I have some questions about the interrupt management under the PPC4xx platform (I'm working with the 405EP evaluation board).
1) At the beginning of the boot code, the EVPR is cleared. The OpenBIOS, whose boot code is substantally the same, sets the EVPR to 0xFFF80000, that is the start address of the Flash. Why do they use such a different approach? 2) I don't understand how the code of vectors is relocated by the trap_init function. Once the whole code is copied from Flash to SDRAM by the relocate_code function, in my understanding the code of vectors is copied again from the end of SDRAM to the start of SDRAM by trap_init. Here r9 is the target address and it set to 0x2100. So why do the interrupt_init function sets the EVPR to 0?
Many thanks in advance.
llandre