evec.c

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/* evec.c -- initintc, set_evec, irq_dispatch */

#include <xinu.h>
#include <stdio.h>

/*#define STKTRACE*/
/*#define REGDUMP*/

extern  void    userret(void);

uint32  intc_vector[128];   /* Interrupt vector */
char    expmsg1[] = "Unhandled exception. Link Register: 0x%x";
char    expmsg2[] = "**** EXCEPTION ****";
/*------------------------------------------------------------------------
 * initintc - Initialize the Interrupt Controller
 *------------------------------------------------------------------------
 */
int32   initintc()
{
    struct  intc_csreg *csrptr = (struct intc_csreg *)0x48200000;

    /* Reset the interrupt controller */

    csrptr->sysconfig |= (INTC_SYSCONFIG_SOFTRESET);

    /* Wait until reset is complete */

    while((csrptr->sysstatus & INTC_SYSSTATUS_RESETDONE) == 0);

    return OK;
}

/*------------------------------------------------------------------------
 * set_evec - set exception vector to point to an exception handler
 *------------------------------------------------------------------------
 */
int32   set_evec(uint32 xnum, uint32 handler)
{
    struct  intc_csreg *csrptr = (struct intc_csreg *)0x48200000;
    uint32  bank;   /* bank number in int controller    */
    uint32  mask;   /* used to set bits in bank     */

    /* There are only 127 interrupts allowed 0-126 */

    if(xnum > 127) {
        return SYSERR;
    }

    /* Install the handler */

    intc_vector[xnum] = handler;

    /* Get the bank number based on interrupt number */

    bank = (xnum/32);

    /* Get the bit inside the bank */

    mask = (0x00000001 << (xnum%32));

    /* Reset the bit to enable that interrupt number */

    csrptr->banks[bank].mir &= (~mask);

    return OK;
}

/*-------------------------------------------------------------------------
 * irq_dispatch - call the handler for specific interrupt
 *-------------------------------------------------------------------------
 */
void    irq_dispatch()
{
    struct  intc_csreg *csrptr = (struct intc_csreg *)0x48200000;
    uint32  xnum;       /* Interrupt number of device   */
    interrupt (*handler)(); /* Pointer to handler function  */

    /* Get the interrupt number from the Interrupt controller */

    xnum = csrptr->sir_irq & 0x7F;

    /* Defer scheduling until interrupt is acknowledged */

    resched_cntl(DEFER_START);

    /* If a handler is set for the interrupt, call it */

    if(intc_vector[xnum]) {
        handler = ( interrupt(*)() )intc_vector[xnum];
        handler(xnum);
    }

    /* Acknowledge the interrupt */

    csrptr->control |= (INTC_CONTROL_NEWIRQAGR);

    /* Resume scheduling */

    resched_cntl(DEFER_STOP);
}

#if 0
static long *fp;
/*------------------------------------------------------------------------
 * trap -- print some debugging info when a trap occurred
 * Note: Need some more work.
 *------------------------------------------------------------------------
*/
#define REGDUMP

void trap(int inum)
{
    long        *sp;
    intmask     mask;

    mask = disable();
    kprintf("TRAP\n");
    //asm("movl %ebp,fp");
    sp = fp + 15;   /* eflags/CS/eip/ebp/regs/trap#/Xtrap/ebp */
    kprintf("Xinu trap!\n");
    if (inum < 16)
        kprintf("exception %d (%s) currpid %d (%s)\n", inum,
            inames[inum], currpid, proctab[currpid].prname);
    else
        kprintf("exception %d currpid %d (%s)\n", inum, currpid,
            proctab[currpid].prname);
#ifdef REGDUMP
    kprintf("eflags %X ", *sp--);
    sp--;   /* skip OLD CS */
    kprintf("eip %X ", *sp);
    sp--;
    if (inum == 8 || (inum >= 10 && inum <= 14)) {
        kprintf("error code %08x (%u)\n", *sp, *sp);
        sp--;
    }
    sp--;   /* skip FP for Xint call */
    kprintf("register dump:\n");
    kprintf("eax %08X (%u)\n", *sp, *sp);
    sp--;
    kprintf("ecx %08X (%u)\n", *sp, *sp);
    sp--;
    kprintf("edx %08X (%u)\n", *sp, *sp);
    sp--;
    kprintf("ebx %08X (%u)\n", *sp, *sp);
    sp--;
    kprintf("esp %08X (%u)\n", *sp, *sp);
    sp--;
    kprintf("ebp %08X (%u)\n", *sp, *sp);
    fp = sp;
    sp--;
    kprintf("esi %08X (%u)\n", *sp, *sp);
    sp--;
    kprintf("edi %08X (%u)\n", *sp, *sp);
    sp--;
#endif // REGDUMP
#ifdef STKTRACE
    stacktrace(currpid);
#endif // STKTRACE

    panic("Trap processing complete...\n");
}
#endif