source: mainline/arch/mips32/src/debugger.c@ dc747e3

/*
 * 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 */
        haltstate = 1;
        kconsole("debug");
        haltstate = 0;
}