Exceptions

[TsuReX]

Implement interrupt handlers for all exceptions as sending special code for each exception via UART

[TsuReX]

Examine exception's life cycle and processing approach. Pay special attention on to disabling/enabling exceptions bits and bits for clearing pending exceptions.

[TsuReX]

For ARM side timer. Do in exception handler:

5. Read IRQ RAW register (0x410);
6. Send it's value via UART;
7. Read Masked IRQ register (0x414);
8. Send it's value via UART;
9. Write 0x1 to IRQ Claer/Ack register (0x40C) to clear pending interrupt;
10. Handle exception;
11. Return from handler.

[TsuReX]

1. Implement special handler subfunction setting up mechanism for each exception:

   • EXC_handler_fcn .word;
   • setup_EXC_handler()).

2. Each default exception handler must do:

   • print_EXCNAME
   • print_cpsr;
   • print_spsr;
   • go to special handler (if it was set up);
   • print "CPU halt" (if there isn't special handler);
   • halt/infinite loop.

3. Check exit address calculation for each handler;

4. Implement setup_exc function to make default configuring of all exceptions. Func must do:

   • place_exc_vector;
   • setup_EXC_handler (for all exceptions).

5. Exceptions 1 + 6:

   • reset (no special handler);
   • undef;
   • svc_smc;
   • pabt;
   • dabt;
   • irq;
   • fiq.