except.c

完整的Bell实验室的嵌入式文件系统TFS

/* except.c:

    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.

    Author: Ed Sutter
    email:  [e-mail]      (home: [e-mail])
    phone:  [phone]            (home: 908-889-5161)
*/
#include "config.h"
#include "cpu.h"
#include "cpuio.h"
#include "monapp.h"
#include "stddefs.h"
#include "genlib.h"

extern  int getreg(), putreg(), putvbr();

ulong   exceptionCause;
ulong   ExceptionAddr;
ulong   VectorTable[256];

void
exception()
{
    extern  void    coldstart();
    int     vnum;
    char    *vname;
    ulong   pc;

    vnum = (int)(exceptionCause & 0xff);
    getreg("PC",&pc);

    /* First check to see if the vector that was just taken is the one */
    /* used by the 'at' command.  If yes, then there are two possibilities: */
    /* 1. If StateOfMonitor == BREAKPOINT, then this trap is the one that */
    /*    is used by the breakpoint handler for the instruction AFTER the */
    /*    breakpoint address to allow the breakpoint to be re-installed. */
    /* 2. Otherwise, it is a trap that must be handed over to attrap(). */

#if INCLUDE_DEBUG
    if (atvector(vnum)) {
        extern  int StateOfMonitor;
        extern  ushort InstAfterBP, *AddrAfterBP;

        pc -= 2;
        putreg("PC",pc);
        if (StateOfMonitor == BREAKPOINT) {
            StateOfMonitor = APPLICATION;
            *AddrAfterBP = InstAfterBP;
            installatpoints();
            resume();       /* will not return */
        }
        else if (StateOfMonitor == SSTEP) {
            *AddrAfterBP = InstAfterBP;
            didStep(pc);    /* will not return */
        }
        else
            attrap(pc); 
        return;
    }
#endif
        
    vname = "";
    printf("EXCEPTION: #%d ",vnum);
    if ((vnum >=64) && (vnum <=71)) {
        pc -= 2;
        putreg("PC",pc);
        printf("(IRQ%d) @ 0x%lx\n",vnum-64,pc);
    }
    else if ((vnum >= 32) && (vnum <= 63)) {
        pc -= 2;
        putreg("PC",pc);
        printf("(TRAP%d) @ 0x%lx\n",vnum-32,pc);
    }
    else if ((vnum >= 72) && (vnum <= 255)) {
        pc -= 2;
        putreg("PC",pc);
        printf("(On-Chip-Peripheral) @ 0x%lx\n",pc);
    }
    else {
        switch(vnum) {
            case 4:
                vname = "(General Illegal Instruction)";
                break;
            case 6:
                vname = "(Slot Illegal Instruction)";
                break;
            case 9:
                vname = "(CPU Address Error)";
                pc -= 2;
                break;
            case 10:
                vname = "(DMAC/DTC Address Error)";
                break;
            case 11:
                vname = "(NMI)";
                break;
            case 12:
                vname = "(User Break)";
                break;
        }
        printf("%s @ 0x%lx\n",vname,pc);
    }
    ExceptionAddr = pc;
    showregs();
    intsoff();
    if (pollConsole("coldstart?"))
        warmstart(APP_EXIT);
    else
        coldstart();
}

void
vinit()
{
    extern  void    Vector4(), Vector5(), coldstart();
    extern  ulong   MonStackEnd;
    int     i, offset, vptr;

    VectorTable[0] = (ulong)coldstart;
    VectorTable[1] = (ulong)&MonStackEnd;
    VectorTable[2] = (ulong)coldstart;
    VectorTable[3] = (ulong)&MonStackEnd;

    offset = (int)Vector5 - (int)Vector4;
    vptr = (int)Vector4;
    for(i=4;i<256;i++) {
        VectorTable[i] = vptr;
        vptr += offset; 
    }
    putvbr(VectorTable);
}


/* Put cacheinit in this file because it is CPU specific... */
/* Enable cache for FLASH and DRAM. */
void
cacheInitForTarget()
{
    int i;
    volatile ushort *addarray;

    addarray = CAAWRS;
    for(i=0;i<256;i++)
        *addarray++ = 0;
    *CCR = CACHEN_CS0 | CACHEN_DRAM;
}