* Question
| How to enter the exception execution program? |
* Answer
| When an exception causes a mode switch, the kernel automatically does the following: saves the return address of the exception handler to the LR in the corresponding exception mode, and returns the exception after the exception handler is removed by subtracting the offset from the value of LR.Write to the PC; save the current value of the CPSR to the SPSR in the corresponding exception mode, |
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