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Machine check handler

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Machine check handler

Machine check handler usually splits into two parts:

•

Low level handler

•

User handler

2.1

Low level handler

Low level handler is responsible for first and last part of the exception execution. It is usually

written in assembly as it needs to execute proper instruction sequence before it can pass

the code execution to higher level routine and accesses special purpose Core registers.

The middle of the interrupt service routine belongs to the user handler where analysis of the

root cause of the exception and fault removal is done.

Once the user handler is finished code execution is given back to the low level driver to

finish the interrupt and return back to the interrupted process.

Figure 1. Machine check exception flow

2.1.1

Start phase

First steps when machine check exception occurs are done by the hardware (Core) which

stores content of the MSR register and address of the current instruction pointer if it is

possible (precise exception).