IT9919 Hacking - part 1 - Reading firmware with flashrom

Summary

Aug 20, 2019
In this series I will be hacking around with the IT9919 media processor that powers the Lenkeng LKV373 HDMI Extender Device and the EZCAP 283S which were reviewed in previous videos.

In this video I will show some tools and techniques for reading and writing to flash chips with the flashrom open-source flash-reader software and “Blue Pill” STM32F103 board

General Info

Firmware Loading

Software

Wiring

Serial Port Pin Blue Pill Pin
GND G
RXD PA9 (TX1)
TXD PA10 (RX1)
3.3V 3.3

Jumpers

  • Boot0 (Outboard): 1
  • Boot1 (Inboard): 0

Reading/Writing Flash

Wiring

23/25/26 Series Pin Blue Pill Pin
1 (CS#) PA4
2 (MISO) PA6
3 (WP#) G for Write Enable, 3.3 for Read-only
4 (GND) G
5 (MOSI) PA7
6 (SCK) PA5
7 (HOLD#) 3.3
8 (VCC) 3.3