Empty microSD adatper
• 3x Breadboard wires

Wiring

SDslot pinout seen from back of slot

 9   1   2   3   4   5   6   7   8
[ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ]

USB-TTL and SDslot wiring

USB-TTL     SDslot
  RXD   ->    7
  TXD   ->    2
  GND   ->   GND

Insert the microSD adapter halfway and get the breaboard wires into the back of SDslot See picture and connect them to the USB-TTL adapter

Connect USB-TTL and open terminal emulator of choice

Baudraute : 1.5M (1500000)
Data bits : 8
Stop bits : 1

Insert USB A Male to Male adapter into the OTG usb port (USB-4) and you should see lots of text scrolling in your terminal window (rejoice!) 👍

How-to Build U-Boot

Follow this guide

or..

One script to handle it all

How to flash new u-boot.img to board

How-To boot the new u-boot.img from SD

How to..

How-to recover

• Start AndroidTool/RKBatchTool
• Shorten pins 8 & 9 on the nand chip (see image and make sure you do this right!!!)
• Power up using the OTG port

You should now see 'Found One MASKROM Device'

• Click the 'Upgrade Firmware' tab, then 'EraseFlash' (i had to select firmware before erasing)
• If successful, hit the 'Upgrade' button

All good?

Repair corrupted SDcard..

Red LED after tampering with the files on SDcard?

sudo fdisk -l
sudo fsck -a /dev/sd[partition]