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/*

 * Copyright (C) 2005 Ondrej Palkovsky

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <arch/debugger.h>

#include <memstr.h>

#include <console/kconsole.h>

#include <console/cmd.h>

#include <symtab.h>

#include <print.h>

#include <panic.h>

#include <arch.h>

#include <arch/cp0.h>

#include <func.h>

bpinfo_t breakpoints[BKPOINTS_MAX];

SPINLOCK_INITIALIZE(bkpoint_lock);

static int cmd_print_breakpoints(cmd_arg_t *argv);

static cmd_info_t pbkpt_info = {

    .name = "pbkpt",

    .description = "Print breakpoint table.",

    .func = cmd_print_breakpoints,

    .argc = 0,

};

static int cmd_del_breakpoint(cmd_arg_t *argv);

static cmd_arg_t del_argv = {

    .type = ARG_TYPE_INT

};

static cmd_info_t delbkpt_info = {

    .name = "delbkpt",

    .description = "delbkpt <number> - Delete breakpoint.",

    .func = cmd_del_breakpoint,

    .argc = 1,

    .argv = &del_argv

};

static int cmd_add_breakpoint(cmd_arg_t *argv);

static cmd_arg_t add_argv = {

    .type = ARG_TYPE_INT

};

static cmd_info_t addbkpt_info = {

    .name = "addbkpt",

    .description = "addbkpt <&symbol> - new bkpoint. Break on J/Branch insts unsupported.",

    .func = cmd_add_breakpoint,

    .argc = 1,

    .argv = &add_argv

};

/** Add new breakpoint to table */

int cmd_add_breakpoint(cmd_arg_t *argv)

{

    bpinfo_t *cur = NULL;

    ipl_t ipl;

    int i;

    if (argv->intval & 0x3) {

        printf("Not aligned instruction, forgot to use &symbol?\n");

        return 1;

    }

    ipl = interrupts_disable();

    spinlock_lock(&bkpoint_lock);

    /* Check, that the breakpoints do not conflict */

    for (i=0; i<BKPOINTS_MAX; i++) {

        if (breakpoints[i].address == (__address)argv->intval) {

            printf("Duplicate breakpoint %d.\n", i);

            spinlock_unlock(&bkpoints_lock);

            return 0;

        } else if (breakpoints[i].address == (__address)argv->intval + sizeof(__native) || \

               breakpoints[i].address == (__address)argv->intval - sizeof(__native)) {

            printf("Adjacent breakpoints not supported, conflict with %d.\n", i);

            spinlock_unlock(&bkpoints_lock);

            return 0;

        }

    }

    for (i=0; i<BKPOINTS_MAX; i++)

        if (!breakpoints[i].address) {

            cur = &breakpoints[i];

            break;

        }

    if (!cur) {

        printf("Too many breakpoints.\n");

        spinlock_unlock(&bkpoint_lock);

        interrupts_restore(ipl);

        return 0;

    }

    cur->address = (__address) argv->intval;

    printf("Adding breakpoint on address: %p\n", argv->intval);

    cur->instruction = ((__native *)cur->address)[0];

    cur->nextinstruction = ((__native *)cur->address)[1];

    cur->executing = false;

    /* Set breakpoint */

    *((__native *)cur->address) = 0x0d;

    spinlock_unlock(&bkpoint_lock);

    interrupts_restore(ipl);

    return 1;

}

/** Remove breakpoint from table */

int cmd_del_breakpoint(cmd_arg_t *argv)

{

    bpinfo_t *cur;

    ipl_t ipl;

    if (argv->intval < 0 || argv->intval > BKPOINTS_MAX) {

        printf("Invalid breakpoint number.\n");

        return 0;

    }

    ipl = interrupts_disable();

    spinlock_lock(&bkpoint_lock);

    cur = &breakpoints[argv->intval];

    if (!cur->address) {

        printf("Breakpoint does not exist.\n");

        spinlock_unlock(&bkpoint_lock);

        interrupts_restore(ipl);

        return 0;

    }

    ((__u32 *)cur->address)[0] = cur->instruction;

    ((__u32 *)cur->address)[1] = cur->nextinstruction;

    cur->address = NULL;

    spinlock_unlock(&bkpoint_lock);

    interrupts_restore(ipl);

    return 1;

}

/** Print table of active breakpoints */

int cmd_print_breakpoints(cmd_arg_t *argv)

{

    int i;

    char *symbol;

    printf("Breakpoint table.\n");

    for (i=0; i < BKPOINTS_MAX; i++)

        if (breakpoints[i].address) {

            symbol = get_symtab_entry(breakpoints[i].address);

            printf("%d. 0x%p in %s\n",i,

                   breakpoints[i].address, symbol);

        }

    return 1;

}

/** Initialize debugger */

void debugger_init()

{

    int i;

    for (i=0; i<BKPOINTS_MAX; i++)

        breakpoints[i].address = NULL;

    cmd_initialize(&pbkpt_info);

    if (!cmd_register(&pbkpt_info))

        panic("could not register command %s\n", pbkpt_info.name);

    cmd_initialize(&delbkpt_info);

    if (!cmd_register(&delbkpt_info))

        panic("could not register command %s\n", delbkpt_info.name);

    cmd_initialize(&addbkpt_info);

    if (!cmd_register(&addbkpt_info))

        panic("could not register command %s\n", addbkpt_info.name);

}

/** Handle breakpoint

 *

 * Find breakpoint in breakpoint table.

 * If found, call kconsole, set break on next instruction and reexecute.

 * If we are on "next instruction", set it back on the first and reexecute.

 * If breakpoint not found in breakpoint table, call kconsole and start

 * next instruction.

 */

void debugger_bpoint(struct exception_regdump *pstate)

{

    char *symbol;

    bpinfo_t *cur = NULL;

    int i;

    symbol = get_symtab_entry(pstate->epc);

    /* test branch delay slot */

    if (cp0_cause_read() & 0x80000000)

        panic("Breakpoint in branch delay slot not supported.\n");

    spinlock_lock(&bkpoint_lock);

    for (i=0; i<BKPOINTS_MAX; i++) {

        if (pstate->epc == breakpoints[i].address || \

            (pstate->epc == breakpoints[i].address+sizeof(__native) &&\

             breakpoints[i].executing))

            cur = &breakpoints[i];

        break;

    }

    if (cur) {

        if ((cur->executing && pstate->epc==cur->address) ||

            (!cur->executing && pstate->epc==cur->address+sizeof(__native)))

            panic("Weird breakpoint state.\n");

        if (!cur->executing) {

            printf("***Breakpoint %d: 0x%p in %s.\n", i,

                   pstate->epc,symbol);

            /* Return first instruction back */

            ((__u32 *)cur->address)[0] = cur->instruction;

            /* Set Breakpoint on second */

            ((__u32 *)cur->address)[1] = 0x0d;

            cur->executing = true;

        } else {

            /* Set breakpoint on first instruction */

            ((__u32 *)cur->address)[0] = 0x0d;

            /* Return back the second */

            ((__u32 *)cur->address)[1] = cur->nextinstruction;

            cur->executing = false;

            spinlock_unlock(&bkpoint_lock);

            return;

        }

    } else {

        printf("***Breakpoint 0x%p in %s.\n", pstate->epc, symbol);

        /* Move on to next instruction */

        pstate->epc += 4;

    }

    spinlock_unlock(&bkpoint_lock);

    printf("***Type 'exit' to exit kconsole.\n");

    /* Umm..we should rather set some 'debugstate' here */

    atomic_set(&haltstate,1);

    kconsole("debug");

    atomic_set(&haltstate,0);

}