I have one basic question related to the first address from where the processor starts executing.
What I understand is that the reset to the CPU is one type of exception. So, based on this, the processor starts executing from the address pointed by the exception table.
So, in the whole process of boot-up, where does this exception processing fall?
1) it is after boot-up
2) before boot-up
3) this itself is the boot-up
It is #3.
It is the starting point of the code, the first instruction you execute when you power on is at the reset vector.
The process of how they are handled is quite different between Cortex-M and Cortex-A, but the functionality is broadly similar... the Reset Handler initializes the system. I sometimes explain it as "everything that happens before main()".
This article may be useful if you are working with Cortex-A:https://developer.arm.com/documentation/102432/0100/Write-a-reset-handler