Behind the Xbox Boot Code

NiteStar writes "The Xbox-Linux team has up a new article about The Hidden Boot Code of the Xbox. The Xbox console contains a 'chain of trust' to allow only legit Microsoft signed code to run on the Xbox. The hidden 'MCP' boot ROM (just 512bytes) is the link between hardware and software in this chain of trust." From the wiki article: "The Xbox, having an external (reprogrammable) 1 MB Flash ROM chip (models since 2003 have only 256 KB), would normally start running code there as well, since this megabyte is also mapped into the uppermost area of the address space. But this would make it too easy for someone who wants to either replace the ROM image with a self-written one or patch it to break the chain of trust ("modchips"). The ROM image could be fully accessed, it would be easy to reverse-engineer the code; encryption and obfuscation would only slow down the hacking process a bit."

Comments

Re:A guess

[Monkelectric]

Yep. Let me describe the situation at a place I work, posting anonymously because there are only 4 or 5 companies in this industry. We make devices used in the semi-conductor manufacturing industry ... so when theres a problem, it ruins very expensive batches of chips.

Me: "The software that validates that units are configured correctly is 8000 lines of unauditable if statements. There is no definition of the policy it implements. This madness is going to cause an accident. We must rewrite the software and have lots of very boring meetings."
Management: "Hmmm...interesting...continue patching the software as issues come up."
Legal Department, "We're being sued because a configuration error ruined a batch of very expensive chemicals."
Me: "We must rewrite the software."
Legal: "We must rewrite the software."
Management: "hmm...interesting...continue patching the software as issues come up."