/*      $NetBSD: db_interface.c,v 1.37 2026/03/28 04:08:40 thorpej Exp $        */

/*
 * Mach Operating System
 * Copyright (c) 1992 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

/*
 * Interface to the "ddb" kernel debugger.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: db_interface.c,v 1.37 2026/03/28 04:08:40 thorpej Exp $");

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/systm.h> /* just for boothowto --eichin */

#include <uvm/uvm_extern.h>

#include <dev/cons.h>

#include <machine/trap.h>
#include <machine/db_machdep.h>

#include <ddb/db_active.h>
#include <ddb/db_command.h>
#include <ddb/db_sym.h>
#ifdef _KERNEL
#include <ddb/db_extern.h>
#endif

int     db_active = 0;
db_regs_t       ddb_regs;

#ifdef _KERNEL
static void kdbprinttrap(int, int);

/*
 * Received keyboard interrupt sequence.
 */
void
kdb_kintr(db_regs_t *regs)
{

        if (db_active == 0 && (boothowto & RB_KDB)) {
                printf("\n\nkernel: keyboard interrupt\n");
                kdb_trap(-1, regs);
        }
}

/*
 * kdb_trap - field a TRACE or BPT trap
 * Return non-zero if we "handled" the trap.
 */
int
kdb_trap(int type, db_regs_t *regs)
{

        switch (type) {
        case T_TRACE:           /* single-step */
        case T_BREAKPOINT:      /* breakpoint */
/*      case T_WATCHPOINT:*/
                break;
        case -1:
                break;
        default:
                kdbprinttrap(type, 0);
                if (db_recover != 0) {
                        /* This will longjmp back to db_command_loop */
                        db_error("Caught exception in ddb.\n");
                        /*NOTREACHED*/
                }
                /*
                 * Tell caller "We did NOT handle the trap."
                 * Caller should panic or whatever.
                 */
                return 0;
        }

        /*
         * We'd like to be on a separate debug stack here, but
         * that's easier to do in locore.s before we get here.
         * See sun3/locore.s:T_TRACE for stack switch code.
         */

        ddb_regs = *regs;

        db_active++;
        cnpollc(true);  /* set polling mode, unblank video */

        db_trap(type, 0);       /* where the work happens */

        cnpollc(false); /* resume interrupt mode */
        db_active--;

        *regs = ddb_regs;

        /*
         * Indicate that single_step is for KDB.
         * But lock out interrupts to prevent TRACE_KDB from setting the
         * trace bit in the current SR (and trapping while exiting KDB).
         */
        (void)spl7();

        /*
         * Tell caller "We HAVE handled the trap."
         * Caller will return to locore and rte.
         */
        return 1;
}

/*
 * Print trap reason.
 */
static void
kdbprinttrap(int type, int code)
{
        printf("kernel: %s\n", trap_desc(type));
}

void
cpu_Debugger(void)
{

        __asm ("trap #15");
}
#endif