except_603.c

umon bootloader source code, support mips cpu.

/* except.c:
 *  This code handles exceptions that are caught by the exception vectors
 *  that have been installed by the monitor through vinit().
 *
 *  General notice:
 *  This code is part of a boot-monitor package developed as a generic base
 *  platform for embedded system designs.  As such, it is likely to be
 *  distributed to various projects beyond the control of the original
 *  author.  Please notify the author of any enhancements made or bugs found
 *  so that all may benefit from the changes.  In addition, notification back
 *  to the author will allow the new user to pick up changes that may have
 *  been made by other users after this version of the code was distributed.
 *
 *  Note1: the majority of this code was edited with 4-space tabs.
 *  Note2: as more and more contributions are accepted, the term "author"
 *         is becoming a mis-representation of credit.
 *
 *  Original author:    Ed Sutter
 *  Email:              [e-mail]
 *  Phone:              908-582-2351
 */
#include "config.h"
#include "warmstart.h"
#include "genlib.h"
#include "cpuio.h"
#include "stddefs.h"
#include "arch_ppc.h"

ulong   ExceptionAddr;
int     ExceptionType;

char *
ExceptionType2String(int type)
{
    char    *string;
    static char buf[16];

    switch(type) {
        case 0x100:
            string = "system_reset";
            break;
        case 0x200:
            string = "machine_check";
            break;
        case 0x300:
            string = "dsi";
            break;
        case 0x400:
            string = "isi";
            break;
        case 0x500:
            string = "external_interrupt";
            break;
        case 0x600:
            string = "alignment";
            break;
        case 0x700:
            string = "program";
            break;
        case 0x800:
            string = "floating_point_unavailable";
            break;
        case 0x900:
            string = "decrementer";
            break;
        case 0xc00:
            string = "system_call";
            break;
        case 0xd00:
            string = "trace";
            break;
        case 0xf00:
            string = "performance_monitor";
            break;
        case 0x1300:
            string = "instruction_addr_breakpoint";
            break;
        case 0x1400:
            string = "system_management_interrupt";
            break;
        case 0x1700:
            string = "thermal_management_interrupt";
            break;
        case 0x0:
        case 0xa00:
        case 0xb00:
        case 0xe00:
        case 0x1000:
        case 0x1100:
        case 0x1200:
        case 0x1500:
        case 0x1600:
            string = "reserved";
            break;
        default:
            sprintf(buf,"0x%x",type);
            string = buf;
            break;
    }
    return(string);
}

void
exception(int type)
{
    ExceptionType = type;
    getreg("SRR0",&ExceptionAddr);
    warmstart(EXCEPTION);
}

void
vinit()
{
    extern  void (*vectortable_start)(), (*vectortable_end)();
    ulong   *from, *to, *end;

    from = (ulong *)&vectortable_start;
    end = (ulong *)&vectortable_end;

    /* Start at 0x100.
     */
    to = (ulong *)0x100;
    while(from < end)
        *to++ = *from++; 

    /* Clear the IP bit in MSR so that we are now pointing to an
     * exception table that is at 0x100...
     */
    ppcMtmsr(ppcMfmsr() & ~ppcMsrIP);
}

ulong
baseofExceptionTable(void)
{
	if (ppcMfmsr() & MSR_EP)
		return(0xFFF00000);
	else
		return(0x00000000);
}