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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 bkpts_info = {

    .name = "bkpts",

    .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

};

static cmd_arg_t adde_argv[] = {

    { .type = ARG_TYPE_INT },

    { .type = ARG_TYPE_INT }

};

static cmd_info_t addbkpte_info = {

    .name = "addbkpte",

    .description = "addebkpte <&symbol> <&func> - new bkpoint. Call func(or Nothing if 0).",

    .func = cmd_add_breakpoint,

    .argc = 2,

    .argv = adde_argv

};

static struct {

    __u32 andmask;

    __u32 value;

}jmpinstr[] = {

    {0xf3ff0000, 0x41000000}, /* BCzF */

    {0xf3ff0000, 0x41020000}, /* BCzFL */

    {0xf3ff0000, 0x41010000}, /* BCzT */

    {0xf3ff0000, 0x41030000}, /* BCzTL */

    {0xfc000000, 0x10000000}, /* BEQ */

    {0xfc000000, 0x50000000}, /* BEQL */

    {0xfc1f0000, 0x04010000}, /* BEQL */

    {0xfc1f0000, 0x04110000}, /* BGEZAL */

    {0xfc1f0000, 0x04130000}, /* BGEZALL */

    {0xfc1f0000, 0x04030000}, /* BGEZL */

    {0xfc1f0000, 0x1c000000}, /* BGTZ */

    {0xfc1f0000, 0x5c000000}, /* BGTZL */

    {0xfc1f0000, 0x18000000}, /* BLEZ */

    {0xfc1f0000, 0x58000000}, /* BLEZL */

    {0xfc1f0000, 0x04000000}, /* BLTZ */

    {0xfc1f0000, 0x04100000}, /* BLTZAL */

    {0xfc1f0000, 0x04120000}, /* BLTZALL */

    {0xfc1f0000, 0x04020000}, /* BLTZL */

    {0xfc000000, 0x14000000}, /* BNE */

    {0xfc000000, 0x54000000}, /* BNEL */

    {0xfc000000, 0x08000000}, /* J */

    {0xfc000000, 0x0c000000}, /* JAL */

    {0xfc1f07ff, 0x00000009}, /* JALR */

    {0,0} /* EndOfTable */

};

/** Test, if the given instruction is a jump or branch instruction

 *

 * @param instr Instruction code

 * @return true - it is jump instruction, false otherwise

 */

static bool is_jump(__native instr)

{

    int i;

    for (i=0;jmpinstr[i].andmask;i++) {

        if ((instr & jmpinstr[i].andmask) == jmpinstr[i].value)

            return true;

    }

    return false;

}

/** 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];

    if (argv == &add_argv) {

        cur->flags = 0;

    } else { /* We are add extended */

        cur->flags = BKPOINT_FUNCCALL;

        cur->bkfunc =   (void (*)(void *, struct exception_regdump *)) argv[1].intval;

    }

    if (is_jump(cur->instruction))

        cur->flags |= BKPOINT_ONESHOT;

    cur->counter = 0;

    /* 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;

    }

    if ((cur->flags & BKPOINT_INPROG) && (cur->flags & BKPOINT_ONESHOT)) {

        printf("Cannot remove one-shot breakpoint in-progress\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);

            printf("     Count(%d) ", breakpoints[i].counter);

            if (breakpoints[i].flags & BKPOINT_INPROG)

                printf("INPROG ");

            if (breakpoints[i].flags & BKPOINT_ONESHOT)

                printf("ONESHOT ");

            if (breakpoints[i].flags & BKPOINT_FUNCCALL)

                printf("FUNCCALL ");

            printf("\n");

        }

    return 1;

}

/** Initialize debugger */

void debugger_init()

{

    int i;

    for (i=0; i<BKPOINTS_MAX; i++)

        breakpoints[i].address = NULL;

    cmd_initialize(&bkpts_info);

    if (!cmd_register(&bkpts_info))

        panic("could not register command %s\n", bkpts_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);

    cmd_initialize(&addbkpte_info);

    if (!cmd_register(&addbkpte_info))

        panic("could not register command %s\n", addbkpte_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)

{

    bpinfo_t *cur = NULL;

    __address fireaddr = pstate->epc;

    int i;

    /* 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++) {

        /* Normal breakpoint */

        if (fireaddr == breakpoints[i].address \

            && !(breakpoints[i].flags & BKPOINT_REINST)) {

            cur = &breakpoints[i];

            break;

        }

        /* Reinst only breakpoint */

        if ((breakpoints[i].flags & BKPOINT_REINST) \

            && (fireaddr ==breakpoints[i].address+sizeof(__native))) {

            cur = &breakpoints[i];

            break;

        }

    }

    if (cur) {

        if (cur->flags & BKPOINT_REINST) {

            /* Set breakpoint on first instruction */

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

            /* Return back the second */

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

            cur->flags &= ~BKPOINT_REINST;

            spinlock_unlock(&bkpoint_lock);

            return;

        }

        if (cur->flags & BKPOINT_INPROG)

            printf("Warning: breakpoint recursion\n");

        if (!(cur->flags & BKPOINT_FUNCCALL))

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

                   fireaddr, get_symtab_entry(pstate->epc));

        /* Return first instruction back */

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

        if (! (cur->flags & BKPOINT_ONESHOT)) {

            /* Set Breakpoint on next instruction */

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

            cur->flags |= BKPOINT_REINST;

        }

        cur->flags |= BKPOINT_INPROG;

    } else {

        printf("***Breakpoint 0x%p in %s.\n", fireaddr,

               get_symtab_entry(fireaddr));

        /* Move on to next instruction */

        pstate->epc += 4;

    }

    if (cur)

        cur->counter++;

    if (cur && (cur->flags & BKPOINT_FUNCCALL)) {

        printf("3.5\n");

        /* Allow zero bkfunc, just for counting */

        if (cur->bkfunc)

            cur->bkfunc(cur, pstate);

    } else {

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

        /* This disables all other processors - we are not SMP,

         * actually this gets us to cpu_halt, if scheduler() is run

         * - we generally do not want scheduler to be run from debug,

         *   so this is a good idea

         */

        atomic_set(&haltstate,1);

        spinlock_unlock(&bkpoint_lock);

        kconsole("debug");

        spinlock_lock(&bkpoint_lock);

        atomic_set(&haltstate,0);

    }

    if (cur && cur->address == fireaddr && (cur->flags & BKPOINT_INPROG)) {

        /* Remove one-shot breakpoint */

        if ((cur->flags & BKPOINT_ONESHOT))

            cur->address = NULL;

        /* Remove in-progress flag */

        cur->flags &= ~BKPOINT_INPROG;

    }

    spinlock_unlock(&bkpoint_lock);

}