This is the mode that can be forced on start or the only one available if the boot loader is damaged.
It is supposed to give some diagnostic about what is wrong with the phone and let you flash the boot loader etc.
Does anybody know how it works and what tools to use? Has anybody reverse engineered the protocol?
So if I have a Question on Development and phone internal should go in Q&A?
Yeah all questions go in Q&A as far as starting threads. Development would be for after you make a tool for the diagnostics then you can post the tool in the development section. It's the section where development is posted for others to use. Welcome to the forums.
As far as your question, Linux can interact with this mode better than any Windows tools I've found.
True unbricking threads are rare because the term is used incorrectly most often, but they often have research into interacting with the QHB_USB mode.
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