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Old 6th April 2007, 00:29   #19  |  Link
Geremia
Registered User
 
Join Date: Feb 2007
Posts: 71
Quote:
Geremia is a highly respected firmware engineer on xboxhacker.net forums. He was one of the folks who collaborated on breaking the protection of the normal Xbox 360 DVD drive.
hehehe, that's too much! about first xbox360 hack, i did nothing special, i was not able to dissassemble anything. After that, i started learning and had my first satisfaction: a firmware patch for dvd media detection for hitachi drive.
Engeneer is too much, i prefer "hobbist who likes to learn on the way".

This time is the second satisfaction, from roaming in the dark till
a volumeID. And arnezami helped a lot with the xor stuff, and when he told me that a bit compensation can be the workaround for both xors and sum, he lighted me and i saw this picture

Code:
000DFFB0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
000DFFC0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
000DFFD0 FF FF FF FE FF FF FF FE FF FF FF FE FF FF FF FE 
000DFFE0 FF FF FF FE FF FF FF FE FF FF FF FE FF FF FF FE
but this trick is quite frustrating for huge code changes, patch must be done with the less bit changes possible, so maybe i'll try to modify the bootloader (with this compensation trick) to skip the sum check but leave the xor check, this way the fw integrity will be guaranteed aswell and the xor calculation could be adjusted with easy.

I'll have some time on weekend to desolder the flash and read again, if nothing weird happened, i think the patch can be shared, but i don't assume any risks if people flash it without an original backup.
Geremia is offline