#include "MCF5475.h"
#include "bas_types.h"
#include "bas_printf.h"

/*
 * provide an early exception vector branch table to catch exceptions _before_ VBR has been setup eventually
 * (to RAMBAR0, in exceptions.S)
 */

typedef void (*exception_handler)(void);
extern exception_handler SDRAM_VECTOR_TABLE[];

void fault_handler(uint32_t format_status, uint32_t pc)
{
	int format;
	int fault_status;
	int vector;
	int sr;

	xprintf("\007\007exception! Processor halted.\r\n");
	xprintf("format_status: %lx\r\n", format_status);
	xprintf("pc: %lx\r\n", pc);

	format = 	    (format_status & 0b11110000000000000000000000000000) >> 28;
	fault_status = ((format_status & 0b00001100000000000000000000000000) >> 26) |
			       ((format_status & 0b00000000000000110000000000000000) >> 16);
	vector       =  (format_status & 0b00000011111111000000000000000000) >> 18;
	sr           =  (format_status & 0b00000000000000001111111111111111);

	xprintf("format: %x\r\n", format);
	xprintf("fault_status: %x ", fault_status);
	switch (fault_status)
	{
	case 0:
		xprintf("(not an access or address error nor an interrupted debug service routine)");
		break;
	case 1:
	case 3:
	case 11:
		xprintf("(reserved)");
		break;
	case 2:
		xprintf("(interrupt during a debug service routine for faults other than access errors)");
		break;
	case 4:
		xprintf("(error (for example, protection fault) on instruction fetch)");
		break;
	case 5:
		xprintf("(TLB miss on opword or instruction fetch)");
		break;
	case 6:
		xprintf("(TLB miss on extension word of instruction fetch)");
		break;
	case 7:
		xprintf("(IFP access error while executing in emulator mode)");
		break;
	case 8:
		xprintf("(error on data write)");
		break;
	case 9:
		xprintf("(error on attempted wrote to write-protected space)");
		break;
	case 10:
		xprintf("(TLB miss on data write)");
		break;
	case 12:
		xprintf("(error on data read)");
		break;
	case 13:
		xprintf("(attempted read, read-modify-write of protected space)");
		break;
	case 14:
		xprintf("(TLB miss on data read or read-modify-write");
		break;
	case 15:
		xprintf("(OEP access error while executing in emulator mode)");
	}
	xprintf("\r\n");

	xprintf("vector = %02x (", vector);
	switch (vector)
	{
	case 2:
		xprintf("access error");
		break;
	case 3:
		xprintf("address error");
		break;
	case 4:
		xprintf("illegal instruction");
		break;
	case 5:
		xprintf("divide by zero");
		break;
	case 8:
		xprintf("privilege violation");
		break;
	case 9:
		xprintf("trace");
		break;
	case 10:
		xprintf("unimplemented line-a opcode");
		break;
	case 11:
		xprintf("unimplemented line-f opcode");
		break;
	case 12:
		xprintf("non-PC breakpoint debug interrupt");
		break;
	case 13:
		xprintf("PC breakpoint debug interrupt");
		break;
	case 14:
		xprintf("format error");
		break;
	case 24:
		xprintf("spurious interrupt");
		break;
	default:
		if ( ((fault_status >= 6) && (fault_status <= 7)) ||
			 ((fault_status >= 16) && (fault_status <= 23)))
		{
			xprintf("reserved");
		}
		else if ((fault_status >= 25) && (fault_status <= 31))
		{
			xprintf("level %d autovectored interrupt", fault_status - 24);
		}
		else if ((fault_status >= 32) && (fault_status <= 47))
		{
			xprintf("trap #%d", fault_status - 32);
		}
		else
		{
			xprintf("unknown fault status");
		}
	}
	xprintf(")\r\n");
	xprintf("sr=%4x\r\n", sr);
}

void handler(void)
{
	/*
	 * for standard routines, we'd have to save registers here.
	 * Since we do not intend to return anyway, we just ignore that
	 */
	__asm__ __volatile__("move.l	(sp),-(sp)\n\t"		/* format, fault status and status register values */
						 "move.l	8(sp),-(sp)\n\t"	/* the program counter where the fault originated */
						 "bra		_fault_handler\n\t"
						 "halt\n\t"
							: : :);
}

void setup_vectors(void)
{
	int i;

	for (i = 0; i < 256; i++)
	{
		SDRAM_VECTOR_TABLE[i] = handler;
	}

	/*
	 * make sure VBR points to our table
	 */
	__asm__ __volatile__("clr.l		d0\n\t"
						 "movec		d0,VBR\n\t"
						 "move.l	d0,_rt_vbr");
}