except_403.c

完整的Bell实验室的嵌入式文件系统TFS

/* 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 "cpu.h"
#include "cpuio.h"
#include "stddefs.h"
#include "genlib.h"
#include "cpu_403.h"
#include "arch_ppc.h"

int     ExceptionType;
ulong   ExceptionAddr;

void
exception(int type)
{
    extern  int getreg();
    ulong srr;

    intsoff();

    /* Critical interrupts store the address of the interrupted instruction
     * in SRR2,  Non-critical interrupts store it in SRR0
     */
    switch (type) {
    case 0x0100:            /* Critical interrupt pin */
    case 0x0200:            /* Machine check */
    case 0x1020:            /* Watchdog timer */
    case 0x2000:            /* Debug exception */
        getreg("SRR2", &srr);
        break;
    default:
        getreg("SRR0",&srr);
        break;
    }

    ExceptionType = type;
    ExceptionAddr = srr;

    /* Some exceptions load SRR with address of next instruction
     * so decrement by 4 (size of 1 instruction) for those cases...
     */
    switch (type) {
        case 0x0100:        /* Critical */
        case 0x0500:        /* External interrupt */
        case 0x0c00:        /* System call */
        case 0x1000:        /* PIT */
        case 0x1010:        /* FIT */
        case 0x1020:        /* WDT */
            ExceptionAddr -= 4;
            break;
    }
    monrestart(EXCEPTION);
}

void
copyGeneralVector(ushort *to, ushort vid)
{
    extern  ulong general_vector;

    memcpy((char *)to,(char *)&general_vector,20);
    *(to+1) = vid;
}

void
vinit()
{
    extern  ulong pit_vector, fit_vector, wdt_vector;
    char    *base;
    int     offset;

    base = (char *)RAM_VECTOR_TABLE;

    for(offset = 0x100; offset < 0x1000; offset += 0x100)
        copyGeneralVector((ushort *)(base+offset),offset);

    memcpy(base+0x1000,(char *)&pit_vector,16);
    memcpy(base+0x1010,(char *)&fit_vector,16);
    memcpy(base+0x1020,(char *)&wdt_vector,16);

    copyGeneralVector((ushort *)(base+0x1100),0x1100);
    copyGeneralVector((ushort *)(base+0x1200),0x1200);
    copyGeneralVector((ushort *)(base+0x2000),0x2000);

    asm("   sync");             /* Wait for writes to complete */
    ppcMtevpr(RAM_VECTOR_TABLE);
}

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

    switch(type) {
        case 0x100:
            string = "Critical Interrupt Pin";
            break;
        case 0x200:
            string = "Machine Check";
            break;
        case 0x300:
            string = "Data Store";
            break;
        case 0x400:
            string = "Instruction Store";
            break;
        case 0x500:
            string = "External Interrupt";
            break;
        case 0x600:
            string = "Alignment";
            break;
        case 0x700:
            string = "Program";
            break;
        case 0xc00:
            string = "System Call";
            break;
        case 0x1000:
            string = "Programmable Interval Timer";
            break;
        case 0x1010:
            string = "Fixed Interval Timer";
            break;
        case 0x1020:
            string = "Watchdog Timer";
            break;
        case 0x1100:
            string = "Data TLB Miss";
            break;
        case 0x1200:
            string = "Instruction TLB Miss";
            break;
        case 0x2000:
            string = "Debug";
            break;
        default:
            sprintf(buf,"vtbl offset 0x%x",type);
            string = buf;
            break;
    }
    return(string);
}