d49c52a4102f6df7bcf8d0617ac475ed
The MCPX is the internal boot ROM found on the Xbox's Southbridge chip. It initializes the CPU's protected mode, sets up memory caching, decrypts the second stage bootloader from the main BIOS chip, and hands off system control. Common Pitfalls & Incorrect Dumps
A valid dump of this ROM must start with the hex values 0x33 0xC0 and end with 0x02 0xEE .
The hash d49c52a4102f6df7bcf8d0617ac475ed is the community-agreed fingerprint for a clean mcpx 1.0.bin . Keep this value saved. Before reporting an emulation bug, always, always MD5 your MCPX file—most "graphical glitches" turn out to be a bad boot ROM.
The "useful blog post" you are likely referring to is a seminal piece of Xbox homebrew history titled by Michael Steil (founder of Xbox-Linux). Why it’s famous